document_title: List of Fairy Tail episodes (season 6)

question_text: what episode does fairy tail win the grand magic games

text: List of Fairy Tail episodes (season 6)

text: Episode list[edit]

text:
No.
Official English title[a]
Original Japanese title
Original air date[b]
English air date[c]

151
"Sabertooth"
"Seibātūsu" (剣咬の虎 (セイバートゥース))
October 6, 2012
November 17, 2015

The Legion Platoon is tasked by Zentopia's archbishop to retrieve the missing pieces of the Infinity Clock and seal them again. Before embarking on their mission, they visit Fairy Tail and make amends with the guild for their previous hostility against them. It is later discovered that Fairy Tail has lost their title as the strongest guild in Fiore to the Saber Tooth guild over the past seven years. Two of the strongest wizards in the guild include a pair of Dragon Slayers named Sting and Rogue, who are obsessed with fighting Natsu and Gajeel, respectively. Meanwhile, Makarov brings Gildarts to their abandoned guildhall and shows him Lumen Histoire, a light that Makarov says is Fairy Tail's greatest secret. Makarov then tells Gildarts that he has been chosen to become the next master of Fairy Tail.

152
"And So We Aim for the Top"
"Soshite Ore-tachi wa Chōjō o Mezasu" (そしてオレたちは顶上を目指す)
October 13, 2012
November 24, 2015

Natsu and his friends discover that a power gap has developed between them and the rest of the guild members who were not on Tenrou Island. The group meets with Poluchka for medicine to strengthen their magic, but are unsuccessful. Wendy recognizes Poluchka's voice and scent as those of Grandine, the dragon who raised her. Poluchka reveals herself as the Edolas counterpart of Grandine, and gives Wendy written instructions for two advanced spells that Grandine failed to teach her. Meanwhile, Makarov announces Gildarts' succession as master to the rest of the guild, only to find he has gone on a journey, leaving a letter of resignation behind. In the letter, Gildarts reinstates Laxus into the guild, returns mastership to Makarov, and tells him to make Fairy Tail the strongest guild in Fiore again. Romeo suggests they participate in the Grand Magic Games, an annual festival designed to determine the guild rankings in Fiore.

153
"Song of the Stars"
"Hoshiboshi no Uta" (星々の歌)
October 20, 2012
December 1, 2015

With the Grand Magic Games occurring in three months time, Natsu and his friends train at a beach resort. On their second day of training, Virgo appears and tells the wizards that the Celestial Spirit World is in danger of destruction. When the wizards arrive, they instead find a surprise party held by the Celestial Spirit King celebrating their return from Sirius Island after seven years. They spend the day in the spirit world partying with the spirits. Before they leave, however, Virgo informs them that one day in the spirit world equals three months in the human world, and they find the Grand Magic Games are upon them.

154
"For All the Time We Missed Each Other"
"Surechigatta Jikan no Bun dake" (すれ违った时间の分だけ)
October 27, 2012
December 8, 2015

While mulling over their lost training time, the Fairy Tail wizards receive a message via carrier pigeon requesting a private meeting in the forest nearby. There they meet a runaway Jellal, Ultear, and Merudy, who have formed their own guild, Crime Sorcière, to defeat Zeref and any dark guilds that try to use his power. The three ask Fairy Tail for their help in determining the source of a magical anomaly similar to Zeref's magic that they have sensed around the Grand Magic Games arena, Domus Flau. In exchange, Ultear uses her magic to invoke their Second Origin in order to double their magic power. As the others undergo the painful process of awakening their Second Origin, Erza talks with Jellal over his regained memories. The two nearly kiss, but Jellal decides that he and Erza cannot be together and lies to her that he has a fiancée. Erza quickly picks up on this and respects his decision, seeing Crime Sorcière off as they leave.

155
"Crocus, the Flower-Blooming Capital"
"Hanasaku Miyako: Kurokkasu" (花笑く都・クロッカス)
November 3, 2012
December 15, 2015

Natsu, Lucy, Gray, Erza, and Wendy are chosen to represent their guild in the Grand Magic Games, which are to be held in Fiore's capital, Crocus. As they tour the city, Natsu and Happy encounter the twin dragon slayers, Sting and Rogue, who mock Natsu for not being able to kill Acnologia, and boast of becoming true dragon slayers by killing the dragons who raised them. At midnight, Fairy Tail and the other participating guilds are put through a preliminary event—a race through a massive floating labyrinth—designed to narrow the number of participating guilds down to eight teams.

156
"Sky Labyrinth"
"Sukai Rabirinsu" (空中迷宮 (スカイラビリンス))
November 10, 2012
December 22, 2015

Natsu's team notices that Wendy has gone missing, so Elfman replaces her to keep them from being eliminated. As they make their way through the enchanted labyrinth, the five encounter various other guilds and steal the maps made by the other guilds to better navigate the maze. They manage to reach the end of the maze and pass the elimination round, confident they have arrived first, only to discover they have barely taken last place. Meanwhile, Happy, Lisanna, and the rest of the guild search for Wendy and Carla. They eventually find the two in the garden of the king's palace, Mercurius, with their magic power depleted.

157
"New Guild"
"Shinki Girudo" (新规ギルド)
November 17, 2012
December 29, 2015

Wendy's body is weakened as a result of losing her magic power. As Poluchka helps her recover, she formally requests Elfman to take her place in the Grand Magic Games. Fairy Tail steps into the arena with a negative audience reception, but they are bolstered by their guild mates and the spirit of Mavis, whom only the Fairy Tail guild members can see. The next four participating teams are revealed to be Quatro Cerberus, Mermaid Heel, Blue Pegasus, and Lamia Scale. Following them is Raven Tail, a former dark guild led by Makarov's son Ivan, who confess to attacking Wendy and Carla. To everyone's shock, the next team is revealed to be a second team from Fairy Tail composed of Gajeel, Juvia, Mirajane, Laxus, and Jellal (disguised as Mystogan to help investigate the arena). The final guild to be announced is Saber Tooth, much to the joy of the audience. With all eight teams announced, they each send out one member to participate in the first contest of the games, with Gray and Juvia representing their teams.

158
"Night of Shooting Stars"
"Hoshi Furu Yoru ni" (星降ル夜ニ)
November 24, 2012
January 5, 2016

The games' first contest, "Hidden", requires the eight participants to score points by finding and attacking each other in a virtual city filled with copies of themselves. Raven Tail member Nalpudding repeatedly targets Gray, who scores last place in the contest while Saber Tooth's Rufus scores first by using his Memory-Make magic to attack all the other participants at once. Humiliated, Gray swears revenge against Raven Tail and Saber Tooth. Afterwards, Lucy is chosen to fight Raven Tail member Flare in the tournament's first battle round.

159
"Lucy vs. Flare"
"Rūshii vs. Furea" (ルーシィ vs. フレア)
December 1, 2012
January 12, 2016

Lucy displays tremendous skill in her battle against Flare by being able to summon two spirits simultaneously. As Lucy gains the upper hand, Flare cheats by using her magic hair to hold Alzack and Bisca's daughter Asuka as a hostage, blackmailing Lucy into not fighting back to keep her from harming Asuka. As Lucy tearfully speaks of Asuka's danger, Natsu is able to hear it and rushes to Asuka to incinerate Flare's hair, allowing Lucy to counterattack with her Urano Metoria spell in combination with Gemini. However, before the spell fully activates, Flare's teammate Obra nullifies Lucy's magic, causing her to collapse and lose the match.

160
"Portent"
"Kyōzui" (凶瑞)
December 8, 2012
January 19, 2016

Blue Pegasus' Ren defeats Mermaid Heel's Araña during the games' second match, while Saber Tooth's Orga effortlessly defeats Quatro Cerberus' War Cry in the third match. For the day's fourth and final match, Jellal is pitted against Lamia Scale's Jura, intending to avenge the humiliated Fairy Tail members. He mimics Mystogan's magic to keep up his disguise, but he finds it ineffective to use against Jura and is forced to use his own magic instead. Before he can cast a spell that will expose his true identity, Ultear uses Merudy's sensory to force Jellal into submission. Meanwhile, the hospitalized Carla awakens after having a troubling premonition of the future.

161
"Chariots"
"Chariotto" (战车 (チャリオット))
December 15, 2012
January 26, 2016

Fairy Tail is undaunted by their poor performance on the first day. As the guild celebrates, they are visited and taunted by Bacchus, Erza's rival from Quatro Cerberus, who has come to replace War Cry. Carla relays her premonition to Poluchka, saying that she saw Mercurius collapsing around what appeared to be a tearfully singing Lucy. The second day of the tournament begins with a footrace atop a train of moving chariots, causing the participants Natsu, Gajeel, and Sting to suffer from motion sickness as a side effect of their Dragon Slayer magic. As Natsu and Gajeel force themselves forward, Sting inquires about their determination to which Natsu responds that it is as a result of the strength of Fairy Tail's bonds. Sting eventually throws the race while Natsu and Gajeel manage to finish as sixth and seventh placers, respectively, earning Fairy Tail the audience's respect.

162
"Elfman vs. Bacchus"
"Erufuman vs. Bakkasu" (エルフマン vs. バッカス)
December 22, 2012
September 1, 2015

Due to a miscomunnication between the king and his knight Arcadios, Elfman is chosen as Bacchus' opponent instead of Erza. Before the match commences, the two opponents make a wager: if Bacchus wins, he will court Elfman's sisters, and if Elfman wins, Bacchus' team name will be changed to "Quatro Puppy" for the rest of the games. Bacchus ruthlessly attacks Elfman with his bare palms, who manages to damage Bacchus with his defensive Lizardman transformation. Elfman manages to outlast Bacchus as he exhausts himself, winning the match and forcing Bacchus' team to be renamed. Meanwhile, Natsu finds Wendy, Carla, and Poluchka being kidnapped by a group of masked men. Upon being caught, the men claim they were hired to kidnap Lucy by Raven Tail. They are soon revealed to have actually been sent by Arcadios, who intends to sow discord between the guilds as he plots to use Lucy for his "Eclipse Project".

163
"Mirajane vs. Jenny"
"Mirajēn vs. Jenī" (ミラジェーン vs. ジェニー)
January 5, 2013
September 1, 2015

The second day of the Grand Magic Games continues, with Mirajane of Fairy Tail Team B fighting against Jenny Realight of Team Blue Pegasus. Since the two competitors are well-known for being magazine models, their battle consists almost entirely of a fashion showdown, much to the pleasure of the audience. Eventually as the showdown becomes redundant, Jenny proposes a wager: the loser must pose nude for the Sorcerer Magazine, which Mirajane accepts. Jenny then transforms into her battle armor while Mirajane shifts into her Satan Soul "Sitri" form and easily defeats Jenny. The final match of the day is announced, with Kagura Mikazuchi of Mermaid Heel pitted against Yukino Aguria of Saber Tooth. Yukino proposes to Kagura that they wager their lives on their battle. Meanwhile, Arcadios is confronted by Darton, the kingdom's defense minister, about his "Eclipse Project".

164
"Kagura vs. Yukino"
"Kagura vs. Yukino" (カグラ vs. ユキノ)
January 12, 2013
September 1, 2015

Yukino is revealed to be a celestial spirit wizard when she summons Libra and Pisces to attack Kagura. Using her gravity-altering magic, Kagura defeats the two spirits, thus forcing Yukino to use a Gatekey that summons Ophiuchus, which is regarded as the strongest among the Celestial Spirits. However, Kagura slays Ophiuchus with her sword still sheathed and easily defeats Yukino. Later, Jellal discusses the fact that he has not sensed the evil power similar to Zeref's even though the second day of the Grand Magic Games has ended. Erza reunites with Milliana, who is revealed to be a member of Mermaid Heel. Meanwhile, Saber Tooth's master Jiemma is dissatisfied with his guild's performance. Though Sting is given another chance, Jiemma humiliates Yukino for her failure.

165
"Hatred at Nightfall"
"Urami wa Yoru no Tobari ni Tsutsumarete" (怨みは夜の帐に包まれて)
January 19, 2013
September 1, 2015

After Yukino is expelled from Saber Tooth, she offers her two golden Gatekeys to Lucy to complete the latter's collection of the Zodiac Gatekeys, stating that when the twelve Zodiac Gatekeys are all gathered, a gateway that changes the world will open; however, Lucy turns down the offer. Meanwhile, Milliana tells Erza that Kagura's sword, Archenemy, is intended to kill Jellal, and that she and Kagura share the same resentment towards Jellal. Natsu and Happy run after Yukino in an attempt to apologize; however, Natsu realizes that Yukino had been expelled, and infiltrates the Crocus Garden to fight Jiemma.

166
"Pandemonium"
"Pandemoniumu" (伏魔殿 (パンデモニウム))
January 26, 2013
September 1, 2015

After Natsu punches out Dobengal, the guild member summoned to fight him, he and Jiemma engage in a duel. However, the guild master's daughter Minerva appears, ends their duel and, taking Happy hostage, convinces Natsu to settle their dispute in the Grand Magic Games. As Natsu leaves, he states that Saber Tooth will never surpass Fairy Tail because they care for their friends, words that are echoed by Rogue, while Sting is left in awe at Natsu's strength. The following day as the Grand Magic Games continue, an event called "Pandemonium" begins. It involves the participants entering a magical citadel filled with 100 monsters of varying strengths and individually doing battle with any number of monsters they choose. Representing Fairy Tail Team A, Erza requests the 100 monsters as her opponents.

167
"100 Against 1"
"Hyaku tai Ichi" (100対1)
February 2, 2013
September 1, 2015

Erza kills the 100 monsters using various types of armor to match their strength and weaknesses. As a result, the crowd praises Fairy Tail, and the guild is awarded with 10 points. Moreover, the game officials decided to determine the ranks of the remaining participants by means of a device called "Magic Power Finder" (sometimes abbreviated as MPF). Using this tool, participants must attack it with their magic power, which will, in turn, calculate and display their equivalent scores depending on the extent of power used. In the end, Cana of Fairy Tail Team B dominates the event by using the Fairy Glitter spell lent to her by Mavis, much to Makarov's surprise. With Cana's victory, Fairy Tail Team B receives 8 points, and the audience began to burst once more into a resounding swarm of cheers and claps due to the finish of the two Fairy Tail teams. Meanwhile, the Raven Tail team somehow managed to get an insider information regarding the battle matchups for the day, so the masked leader Alexei tells his subordinates Flare, Obra, Nalpudding, and Kurohebi that it's about time to proceed with their true mission.

168
"Laxus vs. Alexei"
"Rakusasu vs. Arekusei" (ラクサス vs. アレクセイ)
February 9, 2013
September 1, 2015

In the battle portion of the Grand Magic Games' third day, Milliana of Mermaid Heel beats Semmes of Quatro Puppy while Saber Tooth's Rufus swiftly defeats Blue Pegasus' Eve. For the third match, Laxus of Fairy Tail Team B is chosen to battle against Alexei of Team Raven Tail. Since the opponent is from a suspicious guild, the Fairy Tail members take extra precautions by watching the actions of Ivan Dreyar as well as the other four Raven Tail members. However, as the match commences, the spectators are shocked to see Laxus being beaten by Alexei, although no cautious movements can be seen from the Raven Tail team. It turns out that the two dueling people are just illusions created by Alexei in order for him to have a talk with Laxus. Also, the other Raven Tail members being monitored by Fairy Tail are just lifelike illusions, for in reality they are with Alexei in the battlefield. Alexei reveals himself to be Ivan Dreyar. Unable to interrogate Laxus of the Lumen Histoire's location, Ivan and the Raven Tail members are forced to fight him. Before their battle begins, Ivan declares that Raven Tail is an anti-Fairy Tail guild.

169
"Wendy vs. Shelia"
"Wendi vs. Sheria" (ウェンディ vs. シェリア)
February 16, 2013
September 1, 2015

After Laxus defeats Ivan and the four Raven Tail elite members, Ivan's illusions disappear to the shock of everyone in the stadium. The game officials declare Laxus the victor, and Ivan tells him that Lumen Histoire is Fairy Tail’s 'darkness'. Due to the infraction of the rules, the Raven Tail team is disqualified for the remainder of the Games, and its members are captured by the soldiers. Later, Wendy of Fairy Tail Team A and Sherria Blendy of Team Lamia Scale face off to compete for the final match of the day. As the two exchange attacks, gusts of wind surround the arena since Sherria is revealed to be a Sky God Slayer. Wendy employs an advanced Sky Dragon Slayer attack much to Poluchka's astonishment, causing Sherria to fall on the ground. Wendy is about to be announced as the winner of the bout when Sherria suddenly stands up with her wounds fully healed. Meanwhile, the Crime Sorcière guild senses the nefarious aura, and Jellal proceeds to the Domus Flau audience, oblivious that he bumped into Doranbolt, who, in turn, wonders what is Mystogan doing in Earthland.

170
"Small Fists"
"Chiisana Kobushi" (小さな拳)
February 23, 2013
September 1, 2015

With Cheria being fully healed and Wendy being almost depleted of magic power, their battle continues, with the former casting a high-level spell towards the latter. However, it seems that Wendy enhances Cheria's physical strength, causing the attack to gain much force and thus missing Wendy. The two competitors then engage in a hand-to-hand combat, but due to the time limit and neither side is giving up, their battle resulted in a draw, giving both teams with 5 points. Meanwhile, Jellal manages to track the sinister aura among the crowd in the form of a mysterious, hooded person. Jellal is about to confront the aura source, but he is abruptly cornered by Doranbolt, Lahar, and other Rune Knights. Doranbalt then interrogates Jellal, and as his cover was blown, the Rune Knights, as well as Kagura and Milliana glancing nearby, are startled to see the true identity of Mystogan. Yajima convinces the Rune Knights that Mystogan is Jellal’s Edolas counterpart, prompting Lahar to release the fugitive. Meanwhile, Laxus and Makarov have a small conversation regarding Lumen Histoire when Mavis appears and explains that Lumen Histoire is the ‘light’ of Fairy Tail.

171
"Naval Battle"
"Nabaru Batoru" (海战 (ナバルバトル))
March 2, 2013
September 1, 2015

As the jubilant Fairy Tail members celebrate their victories, the other people, such as Sting, Kagura, and Milliana, are contemplating on their own concerns, while Yukino is enlisted as a sergeant under Arcadios' command. Meanwhile, the fourth day of the competitions comes to a start with an event, "Naval Battle", which involves the participants swimming in a giant water sphere and knocking the other competitors out. After the other participants fall out of the aquatic sphere, a five-minute battle between Lucy and Minerva ensues. However, Minerva quickly attacks Lucy, and she manages to steal the keys of the Celestial Spirit mage. Regardless of this, Lucy refuses to surrender. After hearing Lucy's intentions, Minerva stops from attacking up to the extent that the five-minute mark was reached. However, Minerva resumes attacking Lucy until the game officials decide to halt the match. The Fairy Tail members snap, and Minerva dangles Lucy out of the sphere while the others rush to her aid.

172
"A Parfum for You"
"Kimi ni Sasageru Parufamu" (君に捧げる香り (パルファム))
March 9, 2013
September 1, 2015

While Lucy is hospitalized and taken to the infirmary, the Fairy Tail members warn Saber Tooth that they have angered the worst possible guild to do so. Later, Makarov announces that the two Fairy Tail teams must merge as a result of the disqualification of Raven Tail and to compensate for the odd number of teams for the battle round. He also reveals that the new team will have the former Team A's 35 points to start with. The new Fairy Tail team, consisting of Natsu, Gray, Erza, Gajeel, and Laxus, are well-received as they enter the field. The second part of the tournament begins with a tag battle between Blue Pegasus' Ichiya and "Rabbit" and Quatro Puppy's Rocker and Bacchus. To everyone's shock, it is revealed that "Rabbit" is actually Nichiya in disguise, and after the Exceed is punched by Bacchus, Ichiya bulks up to defeat the Quatro Puppy opponents, awarding Blue Pegasus with 10 points.

173
"Battle of Dragon Slayers!"
"Batoru obu Doragon Sureiyā" (バトル・オブ・ドラゴンスレイヤー)
March 16, 2013
September 1, 2015

Mermaid Heel's Kagura and Milliana and Lamia Scale's Lyon and Yuka face off for the second tag battle of the games. The two teams struggle to earn a victory, only to have their battle ending in a draw due to the time limit. For the third and final match of the day, the spectators look on in silence as Natsu and Gajeel of Team Fairy Tail and Sting and Rogue of Team Saber Tooth enter the field. As the battle commences, Sting and Rogue were about to take the initiative when they were suddenly attacked by Natsu and Gajeel. The four mages then exchange attacks; however, the audience watches in shock as the Fairy Tail Dragon Slayers overpower the Saber Tooth Dragon Slayers. Unable to keep themselves on par with their adversaries, Sting activates 'White Drive' while Rogue powers up using 'Shadow Drive'.

174
"Four Dragons"
"Yonin no Doragon" (四人の竜 (ドラゴン))
March 23, 2013
September 1, 2015

The tag battle continues, with Sting and Rogue beginning to attack Natsu and Gajeel with their powers being increased. After receiving heavy blows from the Saber Tooth Dragon Slayers, Natsu and Gajeel manages to hold them off, thus forcing Sting and Rogue to activate "Dragon Force" on their own will, to the shock of the Fairy Tail audience. Sting decides to finish the Fairy Tail Dragon Slayers alone, for he held a promise to his Exceed friend Lector many years ago. As the three mages fight, the tide turns in favor of Sting as he unleashes a powerful attack on Natsu and Gajeel, resulting in the collapse of the arena floor, and after a hand-to-hand combat underground, Sting was seemingly the victor of the match. However, the Fairy Tail duo stands up, comments on Sting’s strength, and argues about his position while attacking, thereby causing Natsu to drag Gajeel on a mining cart and send it away. While Gajeel is left incapacitated due to motion sickness, Natsu challenges the Twin Dragons of Saber Tooth alone, in retribution to what Sting did earlier on them.

175
"Natsu vs. the Twin Dragons"
"Natsu vs. Sōryū" (ナツ vs. 双竜)
March 30, 2013
September 1, 2015

The tag battle of the Dragon Slayers comes to a close, with Natsu overpowering the combined attacks of Sting and Rogue. The Saber Tooth members watch in dismay, while Jiemma seethes in anger over the defeat of the Twin Dragons, frightening the nearby spectators away. The rest of Fairy Tail celebrates in joy as its team receives 10 points, finally surpassing Team Saber Tooth by a single point. Meanwhile, Gajeel, back to his senses after being dragged by Natsu into a cart earlier, stumbles upon a cave full of dragon skeletons. During that night, Jellal manages to corner the source of the dark aura, standing in disbelief at the identity of the mysterious, hooded person.

text: Notes[edit]

text:
Jump up ^ All English titles are taken from Funimation.
Jump up ^ Date the episode originally aired on TV Tokyo.
Jump up ^ Date the episode first aired on the Funimation Channel in an English dub.

tag: ol


document_title: Z-line

question_text: what is the z line in the stomach

question_tokens: what is the z line in the stomach

root

text: Z-line

text: Z-line can refer to:

tag: p

text:
the borders that separate and link sarcomeres within a skeletal muscle
a ban on a user's IP address for the purposes of blocking their access to Internet Relay Chat. See Z-line.
the gastroesophageal junction that joins the esophagus to the stomach.
Z, a New York City Subway service.

tag: ul

text:
This disambiguation page lists articles associated with the title Z-line.
If an internal link led you here, you may wish to change the link to point directly to the intended article.

tag: table

text: Disambiguation pages

text: All article disambiguation pagesAll disambiguation pages


document_title: List of countries with McDonald's restaurants

question_text: how many mcdonald's stores are there in australia

question_tokens: how many mcdonald 's stores are there in australia

text: Countries and territories with a McDonald's outlet[edit]

text:
1#

Name of country

Date of first store

First outlet location

Number of currently operating outlets

Source and date of source

People per outlet

Notes

1

 United States

May 15, 1940Franchise: April 13, 1955

San Bernardino, CaliforniaDes Plaines, Illinois (Franchise)

14,146

(source: Statista 2016)

22,985

See McDonald's USA

2

 Canada (details)

June 3, 1967

Richmond, British Columbia

1,450

(source: Statista 2016)

24,242

See McDonald's Canada

3

 Puerto Rico

December 6, 1967

San Juan

108

(source: McDonald's 2013)

31,583

First McDonald's in Latin America and in the Caribbean. See McDonald's Puerto Rico

4

 U.S. Virgin Islands

September 5, 1970

St. Croix

6

(source: McDonald's 2013)

17,666

5

 Costa Rica

December 8, 1970

San Jose, 4th street, between 1st and Central Avenue.

54

(source: McDonald's 2013)

84,925

Third country (not U.S. possession) and first outlet outside Northern America where McDonald's opened. See McDonald's Costa Rica

6

 Australia

May 30, 1971

Yagoona, New South Wales[12]

920

(source: McDonald's 2013)

26,613

First outlet in Oceania and first outlet outside the Americas. See McDonald's Australia.

7

 Guam

June 10, 1971

Dededo

6

(source: Statista 2016)

27,166

8

 Japan

July 21, 1971

Tokyo

2,975

(source: McDonald's 2015)

42,598

First outlet in Asia, see McDonald's Japan; McDonald's Holdings Company Japan, Inc.[13]

9

 Netherlands

August 21, 1971

Zaandam

245

(source: McDonald's 2016)

69,797

This was the first outlet in Europe. Opened in 1971 by European Master Franchisees Jan Sybesma & Diet de Wolff (Brother & Sister) - McDonald's Europe is now run by the Dutch Sybesma family & Australian de Wolff family who also own in excess of 80 Stores Worldwide. Sybesma & de Wolff ATF McDonald's Europe - Plan to open 15 more stores in the next 4 years. See McDonald's Netherlands

10

 Panama

September 1, 1971

Panama City

57

(source: McDonald's 2013)

71,192

See McDonald's Panama

11

 Germany

November 22, 1971( West Germany)December 21, 1990(former  East Germany)[14]

Munich( West Germany)Plauen(former  East Germany)

1,476

(source: McDonald's Germany 2018)[15]

56,098

First outlet in West Germany. First outlet in the new states of Germany opened in 1990 following reunification. See McDonald's Germany

12

 France

June 30, 1972

Créteil

1,419

(source: McDonald's December 2016)[15]

45,708

First outlet in Creteil in 1972 even though McDonald's officially recognizes the first outlet in Strasbourg in 1979. See McDonald's France.

13

 El Salvador

July 20, 1972

San Salvador

20

(source: 2018)

490,538

Left in 1980 during the Salvadorian Civil War, but returned after the war in 1992.

14

 Sweden

October 27, 1973

Kungsgatan 4, Stockholm

202

(source: 2018)

44,546

First outlet in Scandinavia. See McDonald's Sweden

15

 Guatemala

June 6, 1974

Guatemala City

94

(source: 2018)

197,268

See McDonald's Guatemala

16

 Curacao

August 16, 1974

Willemstad

5

(source: McDonald's 2013)

31,800

See McDonald's Aruba and Curaçao

17

 United Kingdom

England: 13 November 1974[16]Wales: 3 December 1984Scotland: 23 November 1987[17]Northern Ireland: 12 October 1991

Woolwich, London (England)Cardiff (Wales)Dundee (Scotland)Belfast (Northern Ireland)

1,274

(source: McDonald's December 2016)[15]

51,106

Includes Isle of Man and Jersey (1 each)England: 1,038Scotland: 95Wales: 62Northern Ireland: 26See McDonald's UK

18

 Hong Kong( British Hong Kong at the time)

January 8, 1975

Paterson Street, Causeway Bay, Hong Kong Island.[18]

237

R(source: McDonald's 2013)

31,118

Then a British Crown colony/Dependent Territory. See McDonald's Hong Kong

19

 Bahamas

August 4, 1975

Nassau

3

(source: Dec. 2012)

131,000

First outlet in an independent country of the Caribbean.

20

 New Zealand (details)

June 7, 1976

Porirua Central, Wellington[19]

166

(source: 2018)

29,574

Founded in New Zealand by Wally and Hugh Morris[20]First South Island restaurants opened at Linwood and Merivale, both Christchurch, on 3 November 1987.[21] See McDonald's New Zealand.

21

  Switzerland

October 20, 1976

Geneva

167

(source: 2018)

51,858

see McDonald's Switzerland

22

 Ireland

May 9, 1977

Grafton Street, Dublin

89

(source: McDonald's 2013)

53,505

First drive-thru in Europe opened in Nutgrove, Dublin and first McCafé in Europe Grafton Street, Dublin, see McDonald's Ireland

23

 Austria

July 21, 1977

Schwarzenbergplatz, Vienna

195

(source: McDonald's 2018)

45,246

see McDonald's Austria

24

 Belgium

March 21, 1978

Brussels

74

(source: McDonald's 2015)

152,027

A division of Sybesma & de Wolff (Master Franchisees McDonald's Europe), with most stores being owned by S&DW. See McDonald's Belgium

25

 Brazil

February 13, 1979

Rio de Janeiro

812

(source: McDonald's 2013)

255,357

First outlet in South America and first outlet in a lusophone country. See McDonald's Brazil

26

 Singapore

October 20, 1979

Liat Towers, Orchard Road

136

(source: Dec. 2012)

44,856

First outlet in Southeast Asia. See McDonald's Singapore

27

 Spain

March 10, 1981

Gran Vía, Madrid

507[22]

(source: July 2018)

93,406

First outlet in the Iberian Peninsula, see McDonald's Spain

28

 Denmark

April 15, 1981

Vesterbrogade 2D, Copenhagen

88

(source: 2018)

64,595

See McDonald's Denmark

29

 Philippines

September 27, 1981

Morayta, Sampaloc, Manila

572

(source: February 2018)[23][24]

183,423

See McDonald's Philippines

30

 Malaysia

April 29, 1982

Jalan Bukit Bintang, Kuala Lumpur[25]

271

(source: 2018)

100,417

First outlet in a Muslim-majority country. See McDonald's Malaysia

31

 Norway

November 18, 1983

Nedre Slottsgate, Oslo

73

(source: Jun. 2017)

72,150

see McDonald's Norway

32

 Taiwan

January 28, 1984

Minsheng East Road, Taipei

413

(source: 2015)

56,949

Left in 1992 during investigations of restaurant bombings in Taiwan, but returned that same year after investigations concluded.
See McDonald's Taiwan

33

 Andorra

June 29, 1984

Andorra la Vella

5

(source: 2018)[26]

17,000

34

 Finland

December 14, 1984

Hämeenkatu 17, Tampere

65

(source: June 2017 [2])

84,676

see McDonald's Finland

35

 Thailand

February 23, 1985

Bangkok

240

(source: 2017)

283,162

see McDonald's Thailand

36

 Aruba

April 4, 1985

Oranjestad

4

(source: 2016)

25,750

See McDonald's Aruba and Curaçao

37

 Luxembourg

July 17, 1985

Luxembourg City

10

(source: 2013)

57,600

see McDonald's Luxembourg

38

 Venezuela

August 31, 1985

Caracas

140

(source: 2013 website)

226,964

see McDonald's Venezuela

39

 Italy

March 20, 1985

Piazza di Spagna, Rome

571

(source: 2018)[27]

106,296

see McDonald's Italy

40

 Mexico

October 29, 1985

Mexico City

402

(source: Dec. 2012)

297,340

see McDonald's Mexico

41

 Cuba

April 24, 1986

Guantanamo Bay

1

(source: Dec. 2012)

11,239,000

Guantanamo Bay – Open only to base personnel.

42

 Turkey

October 24, 1986

Istanbul

250

(source: 2018)[28]

313,000

see McDonald's Turkey. First outlet in West Asia.

43

 Argentina

November 24, 1986

Belgrano, Buenos Aires

222

(source: Jun. 2018)

207,736

see McDonald's Argentina.

44

 Macau( Portuguese Macau at the time)

April 11, 1987

Rua do Campo, Cathedral Parish, Macau Peninsula

27

(source: Dec. 2012)

24,111

Then Portuguese territory; McDonald's would only open a restaurant in Portugal itself 4 years later. see List of restaurants.

45

 Serbia(part of  Yugoslavia at the time)

March 24, 1988

Slavija Square, Belgrade

30

(source: October 2016)[29]

271,461

First outlet in a communist country and first outlet in the Balkans. See McDonald's Serbia

46

 South Korea

March 29, 1988

Gangnam District, Seoul

450[30]

(source: June 2017)

113,888

See McDonald's South Korea

47

 Hungary( HPR at the time)

April 13, 1988

Budapest[31]

89

(source: 2018)[32]

109,222

Second communist country, first Warsaw Pact member, thus first outlet behind the Iron Curtain. See McDonald's Hungary

48

 Russia(part of  Soviet Union at the time)

January 31, 1990

Pushkin Square, Moscow

645

(source: January 2017)[33]

223,255

See McDonald's Russia

49

 PR of China

October 8, 1990

Shenzhen

2,391

(source: December 2016)[34]

624,336>

See McDonald's China.

50

 Chile

November 19, 1990

Santiago de Chile

77

(source: Dec. 2012)

233,844

See McDonald's Chile

51

 Indonesia

February 23, 1991

Sarinah, Jakarta

170

(source: 2016)

1,550,058

See McDonald's Indonesia

52

 Portugal

May 23, 1991

CascaiShopping, Cascais

148

(source: Sep. 2015)

69,871

See McDonald's Portugal

53

 Greece

November 12, 1991

Athens Syntagma Sq.

23

(source: 2018)

456,458

See McDonald's Greece

54

 Uruguay

November 18, 1991

Montevideo

21

(source: 2014)

163,190

See McDonald's Uruguay

55

 Martinique

December 16, 1991

Fort-de-France

9

(source: 2016)

42,888

See McDonald's French Antilles

56

 Czech Republic(part of  Czechoslovakia at the time)

March 20, 1992

Vodičkova street, Prague

95

(source: Feb. 2015)

111,094

See McDonald's Czech Republic

57

 Guadeloupe

April 8, 1992

8

(source: 2016)

50,250

See McDonald's French Antilles

58

 Poland

June 16, 1992

Marszałkowska Street, Warsaw in department store "Sezam"

403

(source: 2018)

94,875

See McDonald's Poland

59

 Monaco

November 20, 1992

Monte Carlo

2

19,000

60

 Brunei

December 12, 1992

Bandar Seri Begawan

2

(source: 2016)

208,500

61

 Morocco

December 18, 1992

Casablanca

41

(source: 2018)[35]

846,200

First outlet in Africa – McDonald's is now present in all continents except Antarctica. See McDonald's Morocco

62

 Northern Marianas

March 18, 1993

Saipan

2

(source:August 2011)

26,500

First outlet opened on the island of Saipan – Along with a second outlet in 1997

63

 Israel (details)

October 14, 1993

Ayalon Mall, Ramat Gan

185

(source: 2016)

47,021

First outlet in the Middle East. See McDonald's Israel

64

 Slovenia

December 2, 1993

In Čopova Street, Ljubljana

20

(source: 2016)

103,300

See McDonald's Slovenia

65

 Saudi Arabia

December 8, 1993

Riyadh

263

(source: 2018)

147,321

See McDonald's Saudi Arabia McDonald's Saudi Arabia

66

 Kuwait

June 15, 1994

72

(source: 2018)

57,973

See McDonald's Kuwait

67

 New Caledonia

July 26, 1994

Nouméa

2

(source: 2012)

134,500

68

 Oman

July 30, 1994

23

(source: 2018)

304,866

See McDonald's Oman

69

 Egypt

October 20, 1994

Cairo

100

(source: 2017)

1,260,621

See McDonald's Egypt

70

 Bulgaria

December 10, 1994

Plovdiv

42

(source: 2011)

169,095

See [3]

71

 Bahrain

December 15, 1994

Muharraq City

23

(source: 2018)

68,900

See McDonald's Bahrain

72

 Latvia

December 15, 1994

Riga

12

(source: June 2012)[36]

162,750

First outlet in the Baltics. See McDonald's Latvia

73

 United Arab Emirates

December 21, 1994

Abu Dhabi

165

(source: 2018)

88,938

See McDonald's UAE

74

 Estonia

April 29, 1995

Tallinn

10

(source: June 2015)[37]

131,600

See McDonald's Estonia

75

 Romania

June 16, 1995

Bucharest

70

(source: 2017)

280,543

See McDonald's Romania

76

 Malta

July 7, 1995

Valletta

10

(source: McDonald's 2016, 9 in Malta, 1 in Gozo)

44,500

See McDonald's Malta

77

 Colombia

July 14, 1995

Centro Andino, Bogota

81

(source: July 2013)

607,530

See McDonald's Colombia

78

 Slovakia

October 14, 1995

Banská Bystrica

30

(source: 2015)

180,866

See McDonald's Slovakia

79

 South Africa

November 11, 1995

Blackheath, Gauteng

252

(source: 2018)

244,253

See McDonald's South Africa

80

 Qatar

December 13, 1995

42

(source: 2018)

107,040

See McDonald's Qatar

81

 Honduras

December 14, 1995

Tegucigalpa

8

1,031,250

See McDonald's Honduras

82

 Sint Maarten

December 15, 1995

Philipsburg

3

(source: December 2013)

11,333

83

 Croatia

February 2, 1996

Zagreb

30

(source: 2018)[38]

139,033

See McDonald's Croatia

84

 Samoa(named Western Samoa at the time)

March 2, 1996

Apia

1

192,000

85

 Fiji

May 1, 1996

Suva

4

(source: 2001)

224,690

As of April 2012, Fiji is the only country in the world to still use the 2003 "i'm lovin' it" packaging, even though the other countries are using the 2008 packaging for meals and items. See McDonald's Fiji

86

 Liechtenstein

May 3, 1996

Triesen

1

(source: 2018)

38,111

See McDonald's Switzerland

87

 Lithuania

May 31, 1996

Vilnius

13

(source: 2018)[39]

257,090

See McDonald's Lithuania

88

 India

October 13, 1996[40]

Delhi

290+

(source: 2017)[41][42]

5,306,288>

First outlet in South Asia. See McDonald's India

89

 Peru

October 18, 1996

Lima

40

(source: 2014)

778,800

See McDonald's Peru

90

 Jordan

November 7, 1996

Amman

31

(source: 2018)

352,928

91

 Paraguay

November 21, 1996

Asuncion

11

(source: 2011)

616,636

See McDonald's Paraguay

92

 Dominican Republic

November 30, 1996

Santo Domingo

31

325,000

Country with the second most locations of McDonald's in the Caribbean, after Puerto Rico. See McDonald's Dominican Republic

93

 French Polynesia

December 10, 1996

Tahiti

6

47,666

94

 Belarus

December 10, 1996

Minsk

13

(source: 2017)

864,272

First McDonald's in a non-Baltic former Soviet republic (not including Russia)
The company claimed this as McDonald's "100th country" although this calculation included many non-sovereign territories. See McDonald's Belarus.

95

 Trinidad and Tobago

May 6, 1997

6

225,000

McDonald's previously had stores in Trinidad (May 6, 1997 – October 25, 2003) but closed due to low sales. Re-opened at The Falls At West Mall in 2011 and has expanded to 5 other locations.[43]

96

 Ukraine

May 24, 1997

Kyiv

80

(source: October 2017)

545,410

All three restaurants in the peninsula of Crimea were closed in 2014. See McDonald's Ukraine

97

 Cyprus

June 12, 1997

Larnaca

18

(source: 2016)

63,388

See McDonald's Cyprus

98

 Jersey

August 1, 1997

Saint Helier

1

100,080

99

 Ecuador

October 9, 1997

6 de Diciembre Avenue, Quito

27

(source: 2014)

597,925

See McDonald's Ecuador

100

 Bolivia

October 24, 1997

La Paz

1

10,980,000

McDonald's was open in Bolivia from October 24, 1997 to September 30, 2002, when it closed due to slow sales and cost. A new restaurant opened on October 10, 2017 after fifteen years of absence.

101

 Reunion

December 14, 1997

Saint-Denis

4

(source: 2018)

210,904

102

 Isle of Man

December 15, 1997

Douglas

1

84,000

103

 Suriname

December 18, 1997

Paramaribo

2

(source: 2010)

293,000

104

 Moldova

April 30, 1998

Chișinău

5

(source: 2018)

599,647

See McDonald's Moldova

105

 Nicaragua

July 11, 1998

Managua

6

(source: June 2010)

1,027,833

McDonald's outlets ceased operation during the Nicaraguan civil war and re-established a presence in 1998 after an absence of two decades. During the civil war one continued operating as "Donald's".[44] See McDonald's Nicaragua

106

 Lebanon

September 18, 1998

Beirut

33

(source: 2013)

187,424

107

 Pakistan

September 19, 1998[45]

Karachi

60

(source: 2018)

2,885,757

McDonald's Pakistan

108

 Sri Lanka

October 16, 1998

Colombo

7

(source: March 4, 2013)

2,896,857

see McDonald's Sri Lanka

109

  Georgia

February 5, 1999

Rustaveli Avenue, Tbilisi

14

(source: 2018)

338,181

First outlet in the Caucasus. See McDonald's Georgia

110

 San Marino

July 6, 1999

Borgo Maggiore

1

(source: 2018)

33,328

See McDonald's Italy

111

 Gibraltar

August 13, 1999

Westside

1

(source: 2018)

32,194

See McDonald's Spain

112

 Azerbaijan

November 6, 1999

Fountains Square, Baku

12

(source: 2016)[46]

818,666

See McDonald's Azerbaijan

113

 French Guiana

February 22, 2000

Cayenne

2

(source: 2016)

125,000

See McDonald's French Antilles

114

 American Samoa

September 29, 2000

2

(source: 2008)

27,000

115

 Mauritius

July 4, 2001

Port Louis

7

192,571

117

  Iraq

August 10, 2006

Baghdad

1

(source: 2006)

38,146,000

One location in Baghdad for the U.S. Army, but there is also a knockoff called MaDonal.

118

 Bosnia and Herzegovina

July 21, 2011[47]

Sarajevo

4

(source: 2015)

882,790

After some 10 years of trying to enter the Bosnian market with no success, McDonald's opened its first restaurant in BiH on 20 July 2011. See McDonald's Bosnia and Herzegovina

119

 Vietnam

February 8, 2014

Ho Chi Minh City

17

(source: 2017)

6,180,000

See McDonald's Vietnam

120

 Kazakhstan

March 8, 2016

Astana

9

1,778,844

First outlet in Central Asia. See McDonald's Kazakhstan

121

 Tunisia

Tunis

Coming Soon

122

 Kenya

Coming Soon

Nairobi

(source: 2017)

49,125,325

Announced on December 10, 2017. McDonald's is still yet to open in Kenya.

text: Former locations[edit]

text:
1#

Name of country

Date of first store

Date of closing

Reason to closing

1

 Iran

circa 1971/1972

1979

Closed due to the Islamic Revolution. A lot of foreign companies, specifically American, were forced to leave. McDonald's attempted to re-enter the Iranian market in 1994, but this failed due to a hostile anti-American fundamentalist attack on the building which was under construction where the planned franchise would be opened. McDonald's does not plan on opening any restaurants in Iran at this time.

2

 Barbados [48]

August 25, 1989

December 13, 1990

Closed due to extremely slow sales.

3

 Bermuda [49]

November 10, 1985

March 9, 1995

Closed due to a government law that bans franchised restaurants in the country. The McDonald's restaurant was located on a US Naval Air Station and was thus exempt from the law. When the base closed in 1995 the restaurant was required to do likewise.

4

 Jamaica [50]

April 15, 1995

October 14, 2005

Closed due to governmental problems and declining sales.

5

 Montenegro

June 1, 2004

2007

A seasonal McDonald's restaurant was opened in Budva, but it was closed due to the lack of location.

6

 Iceland [51]

September 1, 1993

October 31, 2009

Closed down by Icelandic affiliate due to both prohibitive costs of importing foreign food products as required by McDonald's and the collapse of the Icelandic krona. Its three former outlets were re-branded as its own chain of Metro restaurants, which offer similar service and menus with domestically produced ingredients.

7

 Macedonia

September 6, 1997

May 15, 2013

Closed due to dispute in contract and contractual obligations with the franchise owner Sveto Janevski.


document_title: Biomass

question_text: land conversion through burning of biomass releases which gas

text: Biomass

text: Sources[edit]

text: In terms of how biomass is used as fuel, percentages were gathered in the United States of 2016. 5% is considered primary energy in the U.S. Making up that 5% of primary energy, about 48% comes from biofuels (mostly ethanol), 41% from wood based biomass, and around 11% from municipal waste.[4] Historically, humans have harnessed biomass-derived energy since the time when people began burning wood to make fire.[5] Even in 2018, biomass is the only source of fuel for domestic use in many developing countries. Biomass is all biologically-produced matter based in carbon, hydrogen and oxygen. The estimated biomass production in the world is 104.9 petagrams (104.9 × 1015 g – about 105 billion metric tons) of carbon per year, about half in the ocean and half on land.[6] Wood remains the largest biomass energy source today;[5] examples include forest residues (such as dead trees, branches and tree stumps), yard clippings, wood chips and even municipal solid waste. Wood energy is derived by using lignocellulosic biomass (second-generation biofuels) as fuel. Harvested wood may be used directly as a fuel or collected from wood waste streams to be processed into pellet fuel or other forms of fuels.

text: Biomass also includes plant or animal matter that can be converted into fibers or other industrial chemicals, including biofuels. Industrial biomass can be grown from numerous types of plants, including miscanthus,[7] switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, bamboo,[8] and a variety of tree species, ranging from eucalyptus to oil palm (palm oil).

text: Based on the source of biomass, biofuels are classified broadly into two major categories. First-generation biofuels are derived from sources such as sugarcane and corn starch. Sugars present in this biomass are fermented to produce bioethanol, an alcohol fuel which can be used directly in a fuel cell to produce electricity or serve as an additive to gasoline. However, utilizing food-based resources for fuel production only aggravates the food shortage problem.[9] Second-generation biofuels, on the other hand, utilize non-food-based biomass sources such as agriculture and municipal waste. These biofuels mostly consist of lignocellulosic biomass, which is not edible and is a low-value waste for many industries. Despite being the favored alternative, economical production of second-generation biofuel is not yet achieved due to technological issues. These issues arise mainly due to chemical inertness and structural rigidity of lignocellulosic biomass.[10][11][12]

text: Plant energy is produced by crops specifically grown for use as fuel that offer high biomass output per hectare with low input energy. Some examples of these plants are wheat, which typically yields 7.5–8 tonnes of grain per hectare, and straw, which typically yields 3.5–5 tonnes per hectare in the UK.[13] The grain can be used for liquid transportation fuels while the straw can be burned to produce heat or electricity. Plant biomass can also be degraded from cellulose to glucose through a series of chemical treatments, and the resulting sugar can then be used as a first-generation biofuel.

text: The main contributors of waste energy are municipal solid waste, manufacturing waste, and landfill gas. Energy derived from biomass is projected to be the largest non-hydroelectric renewable resource of electricity in the US between 2000 and 2020.[14]

text: Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Rotting garbage, and agricultural and human waste, all release methane gas, also called landfill gas or biogas. Crops such as corn and sugarcane can be fermented to produce the transportation fuel ethanol. Biodiesel, another transportation fuel, can be produced from leftover food products like vegetable oils and animal fats.[15] Several biodiesel companies simply collect used restaurant cooking oil and convert it into biodiesel.[16] Also, biomass-to-liquids (called "BTLs") and cellulosic ethanol are still under research.[17][18]

text: There is research involving algae or algae-derived biomass, as this non-food resource can be produced at rates five to ten times those of other types of land-based agriculture, such as corn and soy. Once harvested, it can be fermented to produce biofuels such as ethanol, butanol, and methane, as well as biodiesel and hydrogen. Efforts are being made to identify which species of algae are most suitable for energy production. Genetic engineering approaches could also be utilized to improve microalgae as a source of biofuel.[19]

text: The biomass used for electricity generation varies by region. Forest by-products, such as wood residues, are common in the US. Agricultural waste is common in Mauritius (sugar cane residue) and Southeast Asia (rice husks). Animal husbandry residues, such as poultry litter, are common in the UK.[20]

text: Sewage sludge can be another source of biomass. For example, the Omni Processor is a process which uses sewage sludge as fuel in a process of sewage sludge treatment, with surplus electrical energy being generated for export.[21][22]

text: Comparison of total plant biomass yields (dry basis)[edit]

text: World resources[edit]

text: If the total annual primary production of biomass is just over 100 billion (1.0E+11) tonnes of carbon /yr,[23] and the energy reserve per tonne of biomass is between about 1.5×103 and 3×103 kilowatt hours (5×106 and 10×106 BTU),[24] or 24.8 TW average, then biomass could in principle provide 1.4 times the approximate annual 150×103 terawatt-hours required for current world energy consumption.[25] For reference, the total solar power on Earth is 174 PW. The biomass equivalent to solar energy ratio is 143 ppm (parts per million), given current living system coverage on Earth. The best currently attainable solar cell efficiency is 20–40%. Additionally, Earth's internal radioactive energy production, largely the driver for volcanic activity, continental drift, etc., is in the same range of power, 20 TW. At around 50% carbon mass content in biomass, annual production, this corresponds to about 6% atmospheric carbon content in the form of CO2 (for the current 400 ppm).

text: Common commodity food crops[edit]

text:
Agave: 1–21 tons/acre[26]
Alfalfa: 4–6 tons/acre[27]
Barley: grains – 1.6–2.8 tons/acre, straw – 0.9–2.5 tons/acre, total – 2.5–5.3 tons/acre[28]
Corn: grains – 3.2–4.9 tons/acre, stalks and stovers – 2.3–3.4 tons/acre, total – 5.5–8.3 tons/acre[27]
Jerusalem artichokes: tubers 1–8 tons/acre, tops 2–13 tons/acre, total 9–13 tons/acre[29]
Oats: grains – 1.4–5.4 tons/acre, straw – 1.9–3.2 tons/acre, total – 3.3–8.6 tons/acre[28]
Rye: grains – 2.1–2.4 tons/acre, straw – 2.4–3.4 tons/acre, total – 4.5–5.8 tons/acre[28]
Wheat: grains – 1.2–4.1 tons/acre, straw – 1.6–3.8 tons/acre, total – 2.8–7.9 tons/acre[28]

text: Woody crops[edit]

text: Oil palm: fronds 11 ton/acre, whole fruit bunches 1 ton/acre, trunks 30 ton/acre[30]

text: Not yet in commercial planting[edit]

text:
Giant miscanthus: 5–15 tons/acre [31]
Sunn hemp: 4.5 tons/acre[32]
Switchgrass: 4–6 tons/acre[27]

text: Genetically modified varieties[edit]

text: Energy Sorghum

text: Biomass conversion[edit]

text: This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2010) (Learn how and when to remove this template message)

text: Thermal conversions[edit]

text: Thermal conversion processes use heat as the dominant mechanism to convert biomass into another chemical form. Also known as thermal oil heating, it is a type of indirect heating in which a liquid phase heat transfer medium is heated and circulated to one or more heat energy users within a closed loop system.[33] The basic alternatives of combustion (torrefaction, pyrolysis, and gasification) are separated principally by the extent to which the chemical reactions involved are allowed to proceed (mainly controlled by the availability of oxygen and conversion temperature).

text: Energy created by burning biomass is particularly suited for countries where the fuel wood grows more rapidly, e.g. tropical countries. There are a number of other less common, more experimental or proprietary thermal processes that may offer benefits such as hydrothermal upgrading (HTU) and hydroprocessing. Some have been developed for use on high moisture content biomass, including aqueous slurries, and allow them to be converted into more convenient forms. Some of the applications of thermal conversion are combined heat and power (CHP) and co-firing. In a typical dedicated biomass power plant, efficiencies range from 20–27% (higher heating value basis).[34] Biomass cofiring with coal, by contrast, typically occurs at efficiencies near those of the coal combustor (30–40%, higher heating value basis).[35]

text: Chemical conversion[edit]

text:
A range of chemical processes may be used to convert biomass into other forms, such as to produce a fuel that is more conveniently used, transported or stored, or to exploit some property of the process itself. Many of these processes are based in large part on similar coal-based processes, such as Fischer-Tropsch synthesis, methanol production, olefins (ethylene and propylene), and similar chemical or fuel feedstocks. In most cases, the first step involves gasification, which step generally is the most expensive and involves the greatest technical risk.[36]
Biomass is more difficult to feed into a pressure vessel than coal or any liquid. Therefore, biomass gasification is frequently done at atmospheric pressure and causes combustion of biomass to produce a combustible gas consisting of carbon monoxide, hydrogen, and traces of methane. This gas mixture, called a producer gas, can provide fuel for various vital processes, such as internal combustion engines, as well as substitute for furnace oil in direct heat applications.[37] Because any biomass material can undergo gasification, this process is far more attractive than ethanol or biomass production, where only particular biomass materials can be used to produce a fuel. In addition, biomass gasification is a desirable process due to the ease at which it can convert solid waste (such as wastes available on a farm) into producer gas, which is a very usable fuel.[37]

text: Conversion of biomass to biofuel can also be achieved via selective conversion of individual components of biomass.[38] For example, cellulose can be converted to intermediate platform chemical such a sorbitol,[39] glucose,[40] hydroxymethylfurfural[41] etc. These chemical are then further reacted to produce hydrogen or hydrocarbon fuels.[42]

text: Biomass also has the potential to be converted to multiple commodity chemicals. Halomethanes have successfully been by produced using a combination of A. fermentans and engineered S. cerevisiae.[43] This method converts NaX salts and unprocessed biomass such as switchgrass, sugarcane, corn stover, or poplar into halomethanes. S-adenosylmethionine which is naturally occurring in S. cerevisiae allows a methyl group to be transferred. Production levels of 150 mg L-1H-1 iodomethane were achieved. At these levels roughly 173000 L of capacity would need to be operated just to replace the United States’ need for iodomethane.[43] However, an advantage of this method is that it uses NaI rather than I2; NaI is significantly less hazardous than I2. This method may be applied to produce ethylene in the future.

text: Other chemical processes such as converting straight and waste vegetable oils into biodiesel is transesterification.[44]

text: Biochemical conversion[edit]

text: As biomass is a natural material, many highly efficient biochemical processes have developed in nature to break down the molecules of which biomass is composed, and many of these biochemical conversion processes can be harnessed.

text: Biochemical conversion makes use of the enzymes of bacteria and other microorganisms to break down biomass into gaseous or liquid fuels, such a biogas or bioethanol.[45] In most cases, microorganisms are used to perform the conversion process: anaerobic digestion, fermentation, and composting.

text: Glycoside hydrolases are the enzymes involved in the degradation of the major fraction of biomass, such as polysaccharides present in starch and lignocellulose. Thermostable variants are gaining increasing roles as catalysts in biorefining applications in the future bioeconomy, since recalcitrant biomass often needs thermal treatment for more efficient degradation. Some examples in today´s processing include production of monosaccharides for food applications as well as use as carbon source for microbial conversion into metabolites such as bioethanol and chemical intermediates, oligocaccharide production for prebiotic (nutrition) applications and production of surfactants alkyl glycoside type.[46]

text: Electrochemical conversion[edit]

text: In addition to combustion, biomass/biofuels can be directly converted to electrical energy via electrochemical (electrocatalytic) oxidation of the material. This can be performed directly in a direct carbon fuel cell,[47] direct liquid fuel cells such as direct ethanol fuel cell, a direct methanol fuel cell, a direct formic acid fuel cell, a L-ascorbic Acid Fuel Cell (vitamin C fuel cell),[48] and a microbial fuel cell.[49] The fuel can also be consumed indirectly via a fuel cell system containing a reformer which converts the biomass into a mixture of CO and H2 before it is consumed in the fuel cell.[50]

text: In the United States[edit]

text: The  biomass power generating industry in the United States consists of approximately 11,000 MW of summer operating capacity actively supplying power to the grid, and produces about 1.4 percent of the U.S. electricity supply.[51]

text: Public Service of New Hampshire (later merged with other companies into Eversource) in 2006 replaced a 50 MW coal boiler with a new 50 MW biomass boiler at its Schiller Station facility in Portsmouth, NH.[52]  The boiler's biomass fuel is from sources in NH, Massachusetts and Maine.

text: Currently, the New Hope Power Partnership in Palm Beach County, Florida is the largest biomass power plant in the U.S[53]. The 140 MW facility uses sugarcane fiber (bagasse) and recycled urban wood as fuel to generate enough power for its large milling and refining operations as well as to supply electricity for nearly 60,000 homes.[54][55]

text: In Vermont in 2017, biomass cost $85 per megawatt, and wholesale electricity was about $25 a megawatt, making biomass more expensive, particularly when compared to fracked natural gas.[56]

text: Second-generation biofuels[edit]

text: Second-generation biofuels were not (in 2010) produced commercially, but a considerable number of research activities were taking place mainly in North America, Europe and also in some emerging countries. These tend to use feedstock produced by rapidly reproducing enzymes or bacteria from various sources including excrement[57] grown in cell cultures or hydroponics.[58][59] There is huge potential for second generation biofuels but non-edible feedstock resources are highly under-utilized.[60]

text: Environmental damage[edit]

text: Using biomass as a fuel produces air pollution in the form of carbon monoxide, carbon dioxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants at levels above those from traditional fuel sources such as coal or natural gas  in some cases (such as with indoor heating and cooking).[61][62][63] Use of wood biomass as a fuel can also produce fewer particulate and other pollutants than open burning as seen in wildfires or direct heat applications.[64] Black carbon – a pollutant created by combustion of fossil fuels, biofuels, and biomass – is possibly the second largest contributor to global warming.[65]:56–57 In 2009 a Swedish study of the giant brown haze that periodically covers large areas in South Asia determined that it had been principally produced by open burning of biomass, and to a lesser extent by fossil-fuel burning.[66] Researchers measured a significant concentration of 14C (Carbon-14), which is associated with recent plant life rather than with fossil fuels.[67]

text: Biomass power plant size is often driven by biomass availability in close proximity as transport costs of the (bulky) fuel play a key factor in the plant's economics. Rail and especially shipping on waterways can reduce transport costs significantly, which has led to a global biomass market.[68] To make small plants of 1 MWel economically profitable those power plants need to be equipped with technology that is able to convert biomass to useful electricity with high efficiency such as ORC technology, a cycle similar to the water steam power process just with an organic working medium. Such small power plants can be found in Europe.[69][70][71][72]

text: On combustion, the carbon from biomass is released into the atmosphere as carbon dioxide (CO2). The amount of carbon stored in dry wood is approximately 50% by weight.[73] However, according to the Food and Agriculture Organization of the United Nations, plant matter used as a fuel can be replaced by planting for new growth. When the biomass is from forests, the time to recapture the carbon stored is generally longer, and the carbon storage capacity of the forest may be reduced overall if destructive forestry techniques are employed.[74][75][76][77]

text: Industry professionals claim that a range of issues can affect a plant's ability to comply with emissions standards. Some of these challenges, unique to biomass plants, include inconsistent fuel supplies and age. The type and amount of the fuel supply are completely reliant factors; the fuel can be in the form of building debris or agricultural waste (such as removal of invasive species or orchard trimmings). Furthermore, many of the biomass plants are old, use outdated technology and were not built to comply with today’s stringent standards. In fact, many are based on technologies developed during the term of U.S. President Jimmy Carter, who created the United States Department of Energy in 1977.[5]

text: The U.S. Energy Information Administration projected that by 2017, biomass is expected to be about twice as expensive as natural gas, slightly more expensive than nuclear power, and much less expensive than solar panels.[78] In another EIA study released, concerning the government’s plan to implement a 25% renewable energy standard by 2025, the agency assumed that 598 million tons of biomass would be available, accounting for 12% of the renewable energy in the plan.[79]

text: The adoption of biomass-based energy plants has been a slow but steady process. Between the years of 2002 and 2012 the production of these plants has increased 14%.[80] In the United States, alternative electricity-production sources on the whole generate about 13% of power; of this fraction, biomass contributes approximately 11% of the alternative production.[81] According to a study conducted in early 2012, of the 107 operating biomass plants in the United States, 85 have been cited by federal or state regulators for the violation of clean air or water standards laws over the past 5 years. This data also includes minor infractions.[80]

text: Despite harvesting, biomass crops may sequester carbon. For example, soil organic carbon has been observed to be greater in switchgrass stands than in cultivated cropland soil, especially at depths below 30 cm (12 in).[82] The grass sequesters the carbon in its increased root biomass. Typically, perennial crops sequester much more carbon than annual crops due to much greater non-harvested living biomass, both living and dead, built up over years, and much less soil disruption in cultivation.

text: The proposal that biomass is carbon-neutral put forward in the early 1990s has been superseded by more recent science that recognizes that mature, intact forests sequester carbon more effectively than cut-over areas. When a tree's carbon is released into the atmosphere in a single pulse, it contributes to climate change much more than woodland timber rotting slowly over decades. Current studies indicate that "even after 50 years the forest has not recovered to its initial carbon storage" and "the optimal strategy is likely to be protection of the standing forest".[83][not in citation given][84][85]

text: The pros and cons of biomass usage regarding carbon emissions may be quantified with the ILUC factor. There is controversy surrounding the usage of the ILUC factor.[86]

text: Forest-based biomass has recently come under fire from a number of environmental organizations, including Greenpeace and the Natural Resources Defense Council, for the harmful impacts it can have on forests and the climate. Greenpeace recently released a report entitled "Fuelling a BioMess"[87] which outlines their concerns around forest-based biomass. Because any part of the tree can be burned, the harvesting of trees for energy production encourages whole-tree harvesting, which removes more nutrients and soil cover than regular harvesting, and can be harmful to the long-term health of the forest. In some jurisdictions, forest biomass removal is increasingly involving elements essential to functioning forest ecosystems, including standing trees, naturally disturbed forests and remains of traditional logging operations that were previously left in the forest. Environmental groups also cite recent scientific research which has found that it can take many decades for the carbon released by burning biomass to be recaptured by regrowing trees, and even longer in low productivity areas; furthermore, logging operations may disturb forest soils and cause them to release stored carbon.[citation needed] In light of the pressing need to reduce greenhouse gas emissions in the short term in order to mitigate the effects of climate change, a number of environmental groups are opposing the large-scale use of forest biomass in energy production.[87][88]

text: Supply chain issues[edit]

text: With the seasonality of biomass supply and a great variability in sources, supply chains play a key role in cost-effective delivery of bioenergy. There are several potential challenges unique to bioenergy supply chains:[89]

text: Technical issues

text:
Inefficiencies of the conversion processes
Storage methods for seasonal availability
Complex multi-component constituents incompatible with maximizing efficiency of single purpose use
High water content of many biomass feedstock
Conflicting decisions (technologies, locations, and routes)
Complex location analysis (source points, inventory facilities, and production plants)

text: Logistic issues

text:
Seasonal availability leading to storage challenges and/or seasonally idle facilities
Low bulk-density and/or high water content making transportation of biomass less economical
Finite productivity per area and/or time incompatible with conventional approach to economy of scale focusing on maximizing facility size

text: Financial issues

text:
The limits for the traditional approach to economy of scale which focuses on maximizing single facility size
Unavailability and complexity of life cycle costing data
Lack of required transport infrastructure
Limited flexibility or inflexibility to energy demand
Risks associated with new technologies (insurability, performance, rate of return)
Extended market volatilities (conflicts with alternative markets for biomass)
Difficult or impossible to use financial hedging methods to control cost

text: Social issues

text:
Lack of participatory decision making
Lack of public/community awareness
Local supply chain impacts vs. global benefits
Health and safety risks
Extra pressure on transport sector
Decreasing the esthetics of rural areas

text: Policy and regulatory issues

text:
Impact of fossil fuel tax on biomass transport
Lack of incentives to create competition among bioenergy producers
Focus on technology options and less attention to selection of biomass materials
Lack of support for sustainable supply chain solutions

text: Institutional and organizational issues

text:
Varied ownership arrangements and priorities among supply chain parties
Lack of supply chain standards
Impact of organizational norms and rules on decision making and supply chain coordination
Immaturity of change management practices in biomass supply chains


document_title: Kunekune

question_text: where do kune kune pigs come from originally

text: Kunekune

text: Origin[edit]

text: The kunekune is believed to have descended from an Asian domestic breed introduced to New Zealand in the early 19th century by whalers or traders. They differ markedly from the feral pig of European origin known in New Zealand as a "Captain Cooker".[3] The native Māori people of New Zealand adopted kunekune: the word kunekune means "fat and round" in the Māori language.[4]

text: Rarity[edit]

text: By the 1980s, only an estimated 50 purebred kunekune remained. Michael Willis and John Simister, wildlife-park owners, started a breeding recovery program, which in turn encouraged other recovery efforts. As of 2010[update], the breed no longer faces extinction, with breed societies in both New Zealand and the United Kingdom. In 1993 two were imported into the United States from the UK.

text: Appearance[edit]

text: The kunekune is covered in hair which can be long or short, and straight or curly. Hair colours include black, brown, ginger, gold, cream, and spotted combinations. It has a medium to short snout, that is black and either semilopped or pricked ears. It has a short, round body with short legs and may have two tassels (called piri piri) under its chin. The kunekune stands about 60 cm (24 in) tall, making it one of the smallest domesticated breeds of pig. An adult kunekune can weigh between 60 and 200 kg, well below the 400 kg of commercial pigs.[5]

text: Personality[edit]

text: Kunekune are suitable for a novice owner, as they are placid, friendly, and love human company. They are easy to train and intelligent.

text: Habitat[edit]

text: The natural habitat for kunekune is woodland and pasture. They love being outdoors and are suitable for a range of climates, in addition to being ideal for large gardens. For keeping them as pets, it is best to buy an arc (a house for the pigs) at least 2 m in size, depending on the number of pigs.

text: Diet[edit]

text: Kunekune are very easy to manage as they have the ability to fatten on little more than grass. They are the only true grazing pig and can be maintained with grass alone without supplementary feeding. An acre of grass can sustain as many as 5 kunekune.

text: Breeding[edit]

text: Kunekune boars are fertile at 6 to 7 months and the gilts (young females) can become pregnant at 5 months. However, gilts are not normally put to the boar until they are a year old. The sows are good mothers and the litters vary in size averaging around seven piglets.


document_title: United States presidential approval rating

question_text: who has the lowest approval rating as president

text: President Donald Trump[edit]

text: Most recent polls for President Donald Trump:[2][3][4]

text:
Polling group
Date
Approval
Disapproval
Unsure
Net +/-
Sample size[4]
Population[4]

Rasmussen Reports[a][5]
May 7–9, 2018
48%
50%
2%
-2%
1500 !≈1,500
Likely voters

Ipsos/Reuters[6]
May 3–7, 2018
44%
54%
2%
-10%
1,387
All adults

CBS News[b][7]
May 3–6, 2018
40%
55%
6%
-15%
1,101
All adults

Gallup Poll[c][8]
May 7 – May 13, 2018
43%
52%
5%
-9%
1500 !≈1,500
All adults

CNN[d][9]
May 2–5, 2018
41%
53%
6%
-12%
1015 !1,015
All adults

Investor's Business Daily/TIPP[10]
April 26 – May 4, 2018
38%
56%
1%
-18%
900
All adults

Pew Research Center[11]
April 25 – May 1, 2018
39%
54%
6%
-15%
1503 !1,503
All adults

Monmouth University[12]
April 26–30, 2018
41%
50%
9%
-9%
803
All adults

Kaiser Family Foundation[e][13]
April 20–30, 2018
40%
55%
5%
-15%
2,000
All adults

Fox News[f][14]
April 22–24, 2018
44%
53%
3%
-9%
1,014
Registered voters

Quinnipiac University[15]
April 20–24, 2018
39%
54%
7%
-15%
1,193
Registered voters

NPR/PBS NewsHour/Marist[16]
April 10–13, 2018
38%
54%
8%
-16%
1,011
All adults

ABC News/Washington Post[g][17]
April 8–11, 2018
40%
56%
4%
-16%
1,002
All adults

NBC News/Wall Street Journal[h][18]
April 8–11, 2018
39%
57%
4%
-18%
900
All adults

CNBC[i][19]
March 17–20, 2018
39%
50%
11%
-11%
801
All adults

George Washington University[j][20]
March 4–8, 2018
42%
55%
4%
-13%
1,000
Likely voters

Suffolk University/USA Today[21]
February 20–24, 2018
38%
60%
3%
-22%
1000 !1,000
Registered voters

Public Policy Polling[22]
February 9–11, 2018
44%
50%
6%
-6%
0687 !687
Registered voters

Public Religion Research Institute[k][23]
October 18–30, 2017
41%
54%
5%
-13%
2019 !2,019
All adults

Washington Post/University of Maryland[24]
September 27–October 5, 2017
37%
63%
1%
-26%
1663 !1,663
All adults

Bloomberg News[l][25]
July 8–12, 2017
40%
56%
4%
-16%
1001 !1,001
All adults

text: Historical comparison[edit]

text: Historical Gallup Poll approval highs and lows for each president since 1937:[26][27][28][m]

text:
Order
President
Highest approval
Lowest approval
High –
Low
Highest disapproval
Highest margin
Lowest margin
Final poll
Approval
average[26]
Polls
per year

45[29][30]
Trump
45 (01/24/17)
33 (10/29/17, 12/01/17)
13
62 (10/29/17, 10/30/17, 12/01/17)
1 (01/24/17)
−31 (10/29/17, 12/01/17)

39.1[30][31]

44[32][33]
Obama
69 (01/24/09)
38 (09/05/14)[n]
31
57 (10/10/14)
56 (01/23-24/09)
−18 (10/10/14)
59 (01/19/17)
47.9
348.4

43[34]
G.W. Bush
90 (9/21/01)
25 (10/05/08, 10/12/08, 11/02/08)
65
71 (10/10/08)
83 (09/22/01)
−46 (10/12/08)
34 (01/11/09)
49.4
33.7

42[35]
Clinton
73 (12/19/98)
37 (06/06/93)
36
54 (09/07/94)
45 (12/17/00)
−14 (09/07/94)
66 (01/14/01)
55.1
28.5

41[36]
G.H.W. Bush
89 (02/28/91)
29 (08/02/92, 10/13/92)
60
60 (07/31/92)
82 (03/03/91)
−30 (08/02/92, 10/13/92)
56 (01/11/93)
60.9
39.5

40[37]
Reagan
71 (01/30/86)
35 (01/31/83)
36
56 (01/28/83)
52 (01/30/86)
−21(01/31/83)
63 (12/29/88)
52.8
37.0

39[38]
Carter
74 (03/15/77)
28 (06/26/79, 10/02/79)
46
59 (06/26/79)
66 (03/15/77)
−31 (06/26/79)
34 (12/08/80)
45.5
22.7

38[39]
Ford
70 (08/13/74)
36 (03/25/75)
34
46 (04/15/75, 11/18/75)
26 (08/13/74)
−7 (02/25/75, 03/25/75, 04/15/75)
53 (12/13/76)
47.2
14.7

37[40]
Nixon
66 (01/23/73)
24 (01/02/74)
42
66 (08/05/74)
57 (03/17/69)
−42 (08/05/74)
24 (08/05/74)
49.1
17.7

36[41]
Johnson
79 (03/05/64)
34 (08/12/68)
45
52 (08/12/68)
75 (12/10/63)
−18 (08/12/68)
49 (01/06/69)
55.1
15.3

35[42]
Kennedy
83 (03/05/62)
56 (09/10/63)
27
30 (09/12/63, 11/08/63)
78 (03/05/62)
27 (09/10/63)
58 (11/13/63)
70.1
13.7

34[43]
Eisenhower
77 (11/22/55, 12/19/56)
47 (03/25/58)
30
36 (03/25/58)
66 (04/02/53, 12/19/56)
12 (03/25/58)
59 (12/13/60)
65.0
14.4

33[44]
Truman
87 (08/22/45)
22 (11/16/51, 02/14/52)
65
67 (01/06/52)
85(08/22/45)
−43 (01/04/52)
32 (12/16/52)
45.4
8.4

32[45]
F. D. Roosevelt
83 (01/08/42)
48 (08/18/39)
35
46 (05/22/38, 05/29/38, 11/07/38)
73 (01/23/42)

65 (12/15/43)
63

text: Graphs[edit]

text:
Gallup Poll graphs of approval ratings for Presidents of the United States:

Franklin D. Roosevelt

Harry S. Truman

Dwight D. Eisenhower

John F. Kennedy

Lyndon B. Johnson

Richard Nixon

Gerald Ford

Jimmy Carter

Ronald Reagan

George H. W. Bush

Bill Clinton

George W. Bush

Barack Obama

Donald Trump


document_title: Correlation does not imply causation

question_text: when does correlation allow you to infer causation

text: Correlation does not imply causation

text: Usage[edit]

text: In logic, the technical use of the word "implies" means "is a sufficient circumstance for".[citation needed] This is the meaning intended by statisticians when they say causation is not certain. Indeed, p implies q has the technical meaning of the material conditional: if p then q symbolized as p → q. That is "if circumstance p is true, then q follows." In this sense, it is always correct to say "Correlation does not imply causation."

text: However, in casual use, the word "implies" loosely means suggests rather than requires. The idea that correlation and causation are connected is certainly true; where there is causation, there is a likely correlation. Indeed, correlation is used when inferring causation; the important point is that such inferences are made after correlations are confirmed as real and all causational relationship are systematically explored using large enough data sets.

text: General pattern[edit]

text: For any two correlated events, A and B, the different possible relationships include[citation needed]:

text:
A causes B (direct causation);
B causes A (reverse causation);
A and B are consequences of a common cause, but do not cause each other;
A and B both cause C, which is (explicitly or implicitly) conditioned on. If A and B cause C, why do A and B have to be correlated?;
A causes B and B causes A (bidirectional or cyclic causation);
A causes C which causes B (indirect causation);
There is no connection between A and B; the correlation is a coincidence.

text: Thus there can be no conclusion made regarding the existence or the direction of a cause-and-effect relationship only from the fact that A and B are correlated. Determining whether there is an actual cause-and-effect relationship requires further investigation, even when the relationship between A and B is statistically significant, a large effect size is observed, or a large part of the variance is explained.

text: Examples of illogically inferring causation from correlation[edit]

text: B causes A (reverse causation or reverse causality)[edit]

text: Reverse causation or reverse causality or wrong direction is an informal fallacy of questionable cause where cause and effect are reversed. The cause is said to be the effect and vice versa.

text: In this example, the correlation (simultaneity) between windmill activity and wind velocity does not imply that wind is caused by windmills. It is rather the other way around, as suggested by the fact that wind doesn’t need windmills to exist, while windmills need wind to rotate. Wind can be observed in places where there are no windmills or non-rotating windmills—and there are good reasons to believe that wind existed before the invention of windmills.

text: This argument by Carmen Reinhart and Kenneth Rogoff was refuted by Paul Krugman on the basis that they got the causality backwards: in actuality, slow growth causes debt to increase.[4]

text: In other cases it may simply be unclear which is the cause and which is the effect. For example:

text: This could easily be the other way round; that is, violent children like watching more TV than less violent ones.

text: A correlation between recreational drug use and psychiatric disorders might be either way around: perhaps the drugs cause the disorders, or perhaps people use drugs to self medicate for preexisting conditions. Gateway drug theory may argue that marijuana usage leads to usage of harder drugs, but hard drug usage may lead to marijuana usage (see also confusion of the inverse). Indeed, in the social sciences where controlled experiments often cannot be used to discern the direction of causation, this fallacy can fuel long-standing scientific arguments. One such example can be found in education economics, between the screening/signaling and human capital models: it could either be that having innate ability enables one to complete an education, or that completing an education builds one's ability.

text: A historical example of this is that Europeans in the Middle Ages believed that lice were beneficial to your health, since there would rarely be any lice on sick people. The reasoning was that the people got sick because the lice left. The real reason however is that lice are extremely sensitive to body temperature. A small increase of body temperature, such as in a fever, will make the lice look for another host. The medical thermometer had not yet been invented, so this increase in temperature was rarely noticed. Noticeable symptoms came later, giving the impression that the lice left before the person got sick.[citation needed]

text: In other cases, two phenomena can each be a partial cause of the other; consider poverty and lack of education, or procrastination and poor self-esteem. One making an argument based on these two phenomena must however be careful to avoid the fallacy of circular cause and consequence. Poverty is a cause of lack of education, but it is not the sole cause, and vice versa.

text: Third factor C (the common-causal variable) causes both A and B[edit]

text: The third-cause fallacy (also known as ignoring a common cause[5] or questionable cause[5]) is a logical fallacy where a spurious relationship is confused for causation. It asserts that X causes Y when, in reality, X and Y are both caused by Z. It is a variation on the post hoc ergo propter hoc fallacy and a member of the questionable cause group of fallacies.

text: All of these examples deal with a lurking variable, which is simply a hidden third variable that affects both causes of the correlation. A difficulty often also arises where the third factor, though fundamentally different from A and B, is so closely related to A and/or B as to be confused with them or very difficult to scientifically disentangle from them (see Example 4).

text: The above example commits the correlation-implies-causation fallacy, as it prematurely concludes that sleeping with one's shoes on causes headache. A more plausible explanation is that both are caused by a third factor, in this case going to bed drunk, which thereby gives rise to a correlation. So the conclusion is false.

text: This is a scientific example that resulted from a study at the University of Pennsylvania Medical Center. Published in the May 13, 1999 issue of Nature,[6] the study received much coverage at the time in the popular press.[7] However, a later study at Ohio State University did not find that infants sleeping with the light on caused the development of myopia. It did find a strong link between parental myopia and the development of child myopia, also noting that myopic parents were more likely to leave a light on in their children's bedroom.[8][9][10][11] In this case, the cause of both conditions is parental myopia, and the above-stated conclusion is false.

text: This example fails to recognize the importance of time of year and temperature to ice cream sales. Ice cream is sold during the hot summer months at a much greater rate than during colder times, and it is during these hot summer months that people are more likely to engage in activities involving water, such as swimming. The increased drowning deaths are simply caused by more exposure to water-based activities, not ice cream. The stated conclusion is false.

text: However, as encountered in many psychological studies, another variable, a "self-consciousness score", is discovered that has a sharper correlation (+.73) with shyness. This suggests a possible "third variable" problem, however, when three such closely related measures are found, it further suggests that each may have bidirectional tendencies (see "bidirectional variable", above), being a cluster of correlated values each influencing one another to some extent. Therefore, the simple conclusion above may be false.

text: Richer populations tend to eat more food and produce more CO2.

text: Further research[13] has called this conclusion into question. Instead, it may be that other underlying factors, like genes, diet and exercise, affect both HDL levels and the likelihood of having a heart attack; it is possible that medicines may affect the directly measurable factor, HDL levels, without affecting the chance of heart attack.

text: Bidirectional causation: A causes B, and B causes A[edit]

text: Causality is not necessarily one-way; in a predator-prey relationship, predator numbers affect prey numbers, but prey numbers, i.e. food supply, also affect predator numbers.

text: The relationship between A and B is coincidental[edit]

text: The two variables aren't related at all, but correlate by chance. The more things are examined, the more likely it is that two unrelated variables will appear to be related. For example:

text:
The result of the last home game by the Washington Redskins prior to the presidential election predicted the outcome of every presidential election from 1936 to 2000 inclusive, despite the fact that the outcomes of football games had nothing to do with the outcome of the popular election. This streak was finally broken in 2004 (or 2012 using an alternative formulation of the original rule).
A collection of such coincidences[14] finds that for example, there is a 99.79% correlation for the period 1999-2009 between U.S. spending on science, space, and technology; and the number of suicides by suffocation, strangulation, and hanging.
The Mierscheid law, which correlates the Social Democratic Party of Germany's share of the popular vote with the size of crude steel production in Western Germany.
Alternating bald–hairy Russian leaders: A bald (or obviously balding) state leader of Russia has succeeded a non-bald ("hairy") one, and vice versa, for nearly 200 years.

text: Determining causation[edit]

text: In academia[edit]

text: The nature of causality is systematically investigated in several academic disciplines, including philosophy and physics.

text: In academia, there are a significant number of theories on causality; The Oxford Handbook of Causation (Beebee, Hitchcock & Menzies 2009) encompasses 770 pages. Among the more influential theories within philosophy are Aristotle's Four causes and Al-Ghazali's occasionalism.[15] David Hume argued that beliefs about causality are based on experience, and experience similarly based on the assumption that the future models the past, which in turn can only be based on experience – leading to circular logic. In conclusion, he asserted that causality is not based on actual reasoning: only correlation can actually be perceived.[16] Immanuel Kant, according to Beebee, Hitchcock & Menzies (2009), held that "a causal principle according to which every event has a cause, or follows according to a causal law, cannot be established through induction as a purely empirical claim, since it would then lack strict universality, or necessity".

text: Outside the field of philosophy, theories of causation can be identified in classical mechanics, statistical mechanics, quantum mechanics, spacetime theories, biology, social sciences, and law.[15] To establish a correlation as causal within physics, it is normally understood that the cause and the effect must connect through a local mechanism (cf. for instance the concept of impact) or a nonlocal mechanism (cf. the concept of field), in accordance with known laws of nature.

text: From the point of view of thermodynamics, universal properties of causes as compared to effects have been identified through the Second law of thermodynamics, confirming the ancient, medieval and Cartesian[17] view that "the cause is greater than the effect" for the particular case of thermodynamic free energy. This, in turn, is challenged[dubious – discuss] by popular interpretations of the concepts of nonlinear systems and the butterfly effect, in which small events cause large effects due to, respectively, unpredictability and an unlikely triggering of large amounts of potential energy.

text: Causality construed from counterfactual states[edit]

text: Intuitively, causation seems to require not just a correlation, but a counterfactual dependence. Suppose that a student performed poorly on a test and guesses that the cause was his not studying. To prove this, one thinks of the counterfactual – the same student writing the same test under the same circumstances but having studied the night before. If one could rewind history, and change only one small thing (making the student study for the exam), then causation could be observed (by comparing version 1 to version 2). Because one cannot rewind history and replay events after making small controlled changes, causation can only be inferred, never exactly known. This is referred to as the Fundamental Problem of Causal Inference – it is impossible to directly observe causal effects.[18]

text: A major goal of scientific experiments and statistical methods is to approximate as best possible the counterfactual state of the world.[19] For example, one could run an experiment on identical twins who were known to consistently get the same grades on their tests. One twin is sent to study for six hours while the other is sent to the amusement park. If their test scores suddenly diverged by a large degree, this would be strong evidence that studying (or going to the amusement park) had a causal effect on test scores. In this case, correlation between studying and test scores would almost certainly imply causation.

text: Well-designed experimental studies replace equality of individuals as in the previous example by equality of groups. The objective is to construct two groups that are similar except for the treatment that the groups receive. This is achieved by selecting subjects from a single population and randomly assigning them to two or more groups. The likelihood of the groups behaving similarly to one another (on average) rises with the number of subjects in each group. If the groups are essentially equivalent except for the treatment they receive, and a difference in the outcome for the groups is observed, then this constitutes evidence that the treatment is responsible for the outcome, or in other words the treatment causes the observed effect. However, an observed effect could also be caused "by chance", for example as a result of random perturbations in the population. Statistical tests exist to quantify the likelihood of erroneously concluding that an observed difference exists when in fact it does not (for example see P-value).

text: Causality predicted by an extrapolation of trends[edit]

text: When experimental studies are impossible and only pre-existing data are available, as is usually the case for example in economics, regression analysis can be used. Factors other than the potential causative variable of interest are controlled for by including them as regressors in addition to the regressor representing the variable of interest. False inferences of causation due to reverse causation (or wrong estimates of the magnitude of causation due the presence of bidirectional causation) can be avoided by using explanators (regressors) that are necessarily exogenous, such as physical explanators like rainfall amount (as a determinant of, say, futures prices), lagged variables whose values were determined before the dependent variable's value was determined, instrumental variables for the explanators (chosen based on their known exogeneity), etc. See Causality#Statistics and economics. Spurious correlation due to mutual influence from a third, common, causative variable, is harder to avoid: the model must be specified such that there is a theoretical reason to believe that no such underlying causative variable has been omitted from the model.

text: Use of correlation as scientific evidence[edit]

text: This section's factual accuracy is disputed. Relevant discussion may be found on Talk:Correlation does not imply causation. Please help to ensure that disputed statements are reliably sourced. (July 2015) (Learn how and when to remove this template message)

text: Much of scientific evidence is based upon a correlation of variables[20] – they are observed to occur together. Scientists are careful to point out that correlation does not necessarily mean causation. The assumption that A causes B simply because A correlates with B is often not accepted as a legitimate form of argument.

text: However, sometimes people commit the opposite fallacy – dismissing correlation entirely. This would dismiss a large swath of important scientific evidence.[20] Since it may be difficult or ethically impossible to run controlled double-blind studies, correlational evidence from several different angles may be useful for prediction despite failing to provide evidence for causation. For example, social workers might be interested in knowing how child abuse relates to academic performance. Although it would be unethical to perform an experiment in which children are randomly assigned to receive or not receive abuse, researchers can look at existing groups using a non-experimental correlational design. If in fact a negative correlation exists between abuse and academic performance, researchers could potentially use this knowledge of a statistical correlation to make predictions about children outside the study who experience abuse, even though the study failed to provide causal evidence that abuse decreases academic performance. [21] The combination of limited available methodologies with the dismissing correlation fallacy has on occasion been used to counter a scientific finding. For example, the tobacco industry has historically relied on a dismissal of correlational evidence to reject a link between tobacco and lung cancer,[22] as did biologist and statistician Ronald Fisher.[23][24][25][26][27][28][29]

text: Correlation is a valuable type of scientific evidence in fields such as medicine, psychology, and sociology. But first correlations must be confirmed as real, and then every possible causative relationship must be systematically explored. In the end correlation alone cannot be used as evidence for a cause-and-effect relationship between a treatment and benefit, a risk factor and a disease, or a social or economic factor and various outcomes. It is one of the most abused types of evidence, because it is easy and even tempting to come to premature conclusions based upon the preliminary appearance of a correlation.[citation needed]