Global warming verantwoordelijk voor wereldwijde daling gewas-opbrengsten - studie

C2C · 16 maart 2007, 23:10

Environ. Res. Lett. 2 (March 2007) 014002
doi:10.1088/1748-9326/2/1/014002 Global scale climate–crop yield relationships and the impacts of recent warming
David B Lobell1 and Christopher B Field2
1 Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
2 Department of Global Ecology, Carnegie Institution, Stanford, CA 94305, USA
Received 22 January 2007
Accepted 27 February 2007
Published 16 March 2007

Abstract. Changes in the global production of major crops are important drivers of food prices, food security and land use decisions. Average global yields for these commodities are determined by the performance of crops in millions of fields distributed across a range of management, soil and climate regimes. Despite the complexity of global food supply, here we show that simple measures of growing season temperatures and precipitation—spatial averages based on the locations of each crop—explain ~ 30% or more of year-to-year variations in global average yields for the world's six most widely grown crops. For wheat, maize and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $5 billion per year, as of 2002. While these impacts are small relative to the technological yield gains over the same period, the results demonstrate already occurring negative impacts of climate trends on crop yields at the global scale.

http://www.iop.org/EJ/article/1748-9..._1_014002.html

Dit is overal in de wereldpers verschenen vandaag.

We zijn met andere woorden dik gescheten als we niet snel radicaal ingrijpen.

In lekentermen:

Crops feel the heat as the world warms

Stanford, Calif. – Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study by researchers at the Carnegie Institution and Lawrence Livermore National Laboratory.

From 1981-2002, warming reduced the combined production of wheat, corn, and barley—cereal grains that form the foundation of much of the world’s diet—by 40 million metric tons per year. The study, which will be published March 16 in the online journal Environmental Research Letters, demonstrates that this decline is due to human-caused increases in global temperatures.

"Most people tend to think of climate change as something that will impact the future,” said Christopher Field, co-author on the study and director of Carnegie’s Department of Global Ecology in Stanford, Calif. “But this study shows that warming over the past two decades has already had real effects on global food supply."

The study is the first to estimate how much global food production has already been affected by climate change. Field and David Lobell, lead author of the study and a researcher at Lawrence Livermore National Laboratory, compared yield figures from the Food and Agriculture Organization with average temperatures and precipitation in the major growing regions.

They found that, on average, global yields for several of the crops responded negatively to warmer temperatures, with yields dropping by about 3-5 percent for every 1 degree F increase. Average global temperatures increased by about 0.7 degrees F during the study period, with even larger changes in several regions.

“Though the impacts are relatively small compared to the technological yield gains over the same period, the results demonstrate that negative impacts are already occurring,” said Lobell.

The researchers focused on the six most widely grown crops in the world: wheat, rice, maize (corn), soybeans, barley and sorghum—a genus of about 30 species of grass raised for grain. These crops occupy more than 40 percent of the world’s cropland, and account for at least 55 percent of non-meat calories consumed by humans. They also contribute more than 70 percent of the world’s animal feed.

The main value of this study, the authors said, was that it demonstrates a clear and simple correlation between temperature increases and crop yields at the global scale. However, Field and Lobell also used this information to further investigate the relationship between observed warming trends and agriculture.

"We assumed that farmers have not yet adapted to climate change—for example, by selecting new crop varieties to deal with climate change. If they have been adapting—something that is very difficult to measure—then the effects of warming may have been lower,” explained Lobell.

Most experts believe that adaptation would lag several years behind climate trends, because it can be difficult to distinguish climate trends from natural variability. “A key moving forward is how well cropping systems can adapt to a warmer world. Investments in this area could potentially save billions of dollars and millions of lives,” Lobell added.

http://www.carnegieinstitution.org/f...l/default.html

Dus:

Moeten klimaatontkenners niet stillaan strafbaar worden gesteld?
Moeten zij die de zaak relativeren of van een 'hysterie' spreken rechterlijk vervolgd worden, en met terugwerkende kracht mee verantwoordelijk worden gesteld?
Indien deze ontkenners en relativeerders er niet meer zijn wanneer de zaak omzeep is, moeten hun nakomelingen dan verantwoordelijk worden gesteld? Zo doet men dat in Noord-Korea: begaat ge een grove misdaad, dan wordt ineens heel uw familie én desnoods uw nageslacht mee gestraft. Dat werkt zeer goed.

TomB · 17 maart 2007, 04:51

Uw voorstellen zijn nog belachelijker als de conclusies die u aan dat onderzoek vasthangt.

Sluit mss. ineens iedereen die anders denkt op.

kelt · 17 maart 2007, 08:11

Er mag ook wel eens vermeld worden dat vrijwel overal,gedurende de "groene revolutie" van de jaren vijftig vorige eeuw ,er gronden in gebruik genomen werden die feitelijk,landbouwtechnisch gezien,marginaal te noemen waren....(zowel de VS,Europa als Australie,als de voormalige Sovjet-Unie hebben dat zelfs op immense schaal gedaan )...

Dat voedsel werd dan tot ver in de jaren 90 vorige eeuw "gedumpt" in andermans markten,of desnoods op het stort,en de markt van natuurlijke vezels(katoen) was tijdelijk zelfs overspoeld ...

Ons milieu is nog niet helemaal bekomen van de omlegging en/of oppomping van waters,het massale gebruik van allerlei kunstmatige bemesters,pesticiden,herbiciden enz......

Nu de subsidies aan dergelijke waanzin (waanzinnig zowel vanuit economisch- als ecologisch oogpunt) uitdoven gaat de productie inderdaad achteruit....Overal in Europa worden dergelijke "boeren om te boeren" gronden weer als "natuurwaarde" bestempeld...
De "biobrandstof planten"-rage van momenteel zal deze neergang niet ombuigen...

john bell hood · 17 maart 2007, 08:17

Dat communisten gek zijn,wordt hier nog eens bevestigd.Dank U.

Leviathan · 17 maart 2007, 12:11

Citaat:

Oorspronkelijk geplaatst door TomB

Uw voorstellen zijn nog belachelijker als de conclusies die u aan dat onderzoek vasthangt.

Sluit mss. ineens iedereen die anders denkt op.

Het is een communist, wat had je anders van zo iemand verwacht?

ministe van agitatie · 17 maart 2007, 12:13

Citaat:

Oorspronkelijk geplaatst door Leviathan

Het is een communist, wat had je anders van zo iemand verwacht?

Jullie enige reactie op een ANALYSE is dus op de man spelen. Niveau, mijne heren, niveau ...

"Rechtse zak" · 17 maart 2007, 12:38

Citaat:

Oorspronkelijk geplaatst door TomB

Uw voorstellen zijn nog belachelijker als de conclusies die u aan dat onderzoek vasthangt.

Sluit mss. ineens iedereen die anders denkt op.

De avatar verraadt toch voldoende. Het verheerlijken van een massamoordenaar zegt voldoende. A propos, Stalin was uitstekend in het uithongeren van mensenmassa's.

Global communism vind ik nu wel terecht bestrijdenswaardig.

16 maart 2007, 23:10	#1
C2C Perm. Vertegenwoordiger VN Geregistreerd: 17 december 2006 Berichten: 10.572	Global warming verantwoordelijk voor wereldwijde daling gewas-opbrengsten - studie Environ. Res. Lett. 2 (March 2007) 014002 doi:10.1088/1748-9326/2/1/014002 Global scale climate–crop yield relationships and the impacts of recent warming David B Lobell1 and Christopher B Field2 1 Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA 2 Department of Global Ecology, Carnegie Institution, Stanford, CA 94305, USA Received 22 January 2007 Accepted 27 February 2007 Published 16 March 2007 Abstract. Changes in the global production of major crops are important drivers of food prices, food security and land use decisions. Average global yields for these commodities are determined by the performance of crops in millions of fields distributed across a range of management, soil and climate regimes. Despite the complexity of global food supply, here we show that simple measures of growing season temperatures and precipitation—spatial averages based on the locations of each crop—explain ~ 30% or more of year-to-year variations in global average yields for the world's six most widely grown crops. For wheat, maize and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $5 billion per year, as of 2002. While these impacts are small relative to the technological yield gains over the same period, the results demonstrate already occurring negative impacts of climate trends on crop yields at the global scale. http://www.iop.org/EJ/article/1748-9..._1_014002.html Dit is overal in de wereldpers verschenen vandaag. We zijn met andere woorden dik gescheten als we niet snel radicaal ingrijpen. In lekentermen: Crops feel the heat as the world warms Stanford, Calif. – Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study by researchers at the Carnegie Institution and Lawrence Livermore National Laboratory. From 1981-2002, warming reduced the combined production of wheat, corn, and barley—cereal grains that form the foundation of much of the world’s diet—by 40 million metric tons per year. The study, which will be published March 16 in the online journal Environmental Research Letters, demonstrates that this decline is due to human-caused increases in global temperatures. "Most people tend to think of climate change as something that will impact the future,” said Christopher Field, co-author on the study and director of Carnegie’s Department of Global Ecology in Stanford, Calif. “But this study shows that warming over the past two decades has already had real effects on global food supply." The study is the first to estimate how much global food production has already been affected by climate change. Field and David Lobell, lead author of the study and a researcher at Lawrence Livermore National Laboratory, compared yield figures from the Food and Agriculture Organization with average temperatures and precipitation in the major growing regions. They found that, on average, global yields for several of the crops responded negatively to warmer temperatures, with yields dropping by about 3-5 percent for every 1 degree F increase. Average global temperatures increased by about 0.7 degrees F during the study period, with even larger changes in several regions. “Though the impacts are relatively small compared to the technological yield gains over the same period, the results demonstrate that negative impacts are already occurring,” said Lobell. The researchers focused on the six most widely grown crops in the world: wheat, rice, maize (corn), soybeans, barley and sorghum—a genus of about 30 species of grass raised for grain. These crops occupy more than 40 percent of the world’s cropland, and account for at least 55 percent of non-meat calories consumed by humans. They also contribute more than 70 percent of the world’s animal feed. The main value of this study, the authors said, was that it demonstrates a clear and simple correlation between temperature increases and crop yields at the global scale. However, Field and Lobell also used this information to further investigate the relationship between observed warming trends and agriculture. "We assumed that farmers have not yet adapted to climate change—for example, by selecting new crop varieties to deal with climate change. If they have been adapting—something that is very difficult to measure—then the effects of warming may have been lower,” explained Lobell. Most experts believe that adaptation would lag several years behind climate trends, because it can be difficult to distinguish climate trends from natural variability. “A key moving forward is how well cropping systems can adapt to a warmer world. Investments in this area could potentially save billions of dollars and millions of lives,” Lobell added. http://www.carnegieinstitution.org/f...l/default.html Dus: Moeten klimaatontkenners niet stillaan strafbaar worden gesteld? Moeten zij die de zaak relativeren of van een 'hysterie' spreken rechterlijk vervolgd worden, en met terugwerkende kracht mee verantwoordelijk worden gesteld? Indien deze ontkenners en relativeerders er niet meer zijn wanneer de zaak omzeep is, moeten hun nakomelingen dan verantwoordelijk worden gesteld? Zo doet men dat in Noord-Korea: begaat ge een grove misdaad, dan wordt ineens heel uw familie én desnoods uw nageslacht mee gestraft. Dat werkt zeer goed. Laatst gewijzigd door C2C : 16 maart 2007 om 23:16.

17 maart 2007, 04:51	#2
TomB Perm. Vertegenwoordiger VN Geregistreerd: 6 januari 2003 Locatie: US Berichten: 14.572	Uw voorstellen zijn nog belachelijker als de conclusies die u aan dat onderzoek vasthangt. Sluit mss. ineens iedereen die anders denkt op. __________________ In het begin was er niets, wat ontplofte.

17 maart 2007, 08:11	#3
kelt Secretaris-Generaal VN Geregistreerd: 29 juli 2004 Berichten: 35.465	Er mag ook wel eens vermeld worden dat vrijwel overal,gedurende de "groene revolutie" van de jaren vijftig vorige eeuw ,er gronden in gebruik genomen werden die feitelijk,landbouwtechnisch gezien,marginaal te noemen waren....(zowel de VS,Europa als Australie,als de voormalige Sovjet-Unie hebben dat zelfs op immense schaal gedaan )... Dat voedsel werd dan tot ver in de jaren 90 vorige eeuw "gedumpt" in andermans markten,of desnoods op het stort,en de markt van natuurlijke vezels(katoen) was tijdelijk zelfs overspoeld ... Ons milieu is nog niet helemaal bekomen van de omlegging en/of oppomping van waters,het massale gebruik van allerlei kunstmatige bemesters,pesticiden,herbiciden enz...... Nu de subsidies aan dergelijke waanzin (waanzinnig zowel vanuit economisch- als ecologisch oogpunt) uitdoven gaat de productie inderdaad achteruit....Overal in Europa worden dergelijke "boeren om te boeren" gronden weer als "natuurwaarde" bestempeld... De "biobrandstof planten"-rage van momenteel zal deze neergang niet ombuigen...

17 maart 2007, 08:17	#4
john bell hood Banneling Geregistreerd: 4 augustus 2006 Berichten: 3.460	Dat communisten gek zijn,wordt hier nog eens bevestigd.Dank U.