Global Warming & Climate Change

Steen Ulrik Johannessen/Agence France-Presse — Getty Images

Global warming has become perhaps the most complicated issue facing world leaders. Warnings from the scientific community are becoming louder, as an increasing body of science points to rising dangers from the ongoing buildup of human-related greenhouse gases — produced mainly by the burning of fossil fuels and forests.

Global emissions of carbon dioxide jumped by the largest amount on record in 2010, upending the notion that the brief decline during the recession might persist through the recovery. Emissions rose 5.9 percent in 2010, according to the Global Carbon Project, an international collaboration of scientists. The increase solidified a trend of ever-rising emissions that scientists fear will make it difficult, if not impossible, to forestall severe climate change in coming decades.

However, the technological, economic and political issues that have to be resolved before a concerted worldwide effort to reduce emissions can begin have gotten no simpler, particularly in the face of a global economic slowdown.

For almost two decades, the United Nations has sponsored annual global talks, the United Nations Framework Convention on Climate Change, an international treaty signed by 194 countries to cooperatively discuss global climate change and its impact. The conferences operate on the principle of consensus, meaning that any of the participating nations can hold up an agreement.

The conflicts and controversies discussed are monotonously familiar: the differing obligations of industrialized and developing nations, the question of who will pay to help poor nations adapt, the urgency of protecting tropical forests and the need to rapidly develop and deploy clean energy technology.

But the meetings have often ended in disillusionment, with incremental political progress but little real impact on the climate. The negotiating process itself has come under fire from some quarters, including the poorest nations who believe their needs are being neglected in the fight among the major economic powers. Criticism has also come from a small but vocal band of climate-change skeptics, many of them members of the United States Congress, who doubt the existence of human influence on the climate and ridicule international efforts to deal with it.

A New International Initiative Led by the U.S.

In mid-February 2012, Secretary of State Hillary Rodham Clinton was expected to announce a new international effort focused on reducing emissions of common pollutants that contribute to rapid climate change and widespread health problems.

Impatient with the slow pace of international negotiations, the United States and a small group of countries — Bangladesh, Canada, Ghana, Mexico and Sweden as well as the United Nations Environment Program — are starting a program that will address short-lived pollutants like soot (also referred to as black carbon), methane and hydrofluorocarbons that have an outsize influence on global warming, accounting for 30 to 40 percent of global warming. Soot from diesel exhausts and the burning of wood, agricultural waste and dung for heating and cooking causes an estimated two million premature deaths a year, particularly in the poorest countries.

Global warming has become perhaps the most complicated issue facing world leaders. Warnings from the scientific community are becoming louder, as an increasing body of science points to rising dangers from the ongoing buildup of human-related greenhouse gases — produced mainly by the burning of fossil fuels and forests.

Global emissions of carbon dioxide jumped by the largest amount on record in 2010, upending the notion that the brief decline during the recession might persist through the recovery. Emissions rose 5.9 percent in 2010, according to the Global Carbon Project, an international collaboration of scientists. The increase solidified a trend of ever-rising emissions that scientists fear will make it difficult, if not impossible, to forestall severe climate change in coming decades.

However, the technological, economic and political issues that have to be resolved before a concerted worldwide effort to reduce emissions can begin have gotten no simpler, particularly in the face of a global economic slowdown.

For almost two decades, the United Nations has sponsored annual global talks, the United Nations Framework Convention on Climate Change, an international treaty signed by 194 countries to cooperatively discuss global climate change and its impact. The conferences operate on the principle of consensus, meaning that any of the participating nations can hold up an agreement.

The conflicts and controversies discussed are monotonously familiar: the differing obligations of industrialized and developing nations, the question of who will pay to help poor nations adapt, the urgency of protecting tropical forests and the need to rapidly develop and deploy clean energy technology.

But the meetings have often ended in disillusionment, with incremental political progress but little real impact on the climate. The negotiating process itself has come under fire from some quarters, including the poorest nations who believe their needs are being neglected in the fight among the major economic powers. Criticism has also come from a small but vocal band of climate-change skeptics, many of them members of the United States Congress, who doubt the existence of human influence on the climate and ridicule international efforts to deal with it.

A New International Initiative Led by the U.S.

In mid-February 2012, Secretary of State Hillary Rodham Clinton was expected to announce a new international effort focused on reducing emissions of common pollutants that contribute to rapid climate change and widespread health problems.

Impatient with the slow pace of international negotiations, the United States and a small group of countries — Bangladesh, Canada, Ghana, Mexico and Sweden as well as the United Nations Environment Program — are starting a program that will address short-lived pollutants like soot (also referred to as black carbon), methane and hydrofluorocarbons that have an outsize influence on global warming, accounting for 30 to 40 percent of global warming. Soot from diesel exhausts and the burning of wood, agricultural waste and dung for heating and cooking causes an estimated two million premature deaths a year, particularly in the poorest countries.

Read More...

Scientists say that concerted action on these substances can reduce global temperatures by 0.5 degrees Celsius by 2050 and prevent millions of cases of lung and heart disease by 2030.

The United States intends to contribute $12 million and Canada $3 million over two years to get the program off the ground and to help recruit other countries to participate. The United Nations Environment Program will run the project.

Officials hope that by tackling these fast-acting, climate-changing agents they can get results quicker than through the laborious and highly political negotiations conducted under the United Nations Framework Convention on Climate Change.

2011 Global Talks in Durban

At the 2011 conference delegates from about 200 nations gathered together in Durban, South Africa. One of the issues left unresolved was the future of the Kyoto Protocol, the 1997 agreement that requires major industrialized nations to meet targets on emissions reduction but imposes no mandates on developing countries, including emerging economic powers and sources of global greenhouse gas emissions like China, India, Brazil and South Africa.

The United States is not a party to the protocol, having refused to even consider ratifying it because of those asymmetrical obligations. Some major countries, including Canada, Japan and Russia, have said they will not agree to an extension of the protocol next year unless the unbalanced requirements of developing and developed countries are changed. That is similar to the United States’ position, which is that any successor treaty must apply equally to all major economies.

Expectations for the meeting were low, and it ended with modest accomplishments: the promise to work toward a new global treaty in coming years and the establishment of a new climate fund.

The deal on a future treaty renewed the Kyoto Protocol for several more years. But it also began a process for replacing the protocol with something that treats all countries — including the economic powerhouses China, India and Brazil — equally. The future treaty deal was the most highly contested element of a package of agreements that emerged from the extended talks among the nations here.

The expiration date of the protocol — 2017 or 2020 — and the terms of any agreement that replaces it will be negotiated at future sessions.

The delegates also agreed on the creation of a fund to help poor countries adapt to climate change — though the precise sources of the money have yet to be determined — and to measures involving the preservation of tropical forests and the development of clean-energy technology. The reserve, called the Green Climate Fund, would help mobilize a promised $100 billion a year in public and private financing by 2020 to assist developing countries in adapting to climate change and converting to clean energy sources.

2010 Global Talks in Cancún

The United Nations conference on climate change in Cancún, Mexico, produced only modest achievements but ended with the toughest issues unresolved. The package that was approved, known as the Cancún Agreements, set up a new fund to help poor countries adapt to climate changes, created new mechanisms for transfer of clean energy technology, provided compensation for the preservation of tropical forests and strengthened the emissions reductions pledges that came out of the U.N. climate change meeting in Copenhagen in 2009.

The conference approved the agreement over the objections of Bolivia, which condemned the pact as too weak. But those protests did not block its acceptance. Delegates from island states and the least-developed countries warmly welcomed the pact because it would start the flow of billions of dollars to assist them in adopting cleaner energy systems and adapting to inevitable changes in the climate, like sea rise and drought.

But where the promised aid from wealthy nations — $100 billion — would come from was left unresolved.

The E.U. Gets Tough With Airline Emissions

In December 2011, the European Union’s highest court endorsed the bloc’s plan to begin charging the world’s biggest airlines for their greenhouse gas emissions from Jan. 1, 2012, setting the stage for a potentially costly trade war with the United States, China and other countries.

A group of United States airlines had argued that forcing them to participate in the potentially costly emissions-trading system infringed on national sovereignty and conflicted with existing international aviation treaties.

But in a final ruling , the European Court of Justice in Luxembourg affirmed an opinion issued in October by its advocate general, who had rejected their claim.

The court’s decision came amid increasing pressure from some of the biggest trading partners of the 27-member bloc to suspend or amend application of the legislation to expressly exclude non-E.U. countries — at least initially. Failing that, several governments have vowed to take their own legal action or retaliate with countervailing trade measures.

Although airlines initially will receive most of the permits they will need for free, the European Union estimates that ticket prices could rise by as much as €12, or nearly $16, on some long-haul flights to cover the cost of additional permits required.

Airlines for America, an industry lobby group and one of the plaintiffs in the case, said that its members would be required to pay more than $3.1 billion to the E.U. between 2012 and 2020. It said its members would comply with the system “under protest,” but would also review options for pursuing the case in Britain’s High Court, which had referred the original complaint to the European court in 2009.

The European initiative involves folding aviation into the Union’s six-year-old Emissions Trading System, in which polluters can buy and sell a limited quantity of permits, each representing a ton of carbon dioxide. The legislation mandates that airlines account for their emissions for the entirety of any flight that takes off from — or lands at — any airport in the 27-member bloc.

The goal, European officials have said, is to speed up the adoption of greener technologies at a time when air traffic, which represents about 3 percent of global carbon dioxide emissions, is growing much faster than gains in efficiency.

The U.S. and Climate Change

The United States has been criticized at the United Nations gatherings for years, in part because of its rejection of the Kyoto framework and in part because it has not adopted a comprehensive domestic program for reducing its own greenhouse gas emissions. President Obama has pledged to reduce American emissions 17 percent below 2005 levels by 2020, but his preferred approach, a nationwide cap-and-trade system for carbon pollution, was passed by the House in 2009 but died in the Senate the next year. United States emissions are down about 6 percent over the past five years, largely because of the drop in industrial and electricity production caused by the recession.

In January 2011, the Environmental Protection Agency began imposing regulations related to greenhouse gas emissions. The immediate effect on utilities, refiners and major manufacturers was minor, with the new rules applying only to those planning to build large new facilities or make major modifications to existing plants. Over the next decade, however, the agency plans to regulate virtually all sources of greenhouse gases, imposing efficiency and emissions requirements on nearly every industry and every region.

Steps Toward a Response

The debate over climate questions pales next to the fight over what to do, or not do, in a world where fossil fuels still underpin both rich and emerging economies.

With the completion of the United Nations Framework Convention on Climate Change at the Earth Summit in 1992, the world’s nations pledged to avoid dangerously disrupting the climate through the buildup of greenhouse gases, but they never defined how much warming was too much.

Nonetheless, recognizing that the original climate treaty was proving ineffective, all of the world’s industrialized countries except for the United States accepted binding restrictions on their greenhouse gas emissions under the Kyoto Protocol, which was negotiated in Japan in 1997. That accord took effect in 2005 and its gas restrictions expire in 2012. The United States signed the treaty, but it was never submitted for ratification in the face of overwhelming opposition in the Senate because the pact required no steps by China or other fast-growing developing countries.

It took until 2009 for the leaders of the world’s largest economic powers to agree on a dangerous climate threshold: an increase of 2 degrees Celsius (3.6 degrees Fahrenheit) from the average global temperature recorded just before the Industrial Revolution kicked into gear. (This translates into an increase of 1.3 degrees Fahrenheit above the Earth’s current average temperature, about 59 degrees.)

The Group of 8 industrial powers also agreed in 2009 to a goal of reducing global emissions 50 percent by 2050, with the richest countries leading the way by cutting their emissions 80 percent. But they did not set a baseline from which to measure that reduction, and so far firm interim targets — which many climate scientists say would be more meaningful — have not been defined.

At the same time, fast-growing emerging economic powerhouses, led by China and India, opposed taking on mandatory obligations to curb their emissions. They said they will do what they can to rein in growth in emissions — as long as their economies do not suffer.

In many ways, the debate over global climate policy is a result of a global “climate divide.’' Emissions of carbon dioxide per person range from less than 2 tons per year in India, where 400 million people lack access to electricity, to more than 20 in the United States. The richest countries are also best able to use wealth and technology to insulate themselves from climate hazards, while the poorest, which have done the least to cause the problem, are the most exposed.

Background

Scientists learned long ago that the earth’s climate has powerfully shaped the history of the human species — biologically, culturally and geographically. But only in the last few decades has research revealed that humans can be a powerful influence on the climate, as well.

A growing body of scientific evidence indicates that since 1950, the world’s climate has been warming, primarily as a result of emissions from unfettered burning of fossil fuels and the razing of tropical forests. Such activity adds to the atmosphere’s invisible blanket of carbon dioxide and other heat-trapping “greenhouse” gases. Recent research has shown that methane, which flows from landfills, livestock and oil and gas facilities, is a close second to carbon dioxide as an impact on the atmosphere.

That conclusion has emerged through a broad body of analysis in fields as disparate as glaciology, the study of glacial formations, and palynology, the study of the distribution of pollen grains in lake mud. It is based on a host of assessments by the world’s leading organizations of climate and earth scientists.

In the last several years, the scientific case that the rising human influence on climate could become disruptive has become particularly robust.

Some fluctuations in the earth’s temperature are inevitable regardless of human activity — because of decades-long ocean cycles, for example. But centuries of rising temperatures and seas lie ahead if the release of emissions from the burning of fossil fuels and deforestation continues unabated, according to the Intergovernmental Panel on Climate Change, a group that shared the 2007 Nobel Peace Prize with former Vice President Al Gore.

In addition, a report released by the I.P.C.C. in November 2011 predicted that global warming will cause more dangerous and “unprecedented extreme weather” in the future.

Despite the scientific consensus on these basic conclusions, enormously important details remain murky. That reality has been seized upon by some groups and scientists disputing the overall consensus and opposing changes in energy policies.

For example, estimates of the amount of warming that would result from a doubling of greenhouse gas concentrations (compared to the level just before the Industrial Revolution got under way in the early 19th century) range from 3.6 degrees to 8 degrees Fahrenheit. The intergovernmental climate panel said it could not rule out even higher temperatures. While the low end could probably be tolerated, the high end would almost certainly result in calamitous, long-lasting disruptions of ecosystems and economies, a host of studies have concluded. A wide range of economists and earth scientists say that level of risk justifies an aggressive response.

Other questions have persisted despite a century-long accumulation of studies pointing to human-driven warming. The rate and extent at which sea levels will rise in this century as ice sheets erode remains highly uncertain, even as the long-term forecast of centuries of retreating shorelines remains intact. Scientists are struggling more than ever to disentangle how the heat building in the seas and atmosphere will affect the strength and number of tropical cyclones. The latest science suggests there will be more hurricanes and typhoons that reach the most dangerous categories of intensity, but fewer storms overall.

Global Warming & Climate Change

Steen Ulrik Johannessen/Agence France-Presse — Getty Images

Global warming has become perhaps the most complicated issue facing world leaders. Warnings from the scientific community are becoming louder, as an increasing body of science points to rising dangers from the ongoing buildup of human-related greenhouse gases — produced mainly by the burning of fossil fuels and forests.

Global emissions of carbon dioxide jumped by the largest amount on record in 2010, upending the notion that the brief decline during the recession might persist through the recovery. Emissions rose 5.9 percent in 2010, according to the Global Carbon Project, an international collaboration of scientists. The increase solidified a trend of ever-rising emissions that scientists fear will make it difficult, if not impossible, to forestall severe climate change in coming decades.

However, the technological, economic and political issues that have to be resolved before a concerted worldwide effort to reduce emissions can begin have gotten no simpler, particularly in the face of a global economic slowdown.

For almost two decades, the United Nations has sponsored annual global talks, the United Nations Framework Convention on Climate Change, an international treaty signed by 194 countries to cooperatively discuss global climate change and its impact. The conferences operate on the principle of consensus, meaning that any of the participating nations can hold up an agreement.

The conflicts and controversies discussed are monotonously familiar: the differing obligations of industrialized and developing nations, the question of who will pay to help poor nations adapt, the urgency of protecting tropical forests and the need to rapidly develop and deploy clean energy technology.

But the meetings have often ended in disillusionment, with incremental political progress but little real impact on the climate. The negotiating process itself has come under fire from some quarters, including the poorest nations who believe their needs are being neglected in the fight among the major economic powers. Criticism has also come from a small but vocal band of climate-change skeptics, many of them members of the United States Congress, who doubt the existence of human influence on the climate and ridicule international efforts to deal with it.

A New International Initiative Led by the U.S.

In mid-February 2012, Secretary of State Hillary Rodham Clinton was expected to announce a new international effort focused on reducing emissions of common pollutants that contribute to rapid climate change and widespread health problems.

Impatient with the slow pace of international negotiations, the United States and a small group of countries — Bangladesh, Canada, Ghana, Mexico and Sweden as well as the United Nations Environment Program — are starting a program that will address short-lived pollutants like soot (also referred to as black carbon), methane and hydrofluorocarbons that have an outsize influence on global warming, accounting for 30 to 40 percent of global warming. Soot from diesel exhausts and the burning of wood, agricultural waste and dung for heating and cooking causes an estimated two million premature deaths a year, particularly in the poorest countries.

Global warming has become perhaps the most complicated issue facing world leaders. Warnings from the scientific community are becoming louder, as an increasing body of science points to rising dangers from the ongoing buildup of human-related greenhouse gases — produced mainly by the burning of fossil fuels and forests.

Global emissions of carbon dioxide jumped by the largest amount on record in 2010, upending the notion that the brief decline during the recession might persist through the recovery. Emissions rose 5.9 percent in 2010, according to the Global Carbon Project, an international collaboration of scientists. The increase solidified a trend of ever-rising emissions that scientists fear will make it difficult, if not impossible, to forestall severe climate change in coming decades.

However, the technological, economic and political issues that have to be resolved before a concerted worldwide effort to reduce emissions can begin have gotten no simpler, particularly in the face of a global economic slowdown.

For almost two decades, the United Nations has sponsored annual global talks, the United Nations Framework Convention on Climate Change, an international treaty signed by 194 countries to cooperatively discuss global climate change and its impact. The conferences operate on the principle of consensus, meaning that any of the participating nations can hold up an agreement.

The conflicts and controversies discussed are monotonously familiar: the differing obligations of industrialized and developing nations, the question of who will pay to help poor nations adapt, the urgency of protecting tropical forests and the need to rapidly develop and deploy clean energy technology.

But the meetings have often ended in disillusionment, with incremental political progress but little real impact on the climate. The negotiating process itself has come under fire from some quarters, including the poorest nations who believe their needs are being neglected in the fight among the major economic powers. Criticism has also come from a small but vocal band of climate-change skeptics, many of them members of the United States Congress, who doubt the existence of human influence on the climate and ridicule international efforts to deal with it.

A New International Initiative Led by the U.S.

In mid-February 2012, Secretary of State Hillary Rodham Clinton was expected to announce a new international effort focused on reducing emissions of common pollutants that contribute to rapid climate change and widespread health problems.

Impatient with the slow pace of international negotiations, the United States and a small group of countries — Bangladesh, Canada, Ghana, Mexico and Sweden as well as the United Nations Environment Program — are starting a program that will address short-lived pollutants like soot (also referred to as black carbon), methane and hydrofluorocarbons that have an outsize influence on global warming, accounting for 30 to 40 percent of global warming. Soot from diesel exhausts and the burning of wood, agricultural waste and dung for heating and cooking causes an estimated two million premature deaths a year, particularly in the poorest countries.

Read More...

Scientists say that concerted action on these substances can reduce global temperatures by 0.5 degrees Celsius by 2050 and prevent millions of cases of lung and heart disease by 2030.

The United States intends to contribute $12 million and Canada $3 million over two years to get the program off the ground and to help recruit other countries to participate. The United Nations Environment Program will run the project.

Officials hope that by tackling these fast-acting, climate-changing agents they can get results quicker than through the laborious and highly political negotiations conducted under the United Nations Framework Convention on Climate Change.

2011 Global Talks in Durban

At the 2011 conference delegates from about 200 nations gathered together in Durban, South Africa. One of the issues left unresolved was the future of the Kyoto Protocol, the 1997 agreement that requires major industrialized nations to meet targets on emissions reduction but imposes no mandates on developing countries, including emerging economic powers and sources of global greenhouse gas emissions like China, India, Brazil and South Africa.

The United States is not a party to the protocol, having refused to even consider ratifying it because of those asymmetrical obligations. Some major countries, including Canada, Japan and Russia, have said they will not agree to an extension of the protocol next year unless the unbalanced requirements of developing and developed countries are changed. That is similar to the United States’ position, which is that any successor treaty must apply equally to all major economies.

Expectations for the meeting were low, and it ended with modest accomplishments: the promise to work toward a new global treaty in coming years and the establishment of a new climate fund.

The deal on a future treaty renewed the Kyoto Protocol for several more years. But it also began a process for replacing the protocol with something that treats all countries — including the economic powerhouses China, India and Brazil — equally. The future treaty deal was the most highly contested element of a package of agreements that emerged from the extended talks among the nations here.

The expiration date of the protocol — 2017 or 2020 — and the terms of any agreement that replaces it will be negotiated at future sessions.

The delegates also agreed on the creation of a fund to help poor countries adapt to climate change — though the precise sources of the money have yet to be determined — and to measures involving the preservation of tropical forests and the development of clean-energy technology. The reserve, called the Green Climate Fund, would help mobilize a promised $100 billion a year in public and private financing by 2020 to assist developing countries in adapting to climate change and converting to clean energy sources.

2010 Global Talks in Cancún

The United Nations conference on climate change in Cancún, Mexico, produced only modest achievements but ended with the toughest issues unresolved. The package that was approved, known as the Cancún Agreements, set up a new fund to help poor countries adapt to climate changes, created new mechanisms for transfer of clean energy technology, provided compensation for the preservation of tropical forests and strengthened the emissions reductions pledges that came out of the U.N. climate change meeting in Copenhagen in 2009.

The conference approved the agreement over the objections of Bolivia, which condemned the pact as too weak. But those protests did not block its acceptance. Delegates from island states and the least-developed countries warmly welcomed the pact because it would start the flow of billions of dollars to assist them in adopting cleaner energy systems and adapting to inevitable changes in the climate, like sea rise and drought.

But where the promised aid from wealthy nations — $100 billion — would come from was left unresolved.

The E.U. Gets Tough With Airline Emissions

In December 2011, the European Union’s highest court endorsed the bloc’s plan to begin charging the world’s biggest airlines for their greenhouse gas emissions from Jan. 1, 2012, setting the stage for a potentially costly trade war with the United States, China and other countries.

A group of United States airlines had argued that forcing them to participate in the potentially costly emissions-trading system infringed on national sovereignty and conflicted with existing international aviation treaties.

But in a final ruling , the European Court of Justice in Luxembourg affirmed an opinion issued in October by its advocate general, who had rejected their claim.

The court’s decision came amid increasing pressure from some of the biggest trading partners of the 27-member bloc to suspend or amend application of the legislation to expressly exclude non-E.U. countries — at least initially. Failing that, several governments have vowed to take their own legal action or retaliate with countervailing trade measures.

Although airlines initially will receive most of the permits they will need for free, the European Union estimates that ticket prices could rise by as much as €12, or nearly $16, on some long-haul flights to cover the cost of additional permits required.

Airlines for America, an industry lobby group and one of the plaintiffs in the case, said that its members would be required to pay more than $3.1 billion to the E.U. between 2012 and 2020. It said its members would comply with the system “under protest,” but would also review options for pursuing the case in Britain’s High Court, which had referred the original complaint to the European court in 2009.

The European initiative involves folding aviation into the Union’s six-year-old Emissions Trading System, in which polluters can buy and sell a limited quantity of permits, each representing a ton of carbon dioxide. The legislation mandates that airlines account for their emissions for the entirety of any flight that takes off from — or lands at — any airport in the 27-member bloc.

The goal, European officials have said, is to speed up the adoption of greener technologies at a time when air traffic, which represents about 3 percent of global carbon dioxide emissions, is growing much faster than gains in efficiency.

The U.S. and Climate Change

The United States has been criticized at the United Nations gatherings for years, in part because of its rejection of the Kyoto framework and in part because it has not adopted a comprehensive domestic program for reducing its own greenhouse gas emissions. President Obama has pledged to reduce American emissions 17 percent below 2005 levels by 2020, but his preferred approach, a nationwide cap-and-trade system for carbon pollution, was passed by the House in 2009 but died in the Senate the next year. United States emissions are down about 6 percent over the past five years, largely because of the drop in industrial and electricity production caused by the recession.

In January 2011, the Environmental Protection Agency began imposing regulations related to greenhouse gas emissions. The immediate effect on utilities, refiners and major manufacturers was minor, with the new rules applying only to those planning to build large new facilities or make major modifications to existing plants. Over the next decade, however, the agency plans to regulate virtually all sources of greenhouse gases, imposing efficiency and emissions requirements on nearly every industry and every region.

Steps Toward a Response

The debate over climate questions pales next to the fight over what to do, or not do, in a world where fossil fuels still underpin both rich and emerging economies.

With the completion of the United Nations Framework Convention on Climate Change at the Earth Summit in 1992, the world’s nations pledged to avoid dangerously disrupting the climate through the buildup of greenhouse gases, but they never defined how much warming was too much.

Nonetheless, recognizing that the original climate treaty was proving ineffective, all of the world’s industrialized countries except for the United States accepted binding restrictions on their greenhouse gas emissions under the Kyoto Protocol, which was negotiated in Japan in 1997. That accord took effect in 2005 and its gas restrictions expire in 2012. The United States signed the treaty, but it was never submitted for ratification in the face of overwhelming opposition in the Senate because the pact required no steps by China or other fast-growing developing countries.

It took until 2009 for the leaders of the world’s largest economic powers to agree on a dangerous climate threshold: an increase of 2 degrees Celsius (3.6 degrees Fahrenheit) from the average global temperature recorded just before the Industrial Revolution kicked into gear. (This translates into an increase of 1.3 degrees Fahrenheit above the Earth’s current average temperature, about 59 degrees.)

The Group of 8 industrial powers also agreed in 2009 to a goal of reducing global emissions 50 percent by 2050, with the richest countries leading the way by cutting their emissions 80 percent. But they did not set a baseline from which to measure that reduction, and so far firm interim targets — which many climate scientists say would be more meaningful — have not been defined.

At the same time, fast-growing emerging economic powerhouses, led by China and India, opposed taking on mandatory obligations to curb their emissions. They said they will do what they can to rein in growth in emissions — as long as their economies do not suffer.

In many ways, the debate over global climate policy is a result of a global “climate divide.’' Emissions of carbon dioxide per person range from less than 2 tons per year in India, where 400 million people lack access to electricity, to more than 20 in the United States. The richest countries are also best able to use wealth and technology to insulate themselves from climate hazards, while the poorest, which have done the least to cause the problem, are the most exposed.

Background

Scientists learned long ago that the earth’s climate has powerfully shaped the history of the human species — biologically, culturally and geographically. But only in the last few decades has research revealed that humans can be a powerful influence on the climate, as well.

A growing body of scientific evidence indicates that since 1950, the world’s climate has been warming, primarily as a result of emissions from unfettered burning of fossil fuels and the razing of tropical forests. Such activity adds to the atmosphere’s invisible blanket of carbon dioxide and other heat-trapping “greenhouse” gases. Recent research has shown that methane, which flows from landfills, livestock and oil and gas facilities, is a close second to carbon dioxide as an impact on the atmosphere.

That conclusion has emerged through a broad body of analysis in fields as disparate as glaciology, the study of glacial formations, and palynology, the study of the distribution of pollen grains in lake mud. It is based on a host of assessments by the world’s leading organizations of climate and earth scientists.

In the last several years, the scientific case that the rising human influence on climate could become disruptive has become particularly robust.

Some fluctuations in the earth’s temperature are inevitable regardless of human activity — because of decades-long ocean cycles, for example. But centuries of rising temperatures and seas lie ahead if the release of emissions from the burning of fossil fuels and deforestation continues unabated, according to the Intergovernmental Panel on Climate Change, a group that shared the 2007 Nobel Peace Prize with former Vice President Al Gore.

In addition, a report released by the I.P.C.C. in November 2011 predicted that global warming will cause more dangerous and “unprecedented extreme weather” in the future.

Despite the scientific consensus on these basic conclusions, enormously important details remain murky. That reality has been seized upon by some groups and scientists disputing the overall consensus and opposing changes in energy policies.

For example, estimates of the amount of warming that would result from a doubling of greenhouse gas concentrations (compared to the level just before the Industrial Revolution got under way in the early 19th century) range from 3.6 degrees to 8 degrees Fahrenheit. The intergovernmental climate panel said it could not rule out even higher temperatures. While the low end could probably be tolerated, the high end would almost certainly result in calamitous, long-lasting disruptions of ecosystems and economies, a host of studies have concluded. A wide range of economists and earth scientists say that level of risk justifies an aggressive response.

Other questions have persisted despite a century-long accumulation of studies pointing to human-driven warming. The rate and extent at which sea levels will rise in this century as ice sheets erode remains highly uncertain, even as the long-term forecast of centuries of retreating shorelines remains intact. Scientists are struggling more than ever to disentangle how the heat building in the seas and atmosphere will affect the strength and number of tropical cyclones. The latest science suggests there will be more hurricanes and typhoons that reach the most dangerous categories of intensity, but fewer storms overall.

Bracing for a Bullfrog Invasion

By JOSIE GARTHWAITE

NYTimes,

Kenneth H. Thomas/Photo Researchers On the move in coming decades: the American bullfrog.

The consequences of climate change for animals can seem very direct, as with polar bears in a warming Arctic. Others involve leaps, like the case of an invasive bullfrog: by 2080, it could splash into some of South America’s most ecologically rich protected areas, disrupting unique hotbeds of biodiversity. At least, that’s the prediction of a new study in the journal PLoS One.

Worldwide, researchers have increasingly been focusing on how a changing climate has altered or is likely to alter migration patterns and the habitats that different species may find hospitable.

For example, one recent study suggests that more than a million giant king crabs have ventured into the warming waters of Palmer Deep in the Antarctic shelf in recent decades, destroying native sea life. (Colder waters may have kept these “skeleton-crushing predators” at bay for more than 14 million years, the report said.)

Another, a meta-analysis published in the journal Science, found that a host of animal and plant species are moving to cooler, higher altitudes at a striking speed (an average of eight inches per hour). They have moved farthest in regions where the most warming has occurred, the report said.

And then there’s Lithobates catesbeianus (or Rana catesbeianus), commonly known as the American bullfrog.

Working out of universities in Argentina, Brazil and Colombia, the authors of this latest study have mapped species distribution models against climate models, information about biological preserves and sites where the species currently lives.

The result is a prediction of what places are more likely to be invaded by 2080. If the climate changes as anticipated, it appears that a bullfrog invasion will subside in portions of central western Brazil, Argentina, Paraguay and Bolivia. But it will increase in parts of northern Brazil, southeastern Colombia, eastern Peru and southern Venezuela, the researchers project.

The American bullfrog is a particularly vexing trespasser. “Bullfrogs are superfrogs, very adaptable and seemingly immune to most of the causes of amphibian decline,” said Peter B. Moyle, associate director of the Center for Watershed Sciences at the University of California, Davis. “They live in a wide variety of habitats, colonize new ones readily, and eat everything that fits into their mouths.”

If that seems like an overstatement, consider the United States Geological Survey’s summary of the species’ diet, which includes birds, rodents, frogs, snakes, turtles, lizards, and bats. In short, “they are voracious eaters who will also prey on their own young,” the survey says,

Dr. Moyle noted that the American bullfrog gets so big that people around the world have embraced them for culinary purposes (frog legs), even in Europe, “home of the original edible frog.”

Endemic to the eastern United States and Canada, the species has been introduced in more than 40 countries and four continents, including more than 75 percent of South America.

As areas where the American bullfrog has already taken up residence become less hospitable in a changing climate, the researchers, led by Javier Nori of the Universidad de Córdoba, anticipate that protected forest areas will become more suitable for the species.

Unless steps are taken to prevent the invasion, the authors write, climate change could enable the American bullfrog to thrive in areas of the Andean-Patagonian forest, eastern Paragua and northwestern Bolivia, where the species has not yet been reported.

The authors’ concern is especially high for the Atlantic Forest, a biodiversity hot spot in tropical South America. “Continuous monitoring of the native biodiversity in this biome should be a priority since L. castesbeianus is likely to colonize reserves more efficiently under climate changes,” they write.

Dr. Moyle said the study is of the sort that should be carried out for other species worldwide because “it demonstrates that we can predict alien invasions.”

The American bullfrog has a record that even Cortés might envy. But beyond its history, there are additional reasons that the species seems likely to colonize new territory.

“Amphibians rely on external temperatures, moisture levels, rainfall to regulate their own conditions,” said Robin Moore, an amphibian conservation officer for Conservation International. “They have semi-permeable skin, so even slight changes in rainfall can really affect them. Given their reliance on external temperatures and climate, as the climate changes, they are going to move.”

For native species, the arrival of the American bullfrog often means new competition, predation and the rapid spread of deadly disease among amphibians.The bullfrog is a carrier of amphibian chytrid fungus, Dr. Moore said, “possibly the most devastating disease to affect an entire class of animals, certainly vertebrates.”

According to the International Union for Conservation of Nature, based near Geneva, nearly half of all amphibians are now at risk of extinction for many reasons, climate change among them. Dr. Moore described it as an enormous conservation challenge.

Dr. Moyle said the latest study was quite thorough in its climate modeling and predictions and suggested that this could make it more convincing for policymakers.

But even good models have their limitations.“It is important to keep in mind that these are predictions,” he cautioned, noting that they are based in part on a big assumption: that the areas that conservationists need to protect in 50 years will be the same areas protected for their biodiversity today. “It is unrealistic to assume no change,” he said.

In an e-mail, the study’s authors also emphasized, for example, that their models do not take into account the dispersal capability of the bullfrog and its interactions with other organisms. So while this type of modeling is useful for pinpointing areas prone to invasion and providing management guidelines, Dr. Nori’s team wrote, more work is needed.

The scientists called on governments to redouble their efforts to collaborate with universities, research institutions and environmental groups to address “an imminent biological invasion of the bullfrog in the continent.”

Climate Change Is Shrinking Species, Research Suggests

By RACHEL NUWER

Jennifer Sheridan and David Bickford

A male frog specimen collected on Mount Kinabalu in Malaysia in the 1980’s, left, versus another collected in 2008.

Climate change’s laundry list of impacts — melting glaciers and rising sea levels, shifts in timing for bird migration and flower budding, a poleward shift of species — just got a new addition: shrinking species.

No, not population sizes, but a diminution in the size of the animals by comparison with the pre-global warming days.

It’s not that scientists are expecting humans to shrink in size, or mini-pandas and mini-panthers to join the ranks of miniature poodles.

“I don’t think that organisms will shrink to the degree that you’ll walk outside and see that trees are suddenly half the size that they sued to be,” said Jennifer Sheridan, a conservation biologist at the University of Alabama and a co-author of a paper describing the phenomenon in Monday’s issue of the journal Nature Climate Change.

But the shrinking among species in general is noticeable, Dr. Sheridan said — at least to scientists studying them. And in the long run, she suggests, changes in species sizes could have major implications for crop production and the availability of protein sources like fish.

Judging from the fossil record, creatures like beetles, spiders and pocket gophers shrank during periods of warming in the past like the Paleocene-Eocene Thermal Maximum about 55.8 million years ago, the researchers write. Scientists are increasingly relying on fossils to predict what the planet might anticipate over the next century.

Although climate change is now unfolding at a much faster rate than in past periods of warming, the researchers write, the basic message is the same: warmer temperatures equals smaller animals.

Yet the research community over all has been less than enthusiastic about embracing the idea. “The scientific community is really hesitant to publish things that are potentially inflammatory,” said David Bickford, an evolutionary ecologist at the University of Singapore and a co-author of the paper. “People don’t want to think that this is a new reality, everything shrinking.”

Since he and Dr. Sheridan began documenting the trend over two years ago, Dr. Bickford said, another 20to 30 studies have suggested that the shrinking phenomenon is occurring across species. The two researchers compiled evidence of shrinking species across the globe from the scientific literature, presenting an aggregate view of what has been discovered and deduced so far.

So why all the shrinking?

Although some plants were initially expected to flourish on the extra carbon dioxide in the atmosphere associated with global warming, their growth is also dependent on temperature, humidity and nutrients. So in areas that are getting warmer and dryer, many plants have become smaller and less able to thrive, the researchers write.

Plant growth is also directly controlled by water, which is becoming more limited as regions like the subtropics become drier. Even areas where increased rainfall is predicted, like the equatorial and high-latitude regions, will see increased variability in rainfall, which probably means they will also experience some periods of very limited rain, the authors write.

Droughts in many regions are expected to result in more forest fires, which reduces the nitrogen in soil that is a critical factor in plants’ growth, the study says. As plants respond to these fluctuations by becoming smaller, animals that depend upon plants — from deer to rabbits to insects — will need to eat larger quantities of smaller plants, the scientists say.

And animals that prey upon herbivores will need to eat more of their shrinking prey to maintain their body sizes, the thinking goes. If predators like like wolves, hawks and robins cannot meet their energy demands by catching numerous smaller prey, they may simply adapt by shifting to eating other species, the study says — or they could begin to shrink themselves or even die off.

Drought also generally leads to smaller offspring, who would in turn have smaller offspring.

Evolution will probably favor the small animals who are better able to keep up with energy demands as resources fluctuate on an ever warmer planet, the researchers suggest.

They cautioned that it was too early to make detailed predictions. “Things start falling apart as we try to make generalizations and impose more levels and hierarchies into our hypotheses,” Dr. Bickford said.

The researchers compiled experimental data on various plant and animal species and how they might react to climate change. In one set of experiments, the paper’s authors exposed corals, scallops, and oysters to the increasingly acidic sea conditions that are expected to ensue with climate change, and the animals’ growth rates declined.

In laboratory experiments, for every two degrees the scientists cranked up the temperature, various types of fruit size decreased anywhere from 3 to 17 percent. For fish, the shrinking was even more pronounced, at 6 to 22 percent.

Disparities in size changes are likely to upset the balance of ecosystems, the authors write. “This isn’t a ubiquitous or general law of ecology,” Dr. Bickford says, “but when some animals are affected and others aren’t, that’s when an imbalance will happen, and that’s what we’re most concerned about.”

If all animals were to engage in coordinated shrinking it might not be so bad, the researchers speculate. But if, say, mice are shrinking faster than snakes, the snakes may not be able to capture enough of the mice to meet their energy requirements.

For now, such outcomes are simply possibilities, although the authors believe that shrinking is here to stay.

Dr. Bickford said the paper was intended as an non-alarmist appeal to the world’s ecologists to take notice. “No matter what else they’re doing in the field, we want more ecologists to pay attention to body size and take these measurements,” he explained.

Martin Daufresne, an aquatic ecologist at Cemagref, a government environmental research institute in Aix-en-Provence, France, described the new paper as “very interesting.” It “brings new insights to the topic by discussing the generality of these patterns and their potential causes, and by suggesting future research directions,” he said.

Climate Change Is Shrinking Species, Research Suggests

By RACHEL NUWER

Jennifer Sheridan and David Bickford

A male frog specimen collected on Mount Kinabalu in Malaysia in the 1980’s, left, versus another collected in 2008.

Climate change’s laundry list of impacts — melting glaciers and rising sea levels, shifts in timing for bird migration and flower budding, a poleward shift of species — just got a new addition: shrinking species.

No, not population sizes, but a diminution in the size of the animals by comparison with the pre-global warming days.

It’s not that scientists are expecting humans to shrink in size, or mini-pandas and mini-panthers to join the ranks of miniature poodles.

“I don’t think that organisms will shrink to the degree that you’ll walk outside and see that trees are suddenly half the size that they sued to be,” said Jennifer Sheridan, a conservation biologist at the University of Alabama and a co-author of a paper describing the phenomenon in Monday’s issue of the journal Nature Climate Change.

But the shrinking among species in general is noticeable, Dr. Sheridan said — at least to scientists studying them. And in the long run, she suggests, changes in species sizes could have major implications for crop production and the availability of protein sources like fish.

Judging from the fossil record, creatures like beetles, spiders and pocket gophers shrank during periods of warming in the past like the Paleocene-Eocene Thermal Maximum about 55.8 million years ago, the researchers write. Scientists are increasingly relying on fossils to predict what the planet might anticipate over the next century.

Although climate change is now unfolding at a much faster rate than in past periods of warming, the researchers write, the basic message is the same: warmer temperatures equals smaller animals.

Yet the research community over all has been less than enthusiastic about embracing the idea. “The scientific community is really hesitant to publish things that are potentially inflammatory,” said David Bickford, an evolutionary ecologist at the University of Singapore and a co-author of the paper. “People don’t want to think that this is a new reality, everything shrinking.”

Since he and Dr. Sheridan began documenting the trend over two years ago, Dr. Bickford said, another 20to 30 studies have suggested that the shrinking phenomenon is occurring across species. The two researchers compiled evidence of shrinking species across the globe from the scientific literature, presenting an aggregate view of what has been discovered and deduced so far.

So why all the shrinking?

Although some plants were initially expected to flourish on the extra carbon dioxide in the atmosphere associated with global warming, their growth is also dependent on temperature, humidity and nutrients. So in areas that are getting warmer and dryer, many plants have become smaller and less able to thrive, the researchers write.

Plant growth is also directly controlled by water, which is becoming more limited as regions like the subtropics become drier. Even areas where increased rainfall is predicted, like the equatorial and high-latitude regions, will see increased variability in rainfall, which probably means they will also experience some periods of very limited rain, the authors write.

Droughts in many regions are expected to result in more forest fires, which reduces the nitrogen in soil that is a critical factor in plants’ growth, the study says. As plants respond to these fluctuations by becoming smaller, animals that depend upon plants — from deer to rabbits to insects — will need to eat larger quantities of smaller plants, the scientists say.

And animals that prey upon herbivores will need to eat more of their shrinking prey to maintain their body sizes, the thinking goes. If predators like like wolves, hawks and robins cannot meet their energy demands by catching numerous smaller prey, they may simply adapt by shifting to eating other species, the study says — or they could begin to shrink themselves or even die off.

Drought also generally leads to smaller offspring, who would in turn have smaller offspring.

Evolution will probably favor the small animals who are better able to keep up with energy demands as resources fluctuate on an ever warmer planet, the researchers suggest.

They cautioned that it was too early to make detailed predictions. “Things start falling apart as we try to make generalizations and impose more levels and hierarchies into our hypotheses,” Dr. Bickford said.

The researchers compiled experimental data on various plant and animal species and how they might react to climate change. In one set of experiments, the paper’s authors exposed corals, scallops, and oysters to the increasingly acidic sea conditions that are expected to ensue with climate change, and the animals’ growth rates declined.

In laboratory experiments, for every two degrees the scientists cranked up the temperature, various types of fruit size decreased anywhere from 3 to 17 percent. For fish, the shrinking was even more pronounced, at 6 to 22 percent.

Disparities in size changes are likely to upset the balance of ecosystems, the authors write. “This isn’t a ubiquitous or general law of ecology,” Dr. Bickford says, “but when some animals are affected and others aren’t, that’s when an imbalance will happen, and that’s what we’re most concerned about.”

If all animals were to engage in coordinated shrinking it might not be so bad, the researchers speculate. But if, say, mice are shrinking faster than snakes, the snakes may not be able to capture enough of the mice to meet their energy requirements.

For now, such outcomes are simply possibilities, although the authors believe that shrinking is here to stay.

Dr. Bickford said the paper was intended as an non-alarmist appeal to the world’s ecologists to take notice. “No matter what else they’re doing in the field, we want more ecologists to pay attention to body size and take these measurements,” he explained.

Martin Daufresne, an aquatic ecologist at Cemagref, a government environmental research institute in Aix-en-Provence, France, described the new paper as “very interesting.” It “brings new insights to the topic by discussing the generality of these patterns and their potential causes, and by suggesting future research directions,” he said.

'Acidifying oceans' threaten food supply, UK warns

Acidification of the oceans affects marine life

By Richard Black
Environment correspondent, BBC News website, Copenhagen

Acidification of the oceans is a major threat to marine life and humanity's food supply, Hilary Benn is to warn as the UN climate summit resumes.

The UK environment secretary will say that acidification provides a "powerful incentive" to cut carbon emissions.

Ocean chemistry is changing because water absorbs extra CO2 from the air.

Some believe this could be as big an impact of rising CO2 levels as climatic change, though it is rarely discussed within the UN climate convention.

The UN summit in Copenhagen, which started a week ago, is scheduled to conclude on Friday, when more than 100 world leaders will attend in an effort to agree a new global treaty on climate change.

'Really important'

OCEAN ACIDIFICATION Up to 50% of the CO2 released by burning fossil fuels over the past 200 years has been absorbed by the world's oceans This has lowered the pH value of seawater - the measure of acidity and alkalinity - by 0.1 The vast majority of liquids lie between pH 0 (very acidic) and pH 14 (very alkaline); 7 is neutral Seawater is mildly alkaline with a "natural" pH of about 8.2 The IPCC forecasts that ocean pH will fall by "between 0.14 and 0.35 units over the 21st Century, adding to the present fall of 0.1 units since pre-industrial times" Natural lab shows sea's acid path What is ocean acidification? 'Coral lab' offers acidity insight

The science has come to prominence only within the last five or six years, and most of the details were not available when the convention was signed in 1992.

"We know that the increasing concentration of CO2 [in the air] is making the oceans more acidic," Mr Benn told BBC News.

"It affects marine life, it affects coral, and that in turn could affect the amount of fish in the sea - and a billion people in the world depend on fish for their principal source of protein.

"It doesn't get as much attention as the other problems; it is really important."

In September, the UN-backed study into The Economics of Ecosystems and Biodiversity (Teeb) concluded that the widely-endorsed target of trying to stabilise atmospheric concentrations of CO2 or their equivalent to around 450 parts per million (ppm) would prove lethal to much of the world's coral.

1. Up to one half of the carbon dioxide (CO2) released by burning fossil fuels over the past 200 years has been absorbed by the world's oceans 2. Absorbed CO2 in seawater (H2O) forms carbonic acid (H2CO3), lowering the water's pH level and making it more acidic 3. This raises the hydrogen ion concentration in the water, and limits organisms' access to carbonate ions, which are needed to form hard parts

Mr Benn will be speaking during the summit's "oceans day" at a meeting organised by Stanford University and Scripps Institution of Oceanography, both based in California.

"Unlike global warming, which can manifest itself in nuanced, complex ways, the science of ocean acidification is unambiguous," said Andrew Dickson, a Scripps professor of marine chemistry.

"The chemical reactions that take place as increasing amounts of carbon dioxide are introduced to seawater have been established for nearly a century."

CLIMATE CHANGE GLOSSARY

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Glossary in full

The oceans and atmosphere are constantly exchanging CO2.

Concentrations in the atmosphere are now about 30% higher than in pre-industrial times; a proportion of this is absorbed by seawater, which results in rising concentrations of carbonic acid.

As a result, the pH of seawater has fallen by about 0.1, and a further change of 0.3-0.4 is expected by the end of the century.

This is likely to affect the capacity of organisms including molluscs, coral and plankton to form "hard parts" of calcium carbonate.

A 2007 study showed that rates of coral growth on the Great Barrier Reef had fallen by 14% since 1990.

Mr Benn will say that the Intergovernmental Panel on Climate Change (IPCC) should investigate ocean acidification during its next major assessment of the Earth's climate, scheduled for release in 2013.