Climate experts weigh lull in warming: Trend is tough to explain as gas emissions rise
by Karl Ritter
STOCKHOLM — Scientists working on a landmark U.N. report on climate change are struggling to explain why global warming appears to have slowed in the past 15 years even though greenhouse gas emissions keep rising. Leaked documents obtained by The Associated Press show there are deep concerns among governments over how to address the issue ahead of next week’s meeting of the Intergovernmental Panel on Climate Change.
Climate skeptics have used the lull in surface warming since 1998 to cast doubt on the scientific consensus that humans are cooking the planet by burning fossil fuels and cutting down CO2-absorbing forests. The IPCC’s conclusions are important because they serve as the scientific underpinnings of U.N. negotiations to rein in emissions of CO2 and other greenhouse gases. A global climate treaty is supposed to be adopted in 2015. The IPCC report is expected to affirm the human link with greater certainty than ever, but the panel is under pressure to also address the recent lower rate of warming, which scientists say is likely due to heat going deep into the ocean and natural climate fluctuations.
“I think to not address it would be a problem because then you basically have the denialists saying, ‘Look the IPCC is silent on this issue,’ ” said Alden Meyer, of the Washington based Union of Concerned Scientists. In a June draft of the report’s summary from policymakers, the IPCC said the rate of warming in 1998-2012 was about half the average rate since 1951. It cited natural variability in the climate system, as well as cooling effects from volcanic eruptions and a downward phase in solar activity. But several governments that reviewed the draft objected to how the issue was tackled, in comments to the IPCC obtained by the AP. Germany called for the reference to the slowdown to be deleted, saying a time span of 10-15 years was misleading in the context of climate change, which is measured over decades and centuries. The U.S. also urged the authors to include the “leading hypothesis” that the reduction in warming is linked to more heat being transferred to the deep ocean. First they deny "climate cycles" and now they want to use "cycles" to debunk cooling.
Many skeptics claim that the rise in global average temperatures stopped in the late 1990s and their argument has gained momentum among some media and politicians, even though the scientific evidence of climate change is piling up: the previous decade was the warmest on record and, so far, this decade is even warmer.
STOCKHOLM — Scientists working on a landmark U.N. report on climate change are struggling to explain why global warming appears to have slowed in the past 15 years even though greenhouse gas emissions keep rising. Leaked documents obtained by The Associated Press show there are deep concerns among governments over how to address the issue ahead of next week’s meeting of the Intergovernmental Panel on Climate Change.
Climate skeptics have used the lull in surface warming since 1998 to cast doubt on the scientific consensus that humans are cooking the planet by burning fossil fuels and cutting down CO2-absorbing forests. The IPCC’s conclusions are important because they serve as the scientific underpinnings of U.N. negotiations to rein in emissions of CO2 and other greenhouse gases. A global climate treaty is supposed to be adopted in 2015. The IPCC report is expected to affirm the human link with greater certainty than ever, but the panel is under pressure to also address the recent lower rate of warming, which scientists say is likely due to heat going deep into the ocean and natural climate fluctuations.
“I think to not address it would be a problem because then you basically have the denialists saying, ‘Look the IPCC is silent on this issue,’ ” said Alden Meyer, of the Washington based Union of Concerned Scientists. In a June draft of the report’s summary from policymakers, the IPCC said the rate of warming in 1998-2012 was about half the average rate since 1951. It cited natural variability in the climate system, as well as cooling effects from volcanic eruptions and a downward phase in solar activity. But several governments that reviewed the draft objected to how the issue was tackled, in comments to the IPCC obtained by the AP. Germany called for the reference to the slowdown to be deleted, saying a time span of 10-15 years was misleading in the context of climate change, which is measured over decades and centuries. The U.S. also urged the authors to include the “leading hypothesis” that the reduction in warming is linked to more heat being transferred to the deep ocean. First they deny "climate cycles" and now they want to use "cycles" to debunk cooling.
Many skeptics claim that the rise in global average temperatures stopped in the late 1990s and their argument has gained momentum among some media and politicians, even though the scientific evidence of climate change is piling up: the previous decade was the warmest on record and, so far, this decade is even warmer.
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