Hopes of mild climate change dashed by new research

Hopes of mild climate change dashed by new research

SOURCE: The Guardian DATE: July 5, 2017 SNIP: Hopes that the world’s huge carbon emissions might not drive temperatures up to dangerous levels have been dashed by new research. The work shows that temperature rises measured over recent decades do not fully reflect the global warming already in the pipeline and that the ultimate heating of the planet could be even worse than feared. How much global temperatures rise for a certain level of carbon emissions is called climate sensitivity and is seen as the single most important measure of climate change. “The hope was that climate sensitivity was lower and the Earth is not going to warm as much,” said Cristian Proistosescu, at Harvard University in the US, who led the new research. “There was this wave of optimism.” The new research, published in the journal Science Advances, has ended that. “The worrisome part is that all the models show there is an amplification of the amount of warming in the future,” he said. The situation might be even worse, as Proistosescu’s work shows climate sensitivity could be as high as 6C. Prof Bill Collins, at the University of Reading, UK, and not part of the new research, said: “Some have suggested that we might be lucky and avoid dangerous climate change without taking determined action if the climate is not very sensitive to CO2 emissions. This work provides new evidence that that chance is...
Climate models have underestimated Earth’s sensitivity to CO2 changes, study finds

Climate models have underestimated Earth’s sensitivity to CO2 changes, study finds

SOURCE: Yale News DATE: April 7, 2017 SNIP: A Yale University study says global climate models have significantly underestimated how much the Earth’s surface temperature will rise if greenhouse gas emissions continue to increase as expected. Yale scientists looked at a number of global climate projections and found that they misjudged the ratio of ice crystals and super-cooled water droplets in “mixed-phase” clouds — resulting in a significant under-reporting of climate sensitivity. The findings appear April 7 in the journal Science. Equilibrium climate sensitivity is a measure used to estimate how Earth’s surface temperature ultimately responds to changes in atmospheric carbon dioxide (CO2). Specifically, it reflects how much the Earth’s average surface temperature would rise if CO2 doubled its preindustrial level. In 2013, the Intergovernmental Panel on Climate Change (IPCC) estimated climate sensitivity to be within a range of 2 to 4.7 degrees Celsius. The Yale team’s estimate is much higher: between 5 and 5.3 degrees Celsius. Such an increase could have dramatic implications for climate change worldwide, note the...
‘Game Over’ for Climate? Report Warns Warming Is Still Underestimated

‘Game Over’ for Climate? Report Warns Warming Is Still Underestimated

SOURCE: CommonDreams.org DATE: 11/10/2016 SNIP: Greenhouse gases are rising so fast that it could soon be “game over” for the climate, a leading scientist warned in response to a new study published Wednesday that finds the planet could be heading for more than 7°C warming within a lifetime. The study, published in the journal Science Advances, reported that the United Nations’ most accurate estimates on the “business as usual” rate of global warming may actually be vastly underestimated. The U.N.’s Intergovernmental Panel on Climate Change (IPCC) recently estimated that continuing to use fossil fuels at current rates would put the Earth on track for an average temperature rise of 2.6°C to 4.8°C above pre-industrial levels by 2100. But the authors, a team of climate researchers and scientists at the University of Hawaii at Manoa, the University of Washington, the University of Albany, and the Potsdam Institute for Climate Impact Research, say the range for that same time period is actually 4.78°C to 7.36°C. That’s because the climate has “substantially higher sensitivity” to greenhouse gases during warm phases, they write—which ultimately means that “within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000...
A warm climate is more sensitive to changes in carbon dioxide

A warm climate is more sensitive to changes in carbon dioxide

SOURCE: Science Daily DATE: November 10, 2016 SNIP: A new study, published this week in Science Advances and led by Tobias Friedrich from the International Pacific Research Center (IPRC) at the University of Hawaii at Mānoa (UHM), concludes that warm climates are more sensitive to changes in CO2 levels than cold climates. The researchers project that by the year 2100, global temperatures will rise 5.9°C (~10.5°F) above pre-industrial values. This magnitude of warming overlaps with the upper range of estimates presented by the Intergovernmental Panel on Climate Change...
New research: climate may be more sensitive and situation more dire

New research: climate may be more sensitive and situation more dire

SOURCE: The Guardian DATE: Tuesday, July 5, 2016 AUTHOR: Dana Nuccitelli SNIP: “A recent study, Marvel et al 2015 and prior works suggest that cooling effect of non-CO2 pollution may have been underestimated. This also suggests that climate sensitivity is underestimated (since the net direct impact of human activity would be reduced, requiring a greater sensitivity to achieve the observed temperature change).” “The work that’s out there now, if anything, favours hotter models in general.” …when evaluating dangerous global warming, should we consider measured land-ocean temperatures, or faster-warming air temperatures? As Ed Hawkins notes, if we decide climate targets refer to the latter, it puts us about 24% closer to dangerous thresholds. Thus the climate situation may be even more, not less urgent than previously...