Latest Climate model Stories
The melting of Arctic sea ice may temporarily stabilize, and the ice may even expand, over the coming years, according to new research by scientists at the National Center for Atmospheric Research (NCAR). "As we learn more about climate variability, new and unexpected research results are coming to light," said Sarah Ruth, program director in the Division of Atmospheric and Geospace Sciences, which funds NCAR."What's needed now are longer-term observations to better understand...
The latest evidence of the dominant role humans play in changing Earth's climate comes not from observations of Earth's ocean, atmosphere or land surface, but from deep within its molten core.Scientists have long known that the length of an Earth day - the time it takes for Earth to make one full rotation - fluctuates around a 24-hour average. Over the course of a year, the length of a day varies by about 1 millisecond, getting longer in the winter and shorter in the summer. These seasonal...
A new analysis of the Northern Hemisphere's "albedo feedback" over a 30-year period concludes that the region's loss of reflectivity due to snow and sea ice decline is more than double what state-of-the-art climate models estimate.The findings are important, researchers say, because they suggest that Arctic warming amplified by the loss of reflectivity could be even more significant than previously thought.The study was published online this week in Nature Geoscience. It was funded...
NASA said on Tuesday that plants could grow larger and create a cooling effect on a warming globe due to more carbon dioxide in the atmosphere. One of the mysteries scientists face with climate change is how to predict it over time, or more specifically how to account for Earth's reaction to warmer temperatures. It has long been known that plants are able to adapt to higher carbon dioxide levels by using nutrients more efficiently and growing bigger leaves. "The process is called...
Clouds play a major role in the climate-change equation, but they are the least-understood variable in the sky, observes a Texas A&M University geoscientist, who says mid-level clouds are especially understudied. The professor, Shaima Nasiri, is making those "in-between" clouds the focus of her research, which is being funded by NASA.Mid-level clouds are so understudied, Nasiri says, that scientists have yet to develop a common nomenclature for them. "We do not have a...
Current state-of-the-art global climate models predict substantial warming in response to increases in greenhouse gases such as carbon dioxide. The models, though, disagree widely in the magnitude of the warming we can expect. The disagreement among models is mainly due to the different representation of clouds. Some models predict that global mean cloud cover will increase in a warmer climate and the increased reflection of solar radiation will limit the predicted global warming. Other...
U.S. and British meteorologists said on Monday that not only is Earth's surface warming, but the troposphere is heating up also. The scientists found that warming in this key atmospheric layer was occurring, just as many researchers expected as more greenhouse gases build up and trap heat close to the Earth. This study put to rest a controversy that began 20 years ago when a 1990 scientific report raised questions about whether the troposphere was warming, even as Earth's surface temperatures...
Wildfires may seem like a fixed and unchanging force of nature. They're not. Over long time scales, research has shown that both the climate and humans have a profound effect on wildfire activity around the globe. Now new NASA research shows that while we have been suppressing this natural force for the past century, we may be, inadvertently, about to put nature back in control.Charcoal layers in sediments and methane concentration in ice cores show that the amount of global burning can...
As a result of global warming, much of the Western Hemisphere, as well as large sections of Europe, Asia, Africa, and Australia, face the threat of an extreme drought within the next three decades, experts from the National Center for Atmospheric Research (NCAR) claim in a new report.The study, which was conducted by NCAR scientist Aiguo Dai, analyzed 22 computer climate models, an index of drought conditions, and previously published works from other scientists and determined that extremely...
Water vapor and clouds are the major contributors to Earth's greenhouse effect, but a new atmosphere-ocean climate modeling study shows that the planet's temperature ultimately depends on the atmospheric level of carbon dioxide.The study, conducted by Andrew Lacis and colleagues at NASA's Goddard Institute for Space Studies (GISS) in New York, examined the nature of Earth's greenhouse effect and clarified the role that greenhouse gases and clouds play in absorbing outgoing infrared radiation....
