Lab climate expert is a lead author on the National Climate Assessment.
By the end of this century climate change will result in more frequent and more extreme heat, more drought, and fewer extremes in cold weather in the United States. Average high temperatures could climb as much as 10 or more degrees Fahrenheit in some parts of the country. These are some of the projections made by Lawrence Berkeley National Laboratory (Berkeley Lab) climate scientist Michael Wehner and his co-authors on the National Climate Assessment (NCA). (more…)
Berkeley Lab experts contribute to IPCC 5th Assessment Report.
Over the next century, most of the continents are on track to become considerably warmer, with more hot extremes and fewer cold extremes. Precipitation will increase in some parts of the world but will decrease in other parts. These are some of the conclusions reached by Lawrence Berkeley National Laboratory (Berkeley Lab) scientist Michael Wehner and his co-authors on the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).
Wehner, a climate scientist in Berkeley Lab’s Computational Research Division, and William Collins, head of the Lab’s Climate Sciences Department, were lead authors on the IPCC report’s chapters on long-term climate change projections and climate models, respectively. They are among more than 200 lead authors from more than 30 countries in IPCC’s Working Group I. Their report released today provides a comprehensive assessment of the physical science basis of climate change. (more…)
Computer Models, Satellite Data Reveal Clearest Evidence Yet of Human Influence on Changing Temperatures
New research shows some of the clearest evidence yet of a discernible human influence on atmospheric temperature.
Published online in the Nov. 29 early edition of the Proceedings of the U.S. National Academy of Sciences, the study compared 20 of the latest climate models against 33 years of satellite data. When human factors were included in the models, they followed the pattern of temperature changes observed by satellite. When the same simulations were run without considering human influences, the results were quite different.
“We can only match the satellite record when we add in human influences on the atmosphere,” said Michael Wehner, a research scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) Computational Research Division and a coauthor of the article, which involved colleagues from 16 other organizations and was led by Benjamin Santer, an atmospheric scientist at Lawrence Livermore National Laboratory (LLNL). (more…)
*Berkeley Lab scientists help automate the search for hurricanes and other storms in huge datasets*
You’d think that spotting a category 5 hurricane would never be difficult. But when the hurricane is in a global climate model that spans several decades, it becomes a fleeting wisp among mountains of data.
That’s a problem. As scientists develop ever-more sophisticated computer models to predict the effects of climate change, one of the things they’ll look for are changes in the frequency of extreme weather events such as hurricanes and heavy precipitation. The more data generated by models, however, the more difficult it is to quantify these rare but potent events. (more…)
*Berkeley Lab scientists part of team that analyzed 19 state-of-the-art climate models.*
While the worst drought since the Dust Bowl of the 1930s grips Oklahoma and Texas, scientists are warning that what we consider severe drought conditions in North America today may be normal for the continent by the mid-21st century, due to a warming planet.
A team of scientists from the Lawrence Berkeley National Laboratory (Berkeley Lab), Lawrence Livermore National Laboratory (LLNL), and the National Oceanic and Atmospheric Administration (NOAA) came to this conclusion after analyzing 19 different state-of-the-art climate models. Looking at the balance between precipitation and evapotranspiration—the movement of water from soil to air—they found that no matter how rainfall patterns change over the next 100 years, a warming planet leads to drought. Their results were published in the December 2011 issue of the American Meteorological Society’s Journal of Hydrometerology. (more…)
