Posted on February 1, 2015 by Bob Berwyn
Extreme heat events piling up in cities around the world
South American cities in particular have seen an increase in heat waves, according to a detailed new UCLA study that tracked climate more than 200 urban areas.
FRISCO — The world’s urban areas are shaping their own local climate by affecting regional wind fields, and that is resulting in more frequent heatwaves, researchers say, reporting a climate “double-whammy” of global warming and an intensifying urban heat island effect.
Human activities and the built environment trap heat and prevent cities from cooling down, said UCLA geography professor Dennis Lettenmaier.
“Everything’s warming up, but the effect is amplified in urban areas,” Lettenmaier said after studying 217 urban areas across the globe and finding that prolonged periods of extreme heat increased significantly in 48 percent of them between 1973 and 2012. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: climate change, extreme weather, global warming impacts, heatwaves, Urban heat island | 1 Comment »
Posted on January 31, 2014 by Bob Berwyn
Higher summer spikes could mean more destructive storm surges
Researchers have documented changes in the annual cycle of sea level changes along the Florida Gulf Coast. bberwyn photo.
By Summit Voice
FRISCO — Annual sea level fluctuations have been intensifying along parts of the Gulf Coast, raising concerns about more hurricane flooding and impacts to delicate coastal ecosystems in the region.
There have always been seasonal fluctuations in sea level, which rise in summer and fall in winter. But a new study shows that, from the Florida Keys to southern Alabama, those cycles have amplified in the past 20 years.
The additional summer sea level rise during the past two decades means storm surges can rise higher than previously thought, according to Thomas Wahl, a postdoctoral researcher from the University of Siegen in Germany who is working at the University of South Florida in St. Petersburg and lead author of the study. Continue reading
Filed under: climate and weather, Environment | Tagged: climate, Florida, global warming impacts, Gulf Coast, sea level | Leave a comment »
Posted on October 29, 2013 by Bob Berwyn
Changes in the Arctic likely to have widespread hemispheric impacts
By Summit Voice
FRISCO — A new climate study by scientists at the University of Exeter (UK) adds to the growing body of research looking at the hemispheric impacts of dwinding Arctic sea ice.
The findings suggest that that the loss of ice shifts the jet stream farther south, bringing increased summer rainfall to northwestern Europe, but drier conditions to the Mediterranean region. The study could offer an explanation for the extraordinary run of wet summers experienced by Britain and northwest Europe between 2007 and 2012.
In another recent study, scientists with the Cooperative Institute for Research in Environmental Science found that as sea ice disappeared, the areas of relatively warm open water began to strongly influence the atmosphere, increasing surface temperatures in the region, and shifting low- and high-pressure zones around most markedly in the fall and winter.
And a NOAA study found Arctic warming has shifted the normal west-to-east flowing upper-level winds to a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: Arctic sea ice, extreme weather, global warming impacts, Jet stream | 1 Comment »
Posted on September 1, 2013 by Bob Berwyn
Fruit trees in mid-latitudes could face more pressure as global warming drives the spread of pests. bberwyn photo.
Trend poses food security threat
By Summit Voice
FRISCO — As global temperatures continue to rise, plant-killing pests are spreading toward the poles at the rate of almost two miles per year, posing a potential threat to food production in the world’s temperate crop–producing areas.
“If crop pests continue to march polewards as the Earth warms, the combined effects of a growing world population and the increased loss of crops to pests will pose a serious threat to global food security,” said Dr, Dan Bebber, of the University of Exeter.
Bebber and his colleagues carefully studied insect populations and climate trends, finding a strong relationship between increased global temperatures over the past 50 years and the expanding range of crop pests. The research was published Sept. 1 in Nature Climate Change. Continue reading
Filed under: agriculture, climate and weather, global warming | Tagged: agriculture, climate change, Environment, Food security, global warming, global warming impacts | Leave a comment »
Posted on December 18, 2012 by Bob Berwyn
University of Tennessee researchers say the eastern U.S. can expect more heatwaves and increased precipitation in a warming world. Image courtesy NASA.
New climate model pinpoints predictions down to the city level
By Summit Voice
SUMMIT COUNTY — As climate models become more sophisticated, researchers have started to fine-tune global warming impacts to the regional level, including more drought and water shortages expected in the Southwest, seasonal ice-free conditions in the Arctic, and hotter, wetter conditions in the Eastern U.S., according to a new University of Tennessee study.
The researchers, Joshua Fu, a civil and environmental engineering professor, and Yang Gao, a graduate research assistant, say heat waves will become more severe in most regions of the eastern United States and, that both the Northeast and Southeast will see a drastic increase in precipitation. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: climate change, East Coast, extreme weather, global warming impacts, IPCC, National Center for Atmospheric Research | Leave a comment »