January 20, 2014 at 11:49 am #4460
The water cycle amplifies abrupt climate change
During the abrupt cooling at the onset of the so-called Younger Dryas period 12680 years ago changes in the water cycle were the main drivers of widespread environmental change in western Europe. Thus, the regional impacts of future climate changes can be largely driven by hydrological changes, not only in the monsoonal areas of the world, but also in temperate areas.
The role of the hydrological cycle during abrupt temperature changes is of prime importance for the actual impact of climate change on the continents. In a new study published in Nature Geoscience online (January 19, 2014) scientists from the University of Potsdam, Germany and the GFZ German Research Centre for Geosciences show that during the abrupt cooling at the onset of the so-called Younger Dryas period 12,680 years ago changes in the water cycle were the main drivers of widespread environmental change in western Europe. The team of scientists analyzed organic remains extracted from Meerfelder maar lake sediments from the Eifel region, western Germany, to reconstruct changes in precipitation patterns in unprecedented detail. They were able to show that the intrusion of dry polar air into western Europe lead to the collapse of local ecosystems and resulted in the observed widespread environmental changes at that time.
Unchecked global warming ‘will double extreme El Niño weather events’
Research shows world’s most devastating global weather phenomenon will occur once a decade under current emissions scenario
The world’s most devastating global weather phenomenon – the weather events associated with “El Niño” – will double in frequency to once a decade if global warming remains unchecked, according to what scientists believe is a major step forward in the understanding of such events.
The last extreme El Niño, in 1997-98, resulted in the hottest year on record, and the accompanying floods, cyclones, droughts and wildfires killed an estimated 23,000 people and caused £21bn-£28bn in damage, particularly to food production.
“This is essentially an ‘irreversible’ climate change phenomenon, and it would take a dramatic reduction in greenhouse emissions over a number of generations to reduce the impact. It is even more evidence that cutting emissions would be a good idea.”
Previous work showed that the impacts of El Niño events appeared to double the risk of civil wars breaking out.
BP study: Greenhouse emissions will rise by almost a third in the next 20 years
BP predicts that global emissions will rise 29% by 2035. The Intergovernmental Panel on Climate Change says that emissions must peak by 2020 to give the world a chance to avoid a further two degrees of warming, beyond which the effects of climate change become catastrophic and irreversible.
Tony Bosworth, Friends of the Earth energy campaigner, said: “The case for shale gas is crumbling. Experts say it won’t lead to cheaper fuel bills, and now BP says it won’t cut carbon emissions either.
January 30, 2014 at 3:02 pm #4601
Insects may thrive in the warmer average temperatures predicted by climate models but are threatened by greater temperature variation also anticipated in many areas around the globe, a Yale-led study predicts in the Jan. 29 issue of the Proceedings of the Royal Society B of London.
“There has been some thought that many species will do better because of rising average temperatures,” said David Vasseur, associate professor of ecology and evolutionary biology, who headed the study. “But when coupled with greater temperature variations, the story changes.”
Scientists have tested the impact of temperature on 38 species of insects. Vasseur and researchers from eight other organizations coupled that data with historic climate data and climate projections for 2050 to 2059 in order to assess effects of temperature variability. When only mean temperature rise was considered, insects flourished, but “greater variation impacted them negatively,” Vasseur said.
The frequency of wide temperature swings will impact species like insects more than larger-bodied species with longer lifespans, he said. Also the study suggests effects of climate change on many species will vary greatly by locale.
“Global climate models predict many areas of temperate regions such as the central Midwest and much of Europe will experience more climate variation,” Vasseur said.
A number of floating ice shelves in Antarctica are at risk of disappearing entirely in the next 200 years, as global warming reduces their snow cover. Their collapse would enhance the discharge of ice into the oceans and increase the rate at which sea-level rises. A rapid reduction of greenhouse gas emissions could save a number of these ice shelves, researchers at Utrecht University and the British Antarctic Survey say in a new paper published today in the Journal of Glaciology.
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