jet stream

Killer Heat Waves and Floods Linked to Climate Change

Stephen 1 Must Read, Alaska, arctic, CANADA, CLIMATE CHANGE/GLOBAL WARMING, Energy, ENVIRONMENT, Global Issues and Perspectives, global warming, News, OCEAN, Science , , , , , , , , , , , , , , , , , , , ,
More than 5 million affected by flooding in Pakistan Sept 2011 - a repeat of 2010.
More than 5 million affected by flooding in Pakistan Sept 2011 – a repeat of 2010.

“The first law of humanity is not to kill your children.”

By Stephen Leahy

UXBRIDGE, Canada, Feb 27 2013 (IPS)

Killer heat waves, floods and storms are increasingly caused by climate change, new research reveals.

Scientists in Germany say they have found how greenhouse gases from burning fossil fuels are helping to trap the jet stream, resulting in extraordinary weather such as the 2010 Pakistan flood and the 2011 heat wave in the United States.

Human-driven climate change repeatedly disturbs the flow of atmospheric waves around the globe’s Northern hemisphere, said lead author Vladimir Petoukhov of the Potsdam Institute for Climate Impact Research (PIK) in Germany.rossby.waves1_

Giant atmospheric waves called Rossby waves are meanders in the strong, high-altitude winds known as jet streams and have a major influence on weather. These wave movements are caused by the difference in temperatures between the cold air from the Arctic and hot air from the tropics.

When the waves shift north, they suck warm air from the tropics to Europe, Russia, or the U.S., and when they swing down, they do the same thing with cold air from the Arctic, said Petoukhov.

“During several recent extreme weather events, these planetary waves almost freeze in their tracks for weeks,” he said. “So instead of bringing in cool air after having brought warm air in before, the heat just stays.”

This unnatural pattern is due to human heating of the climate through emissions of greenhouse gases that result from burning fossil fuels, according to the study published this week in Proceedings of the National Academy of Sciences.

However, this heating of the atmosphere is wildly uneven. The Arctic is warming two to three times faster than the global temperature rise of 0.8C and that affects the Rossby waves and is slowing the jet stream.

“(Our research) complements previous research that already linked such phenomena to climate change,” said Hans Joachim Schellnhuber, a co-author of the study. Continue reading →

Ice-Free Arctic Is “Uncharted Territory”

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Arctic sea ice extent. Area of ocean with at least 15 percent sea ice as of Sept 12, 2012. Credit: National Snow and Ice Data Center.

Arctic ice half of what it was 30 years ago. Now affecting weather patterns

Heading for +4C and catastrophe – CBD

By Stephen Leahy

UXBRIDGE, Canada, Sep 20 2012 (IPS)

The melt of Arctic sea ice has reached its lowest point this year, shrinking 18 percent from last year’s near-record low.

Summer ice this year is half what it was 30 years ago and is now affecting weather patterns. The massive declines in ice in recent summers have shocked scientists and Arctic experts. Some predict that in just a few years we will witness an event that hasn’t happened in millions of years: the complete loss of summer ice.

“We are now in uncharted territory,” said Mark Serreze, director of the National Snow and Ice Data Center (NSIDC) in Colorado.

“Few of us were prepared for how rapidly the changes would actually occur” as a result of the burning fossil fuels that are warming the planet, said Serreze.

“We could see an essentially ice-free Arctic ocean in late summer by the year 2030,” he told IPS.

Not long ago experts thought the soonest the Arctic would be ice-free was 2070. Now it’s anywhere from four to 18 years away.

The impacts are already being felt across the entire northern hemisphere. The loss of sea ice in recent years has been affecting weather patterns, recent research has shown. The all-important jet stream – the west-to-east winds that are the boundary between the cold Arctic and the warm mid-latitudes – is slowing down, moving north and become more erratic.Measurement of CO2 levels in atmosphere

“Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic,” said James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States.

“In future, cold and snowy winters will be the rule rather than the exception” in these regions, Overland told IPS in Oslo in 2010.

The summer’s record loss of Arctic sea ice may mean a cold winter for the UK and northern Europe, Jennifer Francis, a researcher at Rutgers University, told the Guardian last week.

The region has been prone to bad winters after summers with very low sea ice, such as 2011 and 2007, Francis said. Continue reading →