Tuesday, August 6, 2013

Climate report warns extreme weather events are now the norm

By North America correspondent Ben Knight

ABC News Online, 7 August 2013

Climate scientists in the United States say extreme weather events and warming temperatures are the new norm.

The American Meteorological Society has released its annual snapshot of the world's climate, which concludes disastrous weather events like Hurricane Sandy in the US and droughts and floods in Australia, Africa and South America will become more frequent.

The report lists a raft of indicators that show a continuously warming planet where ice sheets and glaciers will keep shrinking, and sea and land temperatures will keep rising to record levels.

2012 was a record-breaking year for the world's climate, with new extremes for sea levels, temperatures, snow coverage and ice melts.

Arctic ice levels reached record lows in 2012, and the polar region is warming at twice the rate of the rest of the planet, however on a positive note at the other end of the world, Antarctica's climate remained relatively stable and sea ice cover reached a record maximum.

The report also stated the world's highest levels of greenhouse gases were released by burning fossil fuels last year.

384 scientists from 54 countries contributed to the report, covering all aspects of the planet, from the depths of the oceans to the stratosphere.

Last year was among the top 10 on record for global land and surface temperature since modern data collection began.

Key Points

  • Extreme weather to become the norm: hurricanes and floods
  • Ice sheets and glaciers to keep shrinking
  • Sea and land temperatures to keep rising to record levels
  • The world to become warmer
  • More droughts and unusual rains expected

'Planet as whole becoming warmer place'

"The findings are striking," Kathryn Sullivan, acting administrator of the National Oceanic and Atmospheric Administration (NOAA) told AFP.

"Our planet as a whole is becoming a warmer place."

"It's hard to read the report and not be led to the conclusion that the task of reducing carbon emissions is now more urgent than ever," Michael Mann, a leading US climatologist at Pennsylvania State University who was not involved in the research, said.

Globally, according to four independent analyses cited by the study 2012 ranked as the eighth or ninth warmest year since records began in the mid-to-late 1800s.

"Surface temperatures in the Arctic are increasing at a rate about two times faster than the rest of the world," Jackie Richter-Menge, research civil engineer with the US Army Corps of Engineers, said.

Meanwhile, permafrost temperatures reached record highs in northern Alaska and 97 per cent of the Greenland ice sheet showed some form of melt, four times greater than the average melt for this time of year.

The melt is also contributing to rising sea levels.

Average global sea level reached a record high in 2012, 3.5 centimetres above the 1993 to 2010 average.

"Most recently, over the past seven years or so, it appears that the ice melt is contributing more than twice as much to the global sea level rise compared with warming waters," Jessica Blunden, climatologist at NOAA's National Climatic Data Center, said.

Scientists say the data should be of concern to people living in coastal areas and that weather patterns from the past can no longer be used to predict the future.

The peer-reviewed report did not go into the causes for the trends but experts said it should serve as a guide for policymakers as they prepare for the effects of rising seas and warming weather on communities and infrastructure.

The amount of carbon dioxide emissions from burning fossil fuels also hit new highs, after a slight decline in recent years that followed the global financial crisis.

For the first time, in Spring 2012, the atmospheric CO2 concentration exceeded 400 parts per million (ppm) at seven of the 13 Arctic observation sites, the report said.

Global average carbon dioxide reached 392.6 ppm, a 2.1 ppm increase from 2011, it said.

Droughts and unusual rains struck different parts of the globe last year and the the worst drought in the past three decades was noted in north-eastern Brazil.

The Caribbean observed a very wet dry season and the Sahel had its wettest rainy season in 50 years, according to the report.

Dr Sullivan said the findings, "caution us, perhaps, to be looking at a likely future where extremes and intensity of some extremes are more frequent and more intense than what we have accounted for in the past."


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