World’s top meteorological body concerned about global trends
By Summit Voice
FRISCO —Climate-sensitive economic sectors like agriculture and energy are already feeling the pinch of more extreme fluctuations in the weather, driven by global climate change, according to the World Meteorological Organization, which released its annual climate statement for 2012 last week.
“It is vital that we continue to invest in the observations and research that will improve our knowledge about climate variability and climate change,” said WMO Secretary-General Michel Jarraud. “We need to understand how much of the extra heat captured by greenhouse gases is being stored in the oceans and the consequences this brings in terms of ocean acidification and other impacts,” Jarraud said in the statement.
“We need to know more about the temporary cooling effects of pollution and other aerosols emitted into the atmosphere. We also need a better understanding of the changing behaviour of extreme weather and climate events as a consequence of global warming, as well as the need to assist countries in the most affected areas to better manage climate-related risks with improved climate early warning and climate watch systems,” he added.
Citing climate records compiled by NASA, NOAA and other climate and weather agencies, the WMO confirmed 2012 as the ninth-warmest year on record, even with the global cooling influence of La Niña in the first part of 2012.
According to the WMO, the global land and ocean surface temperature during January–December 2012 was estimated at about .45 degrees Celsius above the 1961 to 1990 average, making it the 27th year in a row with above average temperatures. Every year since 2001 have been in the top 13 warmest years on record.
“Although the rate of warming varies from year to year due to natural variability caused by the El Niño cycle, volcanic eruptions and other phenomena, the sustained warming of the lower atmosphere is a worrisome sign,” Jarraud said. “The continued upward trend in atmospheric concentrations of greenhouse gases and the consequent increased radiative forcing of the Earth’s atmosphere confirm that the warming will continue,” he said.
“The record loss of Arctic sea ice in August-September — 18 percent less than the previous record low of 2007 of 4.17 million km2 — was also a disturbing sign of climate change. “The year 2012 saw many other extremes as well, such as droughts and tropical cyclones. Natural climate variability has always resulted in such extremes, but the physical characteristics of extreme weather and climate events are being increasingly shaped by climate change,” he said.
“For example, because global sea levels are now about 20 cm higher than they were in 1880, storms such as Hurricane Sandy are bringing more coastal flooding than they would have otherwise.”
Above-average temperatures were observed during 2012 across most of the globe’s land surface areas, most notably North America, southern Europe, western Russia, parts of northern Africa and southern South America. Nonetheless, cooler-than-average conditions were observed across Alaska, parts of northern and eastern Australia, and central Asia.
Precipitation across the globe was slightly above the 1961-1990 long-term average. There were drier-than-average conditions across much of the central United States, northern Mexico, northeastern Brazil, central Russia, and south-central Australia. Wetter-than-average conditions were present across northern Europe, western Africa, north-central Argentina, western Alaska, and most of northern China.
Snow cover extent in North America during the 2011/2012 winter was below average, resulting in the fourth smallest winter snow cover extent on record, according to data from the Global Snow Laboratory. This was in marked contrast to the previous two winters (2009/2010 and 2010/2011), which had the largest and third largest snow cover extent, respectively, since records began in 1966.
Meanwhile, the Eurasian continent snow cover extent during the winter was above average, resulting in the fourth largest snow cover extent on record. Overall, the northern hemisphere snow cover extent was above average – 590000 km2 above the average of 45.2 million km2 – and was the fourteenth largest snow cover extent on record.
Antarctic sea-ice extent in March was the fourth largest on record at 5.0 million km2 or 16.0 per cent above the 1979–2000 average. During its growth season, the Antarctic sea-ice extent reached its maximum extent since records began in 1979 on 26 September, at 19.4 million km2. This value surpassed the previous maximum sea-ice extent record of 19.36 million km2 set on 21 September 2006.