The World Meteorological Organization’s Statement on the Status of the Global Climate says that 2012 joined the ten previous years as one of the warmest — at ninth place — on record despite the cooling influence of a La Niña episode early in the year.
“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,” said WMO Secretary-General Michel Jarraud. “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% less than the previous record low of 2007 of 4.17 million km2 — was also a disturbing sign of climate change,” said Mr Jarraud. “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,” said Mr Jarraud.
WMO’s annual statements gather the key climate events of each year. The series stands today as an internationally recognized authoritative source of information about temperatures, precipitation, extreme events, tropical cyclones, and sea ice extent. The newly released statement provided in-depth analysis of regional trends as part of a WMO drive to provide more information at regional and national levels to support adaptation to climate variability and change.