State of the Climate in 2010 is the latest instalment of an annual collection of climate observations from around the globe, edited at NOAA’s National Climatic Data Center and published in the Bulletin of the American Meteorological Society (BAMS). Its purpose is to document dozens of observed climate indicators which, when viewed together, provide a picture of the world’s climate system and our capacity to observe it.
Climate scientists around the world contribute articles about their own regions or areas of specialty and BAMS provides scientific peer reviewers for each chapter. More than 350 scientists from 45 countries contributed to State of the Climate in 2010. The full report runs to 220 pages. What follows is a summary of NOAA’s own 8-page summary. For the longer versions, go to http://www.ncdc.noaa.gov/bams-state-of-the-climate/2010.php
Major Events 2010
Flooding in Australia … Snowstorms in the eastern United States … The coldest winter in modern British history … during 2010, two of the world’s major climate patterns – the El Niño-Southern Oscillation and the Arctic Oscillation – drove many of the year’s most memorable weather events.
Searing heat in Russia … Floods in Pakistan … on the other hand, some events of 2010 had no apparent connection to large-scale climate patterns or trends, but were examples of unusual, extreme weather.
In the background of many unique events, long-term trends are visible in the data: despite snow and cold in some locations, tens of thousands of observations around the world combine to reveal a 2010 average global surface temperature among the two warmest years on record.
El Niño to La Niña
The transition from a warm El Niño climate pattern at the beginning of the year to a strong version of its cool sister pattern, La Niña, by July contributed to some unusual weather around the globe in 2010.
- Floods in Australia: Influenced by the La Niña climate pattern, Australia experienced its wettest spring (September–November) since record keeping began 111 years ago. In December, precipitation in Queensland was more than double the average amount.
- Quiet year for tropical cyclones, except in the North Atlantic: The La Niña pattern brought cooler temperatures to the tropical eastern Pacific Ocean in the second half of 2010. Since cyclones get energy from ocean heat, that cooler water helped give the Eastern Pacific an extremely quiet season.
- Global land and ocean surface temperatures among warmest ever recorded: Warm land and ocean surface temperatures worldwide in 2010 were due in part to the El Niño climate pattern that prevailed in the first half of the year.
The Arctic Oscillation
The Arctic Oscillation, an atmospheric climate pattern that affects large parts of the Northern Hemisphere, most often keeps colder air confined in northern latitudes. When it switches to its negative phase, as it did in 2010, this frigid air can flow out of the Arctic and contribute to unusually cold weather further south.
- Severe winter storms in the eastern United States: Unusually heavy snow blanketed the East Coast at the beginning and end of 2010.
- Cold winter in Europe: The strong negative Arctic Oscillation contributed to Britain’s coldest winter (December 2009–February 2010) since the winter of 1978/79. Britain also experienced its coldest December on record in 2010 as much of Europe was affected once again by the arctic weather.
- Ice growth in the Antarctic: Average sea ice volume in the Antarctic grew to an all-time record maximum in 2010. This buildup was related to a climate phenomenon known as the Southern Hemisphere Annular Mode.
- Heat wave in Russia: From late June through mid-August, Russia suffered from a searing heat wave. After 62 days of above-average heat, Russian officials attributed nearly 14,000 deaths to the unusual temperatures. This heat wave was caused by a persistent blocking pattern, which climate scientists do not currently see as part of any repeating climate pattern.
- Flooding in Pakistan: Floods at the end of July and beginning of August 2010 displaced more than 20 million Pakistanis and inundated a fifth of the country following heavy monsoon rains. Scientists analyzing climate indicators believe that this disaster was in part related to the same blocking pattern that contributed to the heat wave in Russia.
Even as the Earth is influenced by large-scale climate patterns, climate indicators continue to capture the march of underlying long-term trends, such as the steady increase in greenhouse gas concentrations.
- The world’s mountain glaciers lost mass for the twentieth consecutive year. Greenland’s glaciers lost more mass in 2010 than any other year on record.
- Levels of greenhouse gases in the atmosphere continued to rise. Carbon dioxide levels increased at a faster rate in 2010 than in 2009 and also faster than the average rate over the past 30 years.
- Sea levels continued to rise across the world’s oceans on average. Water expands as it warms and ocean heating is responsible for much of the sea-level rise; melting glaciers and ice sheets are responsible for the rest.