Extremes abound in the "State of the Climate 2012" report.
Here are some of them and other findings in the 258-page report by the American Meteorological Society:
- Large-scale climate patterns and extreme weather events affected various regions. A negative phase of the Arctic Oscillation from mid-January to early February contributed to frigid conditions in parts of northern Africa, eastern Europe and western Asia.
- A lack of rain during the wet season led to the worst drought in at least three decades in northeastern Brazil. Central North America also experienced one of its most severe droughts on record.
- The Caribbean had a very wet dry season and it was the Sahel’s wettest rainy season in 50 years.
- The temperature across global land and ocean surfaces in 2012 ranked among the 10 warmest years on record. The average stratospheric temperature was record or near-record cold.
- Heat in the upper 700 meters of the ocean remained near record high levels.
- Sea levels reached record highs.
- Global tropical cyclone activity was near average, with 84 storms compared with the average of 89 for 1981 to 2010. Similar to 2010 and 2011, the North Atlantic was the only hurricane basin that had above-normal activity. Hurricane Sandy brought devastation to Cuba and parts of the eastern North American seaboard.
- Super Typhoon Bopha became the only storm on record to produce winds greater than 130 knots south of 7 degrees north. It was also the costliest storm to affect the Philippines and killed more than 1,000 residents.
- Minimum Arctic sea ice in September and Northern Hemisphere snow cover in June both hit new record lows. June snow cover is declining at a faster rate (17.6 percent per decade) than September sea ice (decreasing 13 percent a decade).
- Permafrost temperatures reached record highs in northernmost Alaska. A new melt record took place on July 11-12 on the Greenland ice sheet, with 97 percent of it showing some form of melt. That's four times greater than the average melt for that time of year.
- In the stratosphere, warm air led to the second smallest ozone hole in the past two decades. Still, the springtime ozone layer above Antarctica likely will not return to its early 1980s state until about 2060.
- Atmospheric carbon dioxide levels increased by 2.1 parts per million to 392.6 ppm. In spring 2012, the level exceeded 400 ppm at seven of 13 Arctic observation sites for the first time.
- Globally, levels of other greenhouse gases, including methane and nitrous oxide, also continued to rise. The combined effect now represents a 32 percent increase in radiative forcing compared with in 1990.
