Figure 1: Source: NOAA.
The 2009 State of the Climate report released today draws on data for 10 key climate indicators that all point to the same finding: the scientific evidence that our world is warming is unmistakable. More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.
Based on comprehensive data from multiple sources, the report defines 10 measurable planet-wide features used to gauge global temperature changes. The relative movement of each of these indicators proves consistent with a warming world. Seven indicators are rising: air temperature over land, sea-surface temperature, air temperature over oceans, sea level, ocean heat, humidity and tropospheric temperature in the “active-weather” layer of the atmosphere closest to the Earth’s surface. Three indicators are declining: Arctic sea ice, glaciers and spring snow cover in the Northern hemisphere.
The entire document is here.
The authors of the report said people shouldn’t draw conclusions that all is well from periods of cool weather.
“A warming climate will still have cold spells, though they will become less frequent and less intense,” according to another NOAA statement. “For example, in the winter of 2009- 2010, a warm air mass moved into Canada and pushed cold air south. Canadians experienced a mild winter, but the mid-Atlantic coast of the United States was extremely cold and snowy.”
While snow records were set in the U.S. from Dallas to New York, the rest of the Northern Hemisphere had “one of the warmest winters on record,” the agency said.
More than 300 authors from 48 countries contributed to the report, according to a NOAA statement.
The data came from more than 7,000 weather stations, according to the report. The editors for the report come from the National Climatic Data Center, and the American Meteorological Society provides scientific reviewers and publishes it.
Update: 7/29, 8:14 Pacific: