What is the average global temperature now?
Climatologists prefer to combine short-term weather records into long-term periods (typically 30 years) when they analyze climate, including global averages. Between 1961 and 1990, the annual average temperature for the globe was around 57.2°F (14.0°C), according to the World Meteorological Organization. According to estimates by the World Meteorological Organization, in 2008 that the global temperature was about 0.56°F (0.31°C) above that long-term average. Why are global temperatures usually expressed this way—as a departure from normal, instead of a simple global temperature? One reason is that there are several different techniques for coming up with a global average, depending on how one accounts for temperatures above the data-sparse oceans and other poorly sampled regions. Since there is no universally accepted definition for Earth’s average temperature, several different groups around the world use slightly different methods for tracking the global average over time. The import
The average air temperature near Earth’s surface in 2006 was estimated by the World Meteorological Organization to be about 57.9°F (14.4°C) as of December 14, 2006. • How much has the global temperature risen in the last 100 years?Averaged over all land and ocean surfaces, temperatures have warmed about 1.35°F (0.75ºC) over the last century. Much of this warming—about 0.72°F (0.4°C)—has occurred since 1979. Because oceans tend to warm and cool more slowly than land areas, continents have warmed the most (about 0.7ºC or 1.26°F since 1979), especially over the Northern Hemisphere. • How much carbon dioxide (and other kinds of greenhouse gas) is already in the atmosphere? One of the strongest pieces of evidence for human-induced climate change is the consistent rise in carbon dioxide (CO2) in modern times, as measured at the Mauna Loa Observatory in Hawaii, where CO2 has been observed since 1958. As of 2005, the concentration of CO2 in Earth’s atmosphere was about 378 parts per million (p
