2005 Warmest Year on Record

A recent study reports that 2005 was either the warmest or tied for the warmest year ever recorded. The NASA Goddard Institute for Space Studies (GISS) reports that over the last 30 years, global temperatures have increased about 1 degree Fahrenheit (0.6 degrees Celsius).

Over the past 100, temperatures have increased about 1.4 degrees Fahrenheit (0.8 degrees Celsius).

Using records from land-based weather stations and ship and satellite measurements of sea-surface temperature, the GISS team compiled a map showing temperature anomalies relative to the 1951-1980 average. Colors ranging from yellow to red indicate warmer-than-average anomalies, and colors ranging from green to purple indicate cooler-than-average anomalies. Most of the map shows warm colors, and temperatures are particularly warm in the Arctic and in south-central Africa. Areas of white indicate no deviation from the mean.

The measurements have a range of uncertainty, and the "real" average global temperature may be a little above or below the reported value. The range of uncertainty for 2005 temperatures overlaps with that of 1998, which means the two years are vying closely for the position of "warmest year on record."

Although these years were very close in temperature, they reached the top of the charts by different means. In 1998, the strongest El Niño in a century occurred. El Niños result in unusually warm temperatures in the eastern Pacific Ocean, and this warmth is significant enough to elevate overall global temperatures. No El Niño occurred in 2005, however, which means that 2005 reached the same record-high temperature as 1998 without the aid of an El Niño.

--LiveScience Staff

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Credit: NASA Goddard Institute for Space Studies