2013 Continues 37-Year Warm Streak

The numbers have been crunched and the results are in: 2013 did not buck the trend of climate change. Last year sailed to the number four slot of the world's hottest years on record, the 37th year of above-average temperatures in a row.

According to the National Oceanic and Atmospheric Administration, “The year 2013 ties with 2003 as the fourth warmest year globally since records began in 1880. The annual global combined land and ocean surface temperature was 0.62°C (1.12°F) above the 20th century average of 13.9°C (57.0°F).” That's a small increase, sure, but it's part of a much longer background trend of increasing global temperatures, which scientists have been watching for decades.

The warming anomaly of 2013 was actually a bit stronger when narrowed down to temperatures over land: “The 2013 global average land surface temperature was 0.99°C (1.78°F) above the 20th century average of 8.5°C (47.3°F)," says NOAA. The ocean is a huge energy sink, so it's harder to heat up the air over the water. The 2013 over-land temperature was also the fourth highest on record.

Using a slightly different measurement technique, says Climate Central, NASA pegged 2013 as the seventh hottest year. “The agencies use different methods for analyzing temperature data, resulting in different rankings, but the numbers behind the rankings are within fractions of a degree of one another, said Gavin Schmidt, a NASA climatologist.” This difference is, really, pretty irrelevant in a 133-year record. It's definitely getting hotter.

All 13 years of the 21st century have ranked among the 15 warmest in the 134-year period of record, with the top three being 2010, 2005, and 1998. Even considering the margin of error, NOAA said that 2013 was “more likely than not” among the top 5 warmest years on record.

Put another way, to date, nine of the 10 warmest years on record since 1880 have occurred during the past decade, and only one year in the 20th century — 1998 — was warmer than 2013.

The Associated Press science reporter Seth Borenstein gave yet another way of thinking about it:

In 1988, Hansen testimony put global warming in news: '88 was hottest year on record at time. Now 2013 just pushed 1988 out of top 20

— seth borenstein (@borenbears) January 21, 2014

And, yes, says NASA's Earth Observatory, the warm year is our fault:

Weather patterns and other natural cycles cause fluctuations in average temperatures from year to year... Regardless of the regional differences in any year, continued increases in greenhouse gas levels in Earth’s atmosphere are driving a long-term rise in global temperatures. Each calendar year will not necessarily be warmer than the year before. But with the current level of greenhouse gas emissions, scientists expect each decade to be warmer than the previous one.

Colin Schultz | | READ MORE

Colin Schultz is a freelance science writer and editor based in Toronto, Canada. He blogs for Smart News and contributes to the American Geophysical Union. He has a B.Sc. in physical science and philosophy, and a M.A. in journalism.