While Americans deal with a wintery January and try to understand what a polar vortex is, one thing is clear: 2013 was one of the ten hottest years since records began in 1880. For the 37th consecutive year, global temperatures were higher than average.
The National Oceanic and Atmospheric Administration (NOAA) reported Tuesday that 2013 was tied with 2003 as the fourth-warmest year since records began in 1880 — annual land and ocean surface temperatures were 0.62°C (1.12°F) higher than average. The National Aeronautics and Space Administration (NASA) reported that along with 2009 and 2006, 2013 was tied for the seventh-warmest year on record, “continuing a long-term trend of rising global temperatures.” NASA used essentially the same data — it just processes it slightly differently than NOAA does. Indeed, the difference between 4th place and 7th place is just two-hundredths of a degree. NASA had the “temperature anomaly” — how much the global temperature deviated from the average — pegged at 0.60°C and NOAA had 0.58°C.
The data from 2013 is just one report, but it is another data point in a trend that people can expect as the atmosphere gets more and more filled with increasing amounts of heat-trapping greenhouse gases. Gavin Schmidt, Deputy Chief at NASA GISS, told reporters on a conference call Tuesday that “long-term trends in climate are extremely robust — there is year-to-year variability, there is season-to-season variability, there are times such as today, when we can have snow, even in a globally warmed world.”
“But the long-term trends are very clear, they’re not going to disappear, and people should be aware of that,” Schmidt said. He cautioned against allowing short memories and cold snaps to get in the way of the data.
Though cold weather might help people lose weight, it does not help them understand the reality of long-term trends like climate change. Studies in recent years have found that colder days make people less likely to be concerned about — and acknowledge — global warming.
Where was the extra warmth in 2013 concentrated? Almost everywhere except the middle of North America and parts of the Pacific Ocean. This map shows how observed temperatures in 2013 compared to the 1951-1980 average:
A map of where these hot and cold temperature anomalies occur can help give a picture of what is happening on a global scale, and just how odd it was for parts of North America to be colder than normal. Much of the rest of the globe had blooms of reds and pinks, signifying hotter-than-average temperatures.
Watching a video that puts six decades of these maps in one constant flow shows quite clearly the warming trend facing everyone on Earth, even if some parts experience periodic cold snaps:
NASA’s Schmidt said that “the warmth that we’ve seen in the last decade clearly makes this decade the warmest in the historical period.” Videos like this help bring a trend like that to life. The complete year-by-year animation of 1880-2013 takes longer, but can be viewed here.
The geographic breakdown shows that recent warming has been concentrated in parts of the Arctic, Australia, South America, and large swaths of Asia and Africa. Many of these areas experienced record warms. January 2013 was the hottest month ever observed in Australia — last summer was the hottest one ever, followed by the third-warmest winter and warmest-ever spring. Despite some slightly colder-than-average periods in the middle of North America and over the Southern Pacific Ocean, not one region of the globe experienced record colds.
Even still, most of North America experienced warmer-than-average temperatures. Alaska had its second-warmest summer on record. Mexico had its hottest summer on record.
This trapped energy in the atmosphere does not just manifest as heat, it also affects the water cycle. Areas that tend to be wet often get wetter, because the heat allows the air to hold more moisture, increasing the strength of precipitation events. Dry areas, as they get hotter, yield more and more of their trapped moisture to evaporation, which often gets blown away, sometimes worsening droughts. In 2013, precipitation was close to average on the whole for the globe, but this fact can hide how some regions experienced record drought and some saw record flooding.
In addition to the massive flash floods on Colorado’s Front Range, many parts of the world experienced damage from extended precipitation or flash floods of their own, including: the coast of Queensland, Australia; La Plata, Argentina; Mozambique and Mali; Germany, Poland, Czech Republic, Austria, and Switzerland; Northwest India and Nepal; the Russian-Chinese border, and much of Mexico. Higher-than-average snowfall hit Moscow, Russia, the United Kingdom, Israel, Lebanon, and Jordan.
Other parts of the planet had a lot less water than normal, and suffered serious and sometimes record droughts, including: Northeastern Brazil, large parts of the Amazon Basin, and the Brazilian Plateau; the Marshall Islands; New Zealand; Angola and Namibia; Southern China, and parts of California.
Another remarkable thing about 2013’s heat is that there was no El Nino — a long-term weather pattern that results in periodic warming of the equatorial Pacific region. Gavin Schmidt said Tuesday that that the long-term trends caused by an increase in greenhouse gases will continue whether there is an El Nino or a La Nina. La Nina years are going to be slightly cooler than normal, El Nino years are going to be slightly warmer than normal. 2013 was one of the warmest neutral years (not a strong El Nino or La Nina) on record.
James Hansen, now an adjunct professor at Columbia University (and formerly head of the NASA Goddard Institute for Space Studies) noted that because of the likelihood of a strong El Nino this year, 2014 or 2015 would probably see another global temperature record.