John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Nine of the 10 hottest years on record all occurred after 2000, says NASA.
It can be difficult to conceive of the long process that's led the world to having its nine hottest years on record all after 2000. That's why it's nice that NASA has generated this nifty animation, which shows temperature abnormalities for every month of the past 13 decades. Watch reddish warm zones spread over the globe as time rolls past, like a virulent fever covering the body of a sick host.
The folks at NASA drop this model along with the bulletin that 2013, while cold for some, was overall the seventh-warmest year since 1880. (It tied with 2006 and 2009; the warmest are still 2005 and 2010.) The United States escaped much of the balminess – it was the 42nd warmest year on the books – but the heat-hammer dropped hard on places like Australia, which experienced its hottest year in known history (and continued to suffer into 2014). As if it's news, a NASA climatologist says: “Long-term trends in surface temperatures are unusual, and 2013 adds to the evidence for ongoing climate change."
The agency's scientists have formulated a rudimentary timetable for what kind of pain to expect in the future. They explain:
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....
It has been 38 years since the recording of a year with cooler than average temperatures.
If you like your evidence for climate change in non-moving form, there's also this new map showing what parts of the world have heated up the most. Warmer decade-by-decade temperature trends are shown in yellow; the dark-ochre areas represent places that have seen rises of as much as 0.5 Celsius in a decade:
Images courtesy of NASA