Adios to 2012 and hello to lucky number 13. Where did climate take us in 2012 and what can we expect for the next 12 -- scratch that, 11 -- months?
I've been writing these year-end climate recaps for four whole years and now they've gotten a whole lot easier, thanks to the NCDC's new ranking of the top climate and weather events of the past year. (You can just skip the rest of this blog and go straight to their list here.)
Even though climate is more than just temperature, that's the place you gotta start. How did 2012 stack up? For us myopic Americans, it was indeed a big year -- the warmest year on record for the continental U.S. That's a big deal. But, shocking as it may seem, the rest of the world does factor in, too, so to get the full picture, we've got to look at the global average.
(Still need proof that there's a world outside our borders? YouTube's top music videos of the year give us indisputable evidence: "Gangnam Style" by South Korean artist PSY -- and did you know Carly Rae Jepsen of "Call Me Maybe" fame is Canadian? Although IMHO the best knock-offs of both were American, from NASA and the Harvard baseball team, respectively.)
Back to temperature and how 2012 stacks up. There are three groups that calculate global temperature. Each of them do it a little differently (Climate Central has a great look at how their techniques vary here), so the results are never quite the same. Taken together, though, they give a good picture of the planet's temperature. NOAA puts 2012 as No. 10 on the hottest years ranking, while NASA and the UK Met Office put it at No. 9.
This makes every year in the 21st century among the 14 warmest years on record. We've closed out the warmest decade on record and we're now embarking on another one, likely to be warmer than the last. This fact is important because climate change only truly emerges in the multi-year to decades range; individual years themselves are still subject to the influence of weather patterns.
The main weather pattern I'm referring to that affects global temperatures is El Niño, more accurately called ENSO when you include the atmosphere component of the Southern Oscillation. ENSO is a multi-month to year fluctuation in ocean temperatures and weather patterns across the equatorial Pacific Ocean that affects temperature and precipitation worldwide. 2012 was largely a La Niña year, which tends to cooler temps than El Niño. 2012 was also notably the warmest La Niña year on record, beating out the previous record for a La Niña year of just the year before.
Getting beyond temperature, there are also some pretty impressive climate and weather events of the last year. The top three on the NCDC list will probably be familiar to all:
Arctic sea ice minimum: In September, the area covered by sea ice in the Arctic reached its lowest extent ever recorded -- 49 percent less than the 1979 to 2000 average. This minimum (with ice loss equal to the area of the U.S. and Mexico combined) impacts not just Arctic ecosystems but also international trade with the opening of the Northwest Passage and even weather patterns in the U.S., including factors that influenced Superstorm Sandy. (See a cool video of the melt from satellite here.)
Drought: Not just in the U.S. where the drought across the Midwest was (and continues to be) extreme. Drought also hit other breadbaskets of the world, including much of Asia. Global food prices rose by 10 percent in July.
Superstorm Sandy: This one we all remember: 185 deaths, thousands of homes lost and billions of dollars in damage, making it one of the costliest storms in U.S. history. An extra foot of storm surge from sea level rise, warmer ocean temps and possibly reduced Arctic sea ice marked the fingerprints of climate change on this particular storm. Debate continues over where to rebuild and how to pay for the cleanup.
Read Nos. 4 to 10 on the NCDC list here, including the super-typhoon in the Philippines and the unprecedented melt of the Greenland ice sheet.
As for 2013? The UK Met Office has predicted another top-10 warmest years ever. ENSO has moved from La Niña to neutral conditions and looks to continue that way for several months. But our main energy source, the sun, will be hitting the peak of its 11-year solar cycle in 2013, lending its strength to a warm year as well. And those pesky heat-trapping greenhouse gases? Well, they just keep going up.