It is that time of year when the weather gets cold — even unexpectedly cold — and online humorists and armchair scientists rise up as one to ask a question: "What happened to 'global warming'???" It's a good gag, see, because it's cold and global warming implies that it will be warm. If you don't get it, please e-mail me and I will explain further.
With the current cold snap that's blanketing the country, even a member of Congress couldn't resist.
Global warming strikes America! Brrrr!
— Rep. Vicky Hartzler (@RepHartzler) November 18, 2014
There are two options for what Hartzler, a Republican who represents Missouri's 4th District, hopes to accomplish here. The first is that she's making a joke about a serious environmental issue that has scientists around the world concerned about how mankind will fare under warmer conditions. We assume a member of Congress wouldn't make such a joke.
So let's assume Hartzler is actually wondering what happened to climate change (which is what conservative message-man Frank Luntz recommended Republicans call the effect). And for that we have an answer.
Hartzler's district sits just southeast of Kansas City, Mo. Over the past four decades, Kansas City has gotten about half a degree warmer on average every decade.
Kansas City is a city, though, and cities experience something called the "heat island effect." All that pavement and concrete tends to exacerbate heating trends, and Kansas City is one of the worst in the country in that regard. It is about 4.6 degrees hotter during the summer than nearby rural areas, such as those that Hartzler represents.
Her district is in Missouri's third climate division, as near as we can tell. That area has gotten about 0.1 degrees warmer each decade for the past century.
The trick with climate change, of course, is that it's hard to pinpoint specific local effects. That's what makes things like "hey, it's cold, where's the climate change?" somewhat effective rhetorically. But the government has outlined a good preview of how climate change is and will affect the Midwest broadly, the sort of analysis that is currently possible.
Here, for example, is the government's projection of the increased number of 95-degree-plus days by 2050 as the climate warms. Hartzler's district is in the dark red part of Missouri.
But heat is just one effect, according to the climate report mentioned above.
Direct effects will include increased heat stress, flooding, drought, and late spring freezes. Climate change also alters pests and disease prevalence, competition from non-native or opportunistic native species, ecosystem disturbances, land-use change, landscape fragmentation, atmospheric and watershed pollutants, and economic shocks such as crop failures, reduced yields, or toxic blooms of algae due to extreme weather events.
That's what the Midwest can expect.
But maybe Hartzler wasn't referring only to the temperature in Missouri or Washington today. Maybe she was wondering about global temperatures, over a long period, and thinks there's no evidence of warming.
There is. This chart is from the United Nations' Intergovernmental Panel on Climate Change, showing warming by decade.
That graph doesn't show Nov. 18, 2014, a day on which temperatures are, in many places, colder than normal. Instead, it shows global warming. (Before you get ready to type "warming hiatus!!!," here.)
The study of climate change is dependent on a lot of extrapolations, and the exact effects are hard to predict. One thing that is clear is that there will still be cold days even as temperatures warm. Another thing that is clear is that those cold days will inspire a lot of good jokes on Twitter about climate change. Hopefully Hartzler, at least, will feel as though her implied question has been answered.