Brad Johnson at Think Progress notes today:
As President Obama brokered a last-minute deal with China, India, and other nations to jointly fight global warming, American conservatives continued their assault on reason when it comes to climate science. All through the week, right-wingers from Rush Limbaugh to Fox News highlighted the fact that Copenhagen, the site of the international climate negotiations, received snow at Christmastime, which they falsely characterized as a “blizzard.” Now the Drudge Report and others are highlighting the real blizzard sweeping up the East Coast as a supposed contrast to “global warming.”
For Drudge to call the dusting Copenhagen received last week a “blizzard is, of course, laughable. To suggest it is ironic to get a little snow in mid-December in Denmark during a climate conference is doubly laughable (see “Snow in Copenhagen: The Good, the Bad, and the Ugly“).
As for the East Coast storm, my home in DC did get 18 inches of snow — although if this had been a true blizzard, I doubt my flight from Copenhagen on Saturday would have been allowed to land in Dulles airport and I wouldn’t of been able to get home 12 hours after I left Denmark. Certainly temperatures in the DC area have been in the normal range over the past week — it’s only the precipitation that has been very anomalous (for actual data on recent warming trend in the U.S., see “Record high temperatures far outpace record lows across U.S.“).
In any case, I have previously discussed the scientific literature, which makes clear that we have seen an increase in intense precipitation in this country, just as climate science predicted we would (see Why the “never seen before” Fargo flooding is just what you’d expect from global warming, as Obama warns). The NOAA-led report by 13 federal agencies Global Climate Change Impacts in the United States issued earlier this year makes the same point.
I’ll review the science shortly, but first, TP points out:
Even CNN’s Ed Henry piled on, saying “DC snowstorm chills Pelosi’s global warming trip,” calling it a “strange twist.”
If having snow around the holidays on the East Coast were strange, I doubt the song “White Christmas” would have been written. Ah, but what about record snow? Capital Climate reports that the DC snowstorm has set multiple records (previous in parentheses):
- National: All-time December daily (11.5″, 12-17-1932) and monthly snowfall (16.2″, 1962)
- Dulles: All-time December daily record (10.6″, 12-12-1982) and second highest December snowfall (24.2″, 1966)
- Baltimore: All-time December daily (11.5″, 12-17-1932) and monthly snowfall (20.4″, 1966)
That may be “strange,” but in fact it is a trend being observed around the country — predicted by climate science — with more extreme weather and a greater fraction of precipitation being generated in extreme events.
In 2004, the Journal of Hydrometeorology published an analysis by NOAA’s National Climatic Data Center that found “Over the contiguous United States, precipitation, temperature, streamflow, and heavy and very heavy precipitation have increased during the twentieth century.”
They found (here) that over the course of the 20th century, the “Cold season (October through April),” saw a 16% increase in “heavy” precipitation events (roughly greater than 2 inches [when it comes as rain] in one day), and a 25% increase in “very heavy” precipitation events (roughly greater than 4 inches in one day)- and a 36% rise in “extreme” precipitation events (those in the 99.9% percentile “” 1 in 1000 events). This rise in extreme precipitation is precisely what is predicted by global warming models in the scientific literature.
In fact, the last few decades have seen rising extreme precipitation over the United States in the historical record, according to NCDC’s Climate Extremes Index (CEI):
Here is a plot of the percentage of this country (times two) with much greater than normal proportion of precipitation derived from extreme 1-day precipitation events (where extreme equals the highest tenth percentile of deluges, click to enlarge):
Didn’t know that our government kept a Climate Extremes Index? Why would you? The media never writes about it.
The U.S. Climate Extremes Index was explicitly created to take a complicated subject (“multivariate and multidimensional climate changes in the United States“) and make it more easily understood by American citizens and policy makers. As far back as 1995, analysis by the National Climatic Data Center showed that over the course of the 20th century, the United States had suffered a statistically significant increase in a variety of extreme weather events, the very ones you would expect from global warming, such as more “” and more intense “” precipitation. That analysis concluded the chances were only “5 to 10 percent” this increase was due to factors other than global warming, such as “natural climate variability.” And since 1995, the climate has gotten much more extreme.
Even the Bush Administration in its must-read U.S. Climate Change Science Program report, Weather and Climate Extremes in a Changing Climate, acknowledged:
Many extremes and their associated impacts are now changing”¦. Heavy downpours have become more frequent and intense”¦.
It is well established through formal attribution studies that the global warming of the past 50 years is due primarily to human-induced increases in heat-trapping gases.“¦ The increase in heavy precipitation events is associated with an increase in water vapor, and the latter has been attributed to human-induced warming.
And yes, this applies to snow. A 2005 study, coauthored by NCDC, “Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States,” found:
The temporal distribution of snowstorms exhibited wide fluctuations during 1901-2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901-2000 was upward, corresponding to trends in strong cyclonic activity.
Finally, we have the 2009 government report on U.S. climate impacts, which concluded:
- “Cold-season storm tracks are shifting northward and the strongest storms are likely to become stronger and more frequent.”
– “In winter and spring, northern areas are expected to receive significantly more precipitation than they do now, because the interaction of warm and moist air coming from the south with colder air from the north is projected to occur farther north than it did on average in the last century. The more northward incursions of warmer and moister air masses are expected to be particularly noticeable in northern regions that will change from very cold and dry atmospheric conditions to warmer but moister conditions. Alaska, the Great Plains, the upper Midwest, and the Northeast are beginning to experience such changes for at least part of the year, with the likelihood of these changes increasing over time.”
– “There is also evidence of an increase in the intensity of storms in both the mid- and high- latitude areas of the Northern Hemisphere, with greater confidence in the increases occurring in high latitudes. The northward shift is projected to continue, and strong cold season storms are likely to become stronger and more frequent, with greater wind speeds and more extreme wave heights.”
So it is inane for anyone in the media to cite this massive DC snowstorm as somehow counterintuitive or ironic against the backdrop of Obama’s Copenhagen deal.
In fact, this record-breaking snowstorm is pretty much precisely what climate science predicts. Since one typically can’t make a direct association between any individual weather event and global warming, perhaps the best approach is to borrow and modify a term from the scientific literature and call this a “global-warming-type” deluge “” see Must-have PPT: The “global-change-type drought” and the future of extreme weather.
If you are a journalist wondering what is a reasonable way to talk about this, one of the best recent examples comes from a New York Times story on Australia made possible by our friend Andrew Revkin:
The firestorms and heat in the south revived discussions in Australia of whether human-caused global warming was contributing to the continent’s climate woes of late “” including recent prolonged drought in some places and severe flooding last week in Queensland, in the northeast.
Climate scientists say that no single rare event like the deadly heat wave or fires can be attributed to global warming, but the chances of experiencing such conditions are rising along with the temperature. In 2007, Australia’s national science agency published a 147-page report on projected climate changes, concluding, among other things, that “high-fire-danger weather is likely to increase in the southeast.”
The flooding in the northeast and the combustible conditions in the south were consistent with what is forecast as a result of recent shifts in climate patterns linked to rising concentrations of greenhouse gases, said Kevin Trenberth, a scientist at the United States National Center for Atmospheric Research.
That’s how it is done.
And no, I’m not say that the media should link every extreme weather event the way Revkin did. But when we have “worst on record” type events, or 100-year floods “” and especially ones that last more than a day and/or hit a broad area “” then I think the reporter has an obligation to include the issue.
Finally, I would note that if we stay on our current emissions path as outlined in the 2009 impacts report — see Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year “” and that isn’t the worst case, it’s business as usual! — then indeed these storms will become incredibly rare in the East-Central part of the country, and the lyrics of the classic song will ring all-too-true:
I’m dreaming of a white Christmas Just like the ones I used to know.
- Why do the deniers try to shout down any talk of a link between climate change and extreme weather?
- Pielke in Nature: “Clearly, since 1970 climate change “¦ has shaped the disaster loss record.”
- Sorry, deniers & delayers, Part 1: Even U.S gov says human emissions are changing the climate
- Sorry, delayers & enablers, Part 2: Climate change means worse droughts for SW and world
- Record Flooding Slams Midwest (2007)
- Global warming will spawn severe storms and tornados, reports NASA
- Early 2007 saw record-breaking extreme weather
- A deluge of extreme weather, thanks to climate change
- Apr¨s nous le deluge
- UK Prime Minister on “weather extremes” and climate change
- UK: Worst Floods In Modern History
- NBC Reports on Hell and High Water
- ABC Reports on Hell and High Water
- The Weather IS Becoming More Extreme