Heads in the Snow

Yes: This Is Global Warming
Yes: This Is Global Warming

This isn’t news to any of our readers, but as a massive winter storm descends on the East Coast, let us be clear about one thing:

The existence of a terrible, extreme snowstorm, far from belying the existence of “global warming”/climate change, actually confirms it.

According to every model and every prediction of the phenomenon, climate change will cause more extreme weather, both in terms of cold and heat.  That the east coast is suffering from a once-in-a-century storm aligns perfectly with the predictions of climate models.

I have heard less of the normal Republican chortling about “some global warming ha ha” on this storm, perhaps because of Hurricane Sandy’s impact and the discussion about it afterwards.  But it’s important to maintaing vigilence against the new medievalism in GOP science.

It affects even normally intelligent people.  I was in North Carolina for the holidays, and an old friend of mine, a law professor no less, told me that the state was experiencing an unseasonably warm winter.  “Some global warming,” he said.  I responded that that is what one would expect from climate models, and he said that that means that the theory is unfalsifiable — every weather event confirms it.

No it doesn’t!  Temperatures can have a high/high, a low/high, a high/low, and a low/low.  If any of these are consistently going outside historic norms, then that confirms the models.  You can have a cold winter, or a warm winter.  Normal weather will tend to contradict the model, and ongoing normal weather will tend to falsify it.  But at least for those who respect data, the confirming evidence has been far more powerful than the contradicting evidence.  And anyone who thinks otherwise (I’m looking at you, Senator Inhofe), has his head in the snow.

To all of our friends on the east coast: stay warm.

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Reader Comments

10 Replies to “Heads in the Snow”

  1. H Jonathan, although it’s true that there’s some recent work indicating that low sea ice conditions can led to a slower progression of atmospheric waves, and thus to longer cold snaps in northern hemisphere winters, I don’t think the phenomenon has been identified in models, and more generally speaking, what the models predict in response to carbon dioxide pollution is warmer temperatures is pretty much all locations and seasons. They predict many more warm extremes than cold extremes, which has in fact been observed. It is just wrong to say that a colder than normal winter is evidence of global warming. There will continue to be colder than normal winters for a long time, even if you define “normal” as the average over the years 1950-1980, and of course if your define normal as the average over the most recent thirty years, there will always be colder-than-normal winters. Global warming doesn’t mean an end to natural variability.

  2. H Jonathan, although it’s true that there’s some recent work indicating that low sea ice conditions can led to a slower progression of atmospheric waves, and thus to longer cold snaps in northern hemisphere winters, I don’t think the phenomenon has been identified in models, and more generally speaking, what the models predict in response to carbon dioxide pollution is warmer temperatures is pretty much all locations and seasons. They predict many more warm extremes than cold extremes, which has in fact been observed. It is just wrong to say that a colder than normal winter is evidence of global warming. There will continue to be colder than normal winters for a long time, even if you define “normal” as the average over the years 1950-1980, and of course if your define normal as the average over the most recent thirty years, there will always be colder-than-normal winters. Global warming doesn’t mean an end to natural variability.

  3. Regarding Jonathan, Mr. Daniel Kirk-Davidoff said,

    “… It is just wrong to say that a colder than normal winter is evidence of global warming…”

    Dear Daniel,
    I don’t mean no disrespect, but this is not the first time that Jonathan has been wrong about global warming. As I recall, he was also incorrect about certain assumptions regarding the purported effectiveness of trading carbon credits for the purpose of reducing global warming. Out of fairness to Jonathan, I will check the archives and try to locate an instance where he has been correct about global warming and let you know.
    Have a good day and thanks for your knowledge and insight.

  4. Regarding Jonathan, Mr. Daniel Kirk-Davidoff said,

    “… It is just wrong to say that a colder than normal winter is evidence of global warming…”

    Dear Daniel,
    I don’t mean no disrespect, but this is not the first time that Jonathan has been wrong about global warming. As I recall, he was also incorrect about certain assumptions regarding the purported effectiveness of trading carbon credits for the purpose of reducing global warming. Out of fairness to Jonathan, I will check the archives and try to locate an instance where he has been correct about global warming and let you know.
    Have a good day and thanks for your knowledge and insight.

  5. @Daniel Kirk-Davidoff

    Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States (Chagnon et al., 2006)

    “Results for the November-December period showed that most of the United States had experienced 61%- 80% of the storms in warmer-than-normal years. Assessment of the January-February temperature conditions again showed that most of the United States had 71%-80% of their snowstorms in warmer-than-normal years. In the March-April season 61%-80% of all snowstorms in the central and southern United States had occurred in warmer-than-normal years…. Thus, these comparative results reveal that a future with wetter and warmer winters, which is one outcome expected (National Assessment Synthesis Team 2001), will bring more snowstorms than in 1901-2000. Agee (1991) found that long-term warming trends in the United States were associated with increasing cyclonic activity in North America, further indicating that a warmer future climate will generate more winter storms.”

    So more intense snowstorms are indicators of climate change. I suppose my post could be read as suggesting that the snowstorms derived from COLDER temperatures, which I did not intend; they derive from warmer temperatures, which of course is precisely what the climate models predict. But in many areas they also predict colder temperatures. So when climate deniers like George Will point to greater amounts of ice in Antarctica as evidence that climate change isn’t occurring, they are in fact pointing to evidence for climate change. At least that’s my understanding.

  6. @Daniel Kirk-Davidoff

    Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States (Chagnon et al., 2006)

    “Results for the November-December period showed that most of the United States had experienced 61%- 80% of the storms in warmer-than-normal years. Assessment of the January-February temperature conditions again showed that most of the United States had 71%-80% of their snowstorms in warmer-than-normal years. In the March-April season 61%-80% of all snowstorms in the central and southern United States had occurred in warmer-than-normal years…. Thus, these comparative results reveal that a future with wetter and warmer winters, which is one outcome expected (National Assessment Synthesis Team 2001), will bring more snowstorms than in 1901-2000. Agee (1991) found that long-term warming trends in the United States were associated with increasing cyclonic activity in North America, further indicating that a warmer future climate will generate more winter storms.”

    So more intense snowstorms are indicators of climate change. I suppose my post could be read as suggesting that the snowstorms derived from COLDER temperatures, which I did not intend; they derive from warmer temperatures, which of course is precisely what the climate models predict. But in many areas they also predict colder temperatures. So when climate deniers like George Will point to greater amounts of ice in Antarctica as evidence that climate change isn’t occurring, they are in fact pointing to evidence for climate change. At least that’s my understanding.

  7. You wrote: ” Temperatures can have a high/high, a low/high, a high/low, and a low/low. If any of these are consistently going outside historic norms, then that confirms the models.” No, the models do *not* predict colder temperatures in “many places”. In *some* models (e.g. NCAR CESM), there is some cooling predicted in a few spots in the north Atlantic, and nowhere else. Which helps build confidence in the models, because in the *observations* show only a few isolated regions of cooling (near Antarctica, a few spots in the Pacific, the Gulf Stream off Florida) since the 1950’s: http://en.wikipedia.org/wiki/File:Global_Warming_Map.jpg

    Fair enough about that snow analysis, although it’s a little complicated to compare the snowiness of warm years over the US with the snowiness of future years in which the whole planet is warmer.

    As far as modeling results for snowfall, I looked at this a couple of years ago, and the model predictions in AR4 were all over the place for the first few decades of the 21st century, as you might expect for a complicated forecasting problem (warmer -> more water, but also less time spent below freezing). By 2100, of course, things are unambiguous- a much warmer planet, with much less snow in mid-latitudes. Here’s a regional study for Wisconsin: Notaro et al: 21st century Wisconsin snow projections based on an operational snow model driven by statistically downscaled climate data, Int. J. Climatology, doi:10.1002/joc.2179. They write: “Snowfall is substantially reduced in response to projected warming and only slightly offset by a projected increase in cold-season precipitation. “

  8. You wrote: ” Temperatures can have a high/high, a low/high, a high/low, and a low/low. If any of these are consistently going outside historic norms, then that confirms the models.” No, the models do *not* predict colder temperatures in “many places”. In *some* models (e.g. NCAR CESM), there is some cooling predicted in a few spots in the north Atlantic, and nowhere else. Which helps build confidence in the models, because in the *observations* show only a few isolated regions of cooling (near Antarctica, a few spots in the Pacific, the Gulf Stream off Florida) since the 1950’s: http://en.wikipedia.org/wiki/File:Global_Warming_Map.jpg

    Fair enough about that snow analysis, although it’s a little complicated to compare the snowiness of warm years over the US with the snowiness of future years in which the whole planet is warmer.

    As far as modeling results for snowfall, I looked at this a couple of years ago, and the model predictions in AR4 were all over the place for the first few decades of the 21st century, as you might expect for a complicated forecasting problem (warmer -> more water, but also less time spent below freezing). By 2100, of course, things are unambiguous- a much warmer planet, with much less snow in mid-latitudes. Here’s a regional study for Wisconsin: Notaro et al: 21st century Wisconsin snow projections based on an operational snow model driven by statistically downscaled climate data, Int. J. Climatology, doi:10.1002/joc.2179. They write: “Snowfall is substantially reduced in response to projected warming and only slightly offset by a projected increase in cold-season precipitation. “

  9. Fair enough: I had read previous reports about pretty large places becoming colder, but if that is no longer what the models say, then that is no longer what the models say!

    The point I was trying to make was that snowstorms now are evidence of warming, not contradictions of it.

    My understanding is also that wet regions will become wetter, and dry regions will become drier, and perhaps I transposed that to temperature implications.

  10. Fair enough: I had read previous reports about pretty large places becoming colder, but if that is no longer what the models say, then that is no longer what the models say!

    The point I was trying to make was that snowstorms now are evidence of warming, not contradictions of it.

    My understanding is also that wet regions will become wetter, and dry regions will become drier, and perhaps I transposed that to temperature implications.

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About Jonathan

Jonathan Zasloff

Jonathan Zasloff teaches Torts, Land Use, Environmental Law, Comparative Urban Planning Law, Legal History, and Public Policy Clinic – Land Use, the Environment and Loc…

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