Does cold weather disprove global warming?

It's freaking cold!

"Austria is today seeing its earliest snowfall in history with 30 to 40 centimetres already predicted in the mountains. Such dramatic falls in temperatures provide superficial evidence for those who doubt that the world is threatened by climate change." (Mail Online)

Comments 1 to 7:

1. Sam Spade at 11:44 AM on 9 November, 2009
   On this issue, "climate change" is more apt than "global warming".
   And "climate is weather averaged over time" is more explicit than "weather is not climate."
   
   The 'weather' skeptic's defense will be: "They do it too. If there's a warm spell, the believers will say its due to global warming."
   After years of temperature increases, it is harder for believers to restrain such statements. But they should be restrained. Weather IS variable.
   In addition, maybe policymakers should just whisper among themselves, about a current event occurring more frequently in a global warming future...to avoid the shortening misquote, that GW caused the event???
   
   WEATHER'S ONE MONTH EFFECT...
   ...even averaged over a month, local weather anomalies (dynamical fluctuations, more-or-less independent of forced long-term climate change) are much larger than the global mean temperature change of recent decades. Weather fluctuations or 'noise' have a noticeable effect even on monthly-mean global-mean temperature, especially in Northern Hemisphere winter. Weather has little effect on global-mean temperature averaged over several months or more. The primary cause of variations on time scales from a few months to a few years is ocean dynamics, especially the Southern Oscillation (El Nino-La Nina cycle)...
   Columbia.edu
   
   COLD EXTREMES HAVE WARMED MORE...
   In the last 50 years for the land areas sampled, there has been a significant decrease in the annual occurrence of cold nights and a significant increase in the annual occurrence of warm nights...Decreases in the annual occurrence of cold days and increases in hot days, while widespread, are generally less marked. The distribution of minimum and maximum temperatures have not only shifted to higher values, consistent with overall warming, but the cold extremes have warmed more than the warm extremes over the last 50 years.
   IPCC AR4 WGI FAQ 3.3
   
   REGIONAL EXCEPTIONALISM FOR GW FUTURE COLD SPELLS..?
   It is also likely that a warmer future climate would have fewer frost days (i.e., nights where the temperature dips below freezing)...There is likely to be a decline in the frequency of cold air outbreaks (i.e., periods of extreme cold lasting from several days to over a week) in (Northern Hemisphere) winter in most areas. Exceptions could occur in areas with the smallest reductions of extreme cold in western North America, the North Atlantic and southern Europe and Asia due to atmospheric circulation changes.
   IPCC AR4 WGI FAQ 10.1
2. Sam Spade at 03:21 AM on 16 November, 2009
   RECORD HIGH TEMPERATURES FAR OUTPACE RECORD LOWS ACROSS U.S.
   ...The ratio of record highs to lows is likely to increase dramatically in coming decades if emissions of greenhouse gases continues to climb...
   If temperatures were not warming, the number of record daily highs and lows being set each year would be approximately even. Instead, for the period from January 1, 2000, to September 30, 2009, the continental United States set 291,237 record highs and 142,420 record lows...
   The study also found that the two-to-one ratio across the country as a whole could be attributed more to a comparatively small number of record lows than to a large number of record highs. This indicates that much of the nation's warming is occurring at night, when temperatures are dipping less often to record lows. This finding is consistent with years of climate model research showing that higher overnight lows should be expected with climate change...
   "One of the messages of the study is that you still get cold days...Winter still comes..."
   ...analyzed several million daily high and low temperature readings taken over the span of six decades at about 1,800 weather stations across the country....a quality control process at the data center..looks for such potential problems as missing data as well as inconsistent readings caused by changes in thermometers, station locations, or other factors...
   Meehl et al, ucar.edu Press Release, November 12, 2009
3. djb95054 at 10:41 AM on 5 January, 2010
   What do you think about Anthony Watts' attempted debunking of the Meehl 2009 report by complaining that it "cherry picked" temp records from 1950 on when 1930 had more record lows than highs? See http://wattsupwiththat.com/2009/11/16/why-ncars-meehl-paper-on-highlow-temperature-records-is-bunk/
   
   It looks to me like Watts is really looking at numbers of record highs and lows and not ratios of highs to lows, but nonetheless it would be nice to see a debunking of the debunking. Overall, it would be even nicer to see a global report on record highs vs record lows to see if the trend Meehl et. al. found in the U.S. is really a global phenomena.
4. rader5 at 12:18 PM on 7 January, 2010
   @djb95054 Watts' attempt isn't much of a debunking. Everything he mentions is addressed in the original paper. I mean what do you think is the more robust analysis, a weatherman's report of the records across a few dozen states or the actual record from 2000 stations over decades. See the y-axis above that's 5e+05! 500,000 measurements! Watts' plots show maybe 50 self-reported measurements. The statistical error on that alone is > 10%. Ask Watts to put this in excel and tell us the error on the slope. And he says things like there were 10 lows and 8 highs in 1930s or something like that. Do yourself a favor, read the original paper--you'll find the analysis 5e+05 times more robust.
5. djb95054 at 06:00 AM on 9 January, 2010
   @rader5 Okay, so the Meehl paper is more robust. I get that. But my question was more about the charge of "cherry picking" data from 1950 on, as opposed to including the 1930's and earlier. Is there a reason the Meehl paper starts in the 1950's?
   Response: The 1950 to 2006 period was chosen because of the decision to use continuous station records. They chose this period to avoid any effect that would be introduced by a mix of shorter and longer records. The final result (the increasing ratio of record high versus record lows) isn't dependent on the start date of 1950.
6. muoncounter at 08:19 AM on 28 March, 2010
   On the lighter side: Since we had such a cold winter in North America, there was an uptick in the 'all that snow means global warming doesn't exist' hysteria. Bet we won't here much about this:
   
   "It’s on the calendar. It’s widely advertised. This year, everybody knows about it but the trees. And they are the central characters in Vermont’s annual maple syrup open house this weekend, when tourists descend on the state to watch trees being tapped and sap being boiled.
   Sugaring season ended early for many syrup farmers in southern Vermont, sabotaged by unseasonably warm weather." NY Times, 27 March 2010 (http://www.nytimes.com/2010/03/27/us/27syrup.html)
7. doug_bostrom at 17:01 PM on 28 March, 2010
   Muoncounter, it's a case of wheels within wheels. Not only are crypto-Communists trying to end our Western lifestyle by confiscating our incandescent lightbulbs, but at the same time the ruthless Canadians are extracting petroleum from tar sands, selling it to us Americans and then tricking us into burning it specifically so more C02 will be released, driving up temperatures, thus pushing the syrup industry north of the Canada-US border. They'll be selling that syrup back to us hungry, desperate pancake eaters later. It's a dastardly plot, one of many.

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