Gwynne Dyer: Do wild weather, heat waves, and torrential rains add up to climate change?

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      It was 42° C in St. Louis, Missouri, last weekend, about the same as in Saudi Arabia. Along the U.S. Atlantic coast, it was cooler, but not much: 41° C in Washington, D.C., just short of the city’s all-time record. And 46 Americans are already dead from the heat wave.

      In Britain, it was incredibly wet. Almost six centimetres of rain fell on July 7 in parts of southern England, and there were over 20 flood warnings and 100 flood alerts in effect. The wettest April ever was followed by the wettest June (more than double average rainfall), and July has started the same way.

      Russia had its hottest summer ever in 2010, with peat wildfires raging out of control—over 5,000 excess deaths in Moscow in July alone—but this summer, it’s wet in Russia, too. On July 6, an astonishing 28 centimetres of rain fell overnight in the Krasnodar region in southern Russia, and flash floods killed 155 people.

      It is a big planet, and some local record for hottest, coldest, wettest, or driest is being broken somewhere or other almost every day. But these are records being broken over very large areas, in regions where records go back a long time.

      As Krasnodar governor Alexander Tkachev said: "No-one can remember such floods in our history. There was nothing of the kind for the last 70 years."

      There are very unusual events happening in winter too: last January only 14.7 percent of the United States was covered by snow, compared to 61.7 percent at the same time in 2011. At least 300 people died in a cold wave in northern India in the previous January.

      One could go on, enumerating comparably extreme weather events in the southern hemisphere in the past couple of years. But that would just be more impressionistic evidence, and no more convincing statistically.

      The events are too few, and the time period is too short. But it does feel like something is going on, doesn’t it?

      The most recent opinion polls indicate that a majority even of Americans now accept that climate change is happening (although, being American, many of them still cling to the belief that it is a purely “natural” event that has nothing to do with human greenhouse-gas emissions). But opinion polls are not a good guide in these matters either. Can we really say that something serious is happening, and that it is evidence that the climate is changing now?

      No, we can’t. It’s a statistical long shot, but it is possible that this is just a random collection of extreme events signifying nothing in particular. Occasionally a tossed coin comes up heads six times in a row. But usually it doesn’t.

      The best way to approach the question is to ask what we would actually see if global warming had crossed some threshold and triggered big changes in weather patterns. The actual change in the average global temperature would be almost imperceptible: only one or two degrees Celsius, or the difference in an average day’s temperature between 9 and 10:30 a.m. What we would notice is that the weather is getting wild.

      We never really experience the climate; what we feel is the daily weather that it produces. A climate that is changing will produce unfamiliar weather—and if it is getting warmer, it will be more energetic weather. Wilder weather, if you like.

      That means hotter, longer heat waves and bigger storms that bring torrential rain and killer wind speeds. But it can also mean prolonged droughts as rainfall patterns change—and much more severe winters, like the “Snowmageddon” storm that hit Washington, D.C., in February 2010 and shut down the U.S. federal government for a week.

      That last phenomenon confuses people who think colder winters prove that the climate isn’t getting warmer, but complex systems like the climate can produce strange local results. As an article by Charles H. Greene and Bruce C. Monger in a recent issue of Oceanography points out, the melting of the Arctic sea ice will cause colder winter weather in the temperate regions of the northern hemisphere.

      “Since the dramatic decline of Arctic sea ice during summer 2007,” the authors point out, “severe winter weather outbreaks have periodically affected large parts of North America, Europe and East Asia. During the winter of 2011–12, an extended and deadly cold snap descended on central and eastern Europe in mid-January (with temperatures approaching -30 ° C)...By mid-February, the death toll had exceeded 550."

      How does melting Arctic sea ice cause colder winters? Much of the solar heat absorbed by the ice-free parts of the Arctic Ocean in the summer is released into the air by evaporation in the autumn.

      The higher atmospheric pressure in the Arctic weakens the Jet Stream, which allows cold Arctic air masses with a high moisture content to spill out into the middle latitudes.

      Hence colder winters and more snow in the U.S., Europe, and northern Asia.

      You can’t prove that all this means we are sliding into a new and steadily worsening climate right now—that the long-threatened future has arrived. The statistics aren’t good enough to support that conclusion yet. But if you have to put your money down now, bet yes.

      Comments

      28 Comments

      NoLeftNutter

      Jul 8, 2012 at 7:47pm

      Gwynne - you must get paid by the inch to write such crap. Warmistas have tailored their predictions so that every outcome "proves" global warming; hotter, colder, wetter, drier, lighter darker, you name it. Someone, somewhere has a pal reviewed paper that claims we are just 2 degrees away from disaster.
      As for melting sea ice causing colder winters - how do you explain that the Arctic ice in the winter of 2011/12 returned to the 1979 - 2000 average, well above the 2007 amount?

      Goldorak

      Jul 8, 2012 at 10:08pm

      "The higher atmospheric pressure in the Arctic weakens the Jet Stream, which allows cold Arctic air masses with a high moisture content to spill out into the middle latitudes".

      Now in the Gorespel according to Dyer, cold High Pressure air holds high moisture... Gwynne, go to school before lecturing on a subject you are an ignoramus.

      peter kratoska

      Jul 8, 2012 at 10:49pm

      hey how'd you lose your left nut? I guess we're just imagining the 15million hectares of pine beetle damaged forest here in BC (an area the size of the UK). Unprecedented, but due to a lack of a cold snap (of several days) that would normally wipe them out. Or we could look at renaming glacier national park something else, since there's not much of a glacier. But my favourite one for the deniers is the fact that none of the oil companies want to pay to fix the Alaska pipeline as it is deteriorating by the slowly melting permafrost it is built on. Because that would mean admitting there is a problem. In any case triple digit oil prices will do more for reducing green house gases than any carbon tax or caps.

      sicntired@mac.comterry mckinney

      Jul 9, 2012 at 1:26am

      While at the same time the Canadian government is defunding anyone who dares to mention this.If you care about the climate you're a terrorist.The recent ad against Mulcair and the NDP stresses their opposition to the tar sands as if it's an insane position.Harper and his Tory government don't believe the climate changing is a problem.They are in total denial.If someone pointed out how much added cost the weather is putting on the Canadian people they would take their funding away and label them as well.That they have said that the Canadian public will never agree to the Gateway pipeline but that it is essential to Canada's economy says everything there is to say about Mr.Harper and his cabinet.

      Geeyore

      Jul 9, 2012 at 4:57am

      My dear departed grandmother - a Canadian who emigrated to the States around 1930 - was firmly convinced that the weather had gotten much worse after the US and Russia started nuclear testing in the 50's and 60's. She stated this in the mid-1970's. Which was around the same time that the US Mid-Atlantic had a 17-20 inch snowfall that began melting the very next day with temperatures in the 50's and 60's. And for those not familiar with the "extreme" weather around DC: the British and Russian embassies (maybe others) used to provide tropical duty pay for DC postings... again in the 1970's. In 1980 I moved north from DC because it was so intolerably hot and humid. Returning in 1999 and 2000, we had a week or more both years of temperatures touching and exceeding 100F. Our memories of what's "extreme" are very much colored by our local experience and selective recollection, but the hysterical warmists will capitalize on any deviation from statistical norms to scare and frighten their fellows.

      JMW

      Jul 9, 2012 at 5:33am

      NoLeftNutter...

      when a system that has been in stable shape gets disturbed, it oscillates wildly out of control. You want a simple analogy? Spin a top. Then, once it's spinning normally, give it a light tap on the side. It will swing over in the direction you tapped it...then swing back past the point of its original equilibrium.

      As for the sea ice, I haven't seen the data you mention - can you provide a helpful link to its source? However, the major problem with arctic sea ice lately hasn't that it has been getting smaller, but that it has been getting thinner - so it melts more quickly in summer. For example, see

      http://nsidc.org/cryosphere/sotc/sea_ice.html

      This paper points out that from 1980 to 2008, the average sea ice thickness declined from 3.64 metres to 1.89 metres - a decline of 1.75 metres, or 48%.

      It also graphs the sea ice extent, and while 2007 was the minimum and sea ice has rebounded somewhat in 2009, it has resumed its decilne, and 2011's maximum was less than the minimums at any time before 1996 (going back to 1953, which is earliest time this study has data for).

      Bottom line, we're still learning about an extremely complex system. New chains of cause an effect are discovered every week. But the broad conclusion is still reliable: humans are pumping more carbon dioxide into the atmosphere, and this means the atmosphere is retaining more heat, and it will change the planet as a result. Climatologists are still discovering the exact details of those changes.

      Former BelieverandLiberal

      Jul 9, 2012 at 6:55am

      We gave Romney the White House on a climate change tray.
      President Romney would like to thank us climate change believers in advance for alienating our own voting base to the Republicans because we didn't know when to stop threatening the voter's children with CO2 death threats.
      Smooth move girls as the climate change blunder will do to us what Bush and "his" false war did for the neocons.

      Hazlit

      Jul 9, 2012 at 7:28am

      I have read about this theory elsewhere (in the NYT, I believe). From my reading the "extreme weather" theory has good scientific evidence behind it.

      miguel

      Jul 9, 2012 at 7:44am

      Melt water from the Arctic has affected the Gulf stream. The current is pushing water up against the eastern seaboard of N. America, rather than crossing to the northeast of the Atlantic.
      That large a of a body of water has it's own climate, and it isn't getting to Atlantic Europe now, but staying close to America.
      Miguel

      prenup

      Jul 9, 2012 at 8:51am

      sure it equals climate change...if you'll admit climate change has been happening since the beginning off weather watching. Everything you describe has been happening for 100s of years.

      Whats amazing to me is that this is already documented, yet people who believe in climate change reach and stretch for all sorts of wild conspiracies.