Any way you look at them, the weather crises of 2010 are human disasters of historic proportion. Thousands of Russians are dying from heat, thousands of Asians are dying in flood. And it is worth keeping in mind that for many of the survivors, for whom the hardships of homelessness, hunger and illness have just begun, the search for "causes" of these events is basically beside the point.
To get a real whopping debate going about the underlying causes of our manifestly changing climate, everybody has to be pretty well fed. In the shorter term, before our eyes, dynamical explanations of weather events will always be so complex and so naturally variable that they challenge our best thinking. If there is a harder science than meteorology - figuring out the atmosphere of Earth - I don't know what it is.
The Northern Hemisphere's atmosphere is dominated this time of year by great cells of rising and falling air. These features are more intense than usual this year, and more stable. This map, below, developed by NOAA's Earth System Research Laboratory, shows upper-atmosphere features that capture the rising air (blue) north of Pakistan and the falling air (red) over Moscow.
Over Asia's disastrous floods and mudslides are towering rainstorms fed by the moist monsoon from an especially warm Indian Ocean and by the northward migration this time of year of the band of tropical rainstorms fueled by converging trade-winds. Observing the upper atmosphere, Houston meteorologist Larry Cosgrove told Discovery News, "I noticed that in the Pakistan event, an upper low sat near the vicinity for a number of days, which probably helped convective development."
Over Moscow's killing heatwave and choking smog is a persistent dome of descending, dry air - high pressure that has blocked the arrival of any relieving weather systems for weeks on end. Russia's chief meteorologist, Alexander Frolov, said the heatwave was an "absolutely unique" phenomenon that hadn't been seen in 1,000 years. At Weather Underground, tropical meteorologist Jeff Masters noted that the area of extreme heat is much greater and more intense that the infamous 2003 European heat wave that killed tens of thousands of people in France and Italy.
On the timescale of climate - the long-term statistics of weather - the events of this summer could have been taken from one of the many computer model scenarios that have established the scientific case for a globally warming climate. Temperature and precipitation extremes are common features of such simulations and have been for years.
Will the events of the summer of 2010 alter the political landscape about climate change? Well, senior meteorologist Stu Ostro at the Weather Channel - a recent convert to the idea of global warming - may have the right idea. As he wrote a few days ago:
There are those who say we should focus more on adaptation to the effects of climate change rather than mitigation of the causes, because of a political/economic agenda and/or because they "believe" that anthropogenic (human-influenced) global warming is a crock. By contrast, I don't "believe" AGW is bunkum; rather, to me it's real and very serious. But I think that its dangerous effects are neither 50 or 100 years away, nor going to wait for the Earth's temperature to rise another one or two degrees C (or F). They're here already. And for that reason, we need to focus more on adaptation. Now.