The last summer it was as consistently hot as this June and July was 1988. Our warm first two months of summer 2012 toppled many high temperature records from that year. The Twin Cities endured 44 days of above 90-degree heat in 1988 (the tally so far in 2012 is 27).
I remember that time well because, working in Michigan state government, I was asked to help other Great Lakes states respond to a request from the Governor of Illinois to triple the amount of Lake Michigan water diverted to the Mississippi River. Seems the river was running so low in the accompanying drought that barges on the Mississippi were stranded, some on sand bars. (The answer to Illinois’ governor was ‘no’ – Lake Michigan was also running low.)
Something else happened that year: testifying before Congress, a NASA scientist named James Hansen made national news. ”It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” he said. For millions of Americans sweating out the hot, dry weather – millions who had never heard of the greenhouse effect before – this was a blockbuster. Humankind, Hansen said, was now perceptibly warming Earth’s climate through the emission of carbon dioxide and other gases, trapping heat that would otherwise escape into space.
Not long after Hansen’s testimony, while running for President, George H.W. Bush said he would take action to protect the climate through “the White House effect.” That offered promise of bipartisan action to attack the sources of climate change.
We know what’s happened since. Climate change is one of the most bitterly fought issues in a time of intensive political division. Without getting into motives of anyone participating in the argument, it’s fair to say we are far from consensus on what, if anything, to do about climate change.
There’s an important lesson to take from 1988. When that summer’s heat wave broke, public concern about the greenhouse effect waned, too. And when an economic recession followed in 1991, climate – and environmental issues in general – fell far down Americans’ priority lists.
So when scientist Hansen recently released a paper linking heat waves to climate change, a recollection of history seemed in order. In the new paper, Hansen and co-authors wrote, “We can state, with a high degree of confidence, extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming, because their likelihood in the absence of global warming was exceedingly small.” In 2011, Texas and Oklahoma had their hottest summer on record. The summer of 2010 in much of Russia was the hottest in 130 years of records.
This was another brief media sensation. But will it lead to change?
Linking particular weather events to climate change may or may not be good science, but it is fraught with unintended consequences. Doing so raises the risk that a major Minnesota winter cold snap or blizzard will be invoked by climate change deniers – even though the hypothesis of climate change does not exclude winter. As meteorologist Paul Douglas says, weather is like Headline News, climate is the History Channel.
The overwhelming body of science is now consistent with the climate change hypothesis. The overwhelming body of American opinion is not, yet. Whether the summer of 2012 is like the summer of 1988 in more ways than temperature is up to us – to our willingness to take the long view, and to make changes that will benefit ourselves and those who come after.