A point or two re weather (since we're discussing the drought): Yes, last year was a mild winter most places, with significantly below average snowfall. And July was the single hottest month on record across the United States. Makes you think maybe Gore was onto something . . .
But then there's this: Prior to last winter, Iowa had suffered 5 winters in a row where the snowfall was either average (30") or above. In 3 of those 5 winters, snowfall was at least 25% above normal, and in one case it was nearly 60% above normal. So isolating last winter as an indication of global warming doesn't resonate well with Iowans.
Likewise, and of equal importance to bird hunters, rainfall for the months of April and May was at or above the long-term average of 8" for 4 out of those 5 years. So, although Iowa has lost habitat (down from 1.9 to 1.3 million acres of CRP, 2003-11), it's weather that has really hammered bird numbers over the last several years. Snowy winter + wet spring = double whammy for a lot of upland species.
And concerning long-term trends in weather: As several have remarked, we only have reliable weather data for about 150 years. However, prior to 2005, looking at available data, Iowa had never experienced 5 winters in succession with above average snowfall. Makes one wonder about the "coming Ice Age" that was the cover headline on Time magazine back in the 70's.
As for feeding the world's population, it's not entirely a question of how much land we can put into production. If we were still getting the same crop yields today we got back in 1950, we'd be in serious trouble feeding the current population. However, where 100 bu/acre corn used to be a very good crop, 200 bu/acre is now quite common. So farmers have become a lot more efficient. But there's definitely a limit, with our rapidly expanding population.
Last edited by L. Brown; 08/10/12 10:30 AM.
