UCAR has created a compelling animation that effectively draws a parallel between increased homerun production during the baseball steriod era and greenhouse gases and warm weather records today.
Keep reading for the animation...
From UCAR: AtmosNews takes a lighthearted look at an unexpected analogy, explaining why some people call carbon dioxide (and the other greenhouse gases) the steroids of the climate system
Just as homerun numbers got an artificial boost in the 1990s, warm weather statistics are inflated today. In the U.S., over the last 12 months, daily warm weather records outpaced cold weather records by a factor of more than two* (60,024 warm weather records compared to 22,474 cold weather records). In Virginia and Maryland, the last 12 months (spanning February 2011-January 2012) were the warmest on record. Washington, D.C.’s last two Julys were the hottest two on record.
But cold weather still happens. As a prominent example, Europe’s currently experiencing one of its worst cold snaps in decades. So just like a steroid-using power hitter could go through a slump, so can the atmosphere - even with its growing carbon load.
The point UCAR is trying to convey is that greenhouse-gas induced global warming tilts the odds, stacks the deck, and loads the dice (to use a variety of analogies) in favor of warm weather, just like steroids did for increased home run production. But we can still go cold.
This a sound metaphor, and a good one to use to explain the next warm weather record or less likely excursion to anomalous cold.
(* Note: the disproportionate number of city-based daily warm weather records should not be attributed to greenhouse gases alone. The urbanization around cities is also a factor in increased warm weather records relative to cold.)