Global warming? The cold summer of 2010 continues
Last Friday’s San Francisco Chronicle had these two articles, both within one page of each other:
How to account for such schizoid reports? According to the first article, although the summer of 2010 hasn’t set a record for cold, it’s been one of the chilliest and most persistently foggy in years, contrasting “sharply with record heat on the East Coast.”
According to the second article, “The past decade was the [world’s] warmest on record” and “Scientific evidence that the world is getting warmer is ‘unmistakable,’ according to…the National Oceanic and Atmospheric Administration.” So, despite the numbskull Tea Party allegations of “Climategate” and know-nothing denialism, the evidence “all point[s] to the same conclusion: Our planet is warming.”
I have written about the cold weather along the California coast for years now on this blog, but even before I started doing so, I was noting, in the vintage diary I keep every year for my reports in Wine Enthusiast, how chilly things have gotten since the notoriously hot summer and fall of 2004. The years 2005-2009, inclusive, all seemed colder to me than any I’d experienced since arriving here in 1978; and now, here we go again. I’ve written here how cold and wet our 2010 “spring” was — a “spring” that never happened until things warmed up, slightly, in June. Now here we are with July over, and both the average temperature and the number of sunny days in San Francisco are down. Here in Oakland, the average July high temperature has been running 2.1 degrees below historic norms.
As it is in San Francisco and Oakland, so it is in wine country. Yesterday (as I write; actually, last Thursday), somebody at Vine Cliff Winery, in Napa Valley, called to tell me “We’re 2-3 weeks behind” in average ripeness due to the chill, which leads naturally to concerns about Fall rains. A Sonoma winemaker wrote on my Facebook page, on July 20, “We’ve had something like 6 days the whole year when it has been over 90°…Our grapes are just barely pea-sized still and I’m think[ing] we could be a month or more behind. Wild.” As July is Sonoma town’s hottest month, on average, the temperature for the rest of the summer is likely to be even more moderate than it has been — a trend that will probably continue, according to the Chronicle article.
Even in the normally baking Central Valley, “There have been few, if any readings of 100 degrees this summer within 100 miles of the coast.” You have to get to practically Las Vegas to experience true, western-style summer heat.
I can’t explain these cooler summers and falls. A weatherman I know once suggested that greater warming in the interior west / Four Corners is creating a gigantic thermal low that sucks in maritime air from the chilly eastern Pacific, where water temperatures struggle to get out of the 50s. It is from these cold waters, of course, that the coast gets its fogs and cool temperatures, driven by prevailing winds from the west/northwest. Maybe that’s the explanation. All I know are two things: People from San Francisco to Los Angeles are grouchy because the summer has been so damned cold, and the winegrapes seem to be loving it. All we can do now is hope that the fall rains hold off until, oh, sometime in November.