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Global warming means local (super) storming

The Earth Day rally was incredible. Well over 100,000 people were in the crowd, well over 10x what the Tea Partiers delivered on tax day, so you can figure out which event the media fawned over.

I ended up spending a lot of time chatting with James Cameron, and I’ll do a separate post on what he’s like in person. I also chatted with a few people in the know about inside-the-beltway climate politics who were relatively optimistic that the climate bill can be put back on track. We’ll know more in a day or two. New WashPost story here.

I’m hoping that the Earth Day folks put together individual video clips that I can post later. I had been scheduled for three minutes and ended up with only getting a little over one minute, so I had to gut my carefully crafted talk.

But there was one science-meets-rhetoric riff that I mostly kept, which I thought was a useful rhetorical device: Global warming means local storming. Here’s what I had written:

Global warming means local storming. Global warming makes storms like Katrina more fierce. Record wild-fire-storms in the West, Record dust-storms in Australia, record snowstorms and rainstorms here on the East Coast. Global warming set the table for those local superstorms.

Before the comments and emails come in on how one can’t scientifically attribute any single hurricane to global warming (duh), I’ll just quote from Dr. Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research, back in 2005:

Sea temperatures have risen nearly 1 degree in the tropics over the last century, with most of the rise coming since 1970, and most of that increase can be attributed to the release of carbon dioxide into the atmosphere through the burning of coal and gasoline, he said.

NCAR researchers have correlated the rise from human influences to a 3.5 percent increase in the amount of water vapor in the Earth’s atmosphere. That vapor and the heat it transports is sucked up by a storm as it intensifies.

By Trenberth’s calculation, global warming has raised the heat available to a major storm by about 7 percent.

“So, when a storm is over land, you are probably getting, on the relative order to the same storm in the 1970s, about 7 percent more water,” Trenberth said. “Maybe that is the straw that breaks the camel’s back. Maybe that is the extra water that causes the levee to break.”

I am using the phrase “set the table” because that’s what Stu Ostro, Senior Meteorologist at the Weather Channel, used in making a comparable point about Georgia’s devastating September rainstorms. Of course, Ostro pointed out there was no way to know if global warming had “caused” the record floods, but

Nevertheless, there’s a straightforward connection in the way the changing climate “set the table” for what happened this September in Atlanta and elsewhere. It behooves us to understand not only theoretical expected increases in heavy precipitation (via relatively slow/linear changes in temperatures, evaporation, and atmospheric moisture) but also how changing circulation patterns are already squeezing out that moisture in extreme doses and affecting weather in other ways.

It is the compounding of “typical” extreme weather events on top of human-caused climate change that creates the devastating, record-smashing “global-warming-type” events. To re-excerpt the Must re-read statement from UK’s Royal Society and Met Office on the connection between global warming and extreme weather:

We expect some of the most significant impacts of climate change to occur when natural variability is exacerbated by long-term global warming, so that even small changes in global temperatures can produce damaging local and regional effects. Year on year the evidence is growing that damaging climate and weather events “” potentially intensified by global warming “” are already happening and beginning to affect society and ecosystems. This includes:

* In the UK, heavier daily rainfall leading to local flooding such as in the summer of 2007;* Increased risk of summer heat waves such as the summers of 2003 across the UK and Europe;* Around the world, increasing incidence of extreme weather events with unprecedented levels of damage to society and infrastructure. This year’s unusually destructive typhoon season in South East Asia, while not easy to attribute directly to climate change, illustrates the vulnerabilities to such events;* Sea level rises leading to dangerous exposure of populations in, for example, Bangladesh, the Maldives and other island states;* Persistent droughts, leading to pressures on water and food resources, and the increasing incidence of forest fires in regions where future projections indicate long term reductions in rainfall, such as South West Australia and the Mediterranean.

These emerging signals are consistent with what we expect from our projections, giving us confidence in the science and models that underpin them. In the absence of action to mitigate climate change, we can expect much larger changes in the coming decades than have been seen so far.

The UK’s Royal Society is the UK’s national academy of science, “the world’s oldest scientific academy in continuous existence,” founded in 1660. The Met Office, the UK’s National Weather Service (i.e. meteorological office), is within the Ministry of Defence.

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The point of the phrase “global warming means local storming” is that one of the key ways people are going to experience climate change is through these blow-out, uber-extreme weather events.

UPDATE: As always, the events I focus on here in this context are the record-smashing ones, usually ones that are regional in scope — the super storms:

In that sense, global warming means local (super) storming. And that is precisely why the anti-science disinformers try to shout down any talk of a link between climate change and extreme weather. Don’t let them.