Top of the News: As someone who misspent more than half his life in Phoenix, let me tell you the prime fact about the heat we've experienced in recent days: It is deadly. That's double so for cities with little air conditioning. Ask Chicago, where 600 died in a 1995 heat wave.

Thanks initially to an urban heat island created by sprawl, Phoenix's temperatures have risen 10 degrees in my lifetime. The fifth most populous city in America just suffered through its hottest July on record. Add in the likely consequences of global warming, and it's hard to believe Phoenix will be habitable as what we would consider a modern American city in 50 years.

Seattle needs to pause from the "you can tell your grandkids about the great heatwave of '09," and take stock of potential climate-change effects here, including, for the sake of this blog's mission, the economic ones. For this may not be a twice-a-century event any longer.

Earlier this year, scientists at the U.S. Climate Change Science Program, issued a sobering report on the gathering evidence that global warming is already affecting America, not merely the Third World (the consequences of which will be mammoth). Unforeseen changes are a particular concern.

For the Northwest, it warned of declining snowpack, wildfires, sea-level rise and additional stresses on species such as salmon. Disappointingly, it did not dwell much on the consequences for metropolitan areas (beyond sea-level change), where most Americans live and where most economic activity is generated.

Meanwhile, NASA released a report indicating that the world will warm much faster than projected over the next five years. This supports several other recent studies about the speed of climate change. In the West, this summer is seeing record temperatures and risk of forest fires.

The issue will continue to be debated -- scientists, who unlike talk-radio screamers, must rely on time-consuming data gathering, won't be able to say definitively that climate change caused our heat wave. So, as with the entire climate change issue, little will be done. And the verities of weather will diffuse a bias for action. If the research holds, Seattle might see a cool summer next year, but then another one like this in three to five years. Then, it will appear every other summer. Then every summer. The debate will continue.

There will be winners (air-conditioning installers, AC-cooled hotels) and losers (the tourist industry, fisheries, forests, public health, where to put "climate refugees," etc.). At some point, the costs of air conditioning an entire nation of 300 million -- especially as places such as Phoenix, Houston and Atlanta suck more from the power grid -- will be very difficult. The economic costs will far outweigh any benefits, even the short-term breather for old industries, of doing nothing to address climate change. This is especially true considering American lethargy in sustainability and green tech, despite hype over "cool concrete" etc.

Yes, my great-grandparents homesteaded in Phoenix in the late 19th century. People wrapped themselves in wet sheets at night (and, again, the summer lows were far cooler than now). But these were people culled by a harsh land. Most of us today couldn't live through it. Most couldn't then.

It's something to think about as much of the media are tittering trivially about the heat and people ask, "Hot enough for you?"

Today's Econ Haiku:

The bubbles have burst
Except for those in China
We'll all take that bath