How Deadly for Your Child -- or World?

Aug. 29, 2006 — -- If a trusted board of experts told you there was a 65 percent chance that poison was laced into the food on the plate in front of your child, would you say, "Go ahead and eat"?

You'd grab your kid and be out of there.

The Hurricane Katrina anniversary, scientists say, may mark a similar watershed for caution in the American public.

Katrina seems to be the event that impressed people, not so much with the threat of global warming but with the gravity of that threat.

The science linking human-induced global warming to a rising severity in hurricanes may not be 100 percent, but for a year, the public has been hearing scientists -- and other commentators, including Al Gore and a growing number of editors -- report that there could well be such a link.

Most credible scientists suggest the likelihood of manmade global warming greatly altering life on Earth -- and quite possibly within the lifetime of today's toddlers, if we keep burning coal, gas and oil unchecked -- is far above 65 percent, and more likely somewhere in the upper 90's percentiles.

"Post-Katrina" is a phrase now used by scientists and other observers to describe a new public awareness of just how serious the global warming threat may be.

The ghastly spectacle of Katrina-soaked New Orleans, linked even tentatively to climate change, somehow made real the potential of global warming to bring death and disease, to unhinge our way of life and overwhelm government.

Where is that scientific debate now?

"Science linking worsening hurricanes to global warming has advanced significantly in the past year," says global warming analyst and author Susan Joy Hassol, a 20-year veteran of the struggle to communicate climate science to the English-speaking world.

Hassol cites a dozen different studies, the first by MIT professor Kerry Emanuel, published a month before Katrina, that found a spike in sea-surface temperatures over the past 30 years that fit exactly with a spike in the intensification and lengthening of hurricanes over the same period.

The second study, published a month after Katrina, by Peter Webster et al, found that while the total number of hurricanes around the world had remained the same over the past 35 years, the number reaching Category 4 or 5 had nearly doubled -- and this during a period in which the global tropical sea surface temperatures (already closely linked to manmade warming) rose nearly a degree (doesn't sound like much, but as a global average, scientists say, it's major).