BOB HERBERT: Hot Enough Yet?

The heat wave burned its way east from California, where it killed more than 100 people. It moved relentlessly across the nation’s midsection, sparking record-high temperatures in state after state, mimicking a heat wave that killed more than 700 people in the Midwest in 1995.

For the past couple of days it has tormented the East Coast, draining power systems and creating a hellish environment for the frail and infirm, and especially for the elderly poor struggling to survive without the blessings of air-conditioning.

You can’t blame any single weather event on global warming. But with polar bears drowning because they can’t swim far enough to make it from one ice floe to another; with the once-glorious snows of Kilimanjaro about to bring down the final curtain on their long, long run; with the virtual disappearance of Lake Chad in Africa, which was once the size of Lake Erie, it may be time to get serious about trying to slow this catastrophic trend.

(It’s also time to aggressively counter the dangerous nonsense of people like Senator James Inhofe, the Oklahoma Republican who has been openly contemptuous of the idea that human activity has contributed to global warming, and Senator Conrad Burns, a Montana Republican whose head has always had the habit of migrating to extremely peculiar places, in this instance into the very hot sand.

(Senator Inhofe has said that “man-made global warming is the greatest hoax ever perpetrated on the American people.” Senator Burns, according to a publication called “Environment and Energy Daily,” shrugged the matter off completely, saying: “You remember the ice age? It’s been warming ever since, and there ain’t nothing we can do to stop it.”)

As I’m writing this, the lights have been dimmed in much of The New York Times Building, in accordance with the request of Mayor Michael Bloomberg that New Yorkers conserve as much energy as possible. The temperature in the city is right around 100 degrees.

It’s certainly true that heat waves in July and August are not unusual. But we need to keep in mind that the first six months of this year were the warmest ever recorded in the United States. And that this summer, according to the National Climatic Data Center, more than 50 cities in the continental U.S. have set records for high temperature.

We should keep in mind, as Al Gore has pointed out, that of the 21 hottest years ever measured, 20 have occurred within the last 25 years. And the hottest year of this recent hottest wave was last year.

Those who are familiar with the cold and fog of the Bay Area in northern California should consider the following summation of the latest heat wave from Sunday’s San Francisco Chronicle: “In northern California, it was hotter for longer than ever on record, hitting 110 degrees four consecutive days in the nine-county Bay Area.”

There’s more. Seth Borenstein, the science writer for The Associated Press, reported yesterday that in recent years, the U.S. has had more than three times its normal share of extremely hot summer nights. “That is a particularly dangerous trend,” Mr. Borenstein wrote. “During heat waves, like the one that now has a grip on much of the East, one of the major causes of heat deaths is the lack of night cooling that would normally allow a stressed body to recover.”

Referring to the spike in nighttime temperatures, Richard Heim, a research meteorologist at the climate center, said in the article: “This is unbelievable. Something strange has happened in the last 10 to 15 years.”

Unlike Senator Burns, there are people who understand that there are things we can do to mitigate the worst effects of global warming. We’d better do something fast. We’re no longer waiting for the tragedies predicted to result from extremely high temperatures, extreme weather events, storm surges and so forth. We’re already enduring them.

Remember New Orleans? And the thousands who died from the heat in Chicago and elsewhere in the Midwest in 1995? And, as incredible as it still seems, the 35,000 killed by a monster heat wave in Europe in 2003?

I think the single most effective thing most ordinary Americans could do to become more informed about global warming — and the steps we need to take to fight it — is to go see Al Gore’s movie, “An Inconvenient Truth,” and read his book of the same title.

It would be a shame if it turns out that Americans have been so deprived of leadership for so long that they fail to recognize it when it’s offered to them.