On June 23, 1988—a blisteringly hot day in Washington, D.C.—James Hansen told a Senate committee that “the greenhouse effect has been detected and is changing our climate now.” At the time, Hansen was the head of NASA’s Goddard Institute for Space Studies, and though his testimony was certainly not the first official warning about the “greenhouse effect”—a report to President Lyndon Johnson, in 1965, predicted “measurable and perhaps marked changes in climate” in the decades to follow—it was the first to receive national news coverage. The Times ran the story at the top of the front page, with a graph showing a long-term rise in average global temperatures.

This week marks the thirtieth anniversary of Hansen’s testimony, and it would be hard to think of a more lugubrious milestone. In the intervening three decades, nearly half of the Arctic ice cap has melted away, the oceans have acidified, much of the American West has burned, lower Manhattan, South Florida, Houston, and New Orleans have flooded, and average temperatures have continued to climb. Just last week, a team of scientists reported in Nature that the rate of melt off Antarctica has tripled in the past decade; as the Washington Post put it, “If that continues, we are in serious trouble.” (Were the Antarctic ice to melt away entirely, global sea levels would rise by two hundred feet; if just the more vulnerable West Antarctic Ice Sheet melted, sea levels would rise by about ten feet.) Also last week, scientists reported that most of Africa’s oldest baobab trees have died, probably because of climate change, and last month researchers showed that rising CO 2 levels were reducing the nutrient content of rice, which is probably the single most important food source for people. Yet Washington continues to ignore the problem, or, worse still, to actively impede efforts to address it. How can this be?

A possible answer, which seems to be the one that Hansen himself, at least in part, subscribes to, is that scientists are to blame. Hansen is now seventy-seven and retired from NASA. He recently told the Associated Press that he regrets not being “able to make this story clear enough for the public.” Many climate scientists seem similarly to believe that they are not good at conveying information to lay audiences, and, as a result, dozens of Web sites and several whole organizations have been created to help them communicate better.

As someone who has interviewed a lot of climate scientists—including, on several occasions, Hansen—I can attest that, as a group, they are not particularly good at expressing themselves. (I once wrote a Profile of Hansen, and watched him lose even audiences predisposed to adore him.) But thirty years into the so-called climate debate—fifty-three years, if you go back to the report to L.B.J.—I also think it’s time to put this particular story line to rest.

Back in 1988, just about the only information available on climate change was written in the dry-as-standard-deviations style of academic science. The following year, Bill McKibben published the first book on the subject aimed at a popular audience, “The End of Nature.” Since then, more generally accessible books have been written on the climate than even the most avid reader could possibly keep up with; these include kids’ books, comic books, and even a coloring book. Meanwhile, countless newspaper and magazine articles, television specials, and documentaries have appeared on the topic. Above all, climate change has become obvious. You don’t need to read or watch or hear about it; in many parts of the world, all you have to do is look around. The southwestern United States, for instance, is currently experiencing such a severe drought that water restrictions are in place and many national forests are closed. “Thirty years ago, we may have seen this coming as a train in the distance,” Deke Arndt, the chief of climate monitoring at the National Oceanic and Atmospheric Administration center in Asheville, North Carolina, recently told the A.P. “The train is in our living room now.”

Instead of using this anniversary to lament the failures of climate scientists, I’d like to propose that we use it to celebrate—well, “celebrate” probably isn’t quite the right word, but maybe recognize—their successes. Three decades ago, led by Hansen, they made a series of predictions; for the most part these have proved to be spectacularly accurate. That we, the general public, have failed to act on these predictions says a lot more about us than it does about them.

I happened to interview Hansen last year, for a video project. I asked him if he had a message for young people. “The simple thing is, I’m sorry we’re leaving such a fucking mess,” he said. Could the message be any clearer than that?