On June 23, 1988 NASA’s James Hansen told the U.S. Congress that global warming had begun — and he predicted it was just going to get worse and worse as levels of human-caused carbon pollution kept rising.

“Thirty years later, it’s clear that Hansen and other doomsayers were right,” the AP explained this week after talking to more than 50 scientists.

Indeed, earlier this year, NASA Goddard Institute for Space Studies (GISS) tweeted out that “the five warmest years on Earth have all occurred since 2010.”

NASA scientists' most recent annual global warming temperature chart.

But 30 years ago, there was nothing like Twitter. To get the message out, then Sen. Tim Wirth (D-CO) held a hearing on a hot summer day about climate change in front of more than a dozen TV cameras and countless reporters. He showcased Hansen, who was director of NASA’s GISS.


“The greenhouse effect has been detected,” Hansen told the Committee on Energy and Natural Resources as temperatures that day hit 101°F in the nation’s capital, “and it is changing our climate now.”

Humans were enhancing the natural greenhouse effect by burning fossil fuels, sending billions of tons of heat trapping CO2 into the air, he explained. That’s why temperatures had been climbing in recent years and over the longer term.

The New York Times featured Hansen’s testimony the next day on its front page with the headline, “Global Warming Has Begun, Expert Tells Senate,” along with a NASA chart of warming temperatures.

NY Times story on James Hansen's famous global warming testimony in June 1988.

The Times explained: “Until now, scientists have been cautious about attributing rising global temperatures of recent years to the predicted global warming caused by pollutants in the atmosphere.” Hansen was bravely sticking his neck out to warn the nation and the world.

The hearing, its media coverage, and the fact that the warming did continue just as Hansen had predicted, made him perhaps the most publicly recognized scientific leader on this issue over the next three decades.


But it’s briefly worth noting that Hansen had in fact been warning about the dangers of global warming for many years before that testimony.

In 1981, he led a team of NASA scientists in a seminal article in the journal Science, entitled “Climate Impact of Increasing Atmospheric Carbon Dioxide.”

They wrote: “Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.”

All of those predictions have come true. Is there anyone else on the planet who has been right for so long about climate change?

Over the decades, Hansen was been joined by thousands of scientists in making accurate predictions of human-caused climate change. Indeed, the White House itself released a massive report in November from America’s own top scientists confirming the science and warning of catastrophe in the decades ahead if we don’t finally start listening to climate scientists.


But despite all of this confirmation by direct observation and scientific analysis — which has been embraced by every other nation in the world — the dangerous reality today is that we have a president and GOP political leadership who not only reject the policies needed to avert catastrophe, they still reject the science.

We are running out of time for America to join the world in adopting the ever-stronger climate policies needed to avoid ruining our livable climates for centuries.

If we fail to act, we can try to say to those suffering the consequences 30 years from now that it was politics that stopped us from doing the right thing. But we won’t be able to say weren’t warned.