James Hansen wishes he was mistaken. He was not there.

The best climatologist at NASA in 1988, Hansen warned the world by a record June day, 30 years ago, that global warming was there and was worsening. In a study that was published a few months later, he even foresaw that it would be hot, depending on the emissions of heat-trapping gas.

The warmer world that Hansen was considering in 1988 has almost become a reality, more or less. Three decades later, most climatologists surveyed are ecstatic about the accuracy of Hansen's predictions given the technology of the time. Hansen will not say, "I told you so."

"I do not want to be right in that sense," Hansen said. This is because being right means that the world is heating up at an unprecedented rate and that the icecaps of Antarctica and Greenland are melting.

Hansen says that what he really wants is "that the warning be taken and that steps be taken". They were not. Hansen, now 77, regrets that he has not been able to make this story clear enough for the public.

Global warming was not what Hansen undertook to study when he joined NASA in 1972. The native of Iowa studied Venus. a frantic race to greenhouse – when he's interested in the Earth's ozone hole. As he created computer simulations, he realized that "this planet was more interesting than Venus". And more importantly.

In his 1988 study, Hansen and his colleagues used three different scenarios for heat-retaining gas emissions. way. Hansen and other scientists focused on the middle scenario.

Hansen predicted that by 2017, the average temperature over five years would be about 1.85 degrees (1.03 degrees Celsius) above the average calculated by NASA from 1950 to 1980. NASA's five-year global average temperature, which ended in 2017, was 1.48 degrees above the average of the past 30 years. (He did not take into account the fact that the sun would cool down a bit, which would reduce warming by almost two-tenths of a degree Fahrenheit, said Jeff Severinghaus of the Scripps Institution of Oceanography.) [19659002] Hansen also predicted a number of days of extreme weather – temperatures above 95 degrees, freezing days, and nights where temperatures do not drop below 75 – a year for four US cities in the decade of 2010. His predictions generally underestimated the warming of this decade in Washington, overestimated in Omaha, New York and Memphis

Clara Deser, head of climate analysis at the National Center for Atmospheric Research , said Hansen's temperature forecast was "unbelievable" and its extremes for cities were "amazing" in their accuracy. Zeke Hausfather of Berkeley Earth gives Hansen's predictions a 7 or 8 for accuracy, out of 10; he said Hansen calculated that the climate would respond a little more to carbon dioxide than scientists now think.

University of Alabama Huntsville John Christy, a favorite of those who question climate change, disagreed. Using mathematical formulas to examine Hansen's projections, he concludes, "Hansen's predictions were false, as hypothesis tests demonstrate."

Hansen testified before Congress on climate change at A public hearing in autumn 1987. It was a cool day, he thought.

The next hearing was scheduled for next summer, and the weather added warmth to Hansen's words. At two o'clock in the morning, the temperature reached a record high of 98 degrees and looked like 102. It was then and there that Hansen broke loose and declared that the warming of the planet was already there. Until then, most scientists have simply warned against future warming.

He left NASA in 2013, devoting more time to what he calls his "anti-government" advocacy work

both for environmental protests. Each time, he hoped to go to trial "to draw attention to the problems" but the cases were dropped. He writes about saving the planet for his grandchildren, including one who is suing the federal government because of inaction in the face of global warming. His plea has been criticized by fellow scientists, but he does not apologize.

"If scientists are not allowed to talk about the political implications of science, who will do it? People with financial interests?" Hansen asked.