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DATE: March 3, 2019

SNIP: After struggling with heart disease for decades, the renowned climate scientist Wallace Smith Broecker had made it clear he was acutely aware of his own mortality. So when he sat down in front of a video camera to record a final message to his fellow scientists in mid-February, the 87-year-old researcher knew his days were few.

The man who popularized the term “global warming” and first described the critical role oceans play on climate had an urgent message for 40 of the world’s top climate scientists. Humanity is not moving quickly enough to slow the production of carbon dioxide that is warming the Earth, Broecker said Feb. 11, his livestreaming image projected onto a big screen at Arizona State University, where researchers had met to discuss untested solutions to global warming.

It was time for humankind and the world’s scientific community to begin to seriously study more extreme solutions to the climate crisis, Broecker said. That included creating a massive solar shield in the Earth’s atmosphere, a tactic known variously as “geoengineering,” “the sulfur solution,” “solar radiation management” and the “Pinatubo Strategy.”

A week after his dramatic appeal, Broecker died of congestive heart failure, inspiring praise for his work as the “grandfather” of modern climate science. His death, and his final message to scientists, re-energized the debate over the sort of re-engineering of the Earth’s climate systems that Broecker and other academics had broached as early as the 1970s.

Many scientists have been hesitant about pursuing such an extreme measure, citing scientific, ethical, legal and political dilemmas. Tampering with Earth’s atmosphere was not a preferred alternative, Broecker had acknowledged, but he insisted that his fellow academics needed to be ready, should last-ditch measures be needed to prevent a climate catastrophe.

Broecker told the symposium that he had worked with another prominent climatologist on mechanical units that might remove carbon dioxide from the atmosphere. But 100 million of the devices would be needed to get the job done, he said, and there was no sign that the world’s leaders had the political will to get the job done.

A majority of the world’s climate scientists may oppose radical geoengineering, but most of those who heard Broecker’s words agreed that research on the sulfur solution should proceed.

“This was the last message from someone who shaped our field for half a century,” said Peter Schlosser, the lead organizer of the symposium and vice president of Arizona State’s Global Futures program. “I don’t think his effort and his determination was lost on anyone.”

That sense of moment was acknowledged even by those … who disagreed with Broecker’s position. Those scientists believe that sulfur injections into the atmosphere have too many potential pitfalls. They could alter weather and rainfall patterns so severely that agriculture would be disrupted on a mass scale. They could trigger unknown collateral weather calamities. And, perhaps the biggest concern of all: They could prompt humanity to continue with the dangerous burning of fossil fuels.