Scientists, speak up on climate change

‘Science has spoken,” UN Secretary General Ban Ki-moon said the other day, presenting the latest dire warning on climate change. “There is no ambiguity in their message. Leaders must act. Time is not on our side.”

One could almost feel the breeze stirred by the broad population’s collective shrug at this news coming from the Intergovernmental Panel on Climate Change meeting in Copenhagen. Almost as astonishing as the looming threat that carbon poisons pose for the planet is the indifference that average Americans seem to feel about it. Such climate denial, now decades old, translates into a lack of political pressure on Washington, which in turn results in the failure of both presidential administrations and Congress to rise vigorously in defense of the environment. Meanwhile the clock is ticking. “Continued emission of greenhouse gases,” the UN panel declared, “will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive, and irreversible impacts for people and ecosystems.”

Science has spoken, Ban said. But have scientists? It seems so: 97 percent of climate scientists say climate change is real, caused by humans, and threatening global catastrophe. Hundreds of scientific societies, academies, agencies, and NGOs have weighed in without ambiguity. Yet reliable polls show that fewer than half of Americans know of this overwhelming scientific consensus. The fossil fuel industry, and the politicians who do its bidding, have waged a remarkably successful disinformation campaign, making it seem that scientists are divided on the question, when they are anything but.

What would it take for the public to get clear both on the unanimity of climate scientists, and on the urgency of what they see coming? An answer from the recent past suggests itself: scientists, instead of merely providing activists and journalists with irrefutable climate data, must leave their cloistered laboratories to become activists themselves. Scientists must take to the streets and lead, even if that means taking hits in the contentious public square.

It happened before, when scientists helped steer the human species away from suicide. The Cold War nuclear arms race might well have run on to Armageddon had not a remarkable cohort of physicists, astronomers, mathematicians, and physicians put their detached analysis at the service of moral fervor. They became passionately engaged advocates of disarmament — organizing international meetings, sounding alarms, headlining demonstrations, and demanding action from politicians. They brought incomparable authority to the debate because they had the ultimate insider knowledge — empirical evidence that the worst nuclear fears were, in fact, not bad enough for what threatened.

In 1977, for example, the MIT-based Union of Concerned Scientists, led by the physicist Henry Kendall (who later won the Nobel Prize in physics), issued the “Scientists’ Declaration on the Nuclear Arms Race.” On the Soviet side, Andrei Sakharov, often called the father of Moscow’s H-Bomb, offered a 1981 declaration, “The Responsibility of Scientists.” Sakharov summoned his global peers, “the only international community which really exists,” to take up the urgent “moral and universally human problems.” Once nuclear annihilation was on the agenda, Soviet and Western scientists began an astounding collaboration, with intermingled groups like The Pugwash Conferences on Science and World Affairs and the Physicians for the Prevention of Nuclear War. For the sake of the formerly “unscientific” question of morality, scientists risked their reputations for analytical objectivity. In some cases they risked careers. In the USSR, Sakharov was condemned to a life of internal exile.

But the scientists’ campaign took hold. In 1984, the astrophysicist Carl Sagan deliberately cultivated a huge audience for his book, written with other scientists, “The Cold and the Dark: The World After Nuclear War,” a dramatic evoking of atmosphere-choking consequences of a nuclear exchange. The popular imagination was so seized by this vision of “nuclear winter” that even a one-time nuclear hawk like Ronald Reagan began to understand that, as he put it, “a nuclear war cannot be won, and must never be fought.” Mikhail Gorbachev invited Sakharov home to Moscow. Having learned from the publicly engaged scientists, and having been pressed from below by masses of citizens who embraced what the scientists taught, Reagan and Gorbachev together steered the world away from nuclear war.

Such a transformation must happen again. The Union of Concerned Scientists is still at it, and so are some others. But compared to the Cold War era, the voices of scientists today are mute. Yet the danger is equivalent. Who but climate scientists can effectively refute the lies of the carbon lobby? Where are you?

Related coverage

James Carroll writes regularly for the Globe.