ANOTHER DAY, another study showing terrible news for the climate. There is a danger that scientists’ findings are coming so often and sounding so dire that even thoughtful observers will tire of being alarmed. But alarm is the only reasonable reaction.
Last week began with the news that greenhouse gas emissions from the United States shot up 3.4 percent last year, a rattling reversal from recent years. Republicans who favor doing little to nothing on climate change often argue that U.S. emissions have been declining without more federal intervention. But it is fantasy to imagine that the pace of decline, let alone the even more aggressive rate of change the world needs, is sustainable without government action. The nation must adopt policies such as a carbon tax that would encourage economic growth without emissions growth.
Also last week, the journal Science published a study finding that the oceans are warming at a terrifying pace, 40 to 50 percent faster than the United Nations had previously estimated. The world’s waters soak up nearly all the extra heat humans help add to the Earth’s energy balance, and the consequences will include more massive coral die-offs, depleted fisheries, sea-level rise, flooding, mega-storms that pack more power and rain, and less oxygen in the ocean that undersea creatures need to live. Already, a fifth of the world’s corals have died in the past three years, a harbinger of the changes to come.
By Monday, yet another study, published in the Proceedings of the National Academy of Sciences, revealed that Antarctica’s enormous ice reserves are melting six times faster now than they were between 1979 and 1989. Warming ocean water and deteriorating ice structures help explain the accelerating pace. Faster melting in the coming years means that ocean levels could rise even higher than the already predicted three feet globally by 2100, barring a change in course. Experts have more research to do, particularly on the state of East Antarctica’s enormous glaciers; the prospect of large-scale ice deterioration there is horrifying.
These findings, particularly the new ocean warming estimates, underscore a crucial point in the climate debate. Critics point to uncertainties around climatic observations and predictions, arguing that things might be better than experts’ median estimates suggest. But things might also be worse. Scientific uncertainty cuts both ways. By doing too little to respond to the warming threat, humans are effectively betting their future on the notion that the climate consequences of their behaviors will fall on the relatively benign end of the spectrum of possibilities. But they could also fall on the far more severe end. World leaders should be scrambling to buy insurance against that risk by investing in emissions-free technologies.
Instead, President Trump ignores the issue except to dismiss it, and even leaders who acknowledge the problem do too little. Future generations will find it unthinkable that the world responded so weakly in the face of such clear warnings.