There are few pragmatists when it comes to climate change, but if they were numerous enough to make their voices heard, their argument against action to reduce emissions might go like this: Humans are already on course to change the climate significantly, and our species is terrible at the long-term planning necessary to slow the increase in emissions. The best we can hope for is a robust adaptation plan, perhaps implemented locally and regionally, where natural-resource management is most nimble.
But let us consider results from climate change projections a bit further into the future. If we examine projected outcomes at the end of the 21st century rather than midcentury, the differences between the business-as-usual and mitigation scenarios are dramatic. In our Los Angeles study, under business as usual the region would experience another large increment of warming over and above what already occurs by midcentury. It would be warmer by a total of eight degrees. Three months of the year would have days when the maximum temperature exceeded 95 degrees, which would mean we’d have a new season of extreme heat. Southern California currently has significant snow at high elevations in the winter, but by the end of the century this snow would nearly disappear. This scenario also sees dramatic changes in water resources and in areas burned by wildfire. The ecological consequences are difficult to quantify, but it doesn’t take much imagination to realize that what’s left of the region’s natural landscape would be transformed beyond recognition, hosting different plant and animal species. Meanwhile, in the mitigation scenario, end-of-century temperatures are similar to their midcentury values. The other climate impacts are also comparable to those projected for the earlier period.
On the global scale, sea level would rise something like 17 inches under mitigation and 29 inches under business as usual. Some summer Arctic sea ice is projected to survive at century’s end if greenhouse-gas emissions are curtailed. But if we don’t curtail emissions, the ice will probably disappear. So our emissions choices will profoundly affect the planet’s condition at the end of the century.
Our pragmatic friends who propose adaptation as the only response have to defend the idea that the effects of climate change on the midcentury world can be considered in the moral equation but the effects on our end-of-century world cannot. At some point in the distant future we stop caring about the well-being of our species and rely instead on intervening generations to do the planning for us. But does it make sense to discount the interests of those who will be living at the end of the century, some of whom are already alive?
It’s also worth examining the other assumption of the pragmatist’s argument, that we are inherently bad at long-term planning. Consider a long-term project that involved profound political and societal change: the struggle for racial equality in the United States. Since the country’s founding, those who promoted racial equality knew it would take an effort extending well beyond the lifetime of any single individual. Among the country’s founders, some, including John Adams, explicitly opposed slavery. They accepted the constitutional arrangements that permitted it because they calculated that the language of equality and individual rights created a contradiction with the institution of slavery. They knew it would eventually have to be confronted. Within a few decades, they were proved right, and the country fought a civil war over slavery. Abraham Lincoln also understood the abolitionist project as part of a long struggle rooted in the promises of the founding documents. In spite of his opposition to slavery, he advanced the abolitionist cause only incrementally. Once slavery was eliminated and the struggle for social equality took center stage, civil rights campaigners also understood that the struggle would take time. The 2008 election of the first U.S. president with African ancestry was understood by most Americans to be an epochal moment. President Barack Obama’s election was an achievement built on at least two centuries of political and social change.
Similarly, the human role in climate took a few centuries to develop. Its roots go back at least to the beginnings of the industrial revolution in the late 18th century. Carbon emissions probably began to have a detectable impact on climate sometime in the mid–20th century. It took generations for the human influence on climate to emerge, and it will probably require generations to slow down or reverse that process. We’ve become accustomed to confronting problems with short-term fixes, and we keep waiting for a silver bullet to make our greenhouse-gas emissions disappear. When it fails to materialize, we throw up our hands and declare the problem beyond addressing. Looking back at the history of race relations in America, it’s easy to imagine how intractable a problem racial inequality must have seemed. For decades, many declared the status quo to be the only practical option.
Yet others kept chipping away at the status quo, and even though racial inequality and discrimination persist, those efforts led to a changed society. According to Martin Luther King Jr., “Faith is taking the first step even when you don’t see the whole staircase.” King would have found my houseguest’s cynicism about the light-rail line to Santa Monica entirely misplaced. The year 2016 is no further in the future now than 1966 was in 1963. And when King led the 1963 March on Washington, he knew it would take longer than three years to achieve a color-blind society. Some may believe the light-rail line to Santa Monica is too small a step or too far in the future to make a difference. But that belief condemns us to put off other small steps that would make a difference when added together.
We have to acknowledge the irreversibility of climate change. Like my disappointed houseguest, we can’t fight the physics of slow ocean warming, and we can’t wave a wand to make greenhouse-gas emissions disappear. Every region needs a climate-change adaptation plan for the coming few decades. But beyond that point, further climatic changes—perhaps to a point where the planet’s state is unrecognizably different—are not inevitable. If we care about the condition of that world, the only way to avoid those changes is to do what people have always done when faced with an overwhelming project: Get started.