The Planet Isn't Doomed. That's Why We Can and Must Act

Like most climate scholars, I worry about the future. I know climate change will cause widespread destruction in the coming century. I fear my children may never escape the sense that things are getting worse. They may take for granted that summer comes with smoky skies and deadly heat; that cities need walls against the sea; that deserts expand and ice sheets retreat; that crops need genetic modification; that coral reefs are dead relics of a gentler time.

But does that mean our human future is doomed? Today, many of the most-read publications and most-shared tweets on the climate crisis predict extinction, and a new survey of young people in 10 countries shows that most of them agree. Climate “doomism” holds that greenhouse gas emissions are soaring beyond control, that runaway heating will continue even if emissions decline, and that ecosystems, then societies, will collapse once heating exceeds thresholds that will soon be reached.

It’s a terrifying thought. But it’s wrong — and dangerous.

To explain why, it’s worth repeating a simple truth: The future of climate change depends, first, on human-generated greenhouse gas emissions and, second, on the sensitivity of Earth’s climate to those emissions.

Let’s start with emissions. Owing in large part to the plummeting cost of solar and wind power, they have plateaued, and should soon begin to decline. Scenarios that forecast soaring emissions, considered likely only a few years ago, now seem implausible.

Yet Earth’s sensitivity to those emissions is so high that, if policies and technologies remain as they are, by century’s end Earth will probably warm by close to three degrees Celsius. Warming of this magnitude, with this speed, could strengthen feedback loops in Earth’s environment that cause still more warming. Heat waves would dry up forests, for example, increasing the likelihood of wildfires that release additional carbon dioxide into the atmosphere, causing more warming, more burning, and so on.

But there’s good news. Emissions — not feedbacks — will probably determine the temperature of the Earth by the end of this century. New research suggests that if we stop releasing more greenhouse gases than environments — and perhaps new technologies — can absorb, the Earth will soon stop warming. How soon would depend on whether we also stop emitting aerosol pollutants and on natural variability in the Earth’s climates. Yet we are not committed to a much hotter future.

“Doomism” also holds that even small changes in average weather have toppled past societies. Some historical societies did indeed suffer when climates changed for natural causes (more modestly than they undoubtedly will this century). Yet the idea of an ideal climate for civilization is based on centuries-old, racist assumptions that only Europe and North America were well suited for human development. Today, research in many fields finds that societies often adapted to past climate changes, and few collapsed. Some societal adaptations were counterintuitive; when land sank relative to sea levels, for example, populations repeatedly gathered near the coast.