Over the weekend, the Intergovernmental Panel on Climate Change released its latest report, a synthesis of scientists' most up-to-date understanding of the slow train wreck of global warming.
For those who keep an eye on climate science, it can be easy to become dismayed. Deadlines slip, political gridlock holds and disheartening records are broken over and over and over again. With all the doom and gloom, one could be excused for thinking that it's already too late to do anything to stop global climate change.
Yet according to the IPCC report there is still hope. The worst of climate change can still be averted, says Brad Plumer for Vox, but we need to get on it like... now.
We're definitely going to see some planetary warming. That part of our fate was sealed by the greenhouse gases we've already released into the air. But climate change is not an all-or-nothing game. There's still time to stop it from getting any worse, says Plumer:
To avoid the worst outcomes, the world would need to act immediately and drastically, reducing emissions 41 to 72 percent below 2010 levels by mid-century. We'd then need to keep cutting and possibly be taking carbon-dioxide back out of the atmosphere by 2100.
As Kabir Chibber puts it for Quartz: “We’ve got 86 years to stop using fossil fuels.”
The scientific consensus is that keeping global temperatures from rising above 2 °C is the threshold for acceptable levels of global warming. The IPCC outlined various approaches to meet this target—but they all end with the elimination of coal, oil, and gas by the end of the century.
We need a huge ramp up in renewable or carbon-free energy sources, like solar or wind, says Plumer, and fossil fuels need to go. This technological switcheroo should be eased by the fact that the price of renewable energy has been plummeting in recent years. Renewable energy is on the rise, but that growth will only matter if fossil fuels are also going down.
Getting rid of greenhouse gas-producing fossil fuels is only part of the problem, says Plumer. We've slipped on our emissions deadlines for so long that the only way we can now keep warming to a reasonable level is if we also develop technologies to pull greenhouse gases out of the air. Those technologies are still under development and are facing severe economic, political and scientific hurdles. But it's possible to see, theoretically at least, how these technologies could work; what's less clear is how humanity would fare in a world of unmitigated warming.
As Justin Gillis notes for the New York Times, the stakes are high. If steps aren't taken to reduce greenhouse gas emissions, climate change “could threaten society with food shortages, refugee crises, the flooding of major cities and entire island nations, mass extinction of plants and animals, and a climate so drastically altered it might become dangerous for people to work or play outside during the hottest times of the year.”
The situation doesn't look great, but it's not hopeless either. Stopping climate change is actually quite feasible, from an economic standpoint, writes Plumer:
The IPCC estimates a cost of only 0.06% of global GDP every year to keep temperatures from rising more than 2 °C in 2100, while global GDP in that same period will grow by 300%. In other words, it is affordable to fight climate change.