To save world from the climate change apocalypse, we need to start cutting greenhouse gas emissions by 2020, a group of scientists claims. We have just three years to do this, or the planet will warm to levels that kick off irreversible, catastrophic climate changes.
To help avoid the worst-case scenario, the scientists set six milestones to reduce carbon emissions across sectors, including energy, transportation, and infrastructure. The goals range from expanding renewables to reducing deforestation, to issuing “green bonds” to finance climate-mitigation efforts. This position paper appears in the journal Nature, just ahead of a meeting of world leaders in Hamburg, Germany.
Next week, a meeting of the world’s 20 major economies, called the G20, is taking place, and members include the US, European Union, China, India, Mexico, and Russia. Together, these countries emit close to 90 percent of all heat-trapping greenhouse gases, says Angel Hsu, the director of the Yale Data-Driven Environmental Solutions Group. The point of the paper isn’t to declare our world doomed, but to serve as a wake-up call to these countries. Ideally, the paper will spur more effort and innovation to halt climate change, said lead author Christiana Figueres during a phone call with reporters.
“I’m the first one that says, it does seem like it’s a heavy lift from where we are now to 2020,” said Figueres, who is the former head of the UN Framework Convention on Climate Change and oversaw the negotiation of the Paris climate agreement. She’s now the leader of the climate change action campaign Mission 2020. “But we’re fully convinced that with intentionality and with ingenuity … we can actually get to 2020 and be able to witness the turning point of greenhouse gas emissions, without which we would put ourselves into a very dangerous situation.”
The article has a lot of specific goals for the world in 2020. Renewable forms of energy like wind and solar should make up at least 30 percent of the world’s electricity supply. Coal-fired power plants should be shut down, and no new ones should be approved. At least 15 percent of all car sales should be electric vehicles, and cities should double mass transit use. We should stop cutting down forests, and instead plant new trees that can suck up carbon dioxide. And governments, banks, and international bodies like the World Bank should mobilize at least $1 trillion a year for climate action.
Ideally, this will slow the pace at which our world is changing. Right now, things are looking scary: every year, our planet seems to break its own temperature records; ice sheets in Antarctica and Greenland are increasingly melting; sea levels are rising faster and faster; and coral reefs are starting to collapse under the weight of warming seas. These changes have been unleashed by a temperature increase of just about 1 degree Celsius (2.1 degrees Fahrenheit) since the late 19th century — that’s how delicate Earth’s balance is.
It’s also why the Paris climate agreement — a landmark deal that commits almost every country in the world to reducing greenhouse gas emissions to fight global warming — set a goal of keeping global warming well below 2 degrees Celsius (3.6 degrees Fahrenheit). Most scientists see this as the “magic threshold” beyond which the climate change is irreversible and apocalyptic, says Hsu. Think melting polar ice caps, rising sea levels and extensive flooding, killer heat waves, bleached coral reefs, food shortages, and deadly diseases. “The list goes on,” says Hsu, who’s one of more than 60 co-signatories of today’s article.
Scientists are scrambling to understand how a warming planet will affect the world, and it’s not entirely clear where runaway climate change kicks in. Still, people need numbers to make policy, so 2 degrees Celsius is where scientists have landed. “Nobody really knows” where the cutoff is, Hsu says. But “if there was no clear targets or concrete benchmarks, we wouldn’t know what to gauge progress against and what we need to be working toward.”
Even if all the Paris agreement pledges are met, the world will still probably warm up by 3 degrees Celsius, according to the United Nations. Many countries pledged to cut part of their greenhouse gas emissions by 2025, 2030, or even 2050, but that’s too late, Hsu says. We need to act now, and that’s why today’s article is so important. “When it comes to climate, timing is everything,” the authors write.
And even the relatively modest requests of the Paris climate agreement faced strong opposition. Earlier this month, President Donald Trump announced that he will pull the US out of the agreement. Trump also directed his administration to repeal several Obama-era policies to reduce carbon pollution and stop new coal mining leases on federal lands.
But Trump’s an outlier. Hundreds of mayors across the US — Democrats and Republicans — have vowed to address climate change and commit to renewable energy. For the past three years, the world’s CO2 emissions from fossil fuels have stayed flat, while economies grew. And renewable energy saw $286 billion in investments in 2015, which is more than six times what it was in 2004.
World leaders should harness this momentum and take action now, the authors say, with milestones for energy, infrastructure, transportation, land, industry, and finance. Hsu, who worked with the authors as well as industry leaders and other scientists to come up with the action items, says they are “politically feasible.” But it’s unclear whether the G20 leaders will decide to embrace them. That’s the most challenging hurdle.
“I’m not sure how realistic capping emissions by 2020 really is,” says Rebecca Robinson, an associate professor of oceanography at the University of Rhode Island’s Graduate School of Oceanography. “It seems really a difficult stretch, especially given the current political climate toward climate action.” The authors admit that “these goals may be idealistic at best, unrealistic at worst.” But Figueres says, that market forces — like the falling prices of renewables — are pushing climate action forward, and countless of businesses have come out in favor of the Paris deal and cutting greenhouse gas emissions.
These scientists remain optimists in the face of a possibly apocalyptic future. “If you work on climate change like I do, it’s really easy to get depressed by the situation,” Hsu says. “But you have to think about what can be done.” If the experts still believe there’s a way to turn this around, maybe it’ll be a little easier for the rest of us to have some hope, too.
