The “breathless media coverage” of this week’s landmark Hothouse Earth study missed the authors’ most important point, veteran climate hawk and meteorologist Eric Holthaus writes on Grist this morning: there’s still time to avert the report’s doomsday scenarios, but right now is the time to get on with the job of decarbonizing the world economy and reducing greenhouse gas concentrations in the atmosphere.
The projections published in the Proceedings of the National Academy of Sciences are just as dire as the cascade of scare headlines suggested—and consistent with what the climate community has been saying since the months before the 2015 UN climate conference in Paris: Even fully meeting the targets in the Paris Agreement won’t be enough to avert a “hothouse Earth”, in which average temperatures increase 4.0 to 5.0°C (6.0 to 8.0°F) above pre-industrial thresholds, sea levels rise by at least nine metres (30 feet), and a domino effect of climate feedbacks releases methane from Arctic permafrost and melts the world’s snow and ice caps.
But Holthaus points to the phrase in the study conclusion that was lost, or at least seriously downplayed, in the resulting news reports: “Humanity is now facing the need for critical decisions and actions that could influence our future for centuries, if not millennia.”
Holthaus stresses that, “yes, the prospect of runaway climate change is terrifying. But this dead world is not our destiny. It’s entirely avoidable. As the authors of the paper have argued in response to the coverage, implying otherwise is the same as giving up just as the fight gets tough.”
The research raises pressing questions about “whether the world’s climate can be safely ‘parked’ near 2.0°C above pre-industrial levels, or whether this might trigger other processes which drive further warming, even if the world stops emitting greenhouse gases,” CBC reports. While the solutions are out there—same as they’ve ever been—the report stresses that attacking carbon pollution directly is just the essential first step.
“Currently, global average temperatures are just over 1.0°C above the pre-industrial period and rising at 0.17°C each decade,” CBC notes, citing the report by scientists from the Stockholm Resilience Centre, the University of Copenhagen, Australian National University, and the Potsdam Institute for Climate Impact Research. That would mean another five to six decades to add another degree Celsius—or to accelerate the full menu of solutions to decarbonize the energy system and draw down greenhouse gases already in the atmosphere.
But the various “feedbacks” that could trigger runaway climate change are the wild card. “It is likely that if a critical threshold is crossed, several tipping points would lead to abrupt change,” including “permafrost thaw; the loss of methane hydrates from the ocean floor; weaker land and ocean carbon sinks; the loss of Arctic summer sea ice; and the reduction of Antarctic sea ice and polar ice sheets,” CBC states.
“These tipping elements can potentially act like a row of dominoes. Once one is pushed over, it pushes Earth towards another,” said study co-author and Stockholm Resilience Centre Executive Director Johan Rockström. “It may be very difficult or impossible to stop the whole row of dominoes from tumbling over. Places on Earth will become uninhabitable if ‘Hothouse Earth’ becomes the reality.”
“Maximizing the chances of avoiding such a hothouse state requires more than just reducing greenhouse gas emissions,” CBC adds. “For example, improved forest, agricultural, and soil management; biodiversity conservation; and technologies that remove carbon dioxide from the atmosphere and store it underground are needed.”
Lead researcher Will Steffen of Australian National University stressed that current efforts to implement the Paris Agreement are “unlikely to help avoid this very risky situation”. He called on countries to “greatly accelerate the transition towards an emission-free world economy,” adding that “collective human action is required to steer the Earth system away from a potential threshold and stabilize it in a habitable interglacial-like state.”
Holthaus says the paper ‘does a masterful job of compiling the evidence (some of which we’ve known for a long time)”. But “we have no choice but to press on through this fear”, since “the next decade will almost surely decide our fate. That should empower us. It means every act has meaning; we have the chance to save the world as we know it every single day. In this scenario we now find ourselves in, radical, disruptive climate action is the only course of action that makes sense.”
He notes that climate scientists, including the report authors, have been responding to the hopelessness in the initial news coverage with exactly that message. “Clearly people aren’t reading the paper we wrote, where our point is exactly that Hothouse Earth is not our destiny and that social system feedbacks are starting to move us to the Stable Earth,” tweeted co-author Diane Liverman. “But media goes for worst case and makes it sound certain.”
The authors “anticipated a defeatist response and published a multi-page document of possible solutions which, when combined with other research on the most important actions people can take, gives a blueprint for hope, not despair,” Holthaus continues. “In the paper, the authors sum this up into a single battle cry. To prevent a hothouse Earth, they say, we need ‘a coordinated, deliberate effort by human societies to manage our relationship with the rest of the Earth System.'”
He adds that “that sounds a lot like the message of a burgeoning global movement targeting the root causes of climate change. That scientists are increasingly comfortable with using language like this—not mincing words anymore—is nothing if not hopeful.”
