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By 2030, we as a collective 7 billion humans will know our fate, or at the very least, the fate of the most vulnerable among us. A landmark report released on Sunday sets the clock ticking for humanity and its quest to keep global warming to within 1.5 degrees Celsius of pre-industrial levels.


The report from the Intergovernmental Panel on Climate Change outlines what a world warmed by 1.5 degree Celsius would look like compared with the 2 degree Celsius warmer world enshrined in the Paris Agreement, and the pathways to get there. It shows that a 1.5 degree warmer world is much less brutal than a 2 degree warmer one, and that we have a lot of work to do in a very limited time in order to achieve it.

If we fail, the poorest among us will suffer the most.

Our world has already warmed about 1 degree Celsius since the start of our carbon pollution bender. Based this observation and physics, scientists have crafted a carbon budget for meeting the 1.5 degree Celsius goal. In the new report, they lay out the pathways to get there.


In the most hopeful scenario, innovations in efficiency and technology spur huge drops in energy demand, speeding along decarbonization of the energy system and obviating the need for unproven carbon capture technology. In another, nations harmoniously come together and we shift to a more sustainable lifestyle and buy fewer tchotckes . We need a little carbon capture to help do some mop up, but with the kumbaya spirit, anything is possible.

If technological innovation or emissions continue on their current trajectory, though, efforts to cap warming at 1.5 degrees Celsius become dicier. We’ll need more carbon capture, more reforestation and more converting crops to biofuels that sequester carbon. In one scenario, the world would have to convert slightly less than the equivalent of the entire U.S. into a biofuel sacrifice zone.

All scenarios that limit warming to 1.5 degrees require massive global investments: on the order of $2.4 trillion annually from 2016-2035. For comparison, the world spent roughly $280 billion installing renewable energy last year. We’re talking an order of magnitude more commitment on top of rejiggering the entire global economy, though one that could come with massive financial upside.

“These systems transitions are unprecedented in terms of scale, but not necessarily in terms of speed, and imply deep emissions reductions in all sectors,” the report states.


But the scientists who wrote the report are undeterred. In fact, the granular nature of the report, which looked at over 6,000 studies, white papers, and policy documents, is a helpful way to think about the various levers we have at our disposal to address carbon pollution.

“There’s a perspective that somehow there’s one solution to climate change. There’s not,” Kristie Ebi, a University of Washington scientist and lead author the summary for policymakers of the new report, told Earther. “There’s a million solutions. When you look at each one of these, they can be relatively small. It’s when you put them together that become large and powerful.”


The report also makes a powerful moral argument for reducing emissions, as well as the inevitable adaptation efforts that will be necessary. Page after page, it lays out how the poor will disproportionately suffer from global warming and how much of a difference a half a degree could make. The report’s authors note that limiting global warming to 1.5 degrees “could reduce the number of people both exposed to climate-related risks and susceptible to poverty by up to several hundred million by 2050.”

We often talk about 2 degrees of warming as “safe.” But what 2 degrees really means is that we lose coral, see massive ecological upheaval, ocean acidification, and multiple feet of sea level rise. It’s a few threads away from the complete unraveling of a planetary fabric that’s allowed humans to thrive.


Limiting warming to 1.5 degrees Celsius will still result in planet-wide suffering. Instead of losing all coral with 2 degrees Celsius, the report shows we’ll lose 70-90 percent of them. Most low-lying islands will become uninhabitable. Both scenarios call for courage and hard work to avert the worst while still preparing to deal with some awful things.

And we’ll know if we’re on track in 12 years time. To keep the planet from warming more than 1.5 degrees Celsius, emissions will have to drop roughly 45 percent below 2010 levels by 2030. All of us can make some lifestyle choices to start to bend the curve. But it’s largely government policies and actions to address the larger economic system today that’ll set the course for humanity.




“The world 50 years ago was different from today,” Natalie Mahowald, another lead author of the report from Cornell University, said. “In 50 years, it’s going to be very different. This is our chance to decide what that world will look like.”

Unfortunately, good decision making has been in short supply at this crucial juncture. The Trump administration—which heads the world’s largest historical emitter—is using the argument that a million actions are needed to address climate change to justify precisely the opposite as well as its intent to pull out of the Paris Agreement. Speaking of, most countries aren’t on track to meet their wholly inadequate pledges to the agreement. Current policies will result in a world that’s up to 3.7 degree Celsius (a devilish 6.66 degrees Fahrenheit) warmer by 2100, upping the risk that we’ll have to put more eggs in the carbon capture basket or the even more disconcerting reflecting sunlight back into space to cool the planet basket. Kumbaya feels a long ways away.


The new report comes two months before the next major international climate conference will be held in Poland. That conference is meant to outline how governments will ramp up actions to address climate change. While I’m not naive enough to think a single report alone will change the course of history, I’m glad that world leaders will have a reminder of the stakes of their actions.