We need to cut global greenhouse gas emissions by more than half over the next decade in order to stave off the worst impacts of climate change, says a blockbuster new report. The next few years represent a crucial crossroads, the international group of scientists said, as the choices we make could make or break our efforts to avert catastrophe.
The Intergovernmental Panel on Climate Change, the world’s leading scientific body on climate change, put out its latest report on Monday. While the world has made some progress in cutting emissions, carbon pollution is outpacing that progress, continuing to rise each year—and the impacts are becoming even more dire. Climate change is reshaping the world and its ecosystems quicker than previous forecasts had predicted. However, there’s still a path forward to reverse the tide—but it’s a “rapidly closing window of opportunity,” the report states.
“The climate time-bomb is ticking,” UN Secretary General António Guterres said in a press call Monday. “But today’s IPCC report is a how-to guide to defuse the climate time-bomb. It is a survival guide for humanity.”
It can seem like news coverage of climate is just an endless series of studies and scientific bad news—but if you’re going to listen to just one report, make it this one. It’ll tell you everything you need to know.
What is the Intergovernmental Panel on Climate Change, and what is this report?
Every five to seven years, the IPCC, which is composed of hundreds of scientists from around the world, reviews the science on climate change to create a huge analysis of where the world is and where it could go; this is the sixth time the IPCC has done this.
For this cycle, the IPCC has already put out three installments of this analysis, based on tens of thousands of studies: one on the physical science behind climate change; one on the impacts climate change is having on the world; and one on the ways the world could move forward to curb warming. This report is the summary of those three installments, as well as three special reports issued within the same timeframe.
There’s a lot of work that went into this particular report, but the science itself isn’t new. Think of this, rather, as a huge cheat sheet to guide the world on what is going on and what we need to do. It’s what governments and businesses will be—or at least, should be—using to guide their strategies over the next several years.
Okay, so what does the IPCC say about where we’re at?
The world has warmed 1.1 degrees Celsius (2 degrees Fahrenheit) above preindustrial levels, and much of that warming has been “unequivocally caused” by human activity, primarily through the use of fossil fuels, the report states. Shockingly, about 42% of our net historic emissions since 1850 occurred between 1990 and 2019. And while we’ve been able to cut some of these emissions, our overall emissions from energy, industry, transportation, agriculture, and buildings have kept climbing. Average annual emissions between 2010 and 2019 were the highest on record.
This shift has led to “widespread and rapid” changes in the atmosphere, the oceans, and ecosystems across the world. This report notes that the scientific links between rising emissions and heatwaves, rising sea levels, droughts, storms, and heavy precipitation are stronger than ever; these changes are only projected to increase as the planet keeps warming. The fallout from these changes—wildfires, species extinction, the collapse of food systems, natural carbon sinks transforming into carbon emitters—is already happening and will accelerate if we keep on emitting.
We’ve been able to adapt to some of these changes, but we’re quickly hitting our limits. And with every additional increment of warming, the fallout will get worse and worse; some ecosystems have seen so many changes that they are “approaching irreversibility.” Many of the projected changes are more intense and/or would happen quicker than previous IPCC reports had estimated, emphasizing how quickly our continuing addiction to fossil fuels is altering the planet.
“Some future changes are unavoidable and/or irreversible but can be limited by deep, rapid and sustained global greenhouse gas emissions reduction,” the report states. “The likelihood of abrupt and/or irreversible changes increases with higher global warming levels. Similarly, the probability of low-likelihood outcomes associated with potentially very large adverse impacts increases with higher global warming levels.”
Is there any hope for the climate?
Importantly: yes. The report finds that we still have legitimate pathways to staving off disaster. In the report, the IPCC modeled several potential scenarios—known as “pathways”—for how we deal with warming over the next few decades, ranging from taking immediate action to aggressively transitioning to renewable energy to, effectively, doing nothing. Prioritizing equity and justice to help everyone on the planet adapt and live in a climate-changed world will be key in this transition, the report states.
The Paris Agreement, which governments signed in 2015 and which forms the backbone of climate policy, set a bare-minimum goal of limiting heating to 2 degrees Celsius (3.6 degrees Fahrenheit) by the end of the century, with a stretch goal of keeping warming under 1.5 degrees Celsius (2.7 degrees Fahrenheit). Half a degree might not sound like a lot, but there’s a gulf between the reality of a 2 degree and a 1.5 degree world: with 2 degrees of warming, an additional 65 million people would experience “exceptionally” extreme heatwaves each year, for instance.
It’s still possible to hit that 1.5 degree target. But to keep warming under that level, the report finds, global greenhouse gas emissions would need to peak within the next two years—and even then, we’ll probably still overshoot that target, relying on technologies and natural resources that create negative emissions to bring us back down. To stick to that 1.5 degree target, the report states, our greenhouse gas emissions need to peak by 2025 and CO2 emissions need to be cut 65% by 2035—a new set of goals set out in this report.
Our current setup isn’t helping the problem. The policies in place in the world make it almost certain that we’ll exceed warming by 1.5 during this century and make it more difficult to keep warming below 2 degrees. What’s more, the existing fossil fuel infrastructure we have in place is itself enough to get us to 1.5 degrees of warming; adding in planned new projects, the report says, would blow us past 2 degrees.
If there’s no new science, why is this report important?
Since these reports only come out every five to seven years, the next one is due to start around 2030; the intervening years between now and then, according to this report, will be crucial for righting the ship. Countries will also be submitting their next round of pledges to cut emissions at the 2025 global climate summit; these cuts will be absolutely essential.
Basically, this report is the guidebook for what will form one of humanity’s defining decades: whether or not we can stave off mass catastrophe.