The United Nations’ climate change research group issued a new report on Monday with an unequivocal finding: We’re in deep trouble.
The new 1,300-page paper from the Intergovernmental Panel on Climate Change is the sixth assessment of its kind, and the most damning in its conclusions. The planet is already 1.1 degrees Celsius warmer than it was in the late 19th century, but we may well reach the 1.5-degree threshold—the level the U.N. Paris Agreement prefers to stay under—by the end of this decade or the next even if we reduce greenhouse gases. We’re now at a point where past emissions, especially those that intensified throughout the 21st century, have locked us in for potential decades of ripple effects.
The worldwide cohort of 234 scientists who contributed to the report stated that humans are “unequivocally” responsible for this state of affairs, which will affect “all regions” of the globe—including supposedly climate-friendly cities—by hastening the frequency of heat waves, formerly once-in-a-century storms, droughts, and sea level rise, as well as the pace of glacial and permafrost melting. And a worst-case outlook of heightened emissions in the coming decades could affect certain areas with an outsize impact, though our best models don’t know for sure yet. This outcome may consign the Greenland ice sheet to nothingness, leading to irreversible sea level rise. The Atlantic Meridional Overturning Circulation, an essential ocean current that helps determine weather patterns, could gradually become less stable and predictable, leading to calamitous rains across the Eastern Hemisphere. And forests could die off at a rate outpacing reforestation efforts. The fact that any of these hypotheses are even being considered as possible is a terrifying acknowledgment of the wrath of the changing climate.
The popular takeaway from the previous major IPCC report in 2018 was that we only had until 2030 to slice global emissions in half before we reached a watershed for human habitability. That was always a somewhat dubious calculation, but there’s no doubt that the pathway for substantial action is narrower than ever before. As the new report explains, the increase in global temperatures recorded since the publication of its predecessor was spurred by “further warming since 2003–2012.” Each oil well or coal plant is a liability that will come due in the future, and we can’t take that back.
So, it all seems pretty bad. But there’s a useful, instructive, and perhaps hopeful way to look at the horrifying numbers.
One of the key lines notes that every half a degree Celsius increase causes “clearly discernible” jumps in the intensity and frequency of global warming effects. We already know what 1.1 degrees Celsius looks like from the tragedies of this summer: heat waves, flooding, relentless rain and storms and disasters, droughts and water depletion. So contemplating further half-degree increases may seem scary, but it also provides a worthy aim: to reduce that increase as much as possible until the world can get to carbon neutrality or, ideally, a majority-renewables-powered global economy.
It’s worth looking at the bounds we’ll be working within. The IPCC laid out five different scenarios, from a future where we move to very low or low emissions to one where we keep pumping more gases. The lower bound will likely keep us under a 1.8-degree Celsius increase, while a doubling down of the status quo could lead to heating of 3.3 degrees to 5.7 degrees Celsius. (If you’re wondering why the worst-case range varies so widely, it’s worth reading about the difficulty of predicting feedback loops.) The report also notes that “changes in several climatic impact-drivers would be more widespread at 2°C compared to 1.5°C global warming,” so preventing that worst-case scenario is imperative—the 2 degree increase cannot be seen as a safety net.
The report also reminds us that we know the villains, and we know solutions. It notes that “global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in CO2 and other greenhouse gas emissions occur in the coming decades.” Those “other greenhouse gas emissions” include sharp spikes in nitrous oxide, primarily from agriculture and melted permafrost, and methane release, primarily from natural gas as well as the gaseous output of farmland cows for the dairy and beef industries. The report also states that the burning of fossil fuels is responsible for more than half of total carbon emissions and contributed the large bulk of harmful gases over the past decade. So it’s clear the burden should fall on global business, especially those extractive energy corporations that operate in larger and wealthier nations. If we are going to cut emissions by the necessary amount—net zero emissions sooner than later—we need to pressure the polluters themselves. And despite skepticism from some activist circles, we will need these very polluters to use carbon capture technology to remove gases directly from the air.
Thankfully, the report arrives to a citizenry more engaged with the issue than ever before. A few hours after the report went online earlier Monday morning, the IPCC’s website crashed from the incoming traffic. Citizens of Paris Agreement signatory countries are already demanding more from their politicians, who are once again tweeting anodyne statements about the key crisis of our lifetimes. Crude oil prices took another plunge following the report’s conclusions, throwing into question the supposed business case for fossil fuels. The eye-opening 2018 report seemed to escalate global awareness of climate change in an unprecedented way, with more protests and lawsuits and policy initiatives flourishing in the aftermath. This new report may spur even more.
We are no doubt in for more horrors to come. This summer has been unbearable all on its own; there will be more seasons like it, and worse. But human and animal and plant life is still here, and the report offers a guide for righting the ship. Now we need our leaders to follow it, or be forced to do so before they find themselves saddled with even bigger disasters.