The climate as we know it may be in the rear-view mirror, and there is precious little time to change course before careening past a dangerous threshold for global warming.

That was the sentiment expressed by United Nations Secretary-General António Guterres during fiery remarks, which followed new data released today by the World Meteorological Organization and the European Commission’s Copernicus Climate Change Service.

“Like the meteor that wiped out the dinosaurs, we’re having an outsize impact. In the case of climate, we are not the dinosaurs. We are the meteor,” Guterres said in the speech he delivered from American Museum of Natural History in New York City — where dinosaur skeletons tower above visitors in the lobby — on World Environment Day today. “We are not only in danger. We are the danger. But we are also the solution,” he said.

Last month was officially the hottest May in history, marking 12 straight months of the hottest on record. We’ve seen that play out with record-smashing heatwaves around the world, and there’s not much relief in sight.

Policymakers and UN climate scientists are focused on a key milestone: the point at which global average temperatures are consistently 1.5 degrees Celsius hotter than they were before the Industrial Revolution. The most ambitious target of the landmark Paris accord is to keep the world from breaching that threshold. Otherwise, the effects of climate change grow markedly worse — straining and potentially surpassing the world’s ability to adapt.

2023 was already the hottest year on record, but likely not for much longer. There’s now an 80 percent chance that at least one of the next five years will be more than 1.5 degrees Celsius hotter than the preindustrial average, according to the World Meteorological Organization (WMO). When the Paris agreement was struck in 2015, there was a near 0 percent chance of that happening.

While one year of extreme heat certainly takes its toll, climate scientists are most worried about those temperatures becoming the new norm. The WMO says there’s now a roughly 50 percent chance that average temperatures over the next five years will also be more than 1.5 degrees Celsius hotter than the preindustrial era. Last year, there was only a 32 percent chance of that happening.

The odds are rising against us because greenhouse gas emissions from fossil fuels continue to climb. Scientists have calculated how much planet-heating carbon dioxide can still be released before that pollution is enough to push the world beyond a permanent 1.5 degrees of warming. That carbon budget is now down to 200 billion metric tons of pollution, Guterres said today. That’s actually a small number considering global carbon dioxide emissions reach about 40 billion metric tons a year.

At those numbers, we have about five years left of business as usual before that Paris target is out of reach. And while there’s much political wrangling about what it would take to avoid 1.5 degrees of warming, Guterres reminded people that there are real-world consequences.

“It is not a goal. It is a physical limit,” he said. “Every fraction of a degree of global heating counts. The difference between 1.5 and 2 degrees could be the difference between extinction and survival for some small island states and coastal communities.”

Compared to 1.5 degrees, 40,000 more people could see their homes inundated at 2 degrees of warming. The proportion of the global population exposed to extreme heatwaves at least once every five years jumps from 14 to 37 percent with just half a degree of warming at the global level.

With a shrinking carbon budget, global CO2 emissions would now have to fall by 9 percent every year this decade to stop global warming at 1.5 degrees Celsius. That is a greater plunge in pollution than the world experienced in 2020, when the covid-19 pandemic curbed economic activity and slashed CO2 emissions by more than 5 percent. Emissions would need to fall to net zero by 2050.

Guterres, at least, is still holding out hope that countries can change course with a sharp turn toward renewable energy. After all, solar and onshore wind farms are already the cheapest source of electricity for most of the world.

Clean energy investments have nearly doubled over the past decade, reaching a record high last year. That progress needs to accelerate, he urged. Renewables make up 30 percent of the world’s electricity mix. But there are big inequities in how that’s rolling out, with only 15 percent of clean energy investments in emerging and developing economies outside of China. Less than 1 percent of new renewable energy capacity was installed in Africa last year.

There’s also a lack of funding to adapt to the effects of climate change, building homes and cities that are more resilient to rising seas and temperatures. There’s only about five cents of funding available for every dollar needed to adapt to extreme weather, Guterres warned.

“If money makes the world go round, today’s unequal financial flows are sending us spinning toward disaster,” he said. “We cannot accept a future where the rich are protected in air-conditioned bubbles, while the rest of humanity is lashed by lethal weather in unlivable lands.”