In 2015, at COP21 in Paris, international leaders settled on a goal to limit global warming to 1.5 degrees Celsius. In the decade since, that has become both a rallying cry and a shorthand for climate action. At multiple United Nations climate conferences, it has been turned into a quippy plea to “keep 1.5 alive.”

But it doesn’t seem as if that messaging has been the most successful. It has been nearly a decade since that goal was first announced, and yet greenhouse gas emissions have continued to soar. 2024 is on track to be the warmest year yet.

At the beginning of November, scientists with the Copernicus Climate Change Service (C3S), part of the European Union’s Earth Observation Program, said it was “virtually certain” that 2024 would be the first year to exceed 1.5 degrees of warming (compared to preindustrial levels). “This marks a new milestone in global temperature records,” said Samantha Burgess, deputy director of C3S.

That report was released before the latest COP climate conference in Baku, Azerbaijan, and yet at those talks, the 1.5 degree messaging still prevailed. That mismatch may be part of the reason why some Americans still don’t believe in climate change, or don’t have a sense of urgency around climate action.

1.5 degrees is a goal—but not a message

To John Marshall of the nonprofit marketing firm Potential Energy Coalition, that insistence on talking about 1.5 degrees of warming is a clear communications problem that holds back the climate movement. For years, Marshall was a marketing executive who worked for companies like Walmart and Bank of America. He started his nonprofit specifically to address the messaging around climate change.

“We’ve known about the scientific problem for a while now, but regular people haven’t known the extent of the human problem very much,” he says. “There’s been a really big gap. And so we haven’t necessarily had the public will that we need on the issue.”

It’s good for leaders to have the goal of limiting global warming to 1.5 degrees, because you can’t make progress without one. But the problem with a goal—especially as the crux of how we talk about climate change—is that it creates a binary. “Climate change is not a binary thing,” Marshall says, noting that 1.5 degrees is talked about as if we must prevent it—or else—but the world doesn’t immediately end at 1.5 degrees.

“We’re gradually warming, so if it’s 1.5 degrees, it’s bad. If it’s 2.5 degrees, it’s pretty darn bad. If it’s 3 degrees, it’s awful,” he says. What that does is downplay the crisis: If we hit 1.6 degrees of warming and the planet is still standing, it gives fuel to detractors. “One of the things you read on conservative blogs about the climate movement is ‘They’ve been saying we’re going to be dead for a long time, and we’re still fine,” Marshall says.

Of course, the planet isn’t fine. Things weren’t fine for residents of Asheville, North Carolina, when they experienced some of the worst impacts from Hurricane Helene (a storm that climate change helped intensify), even though they were above sea level and 300 miles from the coast. Or for any of those living in places destroyed by recent wildfires. But such climate impacts can be localized, so not everyone feels those extreme effects at once. Still, climate change will affect us all, and emphasizing its impact—perhaps with something tangible, like how it will affect people’s energy bills—can be a way to reach people more personally.

Admittedly, 1.5 degrees also sounds like a small number. Marshall’s Potential Energy Coalition surveyed a representative sample of people from 23 different countries to ask them what they thought the U.N.’s target on global warming is. “The average citizen on the planet thought it was 4 degrees,” Marshall says. That illustrates how people don’t understand the stakes behind that goal—and so they aren’t taking it seriously.

So while limiting the increase in average global temperature to 1.5 degrees above preindustrial levels might be the right scientific goal to prevent the worst of climate change, “Should it be the dominant goal from a communications point of view?” Marshall asks. “Does it motivate people?” It seems clear the answer is no.

How to communicate the climate crisis instead

To get people to understand the threat of climate change and actually take action, Marshall says we need to think more about how to motivate individuals. He advocates for goals around pollution, as opposed to temperature, which can be more relatable. (A “net zero” goal, though, comes with many of the same issues as talking about 1.5 degrees Celcius: It’s not clear to people what that actually means, and talking about reaching “zero” isn’t exactly motivating. “Who wants to go to zero?” Marshall says. “People want to go to abundance.”)

Pollution is something people can connect to, and can get directly involved with. They could work to instill better practices at their workplaces, or support something like congestion pricing in their community. Talking about degrees doesn’t allow for the climate conversation to get down to that level of individual action, and most people may not understand how their actions are tied to temperature.

If a politician is talking to his constituents, then, he shouldn’t harp on about 1.5 degrees—but he should talk about ending “expensive, dirty energy.” (This phrasing touches on another point of disconnect: Even though the price of solar has dropped about 90% in a decade, fewer than 20% of people think renewables have gotten less expensive.)

If someone wants to motivate action around transportation emissions, they shouldn’t talk about banning gas cars—another binary that can alienate people. (When the Potential Energy Coalition tested policy messages, ones that used mandate, ban, or phaseout were less effective.) They can get to the same point, Marshall says, by saying, “Let’s reduce tailpipe emissions 4% each year.”

“That’s a much more effective way to communicate with the public,” Marshall says. “No one would disagree with a reduction in pollution every year. The slope of the curve needs to be messaged more than the end point.” The problem of climate change is gradual, and so the solutions should be, too.

Just hearing “keep 1.5 alive” doesn’t explain the consequences of not doing so; and in general, current climate messaging doesn’t talk about consequences in an easily relatable way. It also doesn’t emphasize the irreversibility of climate change. For physical pollution, plastic can be cleaned out of rivers, but carbon pollution stays in the atmosphere, contributing to warming. Mentioning “irreversible” warming could then be one of the most important phrases anyone talking about climate change uses to increase urgency.

“Every incremental amount of pollution that happens creates irreversible overheating . . . that creates damage to our communities and our pocketbooks and home insurance rates and all those kinds of things,” Marshall says. “And we need to act now, because everything we do is irreversible.”