‘No Dumb Questions’: Is there a deadline to fix climate change?

Dave Levitan,  Angelo Leotta, and Tom Nagorski

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In 2018, the world got a particularly sobering report from the Intergovernmental Panel on Climate Change (IPCC): On its current path, the planet would be locked into a rise of more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial temperatures — and it would happen in just 12 years. And that 1.5-degree target, set forth in the landmark 2015 Paris Agreement, has been highlighted as a level of warming beyond which the impacts of climate change grow catastrophic. It appeared that a crucial deadline was fast approaching.

But climate change doesn’t quite work that way — where a date on the calendar arrives and a line in the sand is crossed and only then does it all go to hell. Instead, each ton of greenhouse gases emitted is slowly but surely thickening the warm blanket surrounding the planet, sending temperatures steadily higher and incrementally increasing the risks of extreme heat waves, stronger storms, melting ice sheets and more. So when the question arises, “Is there a deadline to fix climate change,” perhaps the best answer is this: The “deadline” to slow and stop climate change is today, and then tomorrow, and then the day after that.

It’s certainly not a “dumb question.”

A deadline can muddy the waters as to what needs to be done. Along with the temperature targets, scientists also refer to a “carbon budget,” meaning the amount of carbon that can be emitted before the temperature thresholds are crossed. In its most recent update, the Global Carbon Project, which tracks the carbon budget, said: “If current emissions levels persist, there is now a 50% chance that global warming of 1.5°C will be exceeded in nine years.”

And that, of course, sounds like another deadline — when what it is is really more of a warning. The fact is that whether it’s nine years or 12 or some other time frame, each ton of CO2 that is sent into the atmosphere will push the thermometer slightly higher.

None of this is to say that the target temperatures and deadlines associated with them are entirely arbitrary — they do have some science behind them. For example, according to the IPCC, sea level rise by 2100 would be 10 centimeters worse at 2 degrees than at 1.5 degrees — a big difference for some of the low-lying nations and coastal cities of the world. Most impacts, from species extinctions to heat waves, will tick up considerably in that space between the two temperature targets.

And there may be some utility to the idea of a climate “deadline” if it helps paint a clearer picture of the urgency of the problem.

In general, anything that convinces people of the need to act is beneficial. But from a scientific perspective, “deadlines” don’t really exist when it comes to climate change. There’s really just the ever-growing urgency to reduce emissions. And the frequent reminder: The best time to do so was yesterday.