“So record-high CO2 emissions, even though they stay flat, translates directly into a record-high CO2 increase” in the atmosphere, he said.

Because carbon dioxide hangs around for so long, we’ll be feeling the warming effects of this year’s jump in concentration years in the future — even if we stopped all our greenhouse gas emissions today. And Tans added that it’s not only atmospheric levels of carbon dioxide that we have to worry about, but also oceanic levels as well.

There’s a continuous gas exchange that takes place between atmosphere and ocean, Tans noted. Scientists say that  at least half of all the carbon dioxide we’ve poured into the air since the industrial revolution has likely been absorbed into the sea. But it hasn’t disappeared forever, he cautioned.

“If we then proceeded by technical means — by some invention or some chemical engineering development — to pull CO2 out of the atmosphere and bury it, then the additional CO2 that’s in the oceans will come back into the atmosphere,” Tans said. Such technology, often referred to as “negative emissions,” has actually been proposed by scientists as a possible future means of combating climate change. It’s a long way from becoming a reality at the moment, but Tans noted that even if it reached that point, it still wouldn’t be able to completely reverse the climate crisis.

“It’s not enough to pull the excess that’s in the atmosphere at that time — we’d also have to pull out what went into the oceans,” he said. “If we want to undo this, we would have to artificially pull out all of the cumulative emissions since preindustrial times.”