What if global emissions went down instead of up?

SOME time in the near future, perhaps as soon as this year, humans are likely to experience something that has never happened in modern history before.

For the first time, global emissions of planet-warming greenhouse gases might finally stop rising and head into long-term decline.

No one alive today has known a time like this. Nor has any other recent generation because, for most of the last 200 years, emissions have risen steadily on an upward path, interrupted only briefly when something like a financial crisis or pandemic causes a global economic shock.