The most definitive analysis yet of the effect of the #coronavirus on global emissions finds a 17 percent plunge in early April. But this will be short lived, and total 2020 emissions may only fall 3 to 7 percent https://www.washingtonpost.com/climate-environment/2020/05/19/greenhouse-emissions-coronavirus/?tid=ss_tw w/ @brady_dennis @JohnMuyskens

2. Here's another chart by @JohnMuyskens showing the regional emissions declines. The peak decline of about 17 percent would have been higher if all countries had locked down at the same time. But China, the biggest emitter, of course shut down first.

3. And a third figure shows how this works out by sector. Airlines plunged the most but then, they're a smaller net contributor to emissions. Transport drove a huge part of the decline. People hunkering at home actually saw their power use increase for the residential sector.

4. So what do we make of all this?

Well, if an emissions decline like this were to happen 9 more times, or in every year of this decade, it would greatly change the globe's climate trajectory, moving us much further away from 3C of warming by 2100 and down toward 2C or less.

5. But scientists don't expect that at all. Rather, this year is a huge and understandable anomaly due to the pandemic, and the emissions drop is instead expected to be a "blip," according to Stanford's Rob Jackson.

6. Other experts, like Corinne Le Quere of the UK's Tyndall Center, say the lockdowns show what happens if you rely on lifestyles change, rather than energy system changes, to cut emissions. It seems like something much more structural would be needed for sustained reductions.

7. So -- nobody expected this sudden, tragic experiment, but there are lessons from it about emissions. The question now is what happens with economic recoveries, and whether these will include new sustainability measures amid the push to put people back to work. /end