If I could wave my magic wand and we all had electric cars tomorrow, I think this is what the air would look like, says chemistry and earth and planetary sciences professor Ron Cohen, an air quality researcher, referring to the beneficial side-effect of improved air quality during the COVID-19 shutdown. He and his team are monitoring air quality, and through an analysis of satellite measurements they've found a 32% decline in levels of nitrogen dioxide pollution over the first three weeks of shelter-in-place rules in Southern California, compared to the prior three weeks. They also, however, found a 26% reduction between the same periods in 2019, suggesting that spring weather contributed to the effect. "Driving is dramatically lower," he says, "but differences in weather between this year and last still make it hard to put numbers on how much cleaner the air is because of the shelter-in-place." Expressing dismay about how the pandemic is helping his research, he says: "It's terrible to get that view by people getting sick. ... It's not at all how we would design the experiment if we had a choice."