IT IS AN invisible, deadly menace. It’s causing almost unfathomable economic destruction. We knew it was coming, but were caught woefully unprepared. It tricked nations into blaming one another—the US being the primary antagonist—instead of working together to stop it.   It is the novel coronavirus SARS-CoV-2, and it is climate change. The two are intimately linked: As you’d expect, emissions have fallen as people drive less and industries grind to a halt. But dig deeper into how the pandemic is influencing the climate, and surprising and often counterintuitive dynamics begin to emerge. This is your guide to those complexities.   Editor’s note: We’ll be updating this story as more research becomes available.   Yes, Emissions Are Falling. But Not for Long   Back in February, an analysis by the climate group Carbon Brief found that as the pandemic seized hold of China’s economy and heavy industries shuttered, emissions from the country plummeted by an incredible 25 percent. Another analysis by Carbon Brief in early April estimated that globally this year, emissions could fall by 5.5 percent from 2019 levels. That figure may seem low, given that fewer cars are on roads and industries have stalled, but with context, it’s stunning: Until now, emissions have been reliably increasing by a few percent year after year. That’s happening even though the world’s nations pledged to individually reduce their emissions as part of the Paris Agreement, with the ultimate goal of keeping warming below 2 degrees Celsius above pre-industrial global temperatures.   The 5.5 percent figure tops the 3 percent reduction in emissions that followed the 2008 financial crash, when economies also slowed and people traveled less. But emissions bounced right back as the economy recovered. Indeed, says Zeke Hausfather, the director of climate and energy at the Breakthrough Institute, which advocates for climate action, we can expect economies to roar back with fervor to make up for lost income. “Broadly speaking, the only real times we've seen large emission reductions globally in the past few decades is during major recessions,” Hausfather told WIRED in March. “But even then, the effects are often smaller than you think. It generally doesn't lead to any sort of systematic change.”   Electricity Use in the US Has Declined Slightly, But Gasoline Sales Dropped Big Time   Anecdotally, we can say that Americans are driving far less, given all the empty freeways. And now Northern Arizona University climate scientist Kevin Gurney has the data to back it up: The amount of gasoline supplied in the US—a close measurement of direct consumption—fell by 50 percent over the two-week period ending April 3. “Not surprising, given what we all would expect to happen, but it’s just stunning to see it,” Gurney says. “I’ve never seen anything like it in my 25 years of looking at this data.”   Interestingly, the amount of diesel supplied has remained fairly stable. That’s probably due to it being more of a commercial fuel, used for the semi trucks that are still making deliveries while the rest of us keep our cars in the garage.   Electricity use across the country has declined a bit, but nowhere near as dramatically as with fuel supplies. “I think the speculation is a lot of the activity that uses electricity isn’t going down, it’s just shifting where it's occurring,” Gurney adds. “So instead of commercial buildings being leaned on a little more heavily between 9 and 5, we’re at home using energy.”   This might offer a clue to why the emissions reductions worldwide are so much smaller than the 25 percent reduction scientists saw in China’s emissions earlier this year. It could depend on the structure of different nations’ economies. China is a major manufacturing center, which uses massive amounts of energy to keep production running. But the US and many other nations have offshored much of their manufacturing and transitioned into being service economies. When China’s workers go home, those emission-heavy industries close down. When workers in some other nations go home, they keep working, shifting the energy consumption from offices to houses. Don’t assume, though, that industrial energy consumption in the US won’t also change dramatically in the coming weeks. “We’re still in the middle of this,” Gurney says. “I would be hesitant to say that we’re not going to see a big industrial signal. I think it tends to lag a little bit because a lot of industry will continue to produce.”   This Is Our Chance to Reinvent Cities   If the streets are a city’s veins, cars are the blood coursing through them—but they’re a pathogen, of sorts. Cars killed over 6,000 pedestrians in 2018 in the US, and air pollution kills perhaps 200,000 more here each year.   With all those cars now sequestered in garages, air quality around the world has gone through the roof. In March, for instance, researchers at Columbia University calculated that carbon monoxide emissions in New York City, mostly coming from vehicles, fell by 50 percent. With that will come a dramatic improvement in public health, and at just the right time: New research from the Harvard T.H. Chan School of Public Health has shown that air pollution is associated with higher Covid-19 death rates. They did this by looking at 3,000 US counties and comparing Covid-19 deaths and levels of fine particulate matter in the air. They found that even small increases in long-term exposure to the pollutants leads to significantly higher mortality. That makes sense, since this is a disease that attacks the lungs.   But maybe our suddenly clearer skies don’t have to be temporary. We’re getting a taste of how much more livable our cities would be if we designed them for people, not cars. Closing roads to cars altogether—as cities like Boston and Oakland, California, have done during the crisis—means people can walk and bike in safety, itself a boost to public health.   “We call this a ‘psychic outcome,’ of people realizing what we’ve absorbed from the slow intensification of urban life as it relates to vehicles,” Gurney notes. “It’s potentially a moment where we can get a clearer picture of what we’ve slowly kind of numbed ourselves to. Cities are profoundly dominated by vehicles.”   Done incorrectly, though, a rethinking of cities could exacerbate inequalities. Cities have, necessarily, severely curtailed public transportation to curb the spread of the new coronavirus. But this disproportionately affects those who can’t afford cars, and who might rely on public transport to get to their essential jobs or shop for food.   “The actions cities are taking that are purely to give people room to roam, not necessarily room to get anywhere, I think they’re useful,” Tabitha Combs, who studies transportation planning and policy at the University of North Carolina at Chapel Hill, told WIRED in April. “But I don’t think they’re enough and I don’t think they’re equitable.”   In a Weird Way, Some Air Pollution Actually Reduces Warming   In March, researchers at the University of Washington and Goethe University Frankfurt published a study that quantified one of the stranger consequences of air pollution: It can actually bounce the sun’s energy back into space, thus helping cool the planet.   Specifically, they looked at a phenomenon called cloud brightening, in which the particulate sulfate pollution that cargo ships spew makes its way into clouds. The sulfate particles attract water vapor, making a cloud brighter, and therefore better able to reflect sunlight. Ships actually leave trails of brightened clouds known as “ship tracks” as they chug across the oceans.   The researchers analyzed a shipping lane in the south Atlantic Ocean, which conveniently has winds blowing along it, instead of across it. For this reason, they could clearly delineate how reflective the clouds are directly over the lane, and just outside it, and compare the two. The effect turns out to be substantial: The brightened clouds can block an additional 2 watts of solar energy from reaching each square meter of the ocean’s surface.   They then calculated what that would mean at the planetary scale over both land and sea, and found that, in general, pollution-seeded clouds block 1 watt of energy per square meter of planet Earth. For comparison, anthropogenic greenhouse-gas emissions trap 3 watts per square meter. “We’re saying globally, from all types of industrial pollution, that has offset approximately a third of the greenhouse gas warming that we've experienced to the present,” says University of Washington atmospheric scientist Michael Diamond, lead author on the study.   That’s got Diamond and his colleagues wondering how that phenomenon is now playing out across the world as air quality improves. This of course varies with the fuel: The reason cargo ships seed clouds so well is that they use super-dirty fuel that flings lots of sulfate into the air (less so now, though, as international regulations mandating low-sulfur fuel went into effect January 1). Coal and natural-gas power plants on land don’t produce sulfates on the scale that ship fuel does. The researchers also have to factor in how land and sea absorb the sun’s energy differently. While you might think the ocean would be great at reflecting light, if you look at it from space, it’s basically black. That’s why the oceans have been warming so dramatically of late.   To be clear: Air pollution is a major threat to human health. The carbon monoxide cars spew is toxic, and CO₂ has led to runaway global warming. But in a bizarre way, this specific type of emission seems to help cool the planet.   Cheap Oil Means the Pandemic Is Producing Mountains of Plastic Waste   Even before the coronavirus pandemic, the economics of recycling were a mess. For it to make financial sense to recycle plastic bottles, a recycling company has to make more money selling the recycled material than it takes to gather and process those bottles. Given the low price of oil in recent years, it’s often cheaper for companies to buy virgin plastic bottles than recycled ones. (And oil producers’ sales have crashed and the price of oil cratered even further now that we’re all staying home.)   In the age of coronavirus, many recycling facilities are shutting down to protect their workers, so what little was recycled before now isn’t recycled at all. At the same time, we’re consuming more single-use plastic than ever. We’re stocking up on soap and hand sanitizer, and Amazon is hiring 100,000 extra workers to keep up demand, packing individually wrapped products into boxes. People are getting plastic-sheathed takeout from restaurants instead of dining in and eating off of reusable plates with metal utensils. “So disposability is going like crazy,” Tom Szaky, the founder and CEO of the recycling company TerraCycle, told WIRED. “And during Covid, we saw that the recycling equation that was bad anyway and trending down is even worse.”   Every Nation Needs a Big, Bold, New Green Deal   An inconvenient truth about fossil fuels is that they’re an extremely useful and cheap form of energy. For an economically developing country in particular, the allure of fossil fuels is they allow rapid industrialization. Renewable energies like solar wind are still relatively expensive to set up compared with coal and natural gas, which is why governments usually subsidize them to green their economies.   But looking back at the 2008 financial crisis shows a way forward: The stimulus package in the US helped invigorate the green-energy economy by pumping $90 billion into the development of technologies like geothermal power, biofuels, and solar energy. “If you look at the data, a few years after that, you do start to see a huge increase in solar,” says Louisiana State University environmental scientist Brian Snyder.   The likelihood of the Trump administration doing the same has about a snowball’s chance on this increasingly warm planet. But if the feds keep interest rates low to make borrowing easier and jump-start the economy, it’ll be easier to finance a wind farm or solar facility. “So that might be an effect where certainly the administration didn't mean to do it, but they nonetheless sort of juice the ability of some renewable energy systems to replace coal,” adds Snyder. The challenge, though, will be making those systems economically attractive enough given the staying power of oil, which is now even cheaper thanks to the pandemic.   Climate Research in the Coronavirus Age   Scientists, they’re just like us—in the sense that they too are stuck at home during the pandemic. And that’s a big problem for climate science. “It’s disruptive, there’s no question,” says Gurney, the climate scientist at Northern Arizona University. “For anybody who’s got to do fieldwork, or relies on things that aren’t automated instrumentation out there, this is a serious, serious problem.”   If you can’t get on a boat, you can’t collect data on how the oceans are warming and acidifying. Scientists who monitor the effects of climate change on wildlife can’t go out and collect photos from camera traps. Conserving species imperiled by climate change isn’t a passive process—conservationists have to be out there actively monitoring and preserving their habitats. If you study how permafrost is thawing in the Arctic, you’re out of luck as well. Even if a scientist can collect data remotely, for instance by aggregating government data, they may not have access to the requisite computing power at home.   “There will probably be a record gap that’ll be a problem, and if it goes on long enough it’ll be a real problem,” says Gurney. “A few weeks, you could say 'Well, we might be able to deal with that.' But if it turns into months, that becomes a significant problem for anybody who has to go out in the field.”