with Paulina Firozi Greenhouse gas emissions have plunged since the start of the coronavirus pandemic. At the same time, Earth’s carbon dioxide levels are at their highest point in human history. How could those two things happen at once? The new record during the biggest economic downturn since the Great Depression shows just how hard it is to tackle climate change. My colleagues Andrew Freedman and Chris Mooney report that the carbon dioxide levels are so high because it’s incredibly hard to clear them from the atmosphere. The decline in carbon emissions during the pandemic is just a drop in the bucket compared to how much CO2 humans have released over time. A molecule of carbon dioxide released today can remain up in the atmosphere for hundreds of years. Other greenhouse gases are shorter-lived; methane, for example, dissipates out of the air over the course of decades. “The buildup […]