As important as it is to acknowledge progress, it is equally important to counter the disinformation that says we no longer need to worry about the climate future—whether that disinformation comes from the president or from purported climate experts … 3 degrees Celsius, the 2100 outcome of the medium-emissions scenario, would amount to catastrophic, civilization-threatening levels of warming. According to the most recent IPCC report, 3 degrees Celsius of heating would mean that, for around three months of the year, the entire East Coast of the United States—from Maine to the Midwest and the Great Plains—and half of California would be exposed to “hyperthermic conditions that pose a risk of mortality.” Southern California, the Southwest, the Deep South, and Florida would be this fatally hot nearly half the year.