A surge in coronavirus cases across the U.S. fueled by the delta variant is prompting a growing number of public health experts to call for everyone to mask back up, especially indoors. Also, Iraq's prime minister is in Washington to meet with President Biden, and on the table is how long to keep U.S. troops stationed in Iraq. And, more than 200 of the world's leading climate scientists come together today — to summarize how the Earth's climate has changed — and what the future looks like.