Bangladesh, Dec. 8 -- For years, Kim Cobb was the Indiana Jones of climate science. The Georgia Tech professor flew to the caves of Borneo to study ancient and current climate conditions. She jetted to a remote South Pacific island to see the effects of warming on coral.

Add to that flights to Paris, Rome, Vancouver and elsewhere. All told, in the last three years, she's flown 29 times to study, meet or talk about global warming.

Then Cobb thought about how much her personal actions were contributing to the climate crisis, so she created a spreadsheet. She found that those flights added more than 73,000 pounds of heat-trapping carbon to the air.

Now she is about to ground herself, and she is not alone. Some climate scientists and activ...