Most of the vetting files had a section called "red flags," where the vetting team noted concerns about potential top officials. Axios categorized them all — for the nearly 100 people whose vetting documents we received.

Since October of last year, border patrol has arrested almost a quarter of a million child migrants who crossed the border alone or with their family, a Customs and Border Protection official told Axios.

Why it matters: The U.S. immigration system is not set up to handle this surge of young migrants mostly from Central American nations — and it's breaking down.

Capturing carbon dioxide emissions is probably unavoidable to address climate change, but the technology to do it is still in its infancy, expensive and not broadly understood.

The intrigue: We're here to show you something none of us can really see — CO2 emissions are invisible to the naked eye — and the technology that's just getting off the ground. Keep reading to see an illustrated description of the main ways CO2 can be captured.