Overwhelmed by the concept of carbon offsets? Here's where to start.

A carbon credit is like a certificate: it records an accounted-for mass of greenhouse gas emissions. The simple move of tracking these gases opens many new possibilities.

It can be difficult to verify the impact of carbon offset projects—which is why transparency and rigor are key.

Is it really possible to make up for carbon emissions? In the first post of a three-part series, here's a look at the wide variety of projects trying to do just that.