Carbon farming is trendy—but is it all just hype?

Using farms to capture and store more carbon in soil is becoming trendy, but the science is still not settled on how much it can help to address climate change.

The theory: Soil naturally stores some carbon, mostly from decaying plants and animal matter. A study last year estimated that global farmland could capture and store as much as 3 billion additional tons of carbon if farmers adopted several improved practices.

Put into practice: California has started providing small grants to farmers who employ these techniques, and Boston startup Indigo AG is exploring their potential too.

In reality: There is still huge uncertainty over how much of a climate benefit these efforts provide, and whether there are better ways to balance out the farming industry’s greenhouse gas emissions. And some experts say it’s a huge diversion distracting us from more important priorities.

—James Temple