Video: How do we verify climate treaties?

As of May 2017, about 90 percent of all countries around the world have committed to the ambitious Paris Agreement to combat global climate change. The shared goal is to rein in greenhouse gas emissions enough to maintain global temperatures just two degrees Celsius above pre-industrial levels.

But how to confirm that countries are maintaining their pledges, and how can they be encouraged to do better than their pledges? UC Berkeley climate modeler Inez Fung is part of an international scientific team refining the detection skills of the new Orbiting Carbon Observatory 2, launched in 2014.

The powerful mathematical analysis tools that Fung's group has developed use the satellite observations of carbon dioxide around the globe to determine if actual emissions match a country's pledged target.  

In a recent talk for the Cal Futures Forum, Fung argued that "trust but verify" is the only viable strategy.