Host Tony Dokoupil talks to Tom Stoddard about how the 2016 presidential candidates can be carbon neutral. Plus, Shaun Mosson explains what his latest film "Unity" is all about. Later, Dokoupil and Leif Ristrophe try to explain the mystery behind airplane flying. Stacey Leasca from Ryot also stops by to discuss possible solutions to the drought in California. Lastly, Greenpeace explains their fight against Shell's Arctic plan. Greenhouse airs Thursdays at 12pm ET on Shift.Aug. 6, 2015