Lucas Joppa, Microsoft's first chief environmental officer, thinks about climate change through the lens of coding, and he says the world's current net-zero approach simply won't compute. So how do we create a system that actually accounts for all the world's carbon emissions -- and helps us get to zero (as in zero additional carbon added to the atmosphere by 2050)? Joppa shares three "bugs" in our current net-zero code, a four-point plan for fixing them – and how logic can help us change the current course of climate change.