… from the Yale School of Management narrowed in on one, universal metric that is the single biggest driver of climate change: greenhouse gas emissions (GHGs), measured in metric tons … from the Yale School of Management narrowed in on one, universal metric that is the single biggest driver of climate change: greenhouse gas emissions (GHGs), measured in metric tons … from the Yale School of Management narrowed in on one, universal metric that is the single biggest driver of climate change: greenhouse gas emissions (GHGs), measured in metric tons …