It was the Australian bush fire that finally did it. For 12 years Adam Hearne had worked at companies that represented some of the world's largest sources of greenhouse gas emissions. First at Rio Tinto, one of the largest industrial miners, and then at Amazon, where he handled inbound delivery operations across the EU, Hearne was involved in ensuring that things flowed smoothly for companies whose operations spew millions of tons of carbon dioxide into the environment. Amazon's business alone was responsible for emitting 51.17 million metric tons of carbon dioxide last year -- the equivalent of 13 coal-burning power plants, according to a report from the company. Then, Hearne's home country burned.