Estimates of the total cost of stopping climate change range from $300 billion to $50 trillion. Every year the total world expenditure on the military is about $2 trillion. In a completely idealistic situation, if the world diverted its military budget towards saving the planet, we could end the threat of climate change, at the latest, by 2050. The projects necessary to accomplish this would do much to mitigate world poverty. They would also require international cooperation, which would mean the military would no longer be necessary.