When Trump announced our withdrawal from the Paris Accords, I felt that he had done the right thing.Global warming is real, about 1.5°C in the last 250 years, and it is caused by human emission of greenhouse gases. That is a scientific judgement that I will stand behind, based on my own work and on that of my colleagues in the non-profit BerkeleyEarth.org.But the Paris accords did almost nothing to stop the increase. Alas, most of that increase will come from China, India, and the developing world, not from the US or Western Europe. To be effective, anything we rich nations do must set an example that the developing world can follow. That means it must not be expensive, if it isn’t profitable, it isn’t sustainable.There are three things we need to do to slow and stop global warming:More extensive energy conservation.Encourage nuclear power. (For the last decade we are effectively telling the world that nuclear power is unsafe and has no reasonable way to dispose of waste.)Shale gas as an alternative to coal. A gas plant emits ½ to ⅓ the CO₂ of coal.Everything else is just frosting. We tend to do fashionable things without caring if it makes sense for the developing world. For example, electric cars, if used in China, would increase their CO₂ pollution (since 70% of their electricity derives from coal). And they can’t afford lithium ion autos, the $7500 subsidy for electric cars is for show only, it does not address global warming.The problem with the Paris treaty is that it was a political show with no teeth. Countries set their own limits, there is no outside verification. The developing world was enthusiastic in large part because the US had pledged to put $3 billion dollars per year in the sustainable development fund. (China had already indicated that it wanted some of this money to build coal power plants. Their argument was that with the funds they would build more efficient coal plants than they would otherwise build.)My fundamental argument against the Paris treaty is that it gave the illusion of progress, and such an illusion can be detrimental to real progress. Others say it was a small step in the right direction, but it was generally not portrayed that way. And the step was (in my opinion) exceedingly small, too small.The US needs to have truly workable programs to help the developing world take advantage of concepts in energy efficiency, and to make progress on shale gas and nuclear. On shale gas, at least we are setting a good example, but we need to help China develop its own resources (which are greater than those in the US). We need to set the right example in nuclear by showing that we consider it to be a clean and safe technology. Among other things, we need to make it possible to license 4th generation nuclear plants in the US, they cannot be currently licensed! And we need to make it known to the outside world that disposal of nuclear waste is not a challenge, but is a solved problem.