If American policies change, the effect will be considerable, but how much can the policies actually change? Trump holds forth on other things as well, but on the whole, I don’t think he can have much effect on the general trend.
If you have coal, it’s quite cheap to generate power. But it would be out of the question for America to be ignorant of the environmental cost. If Trump forces the issue, if he insists on coal, he could easily face resistance. At any rate, the moment he announced that he was withdrawing from the Paris Agreement, cities and states made commitments to comply with the agreement’s limits anyway. For American politics, this could be a highly interesting test of the power of local government.
That’s the first point. The second is that America is actually one of the leaders in renewable energy. America and Germany are head-to-head here, and both have made major advances in the past few years in renewable generation, especially solar power. In the case of windmills, there really isn’t much further you can go, but there is in solar. It’s possible to make solar panels much more efficient and to reduce the cost of generation. There are major opportunities here. For example, you can now cover the entire exterior of a building with solar panels, not just the roof. Can you imagine? That would generate an incredible amount of power. Take transport, too: City buses are now electric. In short, I believe America and Germany will continue to lead the way in technological development. These advances are an important parameter, because if there’s a relative drop in costs, you might think, “Why should I burn coal? The market will adjust itself anyway!” But one thing to keep in mind is that the American lifestyle is based on high consumption: very large houses, big cars, enormous portions of food. When you consider all these factors, no matter how much environmental awareness you raise, there is an unavoidable ecological footprint. Let’s remember that Earth is finite; if we carry on consuming at this rate, we’ll need a world that's 1.6 times larger, and this factor is increasing steadily.
In summary, one way of reducing our footprint is to move into green technologies and another is to question how we live and consume. America seems to be the nation state with the greatest need to ask these questions. That’s what you conclude when you take into account their population and ecological footprint. Europe comes next. On the other hand, the greatest footprint is made by oil rich countries, despite their relatively low populations. The populations of China and India are very high, but their current ecological footprints per person are very low. They’re rising though. China did a quick about face here, and, frankly, no one was expecting it. It’s a very positive development, of course.