Even if we're fewer, I think we're actually pushing really hard.
Your president and a lot of US citizens don't even acknowledge that there is a climate change. You are far from any kind of leadership in that regard.
I think EU takes the initiative and is king in making the world follow. Either because they want to or simply because they have to.
Southeast Asia contains most of the world's people and a huge fraction of the world's GDP. Apart from China, however, it's uncoördinated. A small action by the United States means more than many large actions by smaller European states. This makes sense from game theoretic as well as simple sociopolitical perspectives. This is part of the package one takes when choosing the confederated structure the EU has opted for.
https://www.theguardian.com/environment/2017/mar/28/only-swe...
People can claim a lot about other countries and there is a lot of things we do shittier than others. But in fighting climate change, there is no better country than Sweden.
Since we can, you can as well. Taking leadership is possible as a little country. We can show you all that it is possible and that you can gain economical benefits from it. In Sweden, fighting climate change is a cultural thing like it should be in the entire world.
Whether we talk about a union of 320M as the US or a union of 510M as the EU, or whether we talk about a state like Michigan with 9M inhabitants or a nation like Sweden with 10M hardly matters. There are roads, electrical grids and similar infrastructure everywhere in the modern world.
It's not the distribution that's the problem. It's political will.
Leadership in fighting climate change? Cmon' every EU-country is better at fighting climate change than the US. Denmark has at least 50% of their energy coming from their huge wind farms. Norway has a huge network of chargers for electrical cars, tax cuts for electrical cars and Sweden is huge in all sorts of environmental savings.
In Sweden you can't even order a fucking burger without seeing how much CO2 that produces and ads for vegetarian burgers that are better for the environment.
If you really think US is good at all at fighting climate change, you should really come to the EU and watch us recycle. Even during the recent terror attack in Stockholm there were people recycling.
Proof:
http://www.cbc.ca/radio-content/archive/undertheinfluence/ma...
http://img.timeinc.net/time/daily/2012/1204/360_intl_healthy...
https://www.reddit.com/r/sweden/comments/64199h/two_swedes_r...