We don't get to have it both ways, being a world leader and not doing enough for the world. It's true that the U.S. Seems to get involved or lead the way in many ways in the international community, and to say that others should be just as responsible or involved is easy and understood. However, since its founding the country has had an idea of exceptionalism, being that 'light on the hill,' and that attitude is very much ingrained in its people. We can't believe ourselves exceptional and at the same time do only what someone else is willing or able to do.
Yes, the U.S. should play a more active role in saving the planet. The United States, being an industrialized nation, needs to set an example for developing countries by being tough on companies and industries that contribute to environmental pollution. There is enough scientific evidence to suggest that humans are directly interfering with the balance of nature, and the U.S. should use its 'power' and 'influence' to not only prevent the U.S. from contributing to the destruction of the environment, but to encourage developing countries to do the same.
The United States is one country who contributes a lot to the loss of the ozone layer and other harmful things to the planet. There is a lot of plastic debris in the Atlantic Ocean that was funneled into the ocean from people and rivers. If something does not change, this will affect the marine life in the ocean, which will ultimately affect us on land.
The United States already contributes a significant amount of funding and resources to saving the planet. It is time that other emerging world powers devote the same level of commitment. Regulations from the EPA are already stifling our already suffering economy. While I believe that natural resource preservation is important, it is to harshly affecting our economy.
Regardless of whether the earth will be able to support life, the planet does not need us to save it. Barring a collision with another, larger planet, the earth will be just fine. When human life is long dead, the earth will still be doing its thing spinning around the sun.