The problem with making it uneconomical to pollute is that the world's economy is heavily reliant on carbon emissions. There has been several attempts at an economic approach to cut emissions like the carbon tax credit system which has only produced mixed results in terms of its effectiveness. This is a big problem because according to the UN's IPCC report we need to cut back 50% of current emissions by 2030 in order to prevent irreversible damage to the climate. This is not a simple problem.

The U.S. has around 1/5 the population of China and competes for the number 1 spot in term of producing pollution, I think it's fair to say the U.S. shares the responsibility with China.

We need to understand that the argument over here is baseless. Every manufacturing process in today’s world has an environmentally sustainable alternative. As such, stopping buying from a country totally is not viable, as concerns of free trade need to be addressed. Instead to reduce the effect of climate change, factories should adopt sustainable alternatives to production and a, thereby also contributing to the economy. By stating this, do you mean imports of cars, clothes, electrical equipments should be stopped completely? Think about it...