China produces about 28% of the greenhouse gases emitted by all countries in the world. The U.S.A. produces about 16% of the greenhouse gases emitted by all countries in the world. 

Canada produces about 1.6% of the greenhouse gases emitted by all countries in the world.

Why is it so important for Canadian governments to impose a price and a tax on carbon or greenhouse gas emissions?

Shouldn't Canadian governments be telling China and the U.S.A. to reduce their greenhouse gas emissions?

If Canadians pay a carbon tax and Canada reduces greenhouse gas emissions and China and the U.S.A. don't, will that stop climate change?