The greenhouse effect is a natural process in which atmospheric gases such as carbon dioxide absorb some of the sun's heat and warm the Earth. Since the Industrial Revolution began, concentrations of CO2 in the atmosphere have increased by 30 percent.
Transportation is the largest contributor to greenhouse gas emissions.
Twenty-five percent of Canada's greenhouse gas emissions are the direct result of activities by individual Canadians. If current emission trends continue, concentrations of CO2 in the atmosphere are expected to at least double during the 21st century. Even if greenhouse gas emissions were to stop immediately, the effects of past emissions on climate would persist for centuries. Global Warming Global warming doesn't mean the world will warm equally. Scientists predict there will be greater warming at polar continental latitudes and in the winter.