What are some natural causes of global warming or climate change?

In the United States, the burning of fossil fuels to make electricity is the largest source of heat-trapping pollution, producing about two billion tons of CO2 every year. Coal-burning power plants are by far the biggest polluters. The country's second-largest source of carbon pollution is the transportation sector, which generates about 1.7 billion tons of CO2 emissions a year.

Cows produce gases that are fairly harmful to the environment, this can cause global warming. Also, cars cause pollution which can also cause global warming and climate change. Climate change can also be affected by the way the earth is facing at what time of the year.