There is no doubt whatsoever that the planet is warming and it is primarily due to increased carbon dioxide in the atmosphere from burning of fossil fuels. (getenergysmartnow.com)
Perhaps no surplus carbon sink exists at all to absorb the emissions caused by burning of fossil fuels accumulated in the earth over millions of years. (realclimate.org)
Some greenhouse gases occur naturally in the atmosphere, while others result from human activities such as burning of fossil fuels such as coal. (sciencedaily.com)