Coal-burning remains the single largest source of all the greenhouse gases dumped into Earth's atmosphere. As a result, climate change continues to gather speed, and molecules of CO2 released into the atmosphere today will continue to trap heat for centuries. In order to mitigate global warming, the world needs to transition to energy technologies that emit dramatically reduced quantities of greenhouse gases as quickly as possible. Even with such an energy transition, it will take decades for the pace of climate change to slow noticeably, as this video explains.
For more on the future of Climate Change read "How Far Can Climate Change Go?" by Ken Caldeira in the September issue of Scientific American.