See this short video by Shrink That Footprint

http://shrinkthatfootprint.com/carbon-emissions-explained

This short video is a simple explanation of how human’s have caused carbon emissions over the last 260 years.

Unless we begin sharp reductions in carbon emissions immediately, we will commit the world to more that two degrees of warming.

Read more at http://shrinkthatfootprint.com/carbon-emissions-explained#FMmTFmoit0Tid5kd.99

All the data discussed in the video is in terms of gigatonnes of carbon (GtC).

The non-rounded historical figures from 1750-2011 are coal (177 Gt), oil (132 GtC), gas (50 GtC), cement (9 GtC), flaring (4 GtC) and land-use (159 GtC). You can read more about them, and where they end up, in their historical carbon emissions and sinks post.

For a more complete analysis of the budget see their 22 years till we blow the 2C carbon budget post. This explains why we are on track to burn straight through the IPCC’s carbon budget in coming decades.

Finally it is worth pointing out that it can be a little dangerous to think that we still have carbon to spend. In terms of ocean acidification and feedback risks, we have already emitted too much. Given that we need to combine fast emission cuts with rising energy use globally, we need to be focused on substituting away from any process that emits carbon into the atmosphere.

Read more at http://shrinkthatfootprint.com/carbon-emissions-explained#FMmTFmoit0Tid5kd.99