Three greenhouse gases predominantly cause the effect of global warming. These are Carbon Dioxide (CO²), Methane (CH4) and Nitrous Oxide (N²O). CO² is responsible for nearly 75% of these greenhouse gases and it has seen the largest absolute increase over the last 70 years. 

Since the industrial revolution in the 19th century, the atmospheric CO² concentration has nearly doubled to 400ppm, clearly outstripping the long-term average (800.000 years) of 250 ppm.

All world regions have contributed to this increase in greenhouse gas emissions. While the developed economies (i.e. USA and Europe) take responsibility for most of the CO² emissions until the 1980s, Asia and the Middle East have taken over the lead for CO² emissions growth. China has become the largest emitter of CO² per year by today. While the CO² emissions of the EU and the US are slowly decreasing, greenhouse gas emissions in Asia and the Middle East are growing at an ever stronger rate.

Rising CO² emissions are the result of increased human activity on earth. The main component of CO² activity is energy. This is followed by transport, agriculture and land-use sources & forestry. When an area is deforested, the captured CO² is emitted into atmosphere and thereby contributes to global warming.