IPCC Greenhouse Gas Emission Trends: The IPCC reports that global greenhouse gas (GHG) emissions have grown since pre-industrial times, with an increase of 70% between 1970 and 2004. Since pre-industrial times, increasing emissions of GHGs due to human activities have led to a marked increase in atmospheric GHG concentrations.
Between 1970 and 2004, global emissions of COB2B, CHB4B, NB2BO, HFCs, PFCs and SF weighted by their global warming potential (GWP), have increased by 70% (24% between 1990 and 2004), from 28.7 to 49 Gigatonnes of carbon dioxide equivalents (GtCOB2B-eq)TPF The emissions of these gases have increased at different rates. COB2B emissions have grown between 1970 and 2004 by about 80% (28% between 1990 and 2004) and represented 77% of total anthropogenic GHG emissions in 2004.
The largest growth in global GHG emissions between 1970 and 2004 has come from the energy supply sector (an increase of 145%). The growth in direct emissions in this period from transport was 120%, industry 65% and land use, land use change, and forestry 40%. Between 1970 and 1990 direct emissions from agriculture grew by 27% and from buildings by 26%, and the latter remained at approximately at 1990 levels thereafter. However, the buildings sector has a high level of electricity use and hence the total of direct and indirect emissions in this sector is much higher (75%) than direct emissions.
A range of policies, including those on climate change, energy security and sustainable development, have been effective in reducing GHG emissions in different sectors and many countries. The scale of such measures, however, has not yet been large enough to counteract the global growth in emissions.
With current climate change mitigation policies and related sustainable development practices, global GHG emissions will continue to grow over the next few decades. In the IPPC modelling where little is done to reduce emissions (such as our current global practice), fossil fuels are projected to maintain their dominant position in the global energy mix to 2030 and beyond. Carbon dioxide emissions between 2000 and 2030 from energy use will grow 45 to 110% over that period.
(Material sourced from the IPCC 4th Report , Mitigation of Climate Change)