Though governments and individuals have taken some steps to reduce emissions of greenhouse gases, including carbon dioxide, current practices and policies are inadequate, and emissions will continue to grow over the next several decades, according to the summary from Working Group III (mitigation) of the Intergovernmental Panel on Climate Change that was released on 4 May. However, there are many options available that could change this outcome.
Emissions of greenhouse gases have been increasing since pre-industrial times. Between 1970 and 2004, overall greenhouse gas emissions increased by 70% and carbon dioxide alone increased by 80%, with the largest increases coming from the energy supply and transport sectors. If practices do not change, IPCC scenarios estimate that by 2030 greenhouse gas emissions will increase by another 25–90%, compared with 2000 levels.