There are already many policies and programs in place to mitigate the effects of climate change, both internationally and within Australia. However, under most of the current policies, global greenhouse gas (GHG) emissions will continue to grow. The IPCC Special Report on Emissions Scenarios (SRES) predicts that without additional mitigation, annual global GHG emissions will increase by 25 to 90 per cent from 2000 to 2030. Developing countries are expected to account for about two-thirds of this growth. Other emissions scenarios published since the SRES do not show significantly different projections.
Climate change mitigation can be achieved through various technological means that are discussed in this section. Development and adoption of these technologies to the extent required to reduce the risks of climate change to acceptable levels is likely to require substantial policy intervention. As discussed in other sections, this may utilise the economic market as well as mandatory measures such as renewable energy targets or energy efficiency standards.
CO2 emissions from fossil fuel combustion are the largest and fastest growing source of GHG emissions. This sector therefore presents the greatest opportunities for mitigation through emissions reductions. Use of fossil fuels can be reduced in the stationary energy sector by replacement with renewable energy sources; replacement with nuclear energy; and by improving energy efficiency. Coal is the dominant source of Australia's electricity production, and emissions from coal-fired power plants can be reduced by introduction of clean coal technologies, carbon capture and storage, and greater use of less carbon-intensive fossil fuels (particularly natural gas). In the transport sector, emissions reductions can be achieved through the increased use of alternative fuels to replace conventional hydrocarbon fuels (petrol and diesel).
Other than reducing emissions, there are also options to decrease the amount of carbon dioxide in the atmosphere by managing natural carbon sinks and utilising other storage reservoirs for carbon sequestration. In addition, various alternative non-natural schemes have also been put forward to sequester carbon dioxide or change the earth's heat balance through large scale geoengineering schemes.
Climate change is a global problem that will require global solutions. Development of competitive industries in alternative technologies and energy sources will be essential to provide for the expected growth in energy demand worldwide. While developing countries are projected to account for an increasing share of GHG emissions in the next decades, developed countries will be required to shoulder much of the burden of investment in development and uptake of alternative energy technologies, and to reduce the emissions-intensity of their economies (see international action and its subsections for more information on the relative roles of developing and developed countries).