Unless greenhouse gas (GHG) emissions, including CO2 concentrations, are checked, increases in average global temperatures will continue and climate change risks will escalate. The shift to renewable energy, improvements in energy efficiency, and limiting deforestation are all climate change mitigation measures which will help reduce GHG emissions and the accompanying risks. Without mitigation, impacts of climate change will be most extreme and severe that no amount of adaptation and preparedness can protect lives, communities, and economies. Experts argue that the dual objective of climate mitigation and spurring economic growth can be achieved by imposing a price on CO2 emissions that reflects the burden it imposes on the environment. With energy emissions comprising two-thirds of global GHG emissions, mitigation measures should zoom in on energy, especially fossil fuels which still account for over 80 percent of world energy supply, and coal combustion which generated the largest share of CO2 emissions in 2012.