Most climate scientists believe that carbon dioxide (CO2) emissions must be reduced by at least 50 percent by 2050 to avoid the most dangerous impacts of global climate change. To achieve this objective while also continuing with current lifestyles, countries must decarbonise by reducing the amount of CO2 emission intensity (CO2 produced for each unit gross domestic product [GDP]) at greater than 4 percent per year. This seems like an achievable target but, this rate is three times the 1.3 percent per year global average rate sustained since the 1860s. Most of the reduction in CO2 emission intensity was achieved without any radical policy interventions. Fuels with higher carbon to hydrogen ratio such as firewood were replaced with cheaper fuels with lower carbon to hydrogen ratio such as coal, oil, and gas. The challenge today is that a shift must be engineered artificially through policy in an environment where no one is sure what alternative fuels one can shift to without compromising on fossil fuel lifestyles.
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