Cleaning up the fossil fuel energy economy would do wonders for human health, the health of the environment and the health of all creatures - so why hasn’t it happened? The costs associated with a change to clean energy is sometimes stated, but those costs are often overstated. The change over will be cheap and the consequences of inaction expensive.
A 2014 report, “Energy Technology Perspectives”, from the International Energy Agency (IEA) showed the switch to renewable energy with a strategy to hold global warming below the 2º Centigrade danger zone (IEA 2DS scenario) would require only 1% of global gross domestic product (GDP) per year.
“The $44 trillion additional investment needed to decarbonise the energy system in line with the 2DS by 2050 is more than offset by over $115 trillion in fuel savings - resulting in net savings of $71 trillion.”
These findings are consistent with other reports and are not really controversial. The politicians, pundits, policy makers and oil, gas & coal barons may be worried about losing their cut of that $115 trillion in fuel savings.
http://thinkprogress.org/climate/2015/01/29/3616382/solving-climate-change-cheap/
http://www.iea.org/newsroomandevents/pressreleases/2014/may/name,51005,en.html