US House of Representatives' Legislation to Restrict EPA Control of Carbon Emission. (June 22, 2013)

Freelancer Steven A Edwards writing in the American Association for the Advancement of Science "MemberCentral" concludes that whether or not the restrictive legislation were to pass both houses of Congress and not be vetoed by President Obama:

Coal plants are already under economic distress as shale-produced natural gas is a cheaper source of energy than coal, while carbon pollution-free wind and solar energy continue to drop in price. Renewable energy (wind, solar and geothermal) accounted for 82% of new electrical generation in the U.S. in the first three months of 2013, with the remainder supplied by natural gas, according to the Energy Infrastructure Update report from the Federal Energy Regulatory Commission’s Office of Energy Projects. There has been no new coal-powered generating capacity added this year.

Currently the same economic considerations don't apply to Australia. Whether or not they will in future remains to be seen as will the extent of the power exercised by Australia's coal mining conglomerates.

Dr Edwards blog in full is available Here.