Exxon Mobil

XTO Energy, a subsidiary of Exxon Mobil (NYSE: XOM), is under investigation by the Pennsylvania Department of Environmental Protection (DEP) after a 13,000 gallon hydraulic fracturing fluid spill at XTO Energy's natural gas drilling site in Penn Township, Lycoming County, PA.

Australia, the world’s largest exporter of coal, relies on the inefficient and dirty resource to supply over 80% of its own electricity. But the cheap and plentiful sedimentary rock's high carbon output happens to be a major contributor to climate change, something that hasn't gone unnoticed by the government (Australia emits more greenhouse gases per capita than any other country).

Fossil fuel baron Exxon Mobil Corp. (NYSE:XOM) has entered the biofuels market by investing $600 million into research and development of photosynthetic algae.