Watchdog steps up crack down on hazardous chemicals, denying firms confidentiality clause that has been used to conceal the identity of around 17,000 chemicals from the EPA
Bosses at more than 80 companies write to members of Congress urging them to pass climate change bill as quickly as possible or risk American firms "falling behind"
Lisa Murkowski pledges to use obscure measure in attempt to strip powers from the Environmental Protection Agency
Massachusetts election defeat and Republican plan to block Environmental Protection Agency from regulating carbon threaten to leave the president's climate change strategy in tatters
As defeat in Massachusetts robs Democrats of their filibuster-proof Senate majority, senator Murkowski plans amendment to stop EPA regulating carbon emissions
Row over US climate change legislation heats up as Republican Senator attempts to block EPA's right to regulate carbon emissions
EPA puts forward tough new air quality standards that would force local authorities to reduce smog levels
Four new chemical groups named as Chemicals of Concern, as EPA also announces new rules to ensure polluters pay to clean up their mess
Moderate Democrats and Republicans increasingly confident they can secure the 60 votes needed to pass cap-and-trade legislation
Landmark ruling strengthens president's ability to deliver climate change deals in both Washington and Copenhagen