The island's peat and blanket bogs support wildlife and act as a natural store of potentially harmful carbon.

BBC: Peat land on Lewis

She pointed out that the Children's Internet Protection Act already requires libraries to block net content that is harmful to children.

BBC: Many schools have already banned social network sites

Some believe that retrofitting ships with equipment like "scrubbers" that remove harmful emissions from vessels could help the industry to clean up its act.

CNN: Shipping looks to clean up its act

It said Congress should act separately to replace the forced spending cuts with alternatives that will be less harmful to the economy.

CNN: STORY HIGHLIGHTS

Yet, despite all the evidence implicating both indoor and outdoor air pollution's harmful impact on public health, we still have so much to do to clean up our act.

WHITEHOUSE: Energy and Environment Latest News | The White House

Eliminating that risk altogether is impossible, but if regulators act now while the rules are still malleable, they can make such crises less likely and reduce their harmful effects.

ECONOMIST: The case for pre-emptive action