Carbon credits are controversial for a number of reasons. They've given rise to emissions-trading schemes and carbon offsets; markets that allow greenhouse gas-producing industries to side-step the need for reducing emissions by paying other companies to reduce theirs instead.

Sure, CO₂ is CO₂, and on a planetary scale it doesn't really matter which congested manufacturer it's coming from (though anyone living next to one might prefer it be a little more evenly distributed...) but this is only the tip of the iceberg when it comes to the complexity of the problems that can arise from dealing in digital pollution.

Science in Seconds digs up the dirt on dirty energy.

_{Host: Brit Trogen}

_{Photo credits: Wikimedia users Stefan Wernli, Sebastian Ritter, Sylvian Pednault and public domain}