The Times said Tuesday that the campaign finance records for Sens. John McCain, R-Ariz., and Barack Obama, D-Ill., show the campaigns didn't cover offsets for the "carbon footprint" of their campaigns.
Sen. Hillary Clinton, D-N.Y., the newspaper said, made significant monthly contributions to cover her "carbon footprint," however.
The "carbon footprint" is the level of carbon emissions emitted from buses, planes, computers and other items. Funds can be given to companies to plant trees or sponsor environmentally friendly programs to offset the "carbon footprint."
Early presidential contenders, former U.S. Sen. John Edwards, D-N.C., and U.S. Sen. Chris Dodd, D-Conn., made contributions to offset their "carbon footprint" but some critics say the reality of the presidential campaign made that contribution difficult to sustain.
"I'm sure that a number of the candidates saw offsets as a good way to show leadership by example but when confronted with the cold reality of a cash crunch, offsets are one of the first things to go," Frank O'Donnell, president of Clean Air Watch, told the Times.