CBC News has found that in some cases compact fluorescent bulbs (C.F.L.s) can have the adverse effect of increasing greenhouse gas emissions, depending on how consumers heat their homes.
Physics professor Peter Blunden at the University of Manitoba said C.F.L. bulbs are certainly more energy efficient than older incandescent bulbs.
But in cold-weather climates such as Canada’s, Blunden said older incandescent bulbs do more than just light our homes. During the long winter months, they also generate heat. The new C.F.L. bulbs, on the other hand, produce minimal heat so the loss has to be made up by fossil-fuel burning gas, oil or wood to heat your home.
“To some extent, the case [in favor of C.F.L.s] has been oversold” because of the offset in higher heating costs, he said.