Dense evergreen plantations in Canada's boreal forest absorb so much winter sunlight that the resulting surface warming can offset 6% to 20% of the climate benefit they are credited with. Canada's current carbon accounting frameworks measure the carbon stored but largely omit the heat absorbed by these forests, according to a new policy brief from the United Nations University Institute for Water, Environment and Health (UNU-INWEH). The result is inflated mitigation estimates and public investment in forests that may not deliver the cooling they promise.