Planting trees is good, right? But where?

Found this at PhysOrg:

"[N]ew forests in mid- to high-latitude locations could actually create a net warming. It also confirms the notion that planting more trees in tropical rainforests could help slow global warming worldwide....

"Forests affect climate in three different ways: they absorb the greenhouse gas carbon dioxide from the atmosphere and help to keep the planet cool; they evaporate water to the atmosphere and increase cloudiness, which also helps keep the planet cool; and they are dark and absorb a lot of sunlight, warming the Earth....

"[T]ropical forests are very beneficial to the climate because they take up carbon and increase cloudiness, which in turn helps cool the planet....

"[B]y the year 2100, forests in mid- and high-latitudes will make some places up to 10 degrees Fahrenheit warmer than would have occurred if the forests did not exist. "

Well, crud.