Hill: Recent Canadian action on climate change helps justify the construction of the Keystone XL pipeline, a TransCanada executive said in a letter to Secretary of State John Kerry this week. The Alberta governments hike of the provinces carbon tax, as well as Canadas commitment to international climate change agreements, means the Keystone project has to meet high environmental standards in both Canada and the United States, Kristine Delkus, TransCanada's executive vice president and general counsel,...