The name 'Dominion Theology' is derived from the Bible where in Genesis 1:28 God grants humanity "dominion" over the Earth. Religion has a long history of being a excellent tool for bonding small disparate groups into a more formidable cohesive group allowing them greater safety.
This commonality of purpose was both politically advantageous and a great comfort to our fear filled fellow humans down through time. None of this was ever a problem to 'the whole' until recently when the conjunction of humanity's technological abilities and self-deluded beliefs began to threaten the underlying interwoven web of life that supports not only humanity but every living thing as well.
Not every Evangelical Christian believes that science generally or climate change specifically is a pagan plot, but most do. The Alliance Church of Canada, which Harper and many of his fellow deluded Conservative cohorts belong to, absolutely believes that they are the chosen stewards of the earth. They believe that man's special relationship with "God" guarantees that everything humans do is part of the divine plan, that all of existence has been created by "God" for our benefit and use. Marci McDonald's book 'The Armageddon Factor' ties together many loose ends to weave a historical account of the people in Harpo's Conservative Party who are leading the charge toward theocracy in Canada.
So when Harpo and his cronies or like minded Republican 'Born Again' Christians or other deluded Evangelicals around the world denigrate any and all attempts to develop a 'green' or environmental ethos they do so out of the deep seated belief that they are following the path "God" wants them to follow, that their ultimate after death reward in "Heaven" depends of their unquestioning belief in the delusion that humanity's material success and comfort is part of the divine plan and that's why they are such a serious threat.