Surprising, isn't it? I'm not sure that many climate change campaigners would be entirely happy to have their views described as a religion. I'm not entirely convinced myself that it is a religious or philosophical belief, though I think there are several points of similarity.
So there are a couple of similarities. Some environmentalism is obviously religious – I'm thinking of the James Lovelock Gaia-theory-esque stuff here. But I don't think all of it necessarily is. Christians can obviously be involved in exercising responsible stewardship of the earth's natural resources without thereby becoming syncretistic. But it does at least invite the question… how easy is it for Christians to be (unwittingly) syncretistic with the new religion of environmentalism when they make statements about climate change? Do we need to outline our theological position (God made the creation; humanity is to exercise stewardship; God is sovereign and is in control of whether and when and how the world will end… for a start) a bit more clearly so as to differentiate between Christian takes on climate change and ecology and competing religious positions?
There is not so ready a Way to Atheism, as this of extinguishing the Sense of Conscience for Worldly Ends; destroy that Internal Rule of Faith, Worship and Practice towards God, and the Reason of my Religion will be Civil Injunctions, and not Divine Convictions; consequently, I am to be of as many Religions as the Civil Authority shall impose, however untrue or contradictory; this Sacred Tye of Conscience thus broken, farewell to all heavenly Obligations in the Soul, Scripture-Authority and ancient Protestant Principles; Christ may at this Rate become what the Jews would have had him, and his Apostles be reputed Turners of the World upside down, as their Enemies represented them, and the godly Martyrs of all Ages so many Self-Murderers; for they might justly be esteemed Resisters of Worldly Authority, so far as that Authority concerns it self with the Imposition of Religion, because they refused the Conformity commanded, even to Death. And it may not be unworthy of Caesar's Consideration, if from these Proceedings People are tempted to infer, there is nothing in Religion but Worldly Aims and Ends, because so much Power is abus'd under the Name of Religion, to vex and destroy Men for being of another Religion, that he hazards the best Hold and Obligation he hath to Obedience, which is Conscience; for where they are taught to obey for Interest, Duty and Conviction are out of Doors: By all Means let Conscience be sacred, and Virtue and Integrity (the under dissenting Principles) cherisht; Charity is more powerful then Severity, Perswasion then Penal Laws.
Whether or not the American Revolution, commemorated tomorrow, was justifiable for North American Christians (John MacArthur famously teaches that it was a violation of Paul's commands in Romans 13; David Barton defends the revolution as justified), I've found the discussions from the seventeenth- and eighteenth-century nonconformists about the Christian's relation to Government really interesting. They lived in an age where the State, while looking remarkably modern (in comparison to earlier conceptions of the State in the Christian era) retained the Constantinian role of adjudicating in religious matters by the establishment of a national church and the requirement that subjects attend Sunday services at an "official" church. Penn here objects that this is a path to Atheism, since religious observance will no longer be founded on the work of faith of God's word in a person's heart, but on civil injunctions. Legislating that all must have faith leads in fact to the loss of that faith, because it becomes founded on the will of man rather than the will of God. It also can foster a cynical attitude to that religion, since it becomes possible to make the claim that it only exists to legitimate the state and its excesses.
Penn also objects that "Christ may at this rate become what the Jews would have had him" – I think he alludes to the concept of the Messiah as a political liberator and ruler, which many of Jesus' disciples clearly expected him to fulfil. In a sense, perhaps linking the Church to political power does this – it certainly undermines the claim of Christ that his Kingdom is "not of this world" and obscures the true nature of his Messiahship.
Obedience to Government in Romans 13 cannot be unconditional, nor does a Christian have an obligation to adhere to the official religion of the State, even if it should be compulsory. If such an obligation did exist, then, as Penn writes, persecution of the Apostles by the authorities would be justified, and the martyrs of Christian history would become suicides, since they died as a result of disobeying the State's commands to conform to an established religion.