In my latest essay for Acton Commentary, I offer some thoughts about climate change, the limits of scientific knowledge and the importance of Christian witness to the environmental movement.

Here’s how I begin:

On September 1, Pope Francis and Ecumenical Patriarch Bartholomew issued a joint message for the “World Day of Prayer for Creation.” Their statement rightfully reminds us that we all have an “obligation to use the Earth’s goods responsibly. “ But exhortations by the pope and patriarch should not be read as a policy prescription.

Unlike theology, science speaks in probability. How the climate will change going forward and the role of human activity has in any such change can’t be answered with absolute certainty. In this case, we need to be careful of broad epistemological claims which necessarily raise questions about the limits of human knowledge.

Epistemological humility also keeps us from assuming that climate change is uniformly negative. Matt Ridley, the British journalist, argues not only that “the risk from global warming is being exaggerated,” but that we are also overlooking the positive effects of elevated atmospheric levels of CO2.  For example, we are seeing a “gradual, but large, increase in green vegetation on the planet.” According to Ridley, this increased greening is “a direct result of rising carbon dioxide levels in the atmosphere, rather than the application of agricultural fertiliser, irrigation, warmer temperatures or increased rainfall.”

You can read the rest here: Knowledge, humility and evangelical witness | Acton Institute