I will not get into the controversy over whether there is actually a global change in climate going on caused by human activity. I think it is likely to be true, but if it's not, there are certainly plenty of other things we are doing to adversely affect our environment, and these also spring from the same root. I will begin by saying I believe the root cause of these environmental problems is greed. I think that greed for more comfort, convenience, and profit works against attempts towards moderation of energy consumption and pollution.
Since greed has been a human problem throughout history, this raises the question of why are we having environmental problems now rather than earlier. There are two reasons which are related to each other. The first is that our technology has enabled a larger population, and greater ability to consume energy and produce pollution. However, the other reason has to do with my previous post about René Descartes.
One of the characteristics of a modern mindset, which is found in Descartes' Discourse on Method is the desire to be "masters and possessors of nature." We want to master nature so that we can have comfortable, trouble-free lives, with good health for many years. This has become so much a part of our thinking that for most people that they don't even think about it. So, if you couple this modern philosophy that we should be masters and possessors of nature for the sake of our own comfort and health with the enduring problem of human greed, it is no wonder that nature suffers as a result.