Black morphs who existed in smaller numbers within the population where selected for since they were camouflaged against the soot covered bark of the trees while those individuals who were white were selected against since they were now easy targets for predation due to their apparency.
We then fast forward to the present day where the consequences are already being felt with atmospheric carbon levels at a staggering 400 ppm which in Earth's history hasn't been the case for at least 800,000 years. We allude to phenomena attributing to greenhouse gas emissions such as the melting of Arctic ice which has for millennia held ancient methane deposits and is now unleashed to contribute to and exacerbate the global warming crisis. In a nutshell, support for an anthropological hypothesis to explain Global Warming at this stage outweighs the notion that we are merely experiencing natural phenomena alone. One mustn't discount that it too could be a contributing factor, however there is just too much support for a correlation between the inception of the Industrial Age and the rise in atmospheric carbon levels. There's no denying these sorts of climate events have happened in the past to which most skeptics will refer, its the rate at which it is happening that raises alarm bells and the responsibility is ours. There are those out there in the science community who feel we are the last generation to make a difference that will last.
Listen: Bandcamp (Demo MMXIII)