Small, almost imperceptible, changes over a long period can result in dramatic differences. This is the mechanism that underlies two somewhat controversial phenomena: evolution and climate change.
Evolution can be observed if one looks at entities with very short life spans, such as bacteria and viruses. We also can observe evolution of ideas, or other nonbiological entities. For example, think about the evolution of computers. The computers of today and the computers of the 1950s are so different that they seem like different “species.” It is more difficult to think about evolution when it comes to humans because one needs to consider such an enormous time frame.
There is no inherent contradiction between evolution and spiritual belief. One can read the book “The Phenomenon of Man” by the Jesuit priest Pierre Teilhard de Chardin to see a nice synthesis of evolution and spirituality. The conflict is between evolution and orthodoxy (or fundamentalism). Our public schools should be a place for enlightened discussion, not for the promulgation of orthodoxy.
Climate change is accepted by the vast majority of scientists. There is no denying the fact that polar ice is decreasing at an alarming rate. There also appear to be more occurrences of more-extreme weather. While it is true that our planet always has had temperature and climate fluctuations, there is a very good chance that the phenomena we have been observing lately are caused in large part by the use of fossil fuels. If the predictions of climate change are correct and we do nothing about it, then we run the real risk of making Earth uninhabitable in the future. What if we take the recommended steps to reverse or mitigate climate change, and it turns out these predictions are wrong? Then we would have misspent some money and cost the fossil fuel industry some profits.
Some people may not remember the controversy in the past about the ozone layer around Earth and the use of aerosol sprays containing chlorofluorocarbons. It took more than two decades to get an international ban on the use of CFCs. The ozone layer is slowly being restored, but it will take several generations before it is back to what it should be. In the meantime, skin cancer rates are increasing. The situation with climate change is somewhat similar, but the fossil fuel industry appears to have much more power and influence than the CFC industry did.
It is not surprising that the governors of Louisiana and Texas, the two states with the most-influential fossil fuel industries, speak out against climate change. They do not have the best interests of the human race in mind when they do this.