This is first of what I hope to be many posts on the science of anthropogenic global warming. This first post will simply be a summary of the basic science with no attempts to prove any points exhaustively or to cite detailed studies. From this initial summary, I then plan to branch off into smaller topics, and from each of those to branch off into even smaller topics, and so on. As I create the smaller topics, links to them will magically appear in this post.

One of my goals in describing this science is to clarify it for myself. The skeptics and outright denialists, as poor as their arguments and their attempts at science are, still make me want to know for sure which side to believe in. It’s not acceptable for me to blindly follow the majority of scientists. Instead, I want to develop my own understanding so I can judge whether the scientists are trustworthy. Nobody has the time to learn and understand in depth all of the disciplines involved in climate science, such as physics, astronomy, statistics, oceanography, atmospheric science, biology, and chemistry. What every person must do is learn enough to separate the frauds from the real scientists.

So here’s the quick summary:

Our planet’s surface temperatures are within a viable range for humans and and millions of other species, but the climate is also subject to various forces that cause regular fluctuations in the temperature. The basic livable temperatures are thanks to the makeup and depth of our atmosphere, and thanks to not being too far or too near the sun. Due to slight changes in the earth’s orbit and the earth’s tilt, for at least the last 2.5 million years the earth has experienced significant but remarkably regular temperature fluctuations, going back and forth between ice ages and interglacial periods.

Into this scenario, humans have contributed additional CO2 to the atmosphere, especially starting in the nineteenth century with the Industrial Revolution. This has resulted in an increase in the CO2 concentration in the last 150 years from about 280 ppm to about 390 ppm. In those same 150 years, the average global temperature has shown an overall upward trend. Because of the known properties of CO2 as a greenhouse gas, one has strong reason to be suspicious that the CO2 increase is driving the observed warming.

But the situation is more complicated and also more alarming. Because the warming has resulted in a reduction in ice in the Artic, the albedo effect of snow and ice has been reduced, thus allowing more warmth to be absorbed at the surface. There is then the strong possibility that temperatures will increase by more than what one would calculate if only considering an increase in CO2. There are other feedback effects to consider as well (that is, events caused by the warming that in turn may lead to either less or more warming), such as methane released by melting of permafrost. Unfortunately for those who would prefer a more stable climate, the feedbacks point more often toward even higher temperatures and a host of serious problems for humans and the other inhabitants of this planet.