Greenhouse Gases, Global Warming, and Climate Change: Introduction
The levels of carbon dioxide, water vapor, and other greenhouse gases in our atmosphere are skyrocketing. The hottest mean annual temperatures in observable Earth history have all been recorded since 1990, with 2005 having been the hottest year on record. Currently our atmospheric CO2 level is about 380 parts per million—at no point during the last 100,000 years, according to the scientific record, has it exceeded about 300 parts per million. According to NASA, not to a left-wing environmentalist faction, CO2 levels are currently projected to exceed 550 parts per million by the year 2100.
Throughout the history of our planet, greenhouse gas levels have been the strongest, most direct, and most consistent regulators of global temperature known. Based on the analysis of gas bubbles trapped in glacial and arctic ice, on the structure of tree rings, and on other proxy evidence, scientists can chart both atmospheric CO2 levels and temperature levels going back at least a half million years. Human beings, for comparison, have existed for about the past 200,000 years. When we compare a graph of changes in CO2 levels against a graph of changes in temperature over a given period of time, we can see that Earth’s temperature is directly proportional to the amount of greenhouse gases in the atmosphere. CO2 levels go up, there is a brief adjustment period, and then temperatures go up in response. Since greenhouse gas levels in our atmosphere are currently at an all-time high for the history of our civilization, it follows that all-time high temperatures will result from these levels at some point in the near future. This is definitely something with which we need to concern ourselves as a species, if we in fact value our continued existence and the continued existences of millions of species of plant and animal life on our planet, among whom we are supposed to be the intelligent and responsible ones.
In this three-part piece on the relationship between human activities and global climate change, we will:
- Take a look at what greenhouse gases are, where they come from, and what they do (Part One);
- Examine the relationship between human industrial activity and escalating greenhouse gas levels (Part Two); and
- Discuss what is currently being done and what should be done in the future to combat global warming (Part Three).
I expect that all three parts will follow within the coming week. Check back soon for more.