In Module 5, we watched a video by Hans Rosling about global development. Let’s begin our discussion of climate change by watching another Hans Rosling video (4:47) that covers similar ground.
Notice that incomes and life expectancies around the world started increasing about 200 years ago. The United States and Great Britain were among the first countries to experience increases. Other countries took more time, but, by now, there have been increases almost everywhere. Why is that? What happened 200 years ago that caused health and wealth to start improving?
The answer is the Industrial Revolution. As societies learned how to develop industrial processes to produce more for us, our health and wealth began improving. By now, industry is so deeply embedded in so many facets of our lives that it’s often difficult to imagine life without it. There are still plenty of people today who produce much of what they use – including food, clothing, and shelter – by hand, but these people are increasingly few. Suffice to say, they are also not the people who tend to find themselves taking online university courses.
Central to the Industrial Revolution and to contemporary industry is the use of fossil fuels: oil, coal, and natural gas. They are called “fossil” fuels because they are sources of energy that derive from living organisms that were alive a long time ago. Originally, the energy from fossil fuels came from the sun. Ancient plants and other organisms trapped the sun’s energy via photosynthesis. Some of that energy found its way into today’s fossil fuels and is released when we burn the fuels for our industry.
The use of fossil fuels is unsustainable because we are using fossil fuels much faster than they are regenerating. Fossil fuels regenerate on timescales of hundreds of millions of years, but we are burning them up in just a few centuries. We can’t keep using fossil fuels forever as we use them today. Eventually, something must change. Given how central fossil fuels are to our industry, and how deeply embedded industry is within our lives, the depletion of fossil fuel resources represents a major challenge for humanity.
But there is another challenge associated with our use of fossil fuels. These fuels contain more than just energy. They also contain certain matter that, when we burn the fuels, ends up in the atmosphere. Some of this matter is in the form of molecules known as greenhouse gases, for reasons we’ll explain shortly. Greenhouse gases are also released into the atmosphere when we chop down and burn trees and other living matter.
Humanity has burned so much fossil fuel since the Industrial Revolution that we have significantly changed the concentrations of greenhouse gases in the atmosphere. The most important change is of carbon dioxide (CO2). 400 years ago, before the Industrial Revolution, there were 280 parts per million (ppm) of CO2 in the atmosphere, meaning that 280 out of every one million molecules in the atmosphere was a CO2 molecule. That might not seem like a lot, but it’s enough to make a big impact on the planet. Today, mainly because of burning fossil fuels (and also because of deforestation and a few other activities), there are about 400 ppm of CO2 in the atmosphere. That’s already a fairly large change, and we’re burning more fossil fuels now than ever before. If we burn all of the fossil fuels available on Earth, there could be about 1700 ppm of CO2 in the atmosphere, though we don’t yet know exactly how much fossil fuel exists across the planet. This is a very major change from the pre-industrial atmosphere, and a frightening thought, given that researchers believe that just 350 ppm may be a planetary boundary.
The change in greenhouse gases in the atmosphere is causing changes to the global climate system. These changes are already impacting natural and human systems worldwide. Much larger and more disruptive changes are projected as greenhouse gases continue to accumulate in the atmosphere. Unfortunately, the consequences of these climate changes are the sorts of things that are generally considered to be bad, whether one adopts an anthropocentric ethical view or an ecocentric ethical view.
Climate change is a difficult issue for several reasons. First, avoiding climate change involves reducing greenhouse gas emissions, which is difficult because fossil fuels are so central to our industry and our lives. Second, the global climate system and its interconnections with human and ecological systems are very complicated. We know a lot about these systems, but some important uncertainty remains. Third, the massive scale of climate change makes it a very difficult collective action problem. It involves everyone across the entire planet, from now until many thousands of years into the future. Finally, the severity of climate change is so great that human civilization may not survive it. For these and other reasons, climate change is perhaps the single most important issue for our civilization today.
