Understanding the Climate Change Conversation
I went to school online recently to take a very basic climate change course. I’ve been studying the subject outside of an academic setting for years now. I thought it was time to listen in on what real experts say about the subject when they have time to be expansive about it. I found, as I expected, that there was stuff I had missed or overlooked in my own studies, and answers to matters which have always puzzled me.
For the information it offered, and the structure it gave to that information, the course was worthwhile. It didn’t make me a fan of online learning, however. I remember as a kid the correspondence courses other kids took and failed. Like those courses, online learning will never replace a legitimate classroom. It is simply an inferior learning experience. Nothing to do with the fine, dedicated people who designed the course. The model is simply flawed. That said, and repeating what I said before, the information offered in the course is first rate, and if you are among the 1% who can function and flourish in an online class, or if you just want to review the science for your own information, go for it.
[The course I enrolled in was offered through Coursera and the University of British Columbia. It’s called Climate Literacy: Navigating Climate Change Conversations and is taught by Sarah Burch and Sara Harris.]
I decided I would take what I have learned and pass it on, as clearly and simply as I can manage without distorting the science. This series is the result. Any mistakes, of course, are my own.
Lesson 1: Where the Stuff Is
Climate science is simply physics applied to the study of climate. Like life itself, all climate is ultimately powered by the Sun. Energy from the Sun encounters matter and materials on the Earth and, depending upon the particular conditions existing on Earth at a particular time, particular climate forces are put into motion. The study of the Earth’s past shows that sometimes the Earth was colder than today, sometimes hotter, and a closer examination of those times and this gives us a strong idea why.
Our first lesson discusses the basic storehouses on Earth of the materials affecting climate.
This little series is about climate. By climate, we mean weather averaged out. Weather is what you see out the window on a particular day. Climate is what you can expect, on the average, to see out the window in a particular place and a particular season.
Climate science, for instance, will tell you the mean temperature, temperature ranges and temperature extremes for your place and season. It arrives at figures of mean average temperature and the like by looking at data over a 30 year period. As of now the period 1971-2000 is being used by scientists to stand in for the average.
The Four Reservoirs
The study of climate involves the study of materials and processes affecting four reservoirs, the atmosphere, the geosphere, the hydrosphere and the biosphere. Materials are continually switching from each of these reservoirs, affecting the overall system.
The atmosphere is made up of 78% nitrogen, 21% oxygen and 1% argon, with the rest consisting of trace gases including greenhouse gases such as CO2, methane, ozone and so on. The concentration of water vapour, unlike the gases like CO2, can vary considerably locally, from zero up to 5%.
The geosphere includes rocks, soils and fossil fuel deposits. Processes like weathering can over long periods of time—millions of years—extract CO2 from the atmosphere. Volcanoes spew CO2 back out, and major eruptions, by tossing materials into the atmosphere that reflect sunlight, can have a temporary cooling effect on Earth’s climate as a whole. Soil, of course, provides a place for plants to grow and fossil fuel deposits like oil, gas and coal provide the raw materials which humanity is currently tossing into the atmosphere.
The hydrosphere refers to where water is stored. 97% is in the oceans, 2% is ice, the rest is in the form of clouds and water vapour. All of these are central to climate.
The biosphere includes all life on Earth. It effects climate by cycling carbon through the atmosphere, taking it out, putting it back, storing it. The nature of the vegetation can affect how much solar radiation is absorbed or reflected. Shelled animals take up carbon and store it. The biosphere is the ultimate source of fossil carbon. Humans, as part of the biosphere, decrease the amount of carbon stored as life by cutting down forests, etc., and increase the amount of carbon in the atmosphere by burning fossil fuels.