Plants, Atmosphere and Climate

Thirty years ago, when teaching basic botany at the University of Guelph, I used to tell my undergraduate classes that the interrelationships of plants, carbon dioxide, the atmosphere and climate would, in their lifetime, be on the front pages of newspapers.  I think they were skeptical — but these topics are indeed now front page news. I am still struck by the number of biology students who still do not understand the simple relationships among plants, atmospheric carbon dioxide levels, and climate. If biology students can’t get these basics right, what hope is there for the rest of our citizens?  To judge from internet postings, many people understand nothing about this important topic.

The first chapter of my text book Plant Ecology therefore begins with the topic – it describes not only how plants affect current atmospheric carbon dioxide levels, but how plants actually created the composition of the Earth’s atmosphere. That is, much of the atmosphere is a biological rather than a geological phenomenon.  To encourage everyone to familiarize themselves with the basic principles, I have posted a copy of this book chapter (note: file is 2MB).

If you are learning basic botany, consider this chapter required reading.  Consider it a personal challenge to cover 3 billion years of biological and geological history in just 30 pages. If you are teaching basic botany, consider this chapter of Plant Ecology as a required reading, to ensure that your classes are exposed to these basic principles.

Whatever your preconceptions may be about humans and climate change, you need to understand the basic principles.  And should I ever serve on one of your thesis committees, I will indeed expect you to know how oxygen and carbon levels have changed over the past billion years (and the past million years too), why coal is called a fossil fuel, why sea levels change during ice ages, and more.  So set aside an evening and find out how plants can regulate the temperature and composition of the atmosphere.

The following illustration is visible in better resolution in the chapter download above.

Charts showing changes in global climate over two time scales.