On this site, I’ll be writing about photosynthesis and plant growth in a CO2-enriched world, as well as providing a Canadian view on climate change.
An appreciation of photosynthesis isn’t necessary to understand climate change, but it can complement it. If we take a long perspective, looking back over Earth’s history, we can see that changes in the rates of photosynthesis, on grand, planet-changing scales, have shaped our evolution and our world. Photosynthetic carbon fixation by photoautotrophs has maintained an atmosphere with free oxygen, life supporting oceans, and vast and heavy food chains of organisms. It is the light from the sun of millions of days captured by photosynthesis and buried and stored in oil and coal and gas, that is now being burned and released in atmosphere-changing proportions.
No method exists on Earth that is as effective at fixing carbon than photoautotrophic growth. It is light and carbon, captured via photosynthesis, that got us into this situation. Photosynthesis is still active, fixing anthropogenic CO2. But will it be enough get us out of trouble?
Forests can absorb some of the extra carbon. New forest growth and expansion of the treeline, maybe still more. Even so, the steady annual rise of the Keeling Curve shows that photosynthesis has not been keeping up. We expect there to be limits, and we would be wise to expect unexpected feedbacks. For example, growth of shrubland tundra may increase the per unit area carbon fixation, but at the expense of permafrost, which currently stores a vast amount of methane and soil carbon.
Much of this topic should be uncontroversial. It is a matter of fact that CO2 has increased in the atmosphere, and a matter of biology that plants will respond to it, and to increasing temperatures. Understanding and observing the consequences of increased CO2 and temperature on plant life and the planet shouldn’t be a political or ideological matter, although it often is.
CO2 levels are increasing. The world, from a plant’s perspective, has already changed.
Contact: carbonfixated (at) gmail.com