Climate Change has become a hot topic. The Stern Report, Al Gore’s An Inconvenient Truth, and more recently the IPCC Report (Climate Change 2007: Impacts,Adaptation and Vulnerability [read the summary here]), have all helped to establish Global Warming high on most political agendas.
Yet, there are still sceptics. Some have claimed that increases in CO2 levels will only lead to better plant growth. After all, plants require CO2, so why wouldn’t more be better?
According to scientists in the US:
“If we maintain our current course of fossil fuel emissions or accelerate our emissions, the land and oceans will not be able to slow the rise of carbon dioxide in the atmosphere the way they’re doing now,” said Inez Y. Fung at the University of California, Berkeley, who is director of the Berkeley Atmospheric Sciences Center, co-director of the new Berkeley Institute of the Environment, and professor of earth and planetary science and of environmental science, policy and management.
“Plants are happy growing at a certain rate, and though they can accelerate to a certain extent with more CO2, the rate is limited by metabolic reactions in the plant, by water and nutrient availability, et cetera.”
“In addition, increasing temperatures and drought frequencies lower plant uptake of CO2 as plants breathe in less to conserve water.”
With CO2, as with food, there is a limit to how much that can be absorbed. But whilst global climate change is relatively slow, there will always be those that doubt. Are we all frogs in the saucepan –as things warm up will be act in time?
Thanks for the comment Carl. I’ve noticed that there have been some recent studies here in Australia regarding CO2 uptake amongst the eucalyptus species which dominate this continent. Plants such as these have been adapted for higher temperatures for many thousands of years. It would appear they have a better ability to absorb higher CO2 amounts as they have evolved to cater for high Australian temperatures and therefore their stomata tend to stay open even if temperatures are extreme. The plants which have limited adaptability would be those which have traditionally grown in mild climates, especially if these climates are now warming. But, it was interesting what you said about nutrients being the limiting factor amongst aquarium plants.
regards
Greg
I have used in CO2 systems with for aquariums personally and for my clients. There is a point (usually over 25 ppm) when CO2 starts becoming a problem for the fish, however the more CO2 added the faster the plants grow. Lack of nurients are the only other limiting factor, and that is rarely a problem. The ceiling for CO2 and plant growth is quite high, much higher than is often suggested.