Home > Global Warming >

Too Much CO2 Causes Plants Not to Cool The Earth As They Should, Says Study


By on May 5, 2010

evaporative cooling map 300x203 Too Much CO2 Causes Plants Not to Cool The Earth As They Should, Says Study

The percentage of predicted warming due to the effect of high carbon dioxide concentrations on plants.

Trees and green plants, generally, are used by the planet as a way to keep itself cool. A regular tree can evaporate as much as ten gallons of water a day, acting as a natural air conditioner for its surroundings. So trees are important for their CO2-sequestration capabilities and keeping things cool(er).

Still, when carbon dioxide levels are too high, the greenhouse gas causes the pores (stomata) that the leaf transpires through to shrink, and thus not to release its normal water amounts. A study performed by scientists from the Carnegie Institute for Science shows that more than a quarter of the warming from increased CO2 levels in some areas of the world is due to this effect.

The warming effects of carbon dioxide as a greenhouse gas have been known for a long time, says study co-author Ken Caldeira of Carnegie’s Department of Global Ecology. But he and fellow Carnegie scientist Long Cao were concerned that it is not as widely recognized that carbon dioxide also warms our planet by its direct effects on plants. Previous work by Carnegie’s Chris Field and Joe Berry had indicated that the effects were important. “There is no longer any doubt that carbon dioxide decreases evaporative cooling by plants and that this decreased cooling adds to global warming,” says Cao. “This effect would cause significant warming even if carbon dioxide were not a greenhouse gas.”

In their model, the researchers doubled the concentration of atmospheric carbon dioxide and recorded the magnitude and geographic pattern of warming from different factors. They found that, averaged over the entire globe, the evapotranspiration effects of plants account for 16% of warming of the land surface, with greenhouse effects accounting for the rest. But in some regions, such as parts of North America and eastern Asia, it can be more than 25% of the total warming. “If we think of a doubling of carbon dioxide as causing about four degrees of warming, in many places three of those degrees are coming from the effect of carbon dioxide in the atmosphere, and one is coming from the direct effect of carbon dioxide on plants.”

The model that the Carnegie researchers presented shows that the excess CO2 will even increase the runoff from the land surface in most of the areas. Water from precipitations will bypass the plants’ natural evaporation system and flow directly into rivers and streams. No earlier model predicted runoffs having as a cause the changes in evapotranspiration due to high CO2 levels.

Seeing how plants respond to various levels of carbon dioxide could help climate predictions and improve the representation of climate models worldwide.

Liked it? Share on
Facebook and Google +1:
No comments yet.
Break the ice!
E-mail Updates

Also share story on:

Become our facebook fan


Read next:


Why is our Earth warming up?

The concentration of carbon in living matter (18%) is almost 100 times greater than its concentration in the earth (0.19%). So living things extract carbon from their nonliving environment. For life to continue, this carbon must be recycled. That is our topic. Carbon exists in the nonliving environment as: carbon dioxide (CO2) in the atmosphere [...]

Hair Conditioning Shampoo Component Captures 90% of Coal Plants' CO2

Aminosilicones are regularly used in hair-conditioning shampoos and fabric softeners, but recently they show usefulness in fighting global warming by filtering carbon dioxide out of flue gases from coal plants.

Geothermal plants could consume CO2

Pumping carbon dioxide through hot rocks could simultaneously generate power and mop up the greenhouse gases produced by fossil fuel power stations, according to a new study. Harnessing geothermal power involves extracting heat from beneath the surface of the Earth. Normally, this means pumping water down through hot rocks and extracting it again. But the [...]

Germany Storing CO2 Underground

Germany has an ongoing plan to store their CO2 emissions underground. They used a special drill during tests earlier this year for the carbon capture project in Ketzin. The GFZ geoscience institute says that Germany will inaugurate Europe’s first underground carbon dioxide storage site.

What to Try on Earth's Day

If you didn’t find out already by typing “google.com”, today’s Earth day, my fellow readers! Enjoy this sunny, or maybe rainy or (I hope not) snowy day, and try to pollute as little as you can. Try to study about how people got into this game of planet destroying, try to understand why and what [...]


Comments from our readers

3167 total comments so far. What's your opinion ?
  1. No comments on this article yet.
(will not be published)



eight × 4 =

Not what you were looking for? Search The Green Optimistic!


Tags: carbon dioxide, climate models, evapotranspiration, Global Warming, high co2 levels, plants as air conditioners, plants cooling, plants transpiration, water runoff