High CO2 and Drought Conditions Result in Increase in Toxic Compounds, Decrease in Protein Content and Decreased Yield in Plants
29 June 2009
Researchers at Monash University in Victoria, Australia have found an increase in toxic compounds, a decrease in protein content and a decreased yield in plants grown under high CO2 and drought conditions.
The research, to be presented by Dr Ros Gleadow on 29 June 2009 at the Society for Experimental Biology Annual Meeting in Glasgow, has shown that the concentration of cyanogenic glycosides, which break down to release toxic hydrogen cyanide, increased in plants in elevated CO2. This was compounded by the fact that protein content decreased, making the plants overall more toxic as the ability of herbivores to break down cyanide depends largely on the ingestion of sufficient quantities of protein.
Data have also shown that cassava, a staple food crop in tropical and subtropical regions due to its tolerance of arid conditions, may experience yield reductions in high CO2. Combined with an increase in cyanogenic glycosides, this has major implications for the types of crops that can be grown in the future if CO2 levels continue to rise.
We need to be preparing for the predicted reduction in nutritional value of many plants in the coming century by developing and growing different cultivars which, for cassava in particular, may not be easy.
—Dr Gleadow
High Ozone Decreases Yield. In a separate paper to be presented at the meeting, researchers found that high ozone conditions cause a 30% decrease in yield and an increase in the concentration of a group of toxic compounds within oilseed rape plants. Combined with the results of previous studies which have shown a decrease in oil, protein and carbohydrate content of oilseed rape seeds in high ozone, these results could signal a significant income loss for farmers and an indirect effect on human health and the safety of food in future climates.
The research, to be presented by Maarten De Bock of the University of Antwerp, showed changes in the concentration of glucosinolates, a family of compounds involved in plant defences against herbivores, in oilseed rape plants. Such changes could influence crop resistance to insect pests, or the palatability of food crops.
As oilseed rape is important as a feed crop, increased levels of glucosinolates may cause problems due to the large quantities of fodder consumed by farm animals. For human consumption, however, an increase in glucosinolates, in cabbage plants for example, would be favorable due to their anticarcinogenic properties. Interaction of these factors and their impact on the food web in changing climates will be investigated further throughout the course of this ongoing project.
This complicates the picture of increased CO2 giving us ever-more-plentiful food drawn by the AGW denialists.
Posted by: Engineer-Poet | 30 June 2009 at 11:52 AM
Right. Because the smart set fully expect plant growth to excel under "drought conditions." Read the paper EP.
Posted by: Reel$$ | 01 July 2009 at 01:10 PM
Since increasing CO2 is expected to produce drought conditions, what would you expect plant growth to do?
Posted by: Engineer-Poet | 01 July 2009 at 04:36 PM
No EP - you are simply wrong. It was during the Devonian Period with CO2 at 1800-2000 ppm, the horsetails, ferns, seed plants, and the first trees and forests appeared all over the Earth. Lycopods in the Devonian grew to 35 meters tall.
First know your science then continue your farce of demonizing CO2.
Posted by: Reel$$ | 01 July 2009 at 10:38 PM
Note: EP's retreat.
Posted by: Reel$$ | 02 July 2009 at 06:24 AM
Your arguement of the Devonian climate system is wrong because not only does temperature effect climate but other factors. You do know the geographical distrubution of the plants in question during the period. Calling it lush could just be the fossil records of what we do see. It is far more likely that we would record data of plants from a lush area rather than Devonian deserts. Areas where the chance of fossilization would occur.
http://en.wikipedia.org/wiki/File:LateDevonianGlobal.jpg
Given wind pattern deserts like the sahara and the gobi, you don't think there were deserts in the Devonian?
As for the CO2 fertilization effect. It is highly contentious that everything would be good. This report and others point out that fact. Find a peer report on the increased nutrientional value from the fertilization effect.
E-P's comment on drought is well placed given the some reports coming out of California or Australia. Will increased temps bring more rain, certainly in some areas. But semi arid conditions especially in the south and in leeward areas of mountains will mostly not get more useful moisture.
Posted by: aym | 02 July 2009 at 08:28 PM
Geez, I spend a day working on other things and it's a "retreat". What a dipstick.
The Devonian was approximately 400 million years ago. The solar constant was quite a bit smaller then (main-sequence stars like the Sun get brighter over time, so CO2 levels would have to have been higher to maintain a similar global temperature.
Posted by: Engineer-Poet | 03 July 2009 at 12:22 PM
First, who asked you? Or is this your job. Second, here's your leading sentence:
"Your arguement of the Devonian climate system is wrong because not only does temperature effect climate but other factors."
Huh? Have you short circuited or something? Not only is the syntax and grammar wrong - it makes no sense. You base your entire rebuttal on a plate tectonic projection map? Drawn by one guy? Published on weakipedia, a heresay-based, non-peer-reviewed source?? This map is less believable than an IPCC climate model! The fossil record - hard empirical data gentlemen - proves my point.
You both suffer the disturbance known as "cognitive dissonance." You are unable to accept that you and your dwindling gaggle of scare mongers have been proven wrong. Over and over and over again. The once-clever idea of disguising your brand of totalitarianism as "environmentalism" has collapsed. This pathetic rebuttal attests to the death rattle of "global warming."
Get some therapy. Accept that you are wrong (on this.) Move on to the good proposition of energy independence and the electrification of transport. It is happening. Without the stupefying pretense of climate change.
Posted by: Reel$$ | 04 July 2009 at 09:51 AM
Looks like you stumped the stalwarts Reel$$!! Nice win.
Posted by: sulleny | 07 July 2009 at 12:49 PM
Yeah, willful ignorance wins every time... in its own mind.
Posted by: Engineer-Poet | 10 July 2009 at 06:54 AM