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TechnoratiCrops Face Toxic Timebomb in Warmer World: Study
SINGAPORE - Staples such as cassava on which millions of people depend become more toxic and produce much smaller yields in a world with higher carbon dioxide levels and more drought, Australian scientists say.
![[A farm worker collects cassava at the expropriated and now redistributed farm of El Charcote in the central state of Cojedes March 25, 2009.
(REUTERS/Jorge Silva)]](http://www.commondreams.org/files/article_images/cassava.jpg "cassava.jpg")
The findings, presented on Monday at a conference in Glasgow,
Scotland, underscored the need to develop climate-change-resistant
cultivars to feed rapidly growing human populations, said Ros Gleadow
of the Monash University in Melbourne.
Gleadow's team tested cassava and sorghum under a series of climate change scenarios, with particular focus on different CO2 levels, to study the effect on plant nutritional quality and yield.
Both species belong to a group of plants that produce chemicals called cyanogenic glycosides, which break down to release poisonous cyanide gas if the leaves are crushed or chewed.
Around 10 percent of all plants and 60 percent of crop species produce cyanogenic glycosides.
The team grew cassava and sorghum at three different levels of CO2; just below today's current levels at about 360 parts per million in the atmosphere, at about 550 ppm and about double at 710 pm.
Current levels in the air are just under 390 ppm, around the highest in at least 800,000 years and up by about a third since the start of the Industrial Revolution.
"What we found was the amount of cyanide relative to the amount of protein increases," Gleadow told Reuters from Glasgow, referring to cassava.
At double current CO2 levels, the level of toxin was much higher while protein levels fell.
The ability of people and herbivores, such as cattle, to break down the cyanide depends largely on eating sufficient protein.
Anyone largely reliant on cassava for food, particularly during drought, would be especially at risk of cyanide poisoning.
HARDY STAPLE
While it was possible to use processing techniques to reduce the level of toxin in the cassava leaves, it was the 50 percent or greater drop in the number of tubers that caused most concern, Gleadow said.
About 750 million people in Africa, Asia and Latin America rely on cassava as a staple. The starchy tubers are used to make flour and the plant is ideal in dry regions because of its hardy nature.
The good news was that the levels of toxin in the tuber didn't increase with CO2, unlike the edible leaves.
"The downside of that is that we found the plant didn't grow nearly as well," she said.
"There's been this common assumption that plants will always grow better in a high CO2 world. And we've now found that these plants grew much worse and had smaller tubers."
At the 550 ppm level, the problem was not as serious and this meant scientists had a bit of breathing space.
"We've got 20 to 30 years to develop cultivars, which is going to be absolutely essential because by then about 1 billion people will probably be reliant on cassava."
Gleadow's group looked at a type of sorghum commonly fed to cattle in Australia and Africa and found it became less toxic at the highest CO2 level. But under drought conditions, leaf toxin levels rose.
She said her team was looking at creating mutations to get rid of the toxin response to drought.
"If we're going to adapt in the future to a world with twice today's CO2 we need to understand how plants are working, how they are responding and what cultivars we need to develop."
Her team plans to carry out additional research in Mozambique and study other tropical crops such as taro.
Editing by Alex Richardson
10 Comments so far
Show AllMalthus was probably right: the world will populate itself to death. Nature abhors an imbalance. Technology can only postpone the day of reckoning.
A solution would be to educate everyone since educated people have fewer children. Also, everyone should become vegans, because to feed carnivours requires at least ten times the water and arable land. Even if this would solve the problem, educated people produce more toxins, polution, and trash. Face it: the future of the earth is bleak.
"No more water, the fire next time"
Ring any bells?
Nature's wonderful balancing act! . . . Too many people - toxic food - fewer people.
Well I guess it's a good thing we're running out of oil then, because we'll spare ourselves having to gene splice veges to save ourselves from global warming.
Incidently, the OBVIOUS solution which this article, with it's scary cyanide issue highlight, doesn't suggest, is to REDUCE the CO2 in the air.
The carbon sink globally is huge. It's every bit of the ocean deep and every bit of vegetation. The air is noticably cleaner on Sunday evening, because the power plants don't have to produce energy to drive the factories over the weekend. This is true on holidays too.
I've seen a thermal image of global warming which showed it is concentrated over industrial centers. Which is to say, as soon as that foul air is over a carbon sink, meaning within minutes, the air is significantly cleaner.
Global warming could be averted to eliminate production of video game systems. Yet we're talking about bioengineering crops to "work with" the insane situation!? Ridiculous. Peak Oil is going to nip global warming in the bud soon enough. Then we'll be smack dab in the middle of year round permafrost ice age, because we ALREADY melted the North Pole sea ice into the oceans, which steps down the ocean dilution (less salt), and slows the ocean current which then ceases carrying warm water up from the equator to the extremes of the globe, voila ice age. Which incidentally has an average 3 year onset, but this time will likely happen a LOT faster, because it should have happened already, but has been held off by the steady heavy industrial pollution which will soon be impossible due our aging so far past Peak Oil into World Oil Production Decline.
It better happen soon though, because if the methane burp much hits the air, this then highly flammable place will suffer extreme global warming like no one is predicting yet.
And so this will be the final cruel gift of the capitalist "industrialized" world to those nations still largely living in simple sustainable ways.
"If we're going to adapt in the future to a world with twice today's CO2 we need to understand how plants are working, how they are responding and what cultivars we need to develop."
Adapting to a world with twice today's CO2? Is this even possible?
No, it's not possible.
We need to begin implementing "Plan B" now more than ever.
The physiology of plants is pretty well known today. We have a LOT more to learn to be sure. I seriously doubt if we can adapt to a world with twice the CO2, not to mention the other gases which go along with it. What the article fails to acknowledge, is that with such a rise in green house gasses, the population of the world would no longer by "rapidly rising", but rather falling dramaticlly. At least by 'best guess' scenarios.
You say the population of the world would not be rapidly rising?
In actuality humanity is quite counter intuitive in this regard. The more people die and are killed, the higher rate of replacement people practice.
The only way the population is ever regressed is by 1) meeting needs, or 2) savage murderous dominance.
I see the savage murderour dominance plans under way. I think, hope might be a better word, I hope humanities average IQ has grown so strong that the savage murderous dominance will be flipped on it's perpetrator this go round. He's gotten away with it very many times before, brutalizing masses into nonexistence. But in those ages people were greatly simple. People are highly advanced right now, so very many people, knowing how to burrow, construct firearms. I see that it's going to be a huge challenge for the top murderer to carry off the militant suppression of the whole world's people. He seemed to really be going for it during WWII. 50m dead in a few years. And even that only boosted the population.
Can't say your wrong. But what I've read is that the health epidemics will take away more than can be replaced... I'm not a doctor, but it seems feasible that with a general warming trend, the diseases will increase, and with more CO2, the instanaces of skin cancer and breathing disorders will go up. Pandemics seem to be the favored theory, along with population displacement due to weather changes and rising water levels at coastal regions. What people do AFTER that is anybody's guess. If the bottleneck is extreme enough, there will be a NEED to populate, just for species survival. I hold with those who belive that the earth will not be distroyed, but perhaps mankind will be.... don't really know. All any one person can do is to try to live without causing harm to others I guess.