The Responsible Survivialist


Swords Above Our Head
January 21, 2010, 10:57 am
Filed under: Climate Change, Peak Oil, The Coming Transition

talk about the various limiting factors, including briefly peak oil and climate change

The nine planetary boundaries

“climate change, stratospheric ozone, land use change, freshwater use, biological diversity, ocean acidification, nitrogen and phosphorus inputs to the biosphere and oceans, aerosol loading and chemical pollution.”

Nature magazine’s articles on this
“The sad thing is it isn’t just climate change. It’s excessive use of fertilizers, which run off into the river, and into the seas causing algae bloom and fish die offs. It’s the increase in ocean acidification which is killing corral reef which are a foundation of the sea ecosystem. It’s giant patches of trash floating in the oceans. It’s fresh water getting harder and harder to find. It’s burning hundred if not thousands of acres a day of forest to convert it into farm land for cash crops.”

Rising CO2 might not be good for us

“Even if you don’t think global warming is manmade, it’s hard to argue that CO2 levels have not risen. Here’s some scary unintended consequences of higher CO2 levels:

Rueters story

“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. 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.

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.”

Plant study

“Research published by three scientists at Southwestern University in Texas suggests that the price of rising carbon dioxide levels in the atmosphere is sharply falling nutritional value in staple crops upon which 40 per cent of the world’s population relies for its dietary protein.

Daniel Taub, Brian Miller and Holly Allen analysed more than 220 experiments in which plants were exposed to levels of carbon dioxide that ranged from the present ambient level to about double the existing level. They discovered that as the carbon dioxide in the atmosphere goes up, the protein in wheat, barley, rice, potatoes and soy beans diminishes, in some cases quite sharply.

Barley lost 15.3 per cent of its protein, potatoes lost 14 per cent, rice and wheat lost almost 10 per cent. Soy beans fared better, but even they lost 1.4 per cent of protein. As these plants absorb more carbon dioxide into their tissues, the researchers found, they do so at the expense of other compounds, including those which are essential parts of proteins.

This may all seem rather esoteric, but a 10- to 15-per-cent shortfall in the protein available to 40 per cent of the world’s population should make everyone sit up and take notice because the effects would be felt pretty quickly by the other 60 per cent, too.

Cereal grains, particularly barley, are key components in feed for the animals — chickens, pigs, cattle — that provide much of the protein in the developed world. A 15-per-cent reduction in the nutritional value of animal feed could only mean less efficiency for farmers and rising costs for consumers of meat, eggs and dairy products as well as for consumers of the two cereal grains — wheat and rice — that dominate world supply.

Well the solution’s easy, some might counter. Just use the additional land that comes available as temperate zones move north to increase production and that will offset any falling nutritional values.

But the climate change jigsaw is complicated and what seems logical doesn’t necessarily follow. For example, the quality of soils in northern latitudes is much poorer than the deep, rich soils that now comprise the North American and European breadbaskets. In Canada, 95 per cent of the land mass will never be suitable for field crops. It doesn’t matter what the climate is like, you can’t grow wheat on glaciated rock or mountains.”

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