View Full Forums : More cheerful news!


Panamah
12-05-2006, 11:45 AM
Massive global starvation from emptying underground aquafers faster than they're refilled?

http://www.newscientist.com/article/mg18925401.500

The Indian underground water anarchy is already being repeated elsewhere. From China to Iran and Indonesia to Pakistan, rivers are running dry under the impact of increased abstractions and, in some places, climate change. Millions of small farmers have bought pumps and are sucking water from beneath their fields. Shah estimates that India, China and Pakistan together probably pump out around 400 cubic kilometres of underground water a year, around twice as much as is recharged by the rains. These three countries account for more than half the world's total use of underground water for agriculture.

But there is some good news here too:Hadeja has redesigned the village's drainage system to slow the passage of the monsoon rain long enough for it to collect in specially dug ponds. The water passes from one pond to the next in a slow cascade. The villagers don't use the water directly from the ponds, but allow it to percolate into the soil to refill underground reserves and replenish their wells. "There is no more rain than before. We just use it better. We don't let it wash away," Hadeja says. As a result, the village has twice as much water as before; and wells find water at only 7 metres down, where once the water had to be hauled up more than 30 metres.

Klath
12-05-2006, 02:12 PM
They need to apply some of the technologies that Israel has come up with to reduce water consumption. Their drip irrigation systems have drastically reduced both the amount of water needed to grow crops and the rate of soil salinization.

Tudamorf
12-05-2006, 02:35 PM
First, they need to stop breeding. North Indian populations are out of control (in some areas, an average brood of about 6 per female), and if they don't stop, water will be the least of their problems.

Second, global warming will just continue to contribute this problem:

http://news.bbc.co.uk/2/hi/science/nature/6200114.stm <b>New crops needed to avoid famines</b>

<b>The global network of agricultural research centres warns that famines lie ahead unless new crop strains adapted to a warmer future are developed.</b>

The Consultative Group on International Agricultural Research (CGIAR) says yields of existing varieties will fall.

New forecasts say warming will shrink South Asia's wheat area by half.

"We're talking about large scale human migration and the return to large-scale famines in developing countries, something which we decided 40 or 50 years ago was unacceptable and did something about."

The most significant impact of climate change on agriculture is probably changes in rainfall. Some regions are forecast to receive more rain, others to receive less; above all, it will become more variable.

But increasing temperatures can also affect crops. Photosynthesis slows down as the thermometer rises, which also slows the plants' growth and capacity to reproduce.

Research published two years ago shows rice yields are declining by 10% for every degree Celsius increase in night-time temperature.

A study from the International Maize and Wheat Improvement Center (Cimmyt) in Mexico, yet to be published, projects a major decline in South Asia's wheat yield. The vast Indo-Gangetic plain produces about 15% of the world's wheat - but the area suitable for growing is forecast to shrink by about half over the next 50 years, even as the number of mouths to feed increases.

"The livelihoods of billions of people in developing countries, particularly those in the tropics, will be severely challenged as crop yields decline due to shorter growing seasons," said Robert Zeigler, Director General of the International Rice Research Institute (Irri), a CGIAR affiliate.While I strongly disagree that genetic modification is the right answer, at least we're all asking the right question (well, most of us, not Fyyr).

Panamah
12-05-2006, 06:54 PM
Why hasn't desalinization every really been done on a large scale?

Tudamorf
12-05-2006, 08:47 PM
Why hasn't desalinization every really been done on a large scale?Cost. If you have to go that far, it's probably cheaper to buy U.S. made genetically engineered plants.

Thicket Tundrabog
12-06-2006, 12:03 PM
Why hasn't desalinization every really been done on a large scale?

It's very energy intensive. There are a number of desalination plants in oil-rich countries on the Arabian peninsula.

Panamah
12-06-2006, 12:08 PM
Well, once we get that cold fusion thing worked out perhaps...

Aidon
12-06-2006, 04:24 PM
Why hasn't desalinization every really been done on a large scale?

It has huge energy requirements. Israel has a desalinzation plant in coordination with their nuclear reactor, but for mass desalinization, you'd have to build a whole bunch of nukes and noone really wants potential chernobyls nearby.