Earth Approaching Limits Of Arable Land

New maps show that the Earth is rapidly running out of fertile land and that food production will soon be unable to keep up with the world's burgeoning population. The maps reveal that more than one- third of the world's land is being used to grow crops or graze cattle.

Scientists at the University of Wisconsin-Madison combined satellite land cover images with agricultural census data from every country in the world to create detailed maps of global land use. Each grid square was 10km across and showed the most prevalent land use in that square, such as forest, grassland or ice. "In the act of making these maps we are asking: where is the human footprint on the Earth?" said Amato Evan, a member of the University of Wisconsin-Madison research team presenting its results this week at a meeting of the American Geophysical Union in San Francisco.

The current map shows a snapshot of global land use for the year 2000, but the scientists also have land use data going back to 1700, showing how things have changed. "The maps show, very strikingly, that a large part of our planet is being used for either growing crops or grazing cattle," said Navin Ramankutty, a member of the Wisconsin-Madison team. By comparison, only 7 percent of the world's land was being used for agriculture in 1700. The Amazon basin has seen some of the greatest changes in recent times, with huge swaths of the rainforest being felled to grow soya beans. "One of the major changes we see is the fast expansion of soybeans in Brazil and Argentina, grown for export to China and the EU," Ramankutty said.

This agricultural expansion has come at the expense of tropical forests in both countries. Meanwhile, intensive farming practices mean that cropland areas have decreased slightly in the US and Europe and the land is being gobbled up by urbanization. The research indicates that there is now little room for further agricultural expansion. "Except for Latin America and Africa, all the places in the world where we could grow crops are already being cultivated. The remaining places are either too cold or too dry to grow crops," Ramankutty said.


EDIT

http://www.taipeitimes.com/News/world/archives/2005/12/07/2003283384

line is a crime. Also attacking Gays & lesbians.

Also why we need world trade to open up - right now. So this generation of people in Africa have access to world markets and like yours and my ancestors in the USA - have a chance to work their butts off so that their kids can have better lives and fewer kids.

As it happens, I'm a childless gay woman who doesn't want to pop out rugrats, but I'm constantly hearing about gay couples who want to raise a family. Some -- if they're allowed -- will adopt babies, but many of the lesbian couples select to get pregnant (using sperm banks or more informal sperm "donation" from a friend or even a one-night stand).

The decision to remain childless is not relevant to gay-straight divisions.

- traditional family roles. Your point is well taken though. But I do think the percentages of childlessness amongst gay men is higher than straight men. Though by how much I could not say. And of course many couples have kids

about 6 1/2 billion people. About 6 months ago, we only had 6 billion people. Population increase is on an exponential curve.

It simply cannot continue the way it has. And not because of the problem of arable land. It's the problem of oil.

Agriculture is extremely petroleum-dependent. Every phase of planting crops, fertilizing the field, harvesting, driving the produce to market, shipping it overseas etc, is all dependent on oil.

I've read that without oil, the world can sustain about 2 billion peoople.

That means that 4 1/2 billion people are at risk. Researchers who are in the know, say that future wars will be fought over oil, land rights, and food.

In fact, we're in an oil war right now. I'd say the future has arrived.

I think you must have looked at 'rounded' figures.

In fact, from the UN Population Division:

World population:
1995 5,692,353,000
2000 6,085,572,000 - increase: 393,219,000
2005 6,464,750,000 - increase: 379,178,000

In other words, the rate of increase in world population is slowing, not on an exponential curve. And an increase of half a billion takes over 6 years, not 6 months.

Malthus may have been right; 150 years later. Eating meat may soon only be for the rich, or well placed Repubs.

I think we'll see the dieoff; at least, the beginnings of it.

It's likely to be a bumpy ride.

and societies need to make progress. The only ethical method of population 'control' occurs naturally as peoples become more educated and free: when women have opportunities to control their bodies, and opportunities to learn and work outside the home.

Agriculture (and every other form of production), need to change and accept the rules of ECOnomics.

and :kick:

(From here). What the hell are they going to eat? Soylent Green?

I read that with our current population it would take the resources of 4 whole earths to bring every one to 1st world standards. Population growth is the main reason Africa has become POORER since the end of the colonial era. We need to get our population under 1 billion, preferably under 500 million, if we want everyone to have a good quility of life and have a healthy planet at the same time.

That which can't go on, won't :-)

The world grain harvest has been short of demand for several years now causing succesive drawdowns of grain reserves. Soon we will reach the point where there are effectively no grain reserves.

Then we're screwed.

http://www.earth-policy.org/Updates/Update40.htm

given that Labor is the most expensive input. In exchange for reducing labor inputs, current practices increase inputs from Land (in the form of acreage, water, and chemical inputs) and Capital (Mechanization, Irrigation equipment, Chemical processing).

This balance is very nearly dictated by the taxes or lack of taxes on those inputs. In addition to the wages labor demands, labor carries a payroll tax of 15% and an income tax of ~25%. In addition to the interest capital demands, capital generally carries a 1% value tax and a ~15% interest / income tax. Land - the only factor that appreciates - generall only carries a 1% value tax and no income tax until the land is sold.

It is not impossible to sustainably increase the yields per acre by a factor of 2-4 depending on the crop and the climate. Such agriculture would then be Land efficient rather than Labor efficient.

This model of production is generally accurate in other fields of production. If tax changes changed to encourage Land efficiency (Green Tax Shift) more labor would be required for a given level of productivity. As more labor is used, it becomes more scarce and can demand better wages.