If you’ve got a bit of land and some energy, you could potentially have enough to feed all of humanity for centuries.
But a new report has found that in the current climate, that kind of land use could be unsustainable.
The report, which was released this week by the World Bank, the International Monetary Fund, the World Resources Institute and the World Economic Forum, was written by the UK’s Centre for Ecology and Hydrology.
It looked at how much energy could be produced by growing more than half of the world’s arable land.
The study’s authors said that in some places the problem was particularly acute.
“If you think about the most arid regions of the planet, it’s just not feasible to grow enough arable crop to feed everybody,” said Andrew Seddon, a researcher with the Centre for Ecological Indicators at the University of Sussex.
“There’s just a huge number of people who just don’t have enough space, there’s just no room for agriculture.”
The report found that the world could get by on 1.3 billion tonnes of food grown in the arid zones that currently account for around 2.5 per cent of the global population, but only about 3 per cent would be sustainable.
If that’s not enough to support all of the people who currently live there, the authors said, “it’s just unsustainable to think of growing enough arabica crops and then building on it”.
The researchers said the problem is most acute in the tropics and subtropics, which account for over a third of the arable-land area in the world.
“We’re seeing this rapid growth in arabia in these regions because the troposphere is so dry,” said Seddos.
“So if you get a lot of arabias, you can harvest them, but you have to be very careful.”
In many of these areas, there is already a lack of land for farming.
The researchers identified some of the main areas of concern in their analysis.
The arid belt that stretches from Africa and Asia to Latin America and the Caribbean is home to a vast swath of arable and semi-arable land, with a range of climate zones from dry to wet.
In the tropic region, the study found, there are roughly 1.2 billion hectares of arid land, or around 3 per head of population.
That’s less than half the arabic population of 2.3 million.
The majority of the area is covered by agriculture, mostly maize and rice, which accounts for a third.
“It’s a very vulnerable zone,” said Anthony Seddons, a senior researcher at the Centre.
“The arid belts are extremely productive.
If we don’t get enough food, we’re going to run out of land.”
In the high-income nations of Latin America, Africa and Europe, there aren’t many arid lands, and those that do are usually located on the edges of aridity.
In these regions, where aridity can reach 90 per cent, farmers often build dams to catch rainwater, then use the excess water to grow crops.
But this approach is unsustainable, because the water that comes out of the dams isn’t really used.
In Africa, the researchers found, arid farming is “largely driven by demand, rather than land” and is “extremely inefficient”.
In Latin America alone, the report found, more than 50 per cent or over one million hectares of land could not be used to grow food in a sustainable way.
The authors pointed to a report by the UN’s World Food Programme, which estimates that by 2050, the world is likely to need as much as 50 per a cent of arctic land for food.
In some parts of the developing world, such as India, aridity has caused severe environmental damage, including widespread desertification, the spread of disease and mass displacement.
Seddo said that arid areas were also particularly vulnerable to climate change.
“These arid conditions are really, really hard for the ecosystem, the ecosystem’s ability to function,” he said.
“You’ve got to feed people.
It’s really difficult to grow, you’ve just got to grow the right crops and you have the right climate conditions to do that.”
If arid countries are not able to meet their food needs, they can face food shortages and conflict.
The World Bank report also warned that climate change is also putting growing arabas on a collision course with agriculture.
In its report, the Bank also warned of the “dramatic” impact of climate change on food production in developing countries, including in sub-Saharan Africa.
“Climate change is going to cause severe changes to the food system,” said Robert Higgs, director of the Centre’s Global Environmental and Development Policy Centre.
Climate change is creating a new, more volatile and extreme food security, where crops will be able