China's urbanisation drive this century will cost it nearly
9% of its crop output by 2030 - with the loss in Egypt more than one-third, a
reflection of the pace at which cities are swallowing up productive land.
The world will in the first 30 years of this century lose
some 30m square kilometres of arable land to urbanisation, an area equivalent
to the size of Italy, or to that of the key US Corn Belt states of Illinois and
Iowa combined, an academic paper said.
"In most parts of the world, urban land is expanding faster
than urban populations," the paper, from nine researchers in institutions
ranging from US-based Texas A&M University to New Zealand's Canterbury
"Whereas urban populations are expected to almost double
from 2.6bn in 2000 to 5bn in 2030, urban areas are forecast to triple between
2000 and 2030."
While that loss – which excludes 16m hectares of urban land viewed
as being kept on in agriculture - is equivalent to 1.8-2.4% of world arable
land, its impact on harvests will be greater, given that the city growth will
occur predominantly on higher-yielding land.
Forecast cropland loss, 2000-30, and (impact as % of total crop output)
China: 7.6m hectares, (8.7%)
India: 3.4m hectares, (3.9%)
Nigeria: 2.1m hectares, (11.7%)
Pakistan: 1.8m hectares, (8.8%)
US: 1.5m hectares, (0.7%)
Brazil: 1.0m hectares, (2.4%)
Egypt: 800,000 hectares, (37%)
Vietnam: 800,000 hectares, (15.9%)
Source: Proceedings of the National Academy of Sciences of the United States of America
"Urban expansion is expected to take place on cropland that
is 1.77 times more productive than the global average," said the paper,
published in Proceedings of the National Academy of Sciences of the United
States of America.
"More than 60% of the world's irrigated croplands are
located near urban areas, highlighting the potential competition for land
between agricultural and urban uses."
And with the loss of land focused on a few areas, notably in
Africa and Asia, "regional impacts will be acute".
'Threat to crop
China alone will lose 7.6m hectares of cropland, equivalent
to 5.4% of domestic arable area - but enough to cut crop output by 8.7% given
that city growth is coming at the expense of relatively productive land.
"Urban expansion in
China is taking place in the country's most productive farmland and over large
areas," the researchers said.
"Therefore, urban expansion could pose a threat to domestic
The comments come as China is attempting to bring extra land into production, with officials last week restating plans to increase by 1.3m hectares by 2020 the country's arable area - -which a separate report said had fallen by 2m hectares since 2003.
'More susceptible to
Vietnam, the world's third-ranked rice exporter, and second biggest shipper of coffee, will lose 10.3% of its arable area, equivalent to 15.9% in crop production terms, the report said.
However, among nations listed, Egypt will see the biggest
impact, in relative terms, losing some 800,000 hectares to cities – equivalent
to 34% of its cropland and 37% of output.
While many sub-Saharan countries will be able to offset land
loss by bringing fresh areas into output, that is not an option for countries
in the likes of Northern Africa and the Middle East, where arable areas have
"nearly reached their maximum potential.
"Countries… such as Egypt are likely to resort to trade to
compensate for cropland loss, which could make them more susceptible to international
food supply shocks."
Egypt is already the top importer of wheat, besides being a
major buyer of the likes of soybeans, beef and sunflowerseed oil.
Brazil, India, US
The US will also lose a substantial amount of cropland, some
1.5m hectares, to cities between 2000 and 2030, but the impact on harvest potential
will be limited by urbanisation occurring in the main on less productive land.
Brazil, which will lose 1.0m hectares, and India, where
cities will swallow 3.4m hectares, will also be well placed to deal with the trend.
"India, the US, and Brazil will also experience high losses
in absolute terms.
"But here urban expansion leaves large expanses of croplands
untouched, and is therefore less likely to threaten domestic crop production."
Agrimoney has published an in-depth report on Chinese agriculture, China 2017: Agricultural Deregulation and Its Global Impact. More information at www.agrimoneyresearchreports.com