ISSUES
: Our Changing Population
Chapter 2: Global population issues
26
high temperatures and pressures. All that heat requires
serious amounts of energy, and the hydrogen is derived
from natural gas, which currently means the Haber
process uses lots of fossil fuels. If we include production,
processing, packaging, transportation, marketing and
consumption, then the food system consumes more
than 30% of total energy use while contributing 20% to
global greenhouse gas emissions.
Feeding the next four billion
If industrialised agriculture can now feed seven billion,
then why can’t we figure out how to feed 11 billion by
the end of this century? There may be many issues that
need to be addressed, the argument runs, but famine
isn’t one of them. However, there are a number of
potentially unpleasant problems with this prognosis.
First, some research suggests global food production
is stagnating. The green revolution hasn’t run out of
steam just yet but innovations such as GM crops, more
efficient irrigation and subterranean farming aren’t
going to have a big enough impact. The low-hanging
fruits of yield improvements have already been gobbled
up.
Second, the current high yields assume plentiful and
cheap supplies of phosphorus, nitrogen and fossil fuels
– mainly oil and gas. Mineral phosphorus isn’t going to
run out anytime soon, nor will oil, but both are becoming
increasingly harder to obtain. All things being equal this
will make them more expensive. The chaos in the world
food systems in 2007–8 gives some indication of the
impact of higher food prices.
Third, soil is running out. Or rather it is running away.
Intensive agriculture, which plants crops on fields
without respite, leads to soil erosion. This can be offset
by using more fertiliser, but there comes a point where
the soil is so eroded that farming there becomes very
limited, and it will take many years for such soils to
recover.
Fourth, it is not even certain we will be able to maintain
yields in a world that is facing potentially significant
environmental change. We are on course towards 2ºC
of warming by the end of this century. Just when we
have the greatest numbers of people to feed, floods,
storms, droughts and other extreme weather will cause
significant disruption to food production. In order to
avoid dangerous climate change, we must keep the
majority of the Earth’s fossil fuel deposits in the ground
– the same fossil fuels that our food production system
has become effectively addicted to.
If humanity is to have a long-term future, we must
address all these challenges at the same time as
reducing our impacts on the planetary processes that
ultimately provide not just the food we eat, but water we
drink and air we breathe. This is a challenge far greater
than those that so exercised Malthus 200 years ago.
12 August 2015
Ö
Ö
The above information is reprinted with kind
permission from
The Conversation
. Please visit
for further information.
© 2010–2015, The Conversation Trust (UK)
The impact of eating meat-heavy diets
Source: onegreenplanet.org/eatfortheplanet/
* The United Nations Food and Agriculture Organization (FAO) estimates that livestock production is responsible for
14.5 percent of global greenhouse gas emissions, while other organizations like the Worldwatch Institute have
estimated it could be as much as 51 percent.
70%
14.5%
45%
33%
Global freshwater supplies
used for agriculture
Global greenhouse
emissions
produced by livestock*
Global land
occupied by the
livestock system
Global arable
land devoted
to livestock feed
