From: Andy Soos, ENN
Published June 25, 2012 07:44 AM
Food or Forests?
Forests are lovely. Food crops are more nourishing. Which is more
important? It is no surprise that the United States and China are the
world’s top greenhouse-gas emitters. What may be surprising is the
country that is third: Indonesia. Indonesia is a major culprit not
because of its traffic or power plants, but because of its massive
deforestation. Deforestation accounts for almost 20 percent of global
emissions — more than the world’s entire transportation sector. But
saving the trees — as beneficial as it would be to the changing climate
— comes at a significant cost as a growing, wealthier population
competes for food, says a new MIT study.
"With a larger and wealthier population, both energy and food demand
will grow," says John Reilly, the lead author of the study and the
co-director of the MIT Joint Program on the Science and Policy of Global
Change. "Absent controls on greenhouse gases, we will see more emissions
from fossil-fuel use and from land-use change. The resulting
environmental change can reduce crop yields, and require even more land
for crops. So this could become a vicious circle."
Reilly’s study, recently published in Environmental Science &
Technology, compares the effects of slashing emissions from energy
sources alone to a strategy that also incorporates emissions associated
with land use.
The report finds that, with a growing global population, fast-developing
nations, and increasing agricultural productivity and energy use, the
world is on the path to seeing average temperatures rise by as much as 6
degrees Celsius by the end of the century. Even with an aggressive
global tax on energy emissions, the planet will not be able to limit
this warming to 2 C — the target world leaders have agreed is needed to
avoid dangerous climate change. But when the tax is applied to land-use
emissions, the world community could come much closer, with temperatures
by the year 2100 rising 2.4 C above pre-industrial levels.
To go one step further in reducing emissions the study incorporates
biofuels production, which could increase carbon storage on land and be
a cleaner source of energy, lessening the use of fossil fuels. The
researchers find that increased biofuels production could cut
fossil-fuel use in half by the end of the century — from 80 percent of
energy without a tax to 40 percent with a tax — and further limit
warming to bring the world just shy of the target.
The world could get even closer to the target, the study shows, by
creating economic incentives for storing carbon on land — such as
through reforestation. In combination with the global carbon tax, this
could “bring the world closer to keeping warming below the 2 degree
Celsius temperature,”� Reilly says.
However, there are always drawbacks.
"The environmental change avoided by reducing greenhouse-gas emissions
is substantial and actually means less land used for crops," Reilly
says. "The big tradeoff is that diverting this amount of land to carbon
storage, and using land to produce biofuels, leads to substantial rises
in food and forestry prices."
Food prices could rise more than 80 percent, the study shows. Along with
this, nations could become wealthier, with global GDP increasing
fivefold. On average, the share of a household’s budget for food, even
with higher prices, might fall from 15 percent to 7 percent. But for
poorer regions of the world, the food budget share could increase,
meaning these food price impacts could have disproportionate effects on
poorer regions.
Food shortages and higher food prices are becoming a major challenge,
according to Jonathan Foley, director of the University of Minnesota’s
Institute on the Environment, who spoke at a recent MIT event.
"In the last 20 years we’ve produced 28 percent more crops. But in the
next 38 years, we need to double that growth," Foley said. "We’re not
going to grow our way out of the problem ”� we must look at other
possibilities."
Reilly agrees, and says his study puts an emphasis on more effective use
of land to produce food. Part of this means more efficient (intensive)
use of pasture and grazing land. But, he says, the carbon tax scenarios
he tests make the problem that much more difficult — with biofuels and
carbon sequestration using up more land.
There is only so much land available. What we use it for is always a
balancing act. Will it be food, biofuels, or carbon storage? Even
after that is what is fair for all of humanity and for the general
environment.
For further information see
Forests or Crops.
Forests image via Wikipedia.
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