Trade-offs between water for food and for curbing climate change

Aug 31, 2012

Earth's growing human population needs fresh water for drinking and food production. However, fresh water is also needed for the growth of biomass, which acts as a sink of carbon dioxide and thus could help mitigate climate change. Does the Earth have enough freshwater resources to meet these competing demands?

Rockstrom et al. estimate the order of magnitude of freshwater consumption needed to feed a population of 9 billion people by 2050 and the amount of water needed to realize the planet's full biomass potential. They analyze these uses of freshwater in a framework of "planetary boundaries" within which the Earth system is resilient; beyond the boundaries, abrupt and irreversible change could take place. For instance, can collapse if water levels become too low due to water withdrawal for human uses.

On a global level, they find that achieving global food security and maximizing carbon sequestration together would require increasing by 3,250 cubic kilometers (780 cubic miles) per year. Combined with the current use of 2,600 cubic kilometers (624 cubic miles) per year, this would be above the safe planetary boundary level of about 5,000 cubic kilometers (1,200 cubic miles) per year.

They stress the need for societies to recognize the trade-offs between using water for food production and for increasing carbon sequestration through biomass. They conclude that since food production is essential, large-scale carbon sequestration through increasing biomass might not be realistic as a major mode of .

Explore further: Rising anger as Nicaragua canal to break ground

More information: The planetary water drama: Dual task of feeding humanity and curbing climate change, Geophysical Research Letters, doi: 10.1029/2012GL051688

add to favorites email to friend print save as pdf

Related Stories

Earth has less water than you think

May 08, 2012

If you were to take all of the water on Earth — all of the fresh water, sea water, ground water, water vapor and water inside our bodies — take all of it and somehow collect it into a single, giant ...

Water: The forgotten crisis

Jul 10, 2008

This year, the world and, in particular, developing countries and the poor have been hit by both food and energy crises. As a consequence, prices for many staple foods have risen by up to 100%. When we examine the causes ...

Farming commercial miscanthus

Aug 31, 2011

An article in the current issue of Global Change Biology Bioenergy examines the carbon sequestration potential of Miscanthus plantations on commercial farms.

Recommended for you

Rising anger as Nicaragua canal to break ground

1 hour ago

As a conscripted soldier during the Contra War of the 1980s, Esteban Ruiz used to flee from battles because he didn't want to have to kill anyone. But now, as the 47-year-old farmer prepares to fight for ...

Hopes, fears, doubts surround Cuba's oil future

Dec 20, 2014

One of the most prolific oil and gas basins on the planet sits just off Cuba's northwest coast, and the thaw in relations with the United States is giving rise to hopes that Cuba can now get in on the action.

New challenges for ocean acidification research

Dec 19, 2014

Over the past decade, ocean acidification has received growing recognition not only in the scientific area. Decision-makers, stakeholders, and the general public are becoming increasingly aware of "the other carbon dioxide ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.