A new projection by the University of Minnesota and the University of California Santa Barbara shows global food demand could rise by 100-110 percent between 2005 and 2050, which would pose a grave threat to remaining tropical rainforests and would lead to again further increasing greenhouse gas emissions.

2007 NASA satellite image showing Amazon deforestation in Brazilian province of Mato Grosso. New research suggests by 2050 we may need another 1,000,000,000 hectares to feed the world. That’s almost twice as much land as covered by the remaining Amazon rainforest.

In their PNAS publication the researchers in fact call for Western intensive agriculture techniques to be deployed elsewhere, in order to prevent catastrophic environmental damage:

Under continuation of current extensive agricultural practices about 1 billion extra hectares of cropland [that’s a lot – the size of the US, a lot more than the planet has on offer] would be required, resulting in extra annual GHG emissions around 3 gigatonnes of CO2 equivalents.

If however existing intensive agricultural techniques were fully implemented the required extra cropland would shrink by 80 percent, to 200,000,000 hectares. In stead of 3 Gt, the annual extra emissions would amount to 1 Gt in the intensive agriculture scenario, is what the Minnesota-led  research group says.

Their food demand forecast is somewhat more pessimistic than that of the FAO, which has projected a 70 percent rise towards 2050.

On all accounts these are figures that can be viewed from different and sometimes contrasting perspectives. In the PNAS publication the Americans specifically name increased nitrogen fertilisation as an important option to increase crop yield per hectare and thereby decrease net GHG intensity.

How sustainable is nitrogen?

Nitrogen fertilisation is however a main contributor to increased nitrous oxide (N2O) emissions, a very potent greenhouse gas (per century 298x as potent as CO2) and which – under accelerating growth – has just reached a concentration of 323.2 ppb.

In fact, a recent Nature Geoscience publication stated the CO2 benefits of nitrogen feritilisation are fully offset by increased N20 emissions. What’s more, under current global agricultural activity, nitrogen fertilisation is already responsible for 1.5 percent of global energy consumption, being in itself an indirect CO2 source. [And that’s if we focus on climate concerns, and still ignore ecological damage of large-scale nitrogen pollution.]

More people consuming ever more

There are of course other and additional solution routes. The rising food demand is not just a result of the global population growth [although the planet can expect (UN medium variant) an estimated 2.3 billion extra people in 2050 – as no one even mentions the possibility of policy on that front] – but also of an increasingly decadent average food consumption pattern, in which (next to globalisation of food production) the rising consumption of animal protein plays a key role. The combined ecological footprint of 9.3 billion carnivores is entirely different from that of 9.3 billion vegetarians or vegans. Much of the world’s food crisis is in fact a protein crisis, which means there is good reason to better investigate alternative proteins, which come at a lower environmental cost – and may even offer some additional benefits.

© Rolf Schuttenhelm | www.bitsofscience.org