Climate-driven farming shifts threaten biodiversity and water quality

A warming world will unlock new areas for growing crops, opening the way for farming in regions that were previously unsuitable for agriculture.  But this could significantly impact biodiversity, water resources, and greenhouse gas emissions worldwide, the authors of a new global analysis warn.

Unchecked expansion of farmland into new areas will increase CO2 emissions, reduce biodiversity, and lead to a loss of water quality for hundreds of millions of people, the authors report. They say these frontiers will need careful management to avoid negative environmental consequences.

Lee Hannah, of Conservation International’s Betty and Gordon Moore Center for Science in Arlington, Virginia, and colleagues present a new analysis of these risks in the open access journal PLOS ONE (see  HERE) 

As Earth’s climate warms, some regions at higher altitudes and latitudes may become more suitable for farming, potentially helping to feed a growing global population.

But research suggests the agricultural push into new “frontiers” threats wildlife, water resources, and other environmental factors. These risks are poorly understood at the global level.

To help clarify these risks, Lee Hannah and colleagues conducted a first-of-its-kind global modeling analysis of climate change-driven shifts in crop suitability and their environmental effects. The analysis incorporated the predictions of 17 global climate models and enabled assessment of different regions’ future suitability for 12 key crops, including corn, sugar, and cotton.

The modelling results suggest  climate change will increase the global amount of land suitable for key crops by more than 30 per cent, mostly in upper latitudes of the Northern Hemisphere and in mountains around the world.

Farming these frontiers could pollute downstream water resources that serve 1.8 billion people. It could also decrease biodiversity in tropical mountains; the predicted frontiers overlap 19 global diversity hotspots, as well as critical bird habitats.

Furthermore, farming of agricultural frontiers has the potential to release up to 177 gigatons of carbon naturally stored in frontier soils into the atmosphere. This amount is equivalent to more than 100 years’ worth of present-day carbon dioxide emissions in the U.S., and its release could accelerate global warming.

The new findings could help shape efforts to manage farming in agricultural frontiers, such that communities can benefit from new farmland while mitigating the environmental consequences.

The authors add:

“In a warming world, there will be new opportunities and challenges in the north. This work highlights how we must approach the idea of developing new farmland very cautiously and be extremely mindful of potential negative environmental impacts.”

Source:  Scimex

Author: Bob Edlin

Editor of AgScience Magazine and Editor of the AgScience Blog

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