The other inconvenient truth: the crisis in global land use

Given our current practices, future increases in food demand will dramatically increase water pollution and ecosystem destruction through agricultural effluent. Ironically, the fertiliser runoff from farmlands compromises another crucial source of food: coastal fishing grounds.

Greenhouse gas emissions. Last, but certainly not least, land use is also one of the biggest contributors to global warming. Of the three most important man-made greenhouse gasses - carbon dioxide, methane and nitrous oxide - land use and agricultural practices, including tropical deforestation, emit 30 per cent of the total. That’s more than the emissions from all the world’s passenger cars, trucks, trains and planes, or the emissions from all electricity generation or manufacturing.

Compared to any other human activity, land use and agriculture are the greatest emitters of greenhouse gasses. The vast majority comes from deforestation, methane emissions from animals and rice fields, and nitrous oxide emissions from heavily fertilised fields. Yet, for some reason, agriculture has been largely able to avoid the attention of emissions reductions policies.

The list of environmental impacts from agricultural land use goes on and on - and clearly threatens human well-being and the health of the biosphere as much as global warming. In fact, in a recent paper in Nature, a number of us documented “planetary boundaries" where large-scale environmental changes could result in catastrophic tipping points. Of those changes, an equal number were tied to climate change and CO2 emissions as were connected to land-use and agriculture.

From these newly revealed facts, it’s clear that we must consider multiple inconvenient truths. The future of our civilisation and our planet requires that we simultaneously address the grand challenges of climate change and land use, ultimately finding new ways to meet the needs of our economy, our security and the environment. Anything less will be a complete catastrophe.

So, what are the solutions to the global land crisis? Here are just a few to start with:

First, acknowledge the problem. Even in circles of well-informed scientists and agricultural experts, the notion that our land use and agricultural practices rival climate change as a global environmental threat comes as a big surprise. Clearly we need to have a larger international conversation about this issue, on par with the recent efforts of the climate change community and Al Gore, to give it the attention it deserves.

Invest in revolutionary agricultural solutions. The Obama administration has invested billions of dollars into new energy technology, research and infrastructure, and aggressive plans for new climate mitigation policies are being developed. These strategies are important, but I wonder where the stimulus funding for new “out of the box” agricultural research is?

Where are we investing public dollars in revolutionary approaches to feeding the world, while reducing the environmental impacts of agriculture? These might include the development of new hybrid crops, designed to use water and nitrogen more efficiently, or the invention of perennial crops that don't need to be planted every year. Don’t such ideas count as national priorities, too? Can’t we afford to launch a “Greener” Revolution?

Bridge the artificial divide between production agriculture and environmental conservation. We cannot solve these problems by boosting agricultural production at the expense of the environment, nor can we ignore the growing need for food in the name of preserving natural ecosystems. Instead, we must find ways to simultaneously increase production of our agricultural systems while greatly reducing their environmental impacts.

This is not going to be easy. Yet, drawing on the lessons from recent research, including the successes and failures of local organic practice, combined with the efficiency and scalability of commercial agriculture, will be crucial. In recent years, for example, US farmers - working with agricultural experts - have dramatically improved practices in the corn and soybean belt, cutting down on erosion, nutrient loss, and groundwater pollution, even as yields have continued to increase.

As a first step, advocates of environmental conservation, organic farming and commercial agriculture all need to put down their guns and work toward solving the problems of food security and the environment - with everyone at the table.

Providing for the basic needs of 9 billion-plus people, without ruining the biosphere in the process, will be one of the greatest challenges our species has ever faced. It will require the imagination, determination and hard work of countless people from all over the world, embarked on one of the noblest causes in history.

But the first step is admitting we have more than one problem.