A looming collision: Population and pollution

Al Gore won a Nobel Prize and was profiled in an Oscar-winning documentary for his work calling attention to global warming, which he called the “An Inconvenient Truth” confronting the world.

Jonathan Foley says there is another – maybe bigger – problem facing the planet: A world population predicted to increase from about 6.8 billion people at present to about 9 billion in 2050, and widespread pollution and over-use of water from the agriculture systems that feed us all.

Foley, the director of the University of Minnesota’s Institute on the Environment, calls that impending collision between population and pollution “The Other Inconvenient Truth.” He has been writing about it, and speaking widely about it. He had a rapt audience when he talked about the conflict at a recent conference on agriculture and water quality sponsored by the Izaak Walton League and the Freshwater Society.



Jonathan Foley at Izaak Walton League-
Freshwater conference on agriculture and
water quality

The Freshwater Society interviewed Foley about the converging demographic and environmental forces. The transcript of that interview, edited for clarity and brevity, follows:

At its core, what is the “Other Inconvenient Truth” that you have been urging people to take seriously?

At its core, we have to feed 9 billion people sometime in the middle of the century, and we have to do that without compromising the environment. But, even today, agriculture is already compromising some aspects of the environment in pretty serious ways, and when you add them all together they become a major global issue. So we have to simultaneously feed the world and also reduce our environmental harm.

What are the demographic, economic and social changes you expect? Do you see any likelihood that an improved standard of living and decreased infant mortality will influence parents to have fewer children?

Despite the fact that people’s behavior as to how many children they have per family is changing and lowering all the time, we still have about 2 billion people who are under the age of 15. So we have a lot of population growth left to happen.  That’s one big force, but also economic growth. The world’s economy — despite what we’re seeing today — is growing, on average, around the world. And people’s diets and consumption patterns are changing accordingly, becoming more like middle-class Europeans and Americans, which means more food, more meat.

You’re saying – are you not? – that the world has to simultaneously double food production in the next 40 or 50 years and, at the same time, figure out how to do that in a way that produces less pollution than agriculture already produces and uses less water?

Yes. That is exactly what I’m saying, but with a caveat, too, that we will double food demand at least in the coming years if everything grows the way they’re growing now in terms of population and diets.  That doesn’t have to be the case.  We can change those, and maybe we should, especially diet. But, at the same time, whatever happens, we also have to dramatically reduce the use of water, kind of the crop-per-drop. We have to produce more with less water, we have to produce more with less pollution, we have to produce more efficiently.

In one of your presentations, you describe agriculture as the biggest source of pollution worldwide and the source of one-third of the greenhouse gases produced every year. Elaborate on that, please.

If you look at all of the greenhouse gases we worry about — carbon dioxide, methane and nitrous oxide — and you look at it by economic sector, it turns out that agriculture and land use taken together are about one-third of that. It’s bigger than all of electricity, bigger than all the transportation and so on. But it’s not always where we think it’s from. It’s mostly from tropical deforestation, not Minnesota farming. It’s mostly from rice paddies and some livestock, and some of it’s from over-fertilizing fields that get too wet and the nitrogen in the soil turns into nitrous oxide. It’s a big issue, but one we can work on.

You also say the human race is over-using water all over the world. What’s the evidence for that?

Critical water supplies — whether it’s the Colorado River, the Aral Sea, the Ogallala Aquifer or Lake Chad in Africa – are drying up. We’re using the water faster than it can be replenished because we’ve diverted the natural flows of water to irrigate someplace, and so that is just inherently unsustainable. We’re spending down our bank account of water and it’s about to go to zero in some places.

You say agriculture consumes 85 percent of the water used each year in the world. And you say irrigation is by far the biggest part of that use. Can we produce more food with less irrigation?

Absolutely we can produce more food using less water in places.  We only have to look to the Israelis and the Australians to see dramatic improvements in irrigation.  There are also some interesting technologies about using salt water, not through desalinization, but running it through pipes where water basically defuses out through evaporation into the soil and then condenses. We can reuse water more efficiently.  Could we use water that has been used for industrial purpose, and then use it for irrigation after that?  There are lots of reuse and efficiency gains.

Do you see climate change seriously aggravating this Other Inconvenient Truth?

I think there’s climate change in some places that will cause a big disruption to water supplies, especially in places that depend on snowmelt for water.  I’m less certain what it will do in places like Minnesota.  There have been a lot of claims about how climate change will affect agriculture; I think this is a place where we don’t know as much as we should.

Briefly go over some of these “myths” that you say people think are the significant problems but are only tiny parts of the problem.

One is the notion that local food is better for the climate.  Well, intuitively, that makes sense. Not shipping food as far must save energy somewhere in the system, but often the people who transport food a long distance ship a large volume of it, and often the volume wins over distance.  So when you actually run the numbers and do comparisons of food from an organic place vs. a commercial farm far away, sometimes the commercial farm has a lower carbon footprint.  One of the other kinds of  myths I hear a lot in the media is how biofuels were single-handedly responsible for the rise in the price of food and hunger in the world in the last few years, and that’s just demonstrably not true.  It was a contributing factor to be sure, but probably a relatively small one, compared to continued population and meat consumption increases, a huge amount of price speculation and kind of chicanery in markets like oil, real estate and the stock market.

What do your fellow environmentalists say when you talk about more genetically modified crops and say local, organic agriculture isn’t going to solve our problem?

I got read the riot act by somebody here about that. Certified organic is feeding less than 1 percent of the world today.  All organic, generously, would be a couple of percent. So my message for organic is to say let’s move from the margins and move to the mainstream and solve the big problem, and that might mean doing things a little differently than you’re doing them, maybe adopting some of the practices from the big commercial guys.