Now in her fifth year at McGill, Bennett’s wide-ranging research interests include everything from agricultural production; soil pollution; ecosystem services; and phosphorus cycles. And, yes, she’s still enthusiastic about giving students the tools to make an impact on their world.
Earlier this week, Bennett stopped by the offices of the McGill Reporter to talk all things environment.
What are ecosystem services?
Basically, it’s all the things that people get from nature. It’s the things we think about all the time like food and fresh water; the things we think about some of the time like aesthetic beauty and places to recreate; and the things we don’t think about very much, like how ecosystems help regulate disease or control floods.
Our lab is working with communities in the Montérégie outside of Montreal and trying to provide them with the tools to make better decisions about managing ecosystem services. Often what communities do is make a decision based on a single service, as in “I’m just going to think about recreation when I make this decision” or “I’m just going to think about food production.”
We’re trying to give them the tools they need so they will say, “If we put a row of trees here or restore a forest there, it will have an impact on a dozen services.” Hopefully it will allow them to be more proactive and able to consider multiple things at once.
Related to that, we are focusing in on a particular set of ecosystem services – agricultural water quality.
Why this focus?
To me the big issue is food and water together. We can’t live without either.
We have a growing population, with many people already suffering from malnutrition. There are one billion people who are hungry, or one in seven. We need agriculture to feed them, but then agricultural water quality becomes the issue. How are we going to feed all these people without wrecking everything else? For me that is the big question for the next decade, maybe even the next century.
What’s at the crux of the problem?
Phosphorus and how people impact phosphorus cycling. Phosphorus is a great fertilizer that greatly increases agricultural productivity. But [through runoff] this nutrient gets into our freshwater where it is a great fertilizer of aquatic systems too. This is why we get these eutrophic lakes with algal blooms. These lakes smell bad, produce toxins and create all sorts of problems for our drinking water and even for activities like swimming.
Can’t we just use an alternative to phosphorus?
No. Nitrogen is really important for growing crops but we can make it from the air. We have the technology. Carbon is really important – we use a lot of fossil fuels. But if we run out of fossil fuels, we can use solar energy or other alternatives. But we can’t make phosphorus and there is no substitute.
So, a double-edged sword…
It’s like two sides of the same coin. The problem is you have too much phosphorus over here and not enough over there. The solution is obvious – take it from where you have too much and put it where you have too little and you solve both problems. But once it is in the marine systems, it is so diffuse that it’s economically unviable to collect it.
The question is coming up with the technology to collect it and to keep it on the farm fields. If you put it on the field you don’t want 50 per cent of it running off.
We don’t do a very good job of recovering phosphorus from animal manures – that would make a huge difference. That being said, there are researchers at the University of British Columbia working to develop technology to recover phosphorus from sewer systems, so that is pretty interesting.
How much phosphorus do we have at our disposal?
Not that much actually. It’s more concentrated in terms of what countries control it than oil. Something like 85 per cent of all the phosphorus is controlled by Morocco, the US and Russia.
Think about oil and the huge political influence the OPEC (the Organization of the Petroleum Exporting Countries) nations have on the rest of the world. Phosphorus is developing into an interesting political element that is just coming into play.
Are we facing a phosphorus crisis?
The estimations vary quite widely, but a lot of experts believe the world will run out within 100 years. It’s coming fast, especially when you consider how slowly governments move.
So how do we feed an increasing world population without, in your words, wrecking everything?
The important thing is to avoid expanding agriculture. Instead we have to get more growth out of land that is already in production. But then we come back to phosphorus. We have too much of it here, but in other parts of the world, they don’t have enough of it – most notably in Africa where most farmers don’t have access to fertilizers.
We have to figure out how to improve production without increasing fertilizer runoff into our water systems. We need to grow food more efficiently and with less waste in all streams – less waste at home, less spoilage in the grainery, less waste in restaurants.
Are you optimistic we can find solutions to these problems?
I am an optimist by nature but I am a hesitant optimist. There are real problems coming down
the pike but I wouldn’t keep working [in the field] if I weren’t optimistic.
Canada has been criticized for withdrawing from the Kyoto Protocol. Is that justified?
[Kyoto] is a difficult set of standards but if we don’t meet them we’re in trouble. I think the criticism is justified in that we have to figure out what we’re going to do and we have to do it soon.
I see small hopeful signs though. Mayors of cities are saying, “we’re going to be climate neutral” so even if Canada as a whole is stepping back from Kyoto, groups and individuals are stepping in to fill that gap.
How is McGill doing in terms of sustainability?
I’m really excited about what’s been happening here. Jim Nicell [AVP, University Services] has taken the lead and is pushing things from the physical perspective; the Sustainability Fund is a wonderful initiative and, of course, the students here so engaged, so energetic, so creative and so on top of what’s happening. We’re at the forefront of what’s going on at universities. I’m excited to see what’s going to happen next.