how getting food from farms to our plates is hurting the environment

greenhouses are one way to cut down on the miles that food travels, but then the challenge becomes controlling energy consumption.

by robin roberts

published aug 25, 2022

6 minute read

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6 minute read

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'food miles' are contributing to climate change

the long journey our food takes from farm to table not only takes its toll on the environment, but on the food itself. getty

as summer comes to an end, so too does the cornucopia of fresh local produce we’ve been feasting on all season. now if we want fresh strawberries and tomatoes, those ruby-red fruits will usually be trucked in from california or mexico. waterloo public health conducted a study that looked at the distances 58 commonly eaten foods traveled to the region, as well as the associated greenhouse gas (ghg) emissions pumped into the air. the report found that, on average, these foods covered 4,497 km and accounted for 51,709 tonnes of ghg emissions annually. producing those same foods, including tomatoes, in southwestern ontario would result in an annual reduction of 49,485 tonnes of ghg, equivalent to taking 16,191 cars off of the roads.

but here’s the weird part: canada imports as many tomatoes as we export, according to dr. sylvain charlebois, professor, director, agri-food analytics lab at dalhousie university.

“our greenhouse sector in ontario is booming, but a lot of tomatoes grown there are for export markets that are willing to pay a premium for canadian tomatoes,” he says.

the reason? tomatoes, like most other products, are a commodity sold on the open market. canadian growers get more money exporting their tomatoes than selling them to their fellow canadians. it’s the same with seafood.

“we export 95 per cent of what we produce and we consume 95 per cent of what we import,” says charlebois. if we were to keep all our tomatoes in canada, he surmises, we’d be paying a lot more.

but shortening those food journeys is imperative for our health and the health of our planet, and plenty of experts are focused on how to do that.

healthy food, unhealthy ecosystem

dr. sarah elton, assistant professor, department of sociology at toronto metropolitan university (formerly ryerson) and author of the 2010 book locavore: from farmers’ fields to rooftop gardens, how canadians are changing the way we eat, says that while the term locavore is no longer commonly used, the concept of eating locally is as relevant as ever — if not more so.

“i like to think of food in terms of how healthy the entire food system is, not how nourishing this kale is for my body,” she says. “[it’s] called the ecological determinants of health. to be healthy as humans we need a stable climate, clean water systems, clean soil systems. so how healthy is our food if its damaging these ecological determinants of health? if it’s nourishing my body, but it’s draining aquifers in california, there’s a larger health impact, in that food is contributing to climate change and that’s bad for everybody’s health.”

she points closer to home with more examples of climate change’s far-reaching consequences of our food systems: last summer’s “heat dome” with temperatures soaring above 40° c in some areas of canada, followed in the fall by devastating floods in b.c. and these extremes will only continue, according to a report by the intergovernmental panel on climate change.

“so how do we balance protecting our ecosystems and our lands with having food production that is resilient and sustainable nearby, while also having international trade and without exporting our problems elsewhere?” elton wonders.

she’s currently leading a study of produce supply chains at the university’s food health ecosystems lab in an attempt to answer some of those questions. in the meantime, she says that while regional food systems are important, we cannot ignore the links between local and global systems as well.

“i see the importance of regional food systems, but everything is connected,” says elton. “we need to think about local food systems, regional food systems and global food systems and how they interact and how we can best support health, not only of humans but of the biosphere.”

at least one company is addressing that by redefining what it means to be “local”.

charlebois cites the california-based berry grower driscoll’s, which controls about one-third of the six-billion-dollar u.s. berry market. with california running out of water, in turn reducing their yields, they struck a deal with some canadian farmers to grow their berries in canada.

“it’s a win-win-win,” he says. “driscoll’s will have access to favourable growing conditions, they don’t have to spend money on r&d, intellectual property and trades and genetics, and consumers have access to a locally grown product even though the brand is international.”

how do we put the ‘green’ into greenhouses?

the long journey our food takes from farm to table not only takes a toll on the environment, but on the food itself. the longer that tomato sits on a truck from mexico or california, the more nutrients that are lost. producers mitigate this by shipping under-ripe produce that will ripen en route, by coating apples in wax or cucumbers in plastic to retain moisture, and by strictly managing cold chain systems. also, many industrial farms are equipped to freeze fresh-picked produce on-site.

but none of that addresses the environmental impacts of water, rail, road and air transport. while the david suzuki foundation encourages eating locally, it maintains that a larger carbon footprint (83 per cent) is left by how our food is grown, versus where it’s grown (11 per cent) — and one way to address both is through greenhouses.

charlebois, however, says greenhouses suck huge amounts of energy. so how do we put the green into greenhouses? well, change the lightbulbs.

montreal-based sollum technologies replicates the sun’s natural light and adapts it to specific crops’ growth cycles using more efficient, longer lasting led lighting.

“farmers traditionally deploy high-pressure sodium bulbs in their greenhouses, which work well with cucumbers and tomatoes but they consume a lot of energy,” says louis brun, ceo. “and the mercury in the bulbs further pollutes when they’re disposed of.”

he says sollum’s led system can save over 40 per cent in energy consumption. ai-powered sensors reproduce the full spectrum of the sun’s natural light year round regardless of the weather outside. growers can control their customized program remotely and in real time using a pc or smartphone.

“with tomatoes, for instance, our sensors measure the light coming in naturally,” says brun. “we analyze that, send the data to the cloud, which measures and calculates the gap between what comes naturally into the greenhouse and your target, and then the system compensates to recreate exactly what you need.”

he says traditional lighting is tailored to a specific crop, whereas sollum’s can adapt to any type of crop from anywhere in the world.

“our solution has been used on over 100 different types of crops, from leafy greens, herbs, root vegetables, tomatoes and a variety of peppers,” he says. “each light can be adapted and adjusted to their specific needs; it’s limitless.”

brun adds that, by year’s end, the system will be adapted by 25 users across the country, including growers, research centres and universities, with increased interest coming from abroad.

“food sustainability has to be addressed on many pillars,” he says. “cereals will never be grown in a greenhouse, but for a wide variety of fruit and vegetables, greenhouses are definitely the future. today, 95 per cent of what is grown in greenhouses are peppers, cucumbers and tomatoes. that’s fine, but food sustainability is not about only getting enough food but also enough variety. greenhouses will play a key role and the smart lighting system is enabling that revolution.”

robin roberts is a vancouver-based writer.

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