Thursday, July 10, 2008

On climate change, rising fuel costs and strawberries

These are the final days of strawberry season in Ontario, and by now pretty much everyone who craves fresh strawberries most of the year has already gorged themselves on this year's crop, stocked their freezers, and may have made a few pots of jam as well. The strawberry is one of the ever-declining number of crops that defies industrialized production. No one has yet created a strawberry that will ripen properly after it has been picked (and you have to pick them by hand, although crop scientists are close to solving that challenge). You can get varieties that turn red after being picked prematurely, but a strawberry grown in South America or California and air-freighted to Canadian supermarkets in March will never taste the same as one you pick yourself from your local U-pick farm.

My family and I picked a couple buckets worth of strawberries at an Eastern Ontario farm in late June, as soon as it was possible to do so. As is my habit, I spent more time talking to the farmer about his operation than I did filling the buckets. In my academic research I have spent a fair amount of time looking at the potential impacts of climate change on the well-being of rural communities, and I am always keen to hear from farmers how they adapt to the ongoing stresses of farming, of which there are many, climate-related and otherwise.  

Climate change research underwent a significant expansion in the late 1980s and early 1990s, when a critical mass of data about past and current climatic conditions and a critical mass of computer modeling power converged to create a widely-accepted understanding that we had entered a period of 'global warming' and that human activity was likely the main cause of it.* Scientists using ever-more robust general circulation models (GCMs) were generating future climate scenarios and were starting to wonder about the implications of such scenarios (the "so what?" type of questions). One of the first "so what"questions concerned the implications of climate change for agriculture and food production. Early on, the typical methodology was to start by selecting a particular agricultural region, generate some future average temperature predictions (which GCMs tended to be best at doing) and perhaps some future precipitation predictions (GCMs are less good at this), add some evapotranspiration estimates and calculate how such changes might affect crop yields for common agricultural crops. Invariably, the predictions were that future food crop production would fall due to climate change.

Everyone at the time recognized such "top-down" models of future food production were fairly crude, but you have to start somewhere. A number of scientists in Canada and the US pointed out that these early models completely ignored the role of the farmer. In a landmark 1992 study of climate impacts on corn production in the US midwest, a research team led by William Easterling (now at Penn State) showed how you could generate wildly divergent predictions of future crop yields using the same climate data but altering your assumptions about farmers' behaviour. For example, in their 'dumb farmer' scenario,  the research team used the assumption that farmers paid no attention to climatic trends or forecasts, but simply made exactly the same choices each year on what to grow, how to grow it, and so on, and never change even when climatic conditions take a turn for the worst (few if any such farmers exist in reality). Not surprisingly, crop production falls in such a scenario. In their 'smart farmer' scenario, it was assumed farmers not only recognized changes in climatic conditions as they emerged, but always chose the best set of adjustments to farm-level practices to ensure they maximized potential crop yields (again, few such clairvoyant farmers exist). In this scenario, future crop production increased even though the climatic parameters stayed the same as in the first scenario.

The message is that, to understand how climate change will affect future agricultural production, we need to have a better understanding of how agricultural producers and rural communities adapt to changing conditions. When you begin talking to farmers, you quickly learn that they are continually adapting to changes in crop prices, interest rates, farm input costs, fuel costs, consumer preferences, and a whole host of other, non-climatic forces. Farmers are keen watchers of the weather, and will adjust as best they can throughout the year to changes in weather patterns (their options may not always be numerous, it differs significantly from one farm to the next). Farmers are also aware of the potential risks associated with long-term changes in prevailing climatic conditions due to anthropogenic climate change, but it tends not to figure much in their day-to-day decision-making. This is partly because there are so many other changing production factors that need to be managed in the short-run; it's also because the types of information that climate models tend to be good at predicting, such as long-term global average temperatures, are not the types of climate information farmers need or use.

So, if we are to better understand the future impacts of climate change on our food supply, we need to spend more time talking to farmers, to better understand their processes of adaptation and start thinking about how we can provide them with climate change information they can use. And so that is one reason why I spent so much time chatting with the strawberry grower I referred to above (he also happens to generally be an interesting character).  There are a number of stresses to which he is adapting at this moment. One is that he can no longer find labourers to pick his strawberries, and he is increasingly reliant on the U-pick client. Few Canadians want to perform back-breaking agricultural work these days, and so our strawberries and other fruit & vegetable crops are increasingly being picked by labourers imported from abroad (often the Caribbean and Central America). Only this particular farmer's strawberry fields are too small in size to justify the costs associated with bringing in foreign workers.

This farmer has left his U-pick prices unchanged from last year, because he doesn't want to discourage city dwellers (who make up most of his clients) who are feeling the heat from rising gasoline prices, and so may be less willing to drive out to the country to pick a few berries. He can do this because many of the farm inputs he is using this year (e.g. fertilizers and chemical sprays) he purchased last fall, before their prices really started to spike. When he goes to replace those items this fall he will face much higher prices, and will have no choice but to offset them by charging higher prices for berries. In the meantime, he has chosen to simply swallow the rising costs of fuel (of which farmers tend to use a lot), which will reduce his net income.

There are a whole bunch of other stresses this farmer told me about, but given the North American public's current obsession with gasoline prices (which Europeans must no doubt find amusing) and with worldwide concern about rising food prices (which is understandably taken seriously by all), I thought I would mention only how he is currently  adapting to changing petroleum prices, and how his current adaptation options are influenced by how he previously adapted to changing labour market conditions by concentrating on the U-pick business.  Current and future adaptation options are path-dependent; choices we make in the past affect the range of choices we now have or will have available to us in the future. My feeling is that monitoring how well this farmer and others like him navigate the next couple growing seasons will be a pretty good indicator of how likely they are to successfully navigate changing climatic conditions over the longer haul.


*I should note that global warming (i.e. a trend toward increasing average global air temperatures in the lower part of the atmosphere) is but one potential manifestation of anthropogenic climate change, others being increasing sea surface temperatures, changes in mean sea levels, changes in oceanic circulation, changes in ocean chemistry, changes in the spatial & temporal distribution of extreme weather events, changes in the intensity of extreme windstorms, changes in precipitation patterns... I have probably omitted some - feel free to remind me of ones I have missed.

1 comment:

Anonymous said...

Interesting article. Did the farmer mention positive impacts caused by our changing world? I can think up a few examples that can be beneficial to his crops. When thinking of climate change to our geographical location on the planet, would climate change lengthen the growing season in regions with a relatively cool spring and fall? I'm guessing the "longer season" for growing fruit would only vary for a few days at the most, but those few extra days would result in profit for the farmer. Lets say his strawberry farm is open an extra week, well that is an extra week of income. Could this compensate for increasing gas prices? Are their any other beneficial impacts that climate change can bring on agriculture?

Now there are several factor that directly connect climate change to agricultural productivity. Theses are average temperature increase, change in rainfall pattern and amount, as well as rising atmospheric concentrations of CO2. From personal observations of the National capital Region, rainfall as been quite abundant this year. Theoretically, I can see many benefits from these changes. I’ve already discusses average temperature....what abut rainfall? Would that not decrease the costs of farmers having to supply water to their crops? Also, plants feed on CO2. Having a more abundant source of CO2 would make them grow more, would it not?

Now for the sake of the argument, some negative impacts of climate change could occur. Of the top of my mind I can think of increase in extreme events, increase in soil evaporation, etc. Also the change in rainfall can affect soil erosion rates and soil moisture, both of which are important for crop yields. And the increase in pollution levels such as tropospheric ozone which inhibits the growth of crops can offset any beneficial yield effects that results from elevated CO2 levels.

To confirm my belief that climate change will be beneficial to this region, the IPCC (2007) as well as the EPA predict that climate change is expected to improve growing conditions for some crops that are limited by length of growing season and temperature. (E.g. fruit production in the Great Lakes region and eastern Canada).

So what do you think? Will Ontario mostly suffer or benefit from these changes?

Krysthle :)