We talk about global warming in absolutes: it’s happening or it’s not happening, it’s a naturally occurring phenomenon or it’s a result of human actions. In reality, global warming is like most things, it’s not black or white. There is a lot of grey area in this debate and a lot of unknowns. This post assumes that global warming is happening, at some unknown speed and the cause is not relevant. I am sure that many of you want to scream at their computer screens right now. Yes, I know, I am oversimplifying a very complex issue and more importantly, I am glazing over the most heated parts of the global warming debate. However, by ignoring these areas I can highlight an interesting side of global warming that is not regularly discussed.
This post will take a cause and affect look at higher temperatures on global food production. It will only look at the impacts of higher temperatures on our food supply and not on changes in tides, storm systems or other weather patterns that are affected by increased global temperatures.
As you may know all crops have ideal or optimal growing conditions, these are the conditions that the farmer will get the largest yields. There are also acceptable growing conditions. Here the crops grow, but the harvest is less abundant than in the ideal or optimal growing conditions. Because of these restrictions certain crops are generally grown in specific regions. It is interesting to think about what small changes in temperature will do to long established growing regions. The increase in temperature will have a major impact on local regions but could also impact the global food supply.
It is unclear if an increase in temperature will cause an overall increase or decrease in the amount of food produced globally. Many people have speculated, but it’s difficult or impossible to know for sure, especially since there are a lot of factors that I am excluding from this post. There are three categories of temperature changes: changes in optimal growing regions and changes in the marginal growing regions. The marginal lands category is broken into barely unsuitable for production and suitable but not ideal.
First let’s look at the optimal growing regions. These are places where a certain crop, for example wheat, will grow very well. If the temperature changes the production in these areas will decline, because the temperatures are no longer within the optimal region. Areas that are colder will warmer up a few degrees making them the new ideal growing regions.
Now onto the marginal lands that are on the edge of the acceptable growing conditions. These are places that barely have the right temperature to grow a specific crop, in this case wheat. People still grow wheat here, but the land does not produce the yields that other places get. Lands that currently slightly too cold for optimal growth will see increases in yields with higher temperatures, while places that are slightly too warm will see declines in yields or might no longer be able to sustain wheat crops.
Then there are the places that are not suitable for production right now. The places that are too cold might become warm enough to support wheat production and in these places the world will increase its net wheat production. The places that are currently too cold will be virgin lands; they will not have been used to produce wheat in the past. It is possible that nothing was grown in these places. This means that they will be very nutrient rich, because agriculture has not removed the nutrients from the soil yet and in the early years crops will produce high yields that in comparable regions with a history of industrial agriculture. No new growth occurs in the places that are currently too warm.
There are two ways to compare current wheat production to future wheat production: on a global scale and on a local or micro-scale. When thinking about the amount of wheat produced globally, the increases from the places that benefit from warmer temperatures and the losses from places that are either less ideal for wheat production or are no longer viable options for wheat production are added together. The sum of these outputs will result in either a net increase or a net decrease in wheat production. It all depends on how much the temperature increases and how the new areas compare to the original areas.
On the mirco-level the changes will not be balanced out by the fact of increased temperatures in other regions of the world. A specific area will either see increases or decreases in wheat production. These changes will severely impact the economics of specific regions.