Water – Agriculture and Changing Weather Patterns
In the last couple of weeks, I’ve talked about water and the unique role it plays in a modern agricultural economy. I mentioned how some nations without adequate rainfall have nonetheless developed thriving agriculture sectors, through the use of “fossil water” – water laid down and locked up thousands or even millions of years ago in aquifers - which countries like Saudi Arabia pump to the surface and use to irrigate strategic food crops, such as grain. That era is coming to an end, because the easily accessible aquifers are being drained dry, and fossil water does not replenish itself in the way that the normal water cycle provides.
In the immediate years to come, that’s probably good news for US farmers, because it means that grain and other commodity crop prices will be rising globally, without a parallel rise in American farmers’ cost of production. Irrigation is important to many US farmers, but most of our crops are grown with dryland techniques – they rely on rainfall, not engineered water systems, for the water every crop needs to grow. In addition, the irrigated crops that we do use don’t tend to use fossil groundwater – instead, we bring water from the natural water cycle to a new geographical location.
In the medium and long term, however, US agriculture may be facing a water crisis of epic scale. The reason is our old friend, climate change. Global warming alarmists are fond of claiming a stronger scientific consensus than actually exists, but regardless of the politics and controversies, there has been one constant in the history of weather and climate: it changes. It changes on the short timescale, and it changes on the long timescale. Northern Britain used to be a tropical forest. The Great Plains used to be a glacial tundra. Whether Al Gore is an idiot or a genius is irrelevant: we can predict with 100% certainty that our current climate expectations will be changing.
And unfortunately for many US farmers, one of the most commonly forecast change is a vast reduction in the amount of snowfall over the western United States. Unlike the eastern half of the country, which is well-watered through rainfall, the west relies on the snowpack to even out water flows throughout the year. Snow accumulates all winter, then melts and runs off all through the spring and summer – turning the Colorado River, among other vital arteries, into a huge torrent of water that is used for drinking and irrigation. Even modest warming can have an enormous impact on the west, because modest warming means rain instead of snow – and rain in wintertime does agriculture no good whatsoever absent some means of storing that water until it is needed. Snowpack provided that service for free – we can construct reservoirs, but the quantity of water involved is truly stupendous and so would be the expense.
The results of continued reduction in the snowpack could be very grim for western farming and ranching in general. Most farmers have water rights, entitling them to a certain amount of water from local sources and from rivers like the Colorado. But those water rights will not be worth much if the water isn’t there to fulfill the contract. Climate change could put a serious cramp in western agriculture’s style in the next few decades.
Next week we’ll see how the water problem is likely to affect agriculture worldwide.