Coffee drinkers tend to be zealous about their coffee, and things can get pretty ugly if, say, they miss their morning fix. So we shudder to think how they will react to the news that the world's coffee supply could be forever on the decline.

The New York Times suggests as much in a report today. The culprit, according to the Times, is climate change. Elisabeth Rosenthal notes that the production of coffee--particularly high-end Arabica beans--in Latin America has fallen in recent years because of "rising temperatures and more intense and unpredictable rains, phenomena that many scientists link partly to global warming." The shortage has resulted in higher coffee prices in supermarkets and cafes in the U.S. and Europe, even as global demand rises with the growth of the middle class in developing countries like India and China.

Since coffee yields, quality, and taste--not to mention coffee pests--depend heavily on the weather, Rosenthal explains, some fear the world is headed for "peak coffee." Rosenthal is alluding to the theory of "peak oil," which holds that global petroleum production will eventually reach (or has already reached, depending on your perspective) a maximum point, after which it inexorably declines.

According to one coffee scientists interviewed by the Times, the world might be able to avoid climate change-induced "peak coffee" if growers expand production globally. Arabica coffee, which mainly comes from Latin America, is more dependent on climate than the cheaper and less popular Robusta coffee, which is primarily produced in Asia and Africa.

Before coffee drinkers panic, let's take the issues raised in the Times article one by one. First, is there a clear link between lower coffee production and climate change? And, secondly, is the world's coffee supply--especially its specialty coffee supply--really in danger?

COFFEE AND CLIMATE CHANGE

The International Coffee Organization claims that “climatic variability is the main factor responsible for changes in coffee yields all over the world," according to the Times, and many others agree. A Starbucks executive, for example, recently informed the Environmental Protection Agency that climate change posed "a direct business threat to our company." 

But a scientist at the International Research Institute for Climate and Society tells the Times that it's unclear whether the severe weather in Latin America "represents natural fluctuations or is a climate change signal." What's more, weather may not be the only factor affecting coffee production. High fertilizer prices, for example, might be playing a role in Colombia, and in Costa Rica farmers struggle with old coffee trees and rising costs stemming from a labor shortage and devalued currency.

And while the Times suggests that "shade-grown" Arabica coffee is threatened by global warming, a University of Michigan study in 2008 found that the technique--in which plants are grown under a canopy of trees--actually protects coffee from the droughts and severe storms associated with climate change, at least relative to coffee grown in more sunlight.

PEAK COFFEE?

While the Times provides reasons why peak coffee may be upon us, it also explains that science is rising to the occasion, as agronomists teach farmers learn how to control the pests who ride in on the warm weather and geneticists develop plants that are better able to withstand severe weather.

In the Times' "Room for Debate" forum, the anthropologist Eugene N. Anderson points out that coffee, unlike oil, is a renewable resource, and is simply going through a cycle: "Coffee is one of those classic commodities, like beef, that goes through cycles: when expensive, people grow more, but the crop takes a few years to mature, by which time the plantings have produced a glut, so people cut production, and the cycle starts over again."