If we look back over the summer then yes it was nice, we had a few pleasant days, but was it really any different to previous summers in the UK?
Well, apparently it was. The UK experienced the hottest period from Jan – July since records began in 1910. You do not need us to tell you it has been a lovely long hot summer! It does not explain why I’m still as pale as freshly polished snooker ball. In fact, seven of the hottest periods (Jan – July) ever recorded have all occurred since the year 2000. Going by these records the UK is warming up, and the trend is occurring throughout the world.
- 80% of the state of California is currently experiencing an extreme drought, severely affecting the agricultural industry throughout the region. The honey industry has been hit particularly hard with production at only 10% of what it was once was.
- Due to the retreating polar ice-caps, global sea levels are about eight inches higher today than they were in 1880, and they are expected to rise another two to seven feet during this century.
So we started to wonder how this would affect our beloved coffee. The Arabica plant is already quite particular as to where it grows and currently exists throughout the thin belt between the Tropic of Cancer and the Tropic of Capricorn. If temperatures continue to increase, how will this affect the regions where coffee is grown?
We spoke to the International Centre for Tropical Agriculture (CIAT) and they very kindly provided us with information on how climate change could alter coffee production throughout Africa. One particular area that will see one of the largest changes is in Tanzania.
Catholic Missionaries first introduced coffee to Tanzania in 1898. Since then it has grown to become one of the countries main exports and indirectly, provides a living for 2.4 million people. 90% of the coffee farmers are small hold, with the remainder consisting of larger plantations. With many of the plantations located around and on the slopes of Mount Kilimanjaro, the volcanic soil provides a rich and fertile land for the coffee plant. The resulting beans give off a strong but pleasant aroma and ensure the coffee is rich in acidity, with a sweet but balanced flavour.
The graph below taken from the CIAT report predicts both the temperature and rainfall changes in both 2030 and 2050 if global warming continues at its current level.
- The rainfall increases from 1,277 millimetres to 1,325 millimetres in 2050 passing through 1,309 in 2030.
While the overall rainfall increases, it actually decreases during the dry period from June to October. This dry period is the most important growth time of the crop as it’s vital to stimulate the flowering of the coffee plant. The level of flowering depends largely on the volume and frequency of heavy rainfall during this period. Less rainfall simply means fewer flowers. Compounded with the fact that much of the crop is cultivated by streams that derive their water from rainfall, irrigation to the crop will also be reduced.
- The average temperature increase is 2.3 C passing through an increment of 1.3 C in 2030.
At 23 C and above, the coffee plant's metabolism starts to increase, leading to a failure to accumulate the right mix of aromatic compounds that deliver coffee's distinctive taste. Higher temperatures will affect both the yield and quality of the coffee.
If we look at the images below, we can see the areas of cultivated land that are well suited to the coffee plant today, and how they will be affected by climate change in 2030 & 2050.
* Area of land suitable for coffee production: Present day
* Area of land suitable for coffee production: 2030
* Area of land suitable for coffee production: 2050
By the year 2050 only areas at a higher altitude (especially around Mount Kilimanjaro in the northeast and Lake Victoria in the south) will be suitable for coffee production.
Today the optimum height for coffee production is at 900-1,800 meters above sea level, by 2050 and with the increase in temperature, the height will increase to anywhere between 1,400 – 2,500 meters.
With much of these higher latitudes protected by forestry commissions, much of the land is unlikely to be turned into farms.
And it’s not just in Tanzania where local farmers are facing problems. Climate change is starting to have an effect on coffee production across the globe.
- Central Americas winter's coffee harvest is down 50% or more for the second year running
- Nicaragua's problem is particularly troubling. Almost a third of its working population depends on coffee for a living. It’s predicted that by 2050, 80% of its current coffee growing areas will no longer be usable.
- Brazil, the world's biggest coffee producer, a temperature rise of 3C would reduce the area suitable for coffee production by two-thirds.
- The berry borer beetle, a pest that damages coffee crops was unknown in Ethiopia, Uganda, Burundi and Rwanda until 2000. It preferred the warmer temperatures at lower altitudes. Global warming has allowed the beetles to move further up the hillsides and into the coffee plantations causing over £300,000 of damage every year.
While all of this can sound a little bleak, there is hope. Dr Tim Schilling, the head of the World Coffee Research organisation, has been conducting research into the genetic diversity of Arabica coffee. Although 70% of the world's coffee comes from the Arabica bean, every plant currently used is derived from only two or three Ethiopian varieties.
The research is hoping to understand the genetic diversity of up to 20 plants and how their individual genes play a part in the quality, taste, how they grow and their resistance to disease.
It’s obviously a complex issue, but the future of many coffee plantations throughout the world will largely depend on our ability to reduce C02 emissions and unlock the genetic diversity of the Arabica plant.