by Valerie Giesen, INESAD
If climate change seemed far away, here are three reasons to reconsider. From basic daily staples to our favourite morning drink, climate change is already affecting crops in South America. The Inter-American Development Bank estimates that Latin America and the Caribbean contribute 11 percent of the value of world food production, making shifts in the region’s agricultural production relevant to global, as well as regional, food security.
1. Potato: According to the International Potato Centre (CIP), the potato is the third most widely consumed food crop in the world, with annual production approaching 300 million tons. According to a 2012 report by the 8th World Potato Congress, South American potato production reached slightly over 14 million tons in 2010. However, production in South America has come under climate-change induced stress. In 2012, the Consultative Group on International Agricultural Research (CGIAR) reported that potato production in the Andes is increasingly threatened by late blight disease, which caused the severe Irish potato famine in the 1850s. The Integrated Pest Management Program at Cornell University outlines the course of the disease: Late blight is particularly severe under warm, humid conditions. it is triggered by the ‘oomycete pathogen’, which is a microorganism that produces millions of spores from infected plants. These survive from one season to the next in infected potatoes and travel through the air causing new infections if the weather is sufficiently wet. Infected potatoes develop dark lesions on the surface and – in many cases – rot from the inside.
According to Manuel Gastelo, agronomist at the CIP, rises in temperature due to climate change are endangering formerly unaffected areas with late blight disease; in 2003, for example, the disease destroyed the native potato harvest of the community of Paucartambo in central Peru. Paucartambo lies at approximately 2,900 meters above sea level and, according to CGIAR, this was the first time that late blight had occurred at such a high altitude. Since 1997, the CIP has been mapping potato farming in the Andes and shows that farmers have ascended the Andes 150 meters during the past 30 years to escape agricultural diseases and pests due to increased temperatures. Similarly, in a 2003 study, Dr. Robert Hijmans of the CIP warned that future potato yields may decrease in many regions due to rising temperatures.However, he points out that there is some scope for adaptation as long-term breeding programs may build on wild potato species that are more tolerant to heat.
2.Banana: Climate change can have a critical impact on the yields of banana and plantain crops and their vulnerability to disease, which, according to Vanessa Meadu of CGIAR, will have a negative effect on food security in South America where bananas constitute a basic staple. CGIAR has found that even slight increases in temperature can damage banana production in the lowland tropics-where temperatures are already extremely high-such as in the Amazon, the Atlantic coast of Colombia, and many other coastal areas of South America.
3.Coffee: In January 2013, the New Scientist asked whether the flow that filled 1.6 billion cups a day might soon dry up as coffee crop yields have reached a 34-year low. Soil erosion and higher levels of rainfall associated with climate change have put stress on coffee farmers, while rising temperatures are increasing the plant’s vulnerability to pests and fungal diseases. According to Dr. Peter Baker, a senior scientist at the Centre for Agricultural Bioscience International (CABI), coffee is vulnerable to changes in temperature and precipitation as it requires cool, dry weather to bud,as well as rain at the right time to trigger blooming. For instance, the optimum mean annual temperature range for the Arabica plant-which, due to its superior taste, is preferred over the other main coffee variety Robusta-lies between 18 and 21°C; above 23°C the beans’ quality decreases. In a 2012 study, Dr. Aaron Davis and colleagues from the Royal Botanic Gardens in Kew and the Environment and Coffee Forest Forum (ECFF) found that rising temperatures are affecting the Arabica bean, predicting that, until 2080, suitable localities for coffee farming will be reduced by at least 65percent. Soon, supplies of the second most traded commodity after oil may, quite literally, dry up
