Threat to food security posed by climate change
What is Crop Diversity?
It is the variance in traits such as morphology, development, biochemical or physiological properties, or behavior in plants used in agriculture. For example crops may vary in seed size, branching pattern, in height, flower color, fruiting time, or flavor. They may also vary in characteristics such as their response to heat, cold or drought, or their ability to resist specific diseases and pests. Crop diversity can also be due to the result of genetic differences: a crop may have genes conferring early maturity or disease resistance. Through combining genes for different traits in desired combinations, plant breeders are able to develop new crop varieties to meet specific conditions. A new variety might, for example, be higher yielding, more disease resistant and have a longer shelf life than the varieties from which it was bred. José Esquinas-Alcázar, a top official at the UN Food and Agriculture Organization in Rome, says, “If you have climate change or environmental change, you need to search through those plants to find one that is adapted to the new conditions.” he said.
Threat to Crop diversity: (Based on an article in the New York Times)
In this article it is stated that the loss of crop diversity is directly related to the 20th century “green revolution,” in which farmers adopted streamlined agricultural techniques to increase production of food. To maximize crop yields, they chose a few high-yield, uniform crops that grew predictably and could be planted and harvested mechanically. With irrigation, mechanization, fertilizers and pesticides at their disposal, farmers in developed nations were able to maintain control over growing conditions. This kind of practice led to far less variety in the types of seeds and foods planted – which, sometimes led to disastrous vulnerability. For example in 1970, more than half of the corn crop in the southern United States succumbed to an unusual fungus because the corn was all grown from one seed type that is particularly susceptible to that disease. Then the scientists modified the U.S. corn seed with a gene borrowed from a type of African maize that was resistant to the fungus.
In this article José Esquinas-Alcázar (who was interviewed by the author of this article) says humans utilized more than 7,000 plant species to meet their basic food needs. Today, due to the limitations of modern large-scale, mechanized farming, only 150 plant species are under cultivation, and the majority of humans live on only 12 plant species. Esquinas asserts that most types of food consist of several different species, and each species may contain dozens, if not hundreds, of varieties. In the last century, dozens of varieties of corn, wheat, tomato and potato have disappeared. According to Esquinas this loss of crop diversity is dangerous for survival as it denies farmers and scientists the ability to breed new types of seed crops that can adapt to changing conditions – a hotter, drier growing season, for example, or the invasion of a new bacterial pest.
Esquinas has spent decades campaigning to preserve plants that are used for food. He says of the nearly 8,000 varieties of apple that grew in the United States at the turn of the century, more than 95 percent no longer exist. In Mexico, only 20 percent of the corn types recorded in 1930 can now be found. Only 10 percent of the 10,000 wheat varieties grown in China in 1949 remain in use.(Once when Esquinas was collecting melon seeds in Spain, he accompanied a farmer to a remote village by donkey, where he was presented with seeds for a melon that the farmer insisted was exceptionally hearty. When he analyzed the seed back in the lab, he discovered that it was resistant to many diseases, and genes from that melon have since been introduced into numerous commercial fruits.)
Source: http://www.nytimes.com/2005/08/17/world/europe/17iht-food.html?pagewanted=1
Global Crop Diversity Trust is an independent international organisation which exists to ensure the conservation and availability of crop diversity for food security worldwide. It was established through a partnership between the United Nations Food and Agriculture Organisation (FAO) and the Consultative Group on International Agricultural Research (CGIAR). The Global Crop Diversity trust is the main supporter of a seed vault in the Arctic archipelago of Svalbard, intended as a global back-up for food crops. It is estimated Svalbard had copies of nearly half a million food crop varieties, representing most of the diversity of major crops, compared with 1 to 1.5 million distinct varieties of all food crops.
Threat to food security posed by climate change
The Global Crop Diversity trust joined 60 agricultural experts (gathered in Rome for the ‘World summit on food security’ being held from Nov. 16 to Nov. 18, 2009) in issuing a statement highlighting the threat to food security posed by climate change. They called on the leaders from all over the world, who will be meeting in December in Copenhagen for the UN Climate Change Conference, to recognize and address the specific threat that climate change poses to the world’s food security.
According to the agricultural scientists meeting in Rome, the magnitude of change now being forecast, even in relatively optimistic scenarios, is historically unprecedented, and our agricultural systems are still largely unprepared to face it. Farmers will encounter problems they have never before experienced: much greater weather variability, higher average temperatures, increased numbers of extremely hot days, shorter growing seasons, much greater moisture stress, added salinity from salt water incursion and irrigation systems, and new combinations of pests and diseases. Getting agriculture ready for such dramatically new growing environments is not a trivial matter.
Fundamental to getting agriculture ready for such dramatically new growing environments is crop diversity. Seed banks could preserve the crops that will emerge as the most resilient to future warming. According to Cary Fowler, the executive director of the Global Crop Diversity trust, more money is needed to support seed banks worldwide. Fowler, told Reuters, “The reality is that this is a resource (i.e. crop diversity) which is still not protected, the wild relatives of our cultivated crops are still endangered in the field but are a potent resource for climate change adaptation. Something in the area of $350 million in an endowment would generate enough income annually to conserve all of crop diversity forever. We have about $100 million now, we’re a third, a quarter of the way there.”
Source: http://www.croptrust.org/main/climatestatemen.php
November 18, 2009