In Defense of Diversity

Svalbard Global Seed Vault. Photo © Mari Tefre/Global Crop Diversity Trust

If you are not familiar with it, I highly recommend taking a look at the TED website. TED is a small nonprofit devoted to “Ideas Worth Spreading”. It organizes conferences where people from different fields and walks of life, scientists, engineers, and politicians, can present their ideas and projects.

The talks are filmed and made available for free on their website, which now contains a vast collection of brilliant presentations and speeches, always informative and at times downright jaw-dropping (in fact, “jaw dropping” is one of the categories you can use to scan through the presentations.)

The presentation that recently caught my attention is one by Cary Fowler, about the importance of genetic diversity in agriculture. Dr Fowler is Executive Director of the Global Crop Diversity Trust, whose mission is to conserve Earth’s agricultural biodiversity. Jointly funded in 2004 by FAO and Biodiversity International the Trust worked with the Norwegian Government and the Nordic Gene bank to create the Svalbard Global Seed Vault, also dubbed by the media “the Doomsday vault,” which was officially opened on February 26, 2008.

The goal of the vault is to collect seeds of all the world’s remaining crop varieties and their wild relatives. The idea is to create a genetic back-up system, an “insurance” for global agriculture against accelerated or disastrous losses of crop diversity. The vault presently contains half a million samples of crop seeds, and at full capacity it will be able to hold 4.5 million samples coming from seed collections across the world. In case of a global catastrophe caused by unchecked climate change or nuclear war, the vault will be able to reboot global agriculture. In case of regional crises or damages to the currently existing seed banks, duplicates of the lost seeds will be retrieved from the vault to replenish the collection. The location of the vault inside a mountain in the frozen landscape of Svalbard was carefully studied. War and natural disasters are a common threat to crop diversity. In recent years seed banks have been all but completely lost in Iraq and Afghanistan, the collection in Burundi was destroyed in the early 90’s, and the seed bank in the Philippines was damaged by a typhoon in September 2006. Moreover, the current collections, about 1400, half of which are in developing countries, vary widely in quality and standards of management and many suffer from a lack of funds and expertise which exposes them to risks of accidents, like loss of power and failure of the  cooling system. The vault in Svalbard is remote, tucked away from zones of war or civil strife, but still accessible; it is in a stable geological area, which limits risks of some natural disasters; it sits at an elevation which is safe by any projections of sea level rise, and the natural frozen conditions will help to keep the seeds viable, and buy precious time, in case of dramatic climate change.

But why do we need  to back up the genetic diversity contained in the world’s collections?  The reason is quite simply that crop diversity is what stands between us and starvation. The history of agriculture is telling us that there is no single best crop variety. Since the Neolithic period, farmers had to develop methods of breeding, and constantly select new crop varieties to respond to changes in the climate and to fend off pests and diseases. And today, like yesterday, adapting to continuously changing threats relies on the availability of a diverse raw material, different crops varieties and their wild relatives carrying genes that are unique, or that are combined in unique ways.

Specifically, a back up plan is more urgently needed today because it could be argued that a sort of perfect storm is brewing for agriculture. On one hand, climatic changes directly increase the pressure on crops through higher temperatures and water stress, and create environmental conditions that increase the likelihood of insurgence of pests and diseases. On the other hand, crop genetic diversity is being lost at alarming rates. In the US, where the record is most complete, several major crops have lost between 80 and 90% of their varieties in the space of 80 years. A similar loss has been reported for rice varieties in India and although hard numbers are difficult to find, it is estimated that in developing countries as a whole, a massive loss in crop diversity has taken place in the second half of the 20th century.

The culprits are various. Accelerated biodiversity loss through habitat destruction and fragmentation has hit crops and their wild relatives. Meanwhile agriculture modernization and the consolidation of the grain industry toward genetically uniform varieties has eroded the wealth upon which plant breeders have drawn the material to produce, maintain and improve the same modern varieties.

By choosing high-yield homogeneous varieties, farmers have decided to accept higher risks. The geographically extensive cultivation of a genetically homogeneous population raises the likelihood of a pest outbreak, as well as the costs of the epidemic. Although we are paying a high price in terms of pollution and erosion of some ecosystem services, the world has benefited enormously from taking these risks - only  consider the huge increase in productivity that allows to feed today’s global population. However, that level of risk may not be acceptable anymore because the rules of the game are changing. Those risks were taken with a certain degree of confidence, as farmers could rely not only on technology, but also on a wealth of accumulated historical knowledge regarding climatic conditions, and could safely assume that changes would occur within a certain ”envelope of variability”. Now that these conditions are changing in further unpredictable ways, the past is less and less useful to forecast the future.

And conditions are changing more rapidly than previously thought. In this swiftly evolving world, genetic diversity gives us options. It is our arsenal against uncertainty.