November 13, 2013

No Plan Bee

This piece from the Financial Times reviews the causes and implications of a “pollination crisis” resulting from an insufficient number of bees and other insects. Most fruits and vegetables and about three-fourths of all crops rely on these pollinators, which are under severe stress. Dave Goulson, a professor of biology at Sussex University in Britain, notes that in California, beekeepers that are needed to pollinate the almond crop are losing nests, tripling prices; in China, apple and pear farmers use children on stepladders to brush pollen on each flower, as pesticides have wiped out the bees. Goulson stresses that knowledge of the overall state of the world’s pollinators is quite limited—“we do not know how many pollinators we have, nor how their abundance has changed over time”—but is sufficient to indicate a grave crisis.
What is happening to our bees? The answer is complicated – but imagine the following. A flu epidemic sweeps the country, and you catch it. You feel awful but you struggle on, going to the shops to get food. The shop has closed down, and you have to walk an extra two miles to find an open shop. Exhausted and shivering, you buy some food and manage to eat some but it has been poisoned. Not enough poison to kill you if you were feeling well, but in this state?
It sounds a bit melodramatic, but it is a pretty good analogy for our poor bees. We have accidentally spread new parasites and diseases of bees around the world; for example, many bumblebees in the UK are infected with a gut parasite originally from Asian honeybees, while honeybees are being ravaged by the Asian Varroa mite. Modern farming has removed most flowers from the countryside, so pollinators have to travel further to find nourishment – and the range of foods available is restricted. Much is contaminated with a cocktail of pesticides; recent studies found up to 35 different pesticides in the food stores of honeybees. Small wonder, then, that pollinators are not thriving.
Global food production has been heading in an unsustainable direction for decades. The UN’s Food and Agriculture Organisation estimates that we will need to double global food production by 2050 to feed the growing population. We continue to clear tropical forests to bring more land in to use, and we try to squeeze ever greater yields from existing land by heavy use of fertilisers and pesticides, creating vast crop monocultures. Yet our efforts are undermining the ability of land to produce food. Agricultural practices are causing soils to be rapidly eroded – washing away in rain or blowing away into the sea – so that 40 per cent of farmed soils are already degraded, and some estimates suggest many countries will have little soil left within 60 years. Aquifers used to irrigate arid soils are fast being depleted. Salt build-up, from poor irrigation practices, is affecting 320m hectares of agricultural lands – an area the size of India.
Extreme climate events expected as a result of build-up of greenhouse gas emissions are likely to cause catastrophic crop failures. Wild fish stocks are being depleted; many have already collapsed. Species are going extinct at about 1,000 times the natural rate, many of which have vital roles in recycling nutrients, storing carbon, creating soil, controlling pests and, of course, pollinating crops. Bees may be canaries in the coal mine, warning us that we must find ways to produce food without destroying the environment on which we depend.
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Dave Goulson, “There is no Plan Bee for when we run out of pollinators,Financial Times, November 8, 2013

November 7, 2013

Threat to Food Supplies

A new report from the Intergovernmental Panel on Climate Change, still under review but leaked to a climate skeptic, warns that rising temperaturees will pose great risks to the world's food supply in coming decades. From the New York Times:

In a departure from an earlier assessment, the scientists concluded that rising temperatures will have some beneficial effects on crops in some places, but that globally they will make it harder for crops to thrive — perhaps reducing production over all by as much as 2 percent each decade for the rest of this century, compared with what it would be without climate change. . . . The document is not final and could change before it is released in March.
The report also finds other sweeping impacts from climate change already occurring across the planet, and warns that these are likely to intensify as human emissions of greenhouse gases continue to rise. The scientists describe a natural world in turmoil as plants and animals colonize new areas to escape rising temperatures, and warn that many could become extinct.
The warning on the food supply is the sharpest in tone the panel has issued. Its previous report, in 2007, was more hopeful. While it did warn of risks and potential losses in output, particularly in the tropics, that report found that gains in production at higher latitudes would most likely offset the losses and ensure an adequate global supply.
The new tone reflects a large body of research in recent years that has shown how sensitive crops appear to be to heat waves. The recent work also challenges previous assumptions about how much food production could increase in coming decades because of higher carbon dioxide levels in the atmosphere. The gas, though it is the main reason for global warming, also acts as a kind of fertilizer for plants. . . .
On the food supply, the new report finds that benefits from global warming may be seen in some areas, like northern lands that are now marginal for food production. But it adds that over all, global warming could reduce agricultural production by as much as 2 percent each decade for the rest of this century.
During that period, demand is expected to rise as much as 14 percent each decade, the report found, as the world population is projected to grow to 9.6 billion in 2050, from 7.2 billion today, according to the United Nations, and as many of those people in developing countries acquire the money to eat richer diets.
Any shortfall would lead to rising food prices that would hit the world’s poor hardest, as has already occurred from price increases of recent years. Research has found that climate change, particularly severe heat waves, was a factor in those price spikes.
The agricultural risks “are greatest for tropical countries, given projected impacts that exceed adaptive capacity and higher poverty rates compared with temperate regions,” the draft report finds.
If the report proves to be correct about the effect on crops from climate change, global food demand might have to be met — if it can be met — by putting new land into production. That could entail chopping down large areas of forest, an action that would only accelerate climate change by sending substantial amounts of carbon dioxide into the air from the destruction of trees. . . .
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Justin Gillis, "Climate Change Seen Posking Risk to Food Supplies: Science Panel Says Output May Drop 2% Each Decade, as Demand Rises," New York Times, November 2, 2013.