Updated May 2016
Fascinating research by Daniel Bebber, Mark Ramotowski and Sarah Gurr, recently published in Nature Climate Change, looks at the impact of global warming on the movement of crop pests and other pathogens.
Fascinating research by Daniel Bebber, Mark Ramotowski and Sarah Gurr, recently published in Nature Climate Change, looks at the impact of global warming on the movement of crop pests and other pathogens.
Pests and pathogens are a big problem for the agricultural sector with
between 10 and 16 percent of crop production lost due
to plant diseases and additional losses ranging from 6 to 10 percent are
experienced after crops are harvested. In total, the amount of lost
agricultural production would be sufficient to feed 8.5 percent of the world's
total population. As shown here, food insecurity is still a huge problem
for large parts of Africa and portions of Asia:
During the period from 2001 to 2003,
average losses for rice (a staple of the diet of many nations) totalled 37.4
percent with 15.1 percent lost due to pests, 10.8 percent due to pathogens and
10.2 percent lost due to weeds. It is estimated that global crop losses
due to disease cost the economy $220 billion, a not insignificant amount.
How and why are these pests moving
to new geographic areas? Some of these pests are introduced to new areas
through the transportation of crops from one area to another, however, weather
is a very important factor in sustaining pests in their new environment.
For example, boring pests tend to prefer drought conditions whereas
chewing insects do not. The drought conditions recently experienced throughout much of the United States has increased the number of wood boring insects and has greatly impacted the health of trees and shrubs in many areas. Warming, as a whole, tends to favour increased
winter survival for many insect species and tends to stimulate insects to
devour more plant material. In the past, cold winter weather could be
counted on to kill off the majority of insect pests in many areas of North
America and Europe; unfortunately, such is no longer the case as many insects
are now able to survive the less rigorous winters that we are currently
experiencing.
Back to the paper by Bebber et al.
Their research of 612 crop pests and pathogens shows an average annual shift of
2.7 kilometres (plus or minus 0.8 kilometres) toward polar regions since 1960. Here is a graphic that shows the movement of some key pests:
Those pests that show movement
toward the equator are, in many cases, newly detected in those areas as
advancements in technology in poorer, equatorial nations are now permitting the
detection and treatment of pests and pathogens that were not previously
monitored.
It is estimated that global food
production will have to increase by 50 percent by 2050 to meet the world's
needs. While global food production has doubled in the last 40 years, the
movement of pests into new geographic areas may well make achieving that goal
more difficult, particularly if climate change negatively impacts the viability
of agricultural operations in areas that have historically been considered some
of the world's key producers of food.
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Latest figures in the Uk show that the population is becoming more skeptical in regard to climate warming. I believe this is due in part to inaccurate and exaggerated claims being made. When later proved to be over exaggerated and they undermine the debate, because that is what this is a debate. If exaggeration makes people skeptical then everyone loses.
ReplyDeleteMy issue with the above article is that there now seems to be scientific consensus that there has been no surface temperature warming of the planet for the last 15 odd years., IF this is the case the spread of pests and pathogens is due to some other cause. Nothing brings more discredit to global warming than claims that are later proved wrong. Inaccurate or misleading science will only further alienate the general population to the idea of global warming.
Changes in the environment are occurring slowly and often go unnoticed by many people who are somewhat insulated from nature. The reasons for the spread of pest and pathogens do not reduce the damage they cause. I have seen several incidents that confirm what you write about in your article, I echo your concern. Please note crop yields are very fragile to a harsh streak of bizarre weather. Two post from my blog touch on your subject,
ReplyDeletehttp://brucewilds.blogspot.com/2012/11/under-reported-weather-events.html
http://brucewilds.blogspot.com/2013/04/bedbugs-as-black-swan.html
. . . shows an average annual shift of 2.7 kilometres (plus or minus 0.8 kilometres) toward polar regions since 1960.
ReplyDeleteWas a time when the globe was warming?
. . . Those pests that show movement toward the equator are, in many cases, newly detected in those areas as advancements in technology in poorer, equatorial nations are now permitting the detection and treatment of pests and pathogens that were not previously monitored. . . .
If the earlier movement toward the polar region was caused by warming thin one would have to conclude not if the migration "is" now toward the equatorial region that it would be for the reverse reason for the previous migration, the globe is no longer warming and is now cooling. Is that assumption correct?