Farmers dislike unpredictable weather patterns, the weather shapes our lives and therefore everyone else's. Impending global climate change worries us, at least those of us who work with natures cycles. The industrial agriculture crowd are, as usual, ready to fight nature in hopes of ultimate victory.
As global temperatures increase and carbon dioxide levels rise, crop yields will rise correspondingly, or so many farmers would like to think. Perhaps, in Northern Canada and Russia, for a time, but eventually heat and drought will shrivel crops even in the northern latitudes..
According to the National Oceanic and Atmospheric Administrations (NOAA) recent study on global climate change, plants will grow larger with higher concentrations of carbon dioxide, but they will also need more water. Yet, fresh water resources are becoming more scarce.
While higher carbon dioxide levels can increase overall plant growth, the grain, or seed portion of the plant, will have less time to to adequately develop due to rising temperatures. Thus high temperatures will also decrease the plants ability to reproduce.
While some food crops may benefit from the changing climate, weeds will benefit more. More weeds mean more competition with food crops, so to compensate, farmers will increase their use of costly herbicides. Climate change will defeat that strategy as well. The most widely used herbicide in the US, Roundup, begins to loose its efficacy as carbon dioxide levels rise.
Insects and crop diseases thrive under warmer conditions. With less winter freezing to control them, they will move northward.
For livestock farmers, increased temperatures will cause increased heat stress on livestock. Graizers will see lowered forage quality and protein content requiring more land to feed increasingly heat and insect stressed animals.
Particularly troubling are the more frequently occurring global climate "surprises". My farm has experienced two "100 year" rains in less than a year. Europe had record heat waves in 2003 and 2007, record cold waves in 2006 and 2009. Australia suffers under prolonged drought and devastating wildfires, while more unpredictable late season frosts threaten fruit, vegetable and winter grain crops in the US.
Still, the most devastating effects of climate change will be seen in the developing world. As temperatures rise, the tropic and subtropic regions of the world will see the most drastic temperature increases. As the worlds glaciers and ice caps continue to melt rising sea levels will inundate many low lying and densely populated agricultural countries like Bangladesh, Vietnam and Egypt.
The January 9, 2009 issue of Science stated that "the hottest seasons on record will represent the future norm in many locations." I remember my fathers stories of the hot, dry summers of the Dust Bowl 1930's. While human activity certainly put the dust in the Dust Bowl, we are now seeing actual changes to physical systems such as glaciers, permafrost and oceans.
NASA scientist James Hanson tells us we must seriously consider the amount of carbon dioxide in the air. He warns that if we wish to maintain a planet somewhat similar to the one we now inhabit, 350 parts per million (ppm) of carbon dioxide is the highest level we can maintain. Considering that current levels are around 390 ppm and growing, we could be in trouble.
If we think agriculture will thrive in a warming world we are deluding ourselves. In addition to cutting industrial and transportation emissions, there are models of sustainable farming systems that can reduce carbon emissions. A long term study by the Rodale Institute showed organic farming methods were capable of sequestering nearly 30% more carbon in the soil than conventional farming methods.
Sustainable agriculture keeps more carbon in the soil and it focuses on food crops, not environmentally damaging commodity crops. Equally important, as shown by last years report of the United Nations Conference on Trade and Development, sustainable agriculture offers developing countries a wide range of economic, environmental, social and cultural benefits.
If we are going to get serious about reducing carbon emissions to the 350 ppm level and if we are going to give the developing world a chance to feed itself, organic and sustainable agriculture need to become the norm, not the exception.