Climate Change & Food Security [ PDF ]

In this Newsletter:

The Challenges of Producing Food on a Warming Planet

Challenges: CO2 Fertilization, Alterations to Hydrology, Rising Average Temperature & Shifting Habitat Ranges, Extreme Weather Events, Pests & Diseases, Sea Level Rise, Ocean Acidification

Adaptations: Forecasting, Genetic Adaptation, A Diversified and Just Global Food Economy

Whether it be the crops we grow, the livestock we raise, or the wild plants and animals that we harvest, every organism that we rely on as a food source depends on a unique confluence of conditions that determine whether it will merely survive, deteriorate, or flourish. These environmental factors can include such things as: access to water and nutrients, temperature, the amount and periodicity of sunlight, and interactions with other
organisms within the same ecosystem.

For thousands of years, each of these individual factors has tended to change only slowly or infrequently. Encouraged by this predictability, people have been able to build civilizations around specific food sources. Over time, their sustained and focused attention has led to the great advances in the science and technology of food production that allow humanity to sustain a rapidly growing population.

Now, however, that progress may be coming undone. The accumulation of greenhouse gasses threatens to simultaneously, and in unpredictable and potentially dramatic ways, alter nearly every variable with an input into the grand equation that is our food production system. Because the timing and magnitude of any one of these changes is hard to forecast, and especially because each individual variable is involved in innumerable and complex interactions, it is nearly impossible to predict, on a large scale, just how our agriculture, livestock, and fisheries will respond to the new climate conditions we have created for ourselves. However, by inspecting the following individual effects, a clearer
picture may begin to emerge:

CO2 Fertilization to top

Higher concentrations of atmospheric carbon dioxide allow plants to grow faster and larger. From a food production standpoint, this is generally good news. Yields should increase, less fertilizer may be needed, and faster growing crops can open new, previously marginal, lands to agriculture. However, not all the effects of carbon dioxide fertilization will prove beneficial. For instance, the magnitude of the CO2 fertilization effect is different for different types of plant species. Among those that will benefit the most are many weed species, triggering concerns from farmers about competition in their fields and from environmentalists about greater use of herbicides. Plants growing under heightened CO2 conditions can exhibit abnormal characteristics with regard to the way they absorb and process nutrients. Also, CO2 fertilization can sometimes cause plants to speed through the growth phase in which they generate their harvestable grains, fruits or vegetable matter. As a result, fields filled with more outright biomass may, at the same time, produce diminished and less nutritious harvests.

Alterations to Hydrology to top

Global warming is certain to produce changes in the way water cycles through our oceans, into the atmosphere and over the land. As rising heat drives accelerated evaporation, land and crops growing on them will potentially dry
out faster. However, at the same time, more moisture will be drawn from the oceans, causing overall precipitation to increase. Rarely will changes in these countervailing forces simply offset each other to preserve the status quo. Much more frequently, specific localities and the food resources supported there will face new trends in water availability.

Areas that currently derive water from melting glaciers and snow-pack are likely to see some dramatic changes as well. Himalayan glaciers, for instance, which now provide the majority of nonmonsoon water flow for some of Asia’s most important agricultural regions, are in danger of shrinking or even disappearing completely as a result of global warming. In other areas, where an annual snow-pack serves as an important water resource, rising temperatures will alter the yearly precipitation timing and mix. For instance, in the American
West, diminished snow pack and earlier, faster melts are likely to leave many areas regularly facing late summer droughts and an increased incidence of forest fires.

Low water availability and abnormally timed flows disrupt more than agricultural irrigation. They can disrupt travel along the rivers and canals that play a large role in low-cost food transportation, diminish our ability to carry out inland aquaculture, and devastate fisheries (such as salmon) that rely on freshwater rivers for spawning.

Rising Average Temperatures & Shifting Habitat Ranges to top

As global warming increases the baseline temperature at most locations on our planet, those organisms or populations that are free to move in order to remain in their ideal temperature range, will. At the global level, this will produce mixed effects. Some food producers, especially those at higher latitudes and altitudes, may welcome the opportunity to grow, raise, and harvest plants and animals in areas formerly too cool for that activity. Those in temperate climate zones will be forced to adopt new practices better suited to a more tropical environement. Still others, especially those in the newly superheated tropics, will face an unprecedented climate zone, for which no food producing species have had time to evolve.

On the whole, this phenomenon of range shifting can pose a real danger to fisheries, livestock, and agriculture. To begin with, temperature-induced range changes may push populations into new areas for which they are otherwise poorly adapted. It may render obsolete local cultures, economies, and infrastructure that had been uniquely shaped around specific food resources Global biodiversity will dwindle as some high altitude and polar climates simply cease to exist. Most menacing of all is the fact that these climate zone shifts are not monolithic, orderly processes that will affect all members of an ecosystem simultaneously. Some species will shift more readily and quickly, while others may experience almost no range shift. This uneven movement of ranges will decouple intricately choreographed intra-species relationships that have developed through thousands, if not millions, of years of co-evolution. The range, migration habits, and life cycles between pollinators and plants, pests and their prey, and wild food-stocks and
their predators, will all be affected. It is unlikely that these environmental services can be replaced by human means.

Extreme Weather Events to top

In general, agricultural producers will face less stress from extreme cold events and freezes but higher stress from more frequent and more intense heat waves. As heat energy accumulates in our atmosphere and oceans it may produce more frequent and powerful storms (including, but not limited to, hurricanes) along
with the tornadoes, hail, lightning, high winds, and flooding that they can bring. Each can damage crops, kill or stress livestock, and disrupt or destroy both natural resources and necessary infrastructure.

Parasites, Diseases, Fungi & Other Pests to top

These organisms can harm, poison, eat, or otherwise reduce the yield of the species we use as food. All tend to thrive and spread more rapaciously in warmer and more humid climates. Furthermore, as fewer and fewer
regions get cold enough for long enough to produce a winter kill-off, populations of these organisms can explode. Keeping them in check will require the use of even more fungicides and insecticides for crops and antibiotics in livestock production and aquaculture.

Sea Level Rise to top

Global warming is causing ocean levels to rise and is therefore rendering agricultural areas, such as low-lying, but usually very fertile river deltas, and brackish estuaries, which often serve as critical nurseries for commercial fish species, increasingly susceptible to saltwater intrusion and inundation.

Ocean Acidification to top

Atmospheric carbon dioxide has always naturally dissolved into our oceans. Now, however, the rate at which this is happening is increasing and, as a result, the ocean is becoming more acidic. Under these conditions it is more difficult for sea creatures to develop and maintain their calcium based shells and exoskeletons. As a result, populations of certain species used directly as food sources ( such as mollusks and clams) and others that form the foundations of important marine structures and food chains (like corals and some plankton species) will experience stress and could eventually even collapse.

Adaptations to top
In the face of these challenges, people around the world must begin to make critical adaptations to our global food production system. Some key areas include:

Forecasting to top

It is important that we develop capacities to better understand global climate trends and extrapolate from them more localized, near-term weather forecasts that can
then be used in order to prepare for the coming changes. The accomplishment of this task will require policies and investments that allow for better integration of, and access to, data sets related to climate change and weather. Multidisciplinary response programs should
be instituted to make sure that ranchers, farmers, and breeders have a reasonably
accurate understanding of upcoming conditions. At the same time financial experts and policy makers need to make sure food producers have the ability to make changes accordingly.

Genetic Adaptation to top

Once future conditions can be forecasted, scientists can begin to breed, or even genetically engineer, our food sources to have characteristics that make them better suited to their environment. This process, carried out through selective breeding is nothing new and has served humanity well throughout history. Now however, the speed of environmental changes is outpacing our capacity to breed new characteristics through traditional methods. Some see genetic engineering as the answer. Through the use of advanced technology, we can now implant (even from completely different species) the genetic code associated with a desirable genotype directly into a food species.

While this technology holds great promise, it is not without its drawbacks. Chief among them is the concern that genetically modified organisms willinterbreed with and therefore “pollute” or reduce the diversity in a species’s gene pool. Doing so would limit the variety of traits exhibited by a species and therefore also limit the pool from which desirable traits can be identified and propagated. Special attention must also be given to preserving a wide and diverse gene pool against the threats to biodiversity posed by habitat loss and a
growing propensity toward widespread monocropping. Monocropping (a practice in which entire farms or even whole regions of a country are planted with nearly identical seed) may be unwise in the uncertain times that lie ahead. Less genetic variation in our food-stocks
means that an increasing percentage of any year’s harvest could be wiped-out by a single common threat. Policies should be derived to incentivise, as a form of food security insurance, the cultivation of more genetically diverse crops even if, individually, they may prove to be less productive.

A Diversified, Adaptable, and Just Global Food Economy to top

In almost every way, the expected distribution of positive and negative climate change effects has the appearance of being unfair. As we have read, climate change, at least in the short and medium time frame, may produce positive as well as negative effects. However, these effects are not equally distributed. The preponderance of those beneficial effects will occur in higher latitudes, mostly in well-developed Northern Hemisphere countries -- the same ones, incidentally, that have historically played the biggest role in emitting the greenhouse gasses that are now causing climate change. By contrast, equatorial regions, populated
by less developed countries that not only have the least ability to respond to these
challenges, but also are responsible for only a small percentage of historic greenhouse gas emissions, are the most likely to bear the burden of the negative effects of climate change.

In any instance where food is made scarce or prohibitively expensive, and
especially in cases where there is some perceived injustice at play, border-crossing
problems like political instability, forced migrations, widespread health emergencies, collapsed markets, and war can quickly follow. To head off these types of scenarios, the international community must help to bolster stable, responsive governments, an informed
and interlinked scientific community, adequate access to capital, and suitable infrastructure for all. These improvements are not only positive in their own right, but also required in any region that hopes to successfully cope with climate change.

Regardless of whether this situation is viewed from the perspective of social justice or simple practicality, our global economic and political systems should recognize this phenomenon and take action to ensure a more equitable distribution of risks and rewards in our world-wide food production system.

Summer 2008 Climate Alert

Climate Change & Food Security [ PDF ]

In this Newsletter:

The Challenges of Producing Food on a Warming Planet

Other Articles in this Newsletter: