Climate Change and its Effects on Food Production
In a recent post I wrote about Overpopulation: Food Crisis and future Hunger Wars. The article focused on the impact of the population explosion on food supplies – will there be enough food for a population of 9 billion in 2050? There are many interrelated and complex factors affecting worldwide food production. Climate change is singularly the most critical factor.
The “Final” Wake-up Call
There have been many so-called wake-up calls about the environmental slippery slope humanity finds itself on. The summer of 2012 – raging wildfires, drought, extreme heat, (more than 3000 high-temperature records broken) “affecting 87 per cent of the land dedicated to growing corn, 63 per cent of the land for hay and 72 per cent of the land used for cattle” and now hurricane Sandy. Americans collectively have reached the “wow” moment. Even prior to hurricane Sandy, 70% of Americans believed that climate change is not a hoax. See previous blog – Common Sense Revolution.
The U.S. drought is having global effects as the world’s biggest grain exporter struggles with shortfalls. Drought conditions affected over more than 60 percent of the lower 48 states, the government said. The same is happening elsewhere around the globe.
A Centre for Strategic & International Studies report by (Johanna Nesseth Tuttle & Anna Applefield) stresses that corn prices have risen 45 per cent since mid-June as a result of the drought. Global food prices are at an all-time high. Since the United States is the world’s top exporter of both of these crops, significant disruptions in domestic production can impact global food prices. In fact, 40 percent of the wheat and soya beans traded on the global market last year were grown in the United States.
Climate change is now widely believed to be the cause of the intensification of weather patterns that disrupt food production around the globe. Human-induced climate change will intensify the geographic extent, duration and severity of storms – winds, flooding, drought, extreme heat and snowfalls.
“Perhaps the biggest single question about climate change is whether people will have enough to eat in coming decades”, says Justin Gillis in the NYT Environment/Green Blog:
Rising temperatures during the growing season in many large producing countries are cutting yields below their potential, the research suggests. On top of that background factor, extreme events like droughts or torrential rains can destroy crops altogether. Extremes have always been part of the agricultural picture, of course, but they are expected to increase on a warming planet.
Extreme weather will intensify and aggravate future food crises. An article appearing in Arctic News recently highlights that:
Storms and floods do damage to crops and cause erosion of fertile topsoil, in turn causing further crop loss. Similarly, heatwaves, storms and wildfires do damage to crops and cause topsoil to be blown away, thus also causing erosion and further crop loss. Furthermore, they cause soot, dust and volatile organic compounds to settle on snow and ice, causing albedo loss and further decline of snow and ice cover.
Arctic News also features the Diagram of Doom which pictures three kinds of warming and 10 catastrophic feedbacks.
Changing extreme events
An IPCC Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (November 2011) highlights the following findings:
• Observations since 1950 show changes in some extreme events, particularly daily temperature extremes, and heat waves
• It is likely that the frequency of heavy precipitation will increase in the 21st century over many regions
• It is virtually certain that increases in the frequency of warm daily temperature extremes and decreases in cold extremes will occur…very likely—90 per cent to 100 per cent probability—that heat waves will increase in length, frequency, and/or intensity over most land areas.
• It is likely that the average maximum wind speed of tropical cyclones (also known as typhoons or hurricanes) will increase throughout the coming century
• There is evidence… that droughts will intensify over the coming century in southern Europe and the Mediterranean region, central Europe, central North America, Central America and Mexico, northeast Brazil, and southern Africa.
• It is very likely that average sea level rise will contribute to upward trends in extreme sea levels in extreme coastal high water levels.
Impacts of Climate Change on Yield
The following excerpts are from a UNEP study about the impact of environmental changes on world food production – The environmental food crisis – The environment’s role in averting future food crises:
Global climate change may impact food production across a range of pathways… 1) by changing… general rainfall distribution, temperature regime and carbon; 2) by inducing more extreme weather such as floods, drought and storms; and 3) by increasing extent, type and frequency of infestations
The estimated impacts of changes in the general climate regime vary with the different models in the short to mid-term (2030–2050), but after 2050 an increasing number of models agree on rising negative impacts
Furthermore, projected changes in the frequency and severity of extreme climate events are predicted to have more serious consequences for food
…by 2080, assuming a 4.4° C increase in temperature and a 2.9% increase in precipitation, global agricultural output potential is likely to decrease by about 6%, or 16% without carbon fertilization…as climate change increases, projections have been made that by 2080 agricultural output potential may be reduced by up to 60% for several African countries, on average 16–27%… these effects are in addition to general water scarcity as a result of melting glaciers, change in rainfall patterns, or overuse.
Impacts of Water Scarcity
Water is essential not only to human survival but in food production. The UNEP study reports that:
Agriculture accounts for nearly 70% of the water consumption, with some estimates as high as 85% (Hanasaki et al., 2008a,b). Water scarcity will affect over 1.8 billion people by 2025 (WHO, 2007).
Projections suggest that water demand is likely to double by 2050…one major factor beyond agricultural, industrial and urban consumption of water is the destruction of watersheds and natural water towers, such as forests in watersheds and wetlands, which also serve as flood buffers.
It is evident that in regions where snow and glacial mass are the primary sources of water for irrigation, such as in Central Asia, parts of the Himalayas Hindu Kush, China, India, Pakistan and parts of the Andes, melting will eventually lead to dramatic declines in the water available for irrigation, and hence, food production…of great importance, therefore, is the effect of climate change on the extent of snow and glacial mass and on the subsequent supply of water for irrigation. Climate change could seriously endanger the current food production potential, such as in the Greater Himalayas Hindu Kush region and in Central Asia. Currently, nearly 35% of the crop production in Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan is based on irrigation, sustaining over 2.5 billion people. Here, water demand is projected to increase by at least 70–90% by 2050.
The wars of the future will be ‘Hunger Wars’ fought over the resources that are left.