Locusts, a group of swarming grasshoppers, are legendary pests. Plagues of locusts that demolished crops are described in the Bible and Quran; more recently, such plagues have occurred episodically in North Africa, the Middle East, and elsewhere. And research suggests that climate change may make such plagues even more frequent in the future. Locusts include species of grasshoppers that have solitary and swarming phases in their life cycle. Research indicates that swarming occurs when the density of locusts is elevated. Swarms can include billions or even trillions of individuals and each locust can fly as far as 500 km and eat the equivalent of their own weight in a day. A single swarm can eat enough food for 2,500 people in one day! Locusts, especially the desert locust of North Africa, have been known to completely demolish crops, and the only strategy is to hold populations in check with pesticides. There is evidence that swarms develop best when unusually wet weather is followed by prolonged warm conditions. The wet phase, which causes lush vegetation to grow, allows for prolific reproduction, and the warm phase enhances the gregarious, swarming behavior. Since climate change will cause more frequent intervals of elevated precipitation and heat waves, plagues may be more frequent, more populous in places such as North Africa, Southern Europe, the Middle East, China, and Australia. Such massive and unrelenting plagues will be difficult to control with pesticides.
Insects are just one of many challenges that will make it harder and harder for humankind to receive ample nutrition. As we will show in this module, food is most definitely one of the Grand Challenges of the 21st Century, and feeding the increasing global population will require a very different approach to the production and distribution of crops and other sources of nutrition. Climate change will make matters increasingly difficult, in particular in regions where food shortages already exist.
On completing this module, students are expected to be able to:
After completing this module, students should be able to answer the following questions:
Below is an overview of your assignments for this module. The list is intended to prepare you for the module and help you to plan your time.
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Earth is becoming increasingly crowded. Global population stands at just over 7 billion and is rising by 78 million people per year. Now, if that number does not sound like a lot to you, think about it this way--we are adding close to the population of Germany every year to our crowded planet! Currently, 134 million children are born every year, that is 367 thousand per day, and there are approximately 56 million deaths per year. At this rate, the population is predicted to reach 8 billion by 2027 and about 9 billion by 2046. It's mind-boggling to think that global population when many of you were born stood at just over 5 billion! The graph below shows the massive increase in global population as well as these scary projections. It demonstrates how global population increase has been driven by surging populations of Africa and, especially, Asia.
The video below portrays the recent growth in population as well as the outlook.
In 1798, Thomas Malthus wrote An Essay on the Principle of Population. In this work, he predicted that populations of nations would be restricted by the availability of food because nations would not be able to control birth rate. The essay has been intensely debated by evolutionary biologists, economists, and many others for the last two centuries. Repeated famines around the globe generally support Malthus' hypothesis.
Regardless, we find ourselves in a position today where the world is currently not able to feed all of its inhabitants. Currently, more than one billion people are estimated to lack sufficient food, and more than twice that number do not receive adequate nutrition. This situation will likely become a lot more dire in the future. In fact, predictions for population increase diverge significantly in the later parts of the century because some models assume mass mortality due to widespread famine. To make matters worse, climate change is predicted to cause major problems to crop yields, especially in parts of the world where the population is growing the fastest. These shortages will likely lead to mass migration of huge numbers of people, possibly entire nations.
Agriculture is an essential part of every society. Forty percent of the Earth’s surface is managed for cropland and pasture. That is more than for any other activity including forestry, which comprises 30% of Earth's area. In underdeveloped countries, approximately 70% of the population live in rural areas where agriculture is the major activity. There are many diverse sources of food, and populations around the world have very different diets and demands. In addition to crop and livestock, fish is a stable diet in many countries. Projections for climate change differ significantly for these various food sources, thus we will discuss them separately. For crop farming, in particular, the impact of climate change is very different for agro-businesses run by multinational corporations in the developed nations than for family-operated farms in the developing world.
Climate change will have very different impacts on different continents, and socio-economic factors will govern the abilities of nations to respond. Even though the south-central and southwestern US are likely to face extreme drought in the coming decades, inhabitants and businesses should by and large be able to adapt. It will be a starkly different situation in Southern Africa, India and Southeast Asia, Mexico, northeast Brazil, southern Africa, and West Africa, where climate change will be coupled with a general lack of coping mechanisms. In all of these regions, the impact of climate change, and the inability of societies to fully cope with it will potentially result in security issues including soaring food prices and military conflicts.
Food shortages will not be a new problem in many places. Mass migrations driven by food supply have been an important part of human evolution and a tragic part of the history of many nations, especially those in Africa. As we saw in Module 2, famine caused by drought is thought to have caused the collapse of the Mayan civilization in Central America around 850 AD. More recently in China, famine in the late part of the 19th century caused the death of some 60 million people. Famine is possible even in the developed world. The Irish potato famine between 1845 and 1852 caused by a potato disease called potato blight led to approximately 1 million deaths, between 20 and 25% of the population of that country. This problem does not appear to be improving with time. In the 20th century, 70 million people are thought to have died during famines: 30 million alone in China between 1958 and 1961, and 7-10 million in India in 1943.
Nowhere is the history of famine more devastating than in Africa. Famines on the African continent, like elsewhere, have often resulted from a combination of drought and political conflicts, oppressive military regimes, and war. Most recently, the conflict in the Darfur region of Sudan erupted over water in 2003. One side of the conflict, consisting of migratory farmers, has displaced large numbers of sedentary farmers to parts of the country without sufficient food and water. Mass mortality has largely been caused by disease. Estimates of the number of dead are uncertain, but are between 180,000 and 460,000. This number is much less than the number of mortalities in the Biafran conflict of Nigeria between 1967 and 1970 when nearly a million people died from conflict and starvation. Today, more than a third of Africans suffer from hunger.
The following video portrays the tragic history of famines.
A number of different physical variables impact agriculture. These include temperature, precipitation, humidity, wind speed, and radiation. The absolute levels of these variables and their variability on a daily, monthly, and annual basis, affect crop yields as well as livestock health.
Crops are particularly sensitive to absolute temperature variation even over short time scales, in some cases a few hours (for extreme cold) and days (for warmth). Likewise, extreme events such as floods, and inter-annual variations in rainfall connected with cycles such as ENSO can also impact crops significantly. For example, the major drought in Australia from 1998-2010 led to significantly lower crop yields. Major cold snaps in Florida in 1983 and 1985 killed a third of all citrus trees, with an accompanying loss of $2 billion. At the other end of the spectrum, the North Atlantic Oscillation has caused sunnier summers in Britain, leading to increased wheat yields.
As it turns out, anthropogenic impacts can greatly magnify the effects of climate change on crops, livestock, and fisheries. For example, soil erosion, overgrazing, air pollution, salinization of groundwater, and pests and overuse of pesticides tend to exacerbate the impacts of the changing climate such as droughts and heatwaves. Here, we describe the forecasts and impacts of changes in climate variables, followed by anthropogenic changes.
Model forecasts under SRES A1B and A2 are for 2-4oC warming by 2100 with the most significant increase in high-latitude regions. In addition, the forecasts indicate a much higher likelihood of heat waves in the future. As it turns out, an increase in average temperature can have a positive impact on agriculture, lengthening the growing season in regions with cool spring and fall seasons. Regional and global simulations allow predictions of temperature increase on crop yield. The results (see figure below) show that modest temperature increases produce increased yields for some crops. Warming will also lead to a decrease in the occurrence of severe winter cold stress on crops, causing a pole-ward shift in the feasibility of regions for agricultural activities. This is especially important for high-yield tropical crops such as rice. Warming will have a greater impact in the Northern Hemisphere, where there is more cultivated area in high latitude areas.
However, warming ultimately reaches a limit where yield curves start to decrease for all crops. Globally, this threshold is reached at temperature increases over about 3oC. Crop yields also decline precipitously at temperatures above 30oC; although plants develop faster in warm temperatures, photosynthesis has a temperature optimum in the range of 20° to 25°C, and, above this range, plants have less time to accumulate carbohydrates, fats, and proteins. Because individual plants cannot move, they have developed mechanisms that allow them to tolerate higher temperatures and adapt to changing soil conditions. These mechanisms include the production of proteins that lessen heat-shock, as well as the ability to conduct photosynthesis during periods of heat. Such adaptations will partially determine where a crop can survive the impact of climate change.
Warming will have negative impacts on crop yield in regions where summer heat limits production, and it will lead to more frequent extreme high heat stress on crops. Heat stress varies by plant but includes lack of emergence of new plant material or damage to it, water deficit as a result of high evaporation, damage to reproductive development, and death. In addition, climate change will lead to increased soil evaporation rates, which stress crops and also increase the intensity of droughts.
Heat waves are usually known for their human toll. For example, the Great Chicago heat wave of 1995 led to over 700 deaths as a result of five extremely warm and humid days with a heat index reaching 125 degrees. A prolonged heat wave in Northern Europe in 2003 killed more than 40,000 people and led to a 20 to 36% decrease in the yields of grains and fruits. Heat waves are defined differently in different places, but usually, are defined as a specific number of days over a certain temperature. Prolonged heat waves can also cause significant damage to crops and livestock, with major economic losses. In Russia, an extended heat wave in 2010 caused 50,000 deaths and a loss of 25% of the grain yield at a cost of $15 billion. In the central US, more than 6000 cattle died in the July 2011 heat wave. And the heat wave of 2012 in the same region resulted in the worst corn crop in two decades.
Models indicate that precipitation will increase in high latitudes including places such as Northern Europe and Canada, but decrease in most subtropical land regions, including the southern tier of states from Texas to California. Droughts will become longer and more intense in these areas. A decrease in precipitation can reduce soil moisture over the short term and increase soil erosion rates over the long term. Likewise, as we have seen, the intensity of extreme events such as cyclones and hurricanes is likely to increase, also leading to potentially more significant crop damage, and also potentially, soil erosion. Waterlogged soils can cause severe damage to root systems and limit the uptake of nutrients. Flooding can cause permanent loss of many crops. One of the most significant periods of flooding in the US took place in the Midwest in 1993 when the Mississippi and Missouri rivers flooded their banks and submerged huge areas of farmland, a total of nine million acres. The estimated crop losses during this event were $7 billion. In the 2008 Midwest floods, Iowa alone lost $4 billion in damaged crops.
Precipitation may be crucial for determining the impact of climate on crops. Decreases in precipitation and evaporation-precipitation ratios in marginal areas that are currently entirely fed by rain may change ecosystem function to the point where irrigation is required. Estimates suggest that impact of increased evaporation will require increased irrigation requirements of 5-8% globally with higher amounts (15%) in Southeast Asia.
A key variable controlled by a combination of heat stress and rainfall is the 120-day growing period, the minimum duration required for crops such as corn to survive. Climate change has the potential to shrink the 120-day growing period, and this will greatly impact the sustainability of crop production.
Drought can be devastating to agriculture. During the decade-long “Federation” drought in Australia, from 1901-1903, an estimated 52 million sheep perished. In the long Dustbowl of the 1930s, over 75% of topsoil was lost in areas of Kansas, Oklahoma, and Texas, and crops were ruined. In fact, in many areas, agriculture never recovered from the drought, and the economic losses and human suffering are still legendary.
The following videos describe recent droughts in Texas and Australia:
All SRES emission scenarios call for CO2 levels to increase significantly over the course of the 21st century. Even with drastic actions, levels are predicted to reach 550 ppm mid-century before decreasing. Worst-case scenarios have levels continuing to rise beyond 650 ppm at the end of the century. Compared to other climate variables, increasing CO2 generally has a positive impact on crops, leading to increased crop yields (see figure below). CO2 is key to photosynthesis; the gas is what is known as a limiting nutrient for plant growth. Without a certain amount of CO2, plants will fail to grow. CO2 acts as a fertilizer for crops like rice, soybeans, and wheat and enhances growth rates. The impact of increased CO2 is only known via experiments, and they show increases in production from 5-20% at CO2 levels of 550 ppm. The key uncertainty is how realistic experiments are at predicting the real world. There is a consensus among scientists that the real changes in yield might be slightly less than those in the lab.
Pollution from industry will increase tropospheric ozone levels. Ozone levels in the lower atmosphere are determined by both emissions and temperature, thus ground levels are almost certain to increase. Higher levels of ground-level ozone limit the growth of crops.
As with temperature and precipitation, the negative impact of increasing ozone on crops will offset the beneficial impact from elevated CO2 levels. At the same time, the ozone layer is becoming thinner in other areas, leading to increases in UV-B exposure. The future impact of ozone and UV-B on crops is not completely understood, as the increasing CO2 may possibly increase or decrease the effect. Increasing ozone and UV-B exposure can lead to reduced rates of photosynthesis and a number of other measures of crop stress, including sensitivity to drought.
Food production will be affected by a number of other factors, including rising sea level (see Module 10) that will swamp low-lying coastal areas that include some of the most productive areas of the world today. The potential area of crop production is also being reduced by desertification and salinization (increase in harmful salt levels in topsoil as a result of excess evaporation) as well as soil erosion over vast areas of the world. Soil erosion can result directly from climate change, for example, from increased precipitation in major storms. However, it is also a product of over-cultivation of crops and other poor agricultural practices.
The impact of climate change (summarized in the figures below) on North American agriculture varies significantly by region. Projections suggest yield increases of 5-20 percent over the first decades of the century as a result of warming and higher CO2, with generally positive effects for the nation as a whole for much of the century. However, regions of the continent will be much more vulnerable than others. In particular, the Great Plains will likely face declining yields as a result of drought. Crops that are limited by growing season, for example, fruit in the northeastern US, will benefit from improved growing conditions, whereas those crops that are near their climate thresholds, for example, grapes in California (as a result of low rainfall) will likely face lower yields and poorer quality. Drought in California will likely impact the yields of numerous crops.
To feed the burgeoning global population, food supply is going to have to increase, but it is not going to be easy. The Food and Agriculture Organization (FAO) predicts there will be a 55% increase in crop production from 2030 and an 80% increase by 2050 (both compared to 2000 levels). To allow for this increase, a 19% increase in rain-fed land area and a 30% increase in the area of irrigated land will be required. This areal increase will take place in developing countries, including Latin America and Sub-Saharan Africa. Crop yields/acre are expected to rise in these countries. Even still, the rate of growth in global crop production is predicted to decline from 2.2%/year in 1970-2000 to 1.6%/year in 2000-2015, 1.3%/year from 2015 to 2030 to 0.8%/year from 2030 to 2050. Thus, producing sufficient food to feed our growing population will become increasingly challenging. Here, we discuss the different types of agricultural business and how they will change in the future.
Subsistence agriculture refers to rural production in developing countries where farms are run by families, and farming provides the main source of income. Seventy-five percent of the world's 1.2 billion poor people live in rural areas. These people, with poor technology and more limited access to markets, have a much more difficult time farming than large agribusinesses. Subsistence and smallholder agriculture (SSA) is more threatened by climate change than any other type of agriculture largely because of the lack of technology and limited resources to fall back on during tough times. However, SSA is also remarkably resilient. The availability of extended family labor and indigenous knowledge can overcome significant hardship.
SSA will likely decrease in importance with the gradual migration of the population of under-developed countries from rural to urban areas. Urban population recently overtook rural population, and in rural areas, there has been a movement away from SSA to other forms of subsistence. Thus, in many areas of the world, SSA is becoming increasingly rare as a way of life.
By far, the most important source of food for humans are grains, wheat, corn, and rice. All three crops will be hit hard by heatwaves in places such as the Canadian, US and Russian heartlands which are key grain producing regions. However, wheat is likely the most susceptible crop. Wheat is a cool season crop and recent research suggests that warming over the last 50 years has resulted in a 5 percent decline in production. Climate change is projected to cause a hotter summer every other year than the hottest summer recorded, and this would cause a 25% decrease in wheat production.
Drought will impact the production of all three grains, drive up their prices, and potentially lead to famine and political unrest.
Pasture includes both grassland and an ecosystem known as rangeland, which includes deserts, scrub, chaparral, and savannah. Grassland often occurs in semi-arid locations, such as the steppes of Central Asia and the prairies of North America. Grassland can also be found in wetter locations, for example, northwestern Europe. Rangeland is found on every continent, especially in locations where temperature and rainfall limit other vegetation types. Grassland is very sensitive to climate change because many grass species are fast growing and have short growing seasons. In the lab, increases in CO2 has been shown experimentally to decrease grassland diversity.
As we have seen, heat stress also decreases the productivity of livestock, especially cattle, as well as fertility, and can be life-threatening. Conception rates are also particularly an issue for cattle that breed in spring and summer months. Heat stress puts a limit on dairy milk yield regardless of food consumption.
The world’s fisheries are in a state of crisis. Environmental changes and pollution combined with over-fishing and the rise of invasive species are deteriorating the health of the global fishing industry. Nothing is more symptomatic of this decline than the history of cod in the North Atlantic. Cod has long been a staple diet for societies in the region including Iceland and Scandinavia, and a century ago, they were so abundant that whole fisheries thrived on this one fish. Now, however, cod has been so overfished that conflicts over fishing rights have erupted (between Iceland and England in the 1950s to 1970s, dubbed the "cod wars") and populations have plummeted. The same countries that depleted the stock of cod are now overfishing other species, including haddock and skate.
All of this comes at a time of growing consumption of fish. The Intergovernmental Panel on Climate Change (IPCC) predicts that global fish production will increase from 2012 to 2020, but not as rapidly as will demand. Wild fish will comprise the majority of fish caught in sub-Saharan Africa and the US, but in other parts of the world, aquaculture will increase in importance. It could be that aquaculture or fish farming will dominate fisheries by the end of the century. However, aquaculture has its own set of issues. For carnivorous fish such as salmon, fish farming utilizes a considerable supply of feeder fish. Moreover, fish farms are at a significant risk of environmental problems and are susceptible to outbreaks of disease.
The superb overview of the state of the modern ocean by Jeremy Jackson identifies several distinct habitats and ecosystems that are in a significant state of decline:
As a result of all of these changes, over 100 species of fish are currently on the extinction watch list. Estimates suggest that biomass produced by fish has declined by more than 50% in the last 40 years. Some scientists are warning of a complete collapse of marine fisheries by 2050, which would be a devastating problem for communities that rely on fish as the major source of food.
The following video describes the stark future of global fisheries as a result of overfishing:
“For every pound [of seafood] that goes to market, more than 10 pounds, even 100, may be thrown away as by-catch.” Sylvia Earle 90% of large predatory fish such as tuna, swordfish, sharks, are now gone.
90% of large whales, 60% of the small ones are also now gone from estuaries and coastal waters. 100 million sharks are killed every year. 100,000 albatross are killed every year while fishing!
A study done by the Dalhousie University of Canada projects that by 2048 all the species that we fish today will be extinct. That is in 38 years.
So, aside from those of us who enjoy the occasional salmon sashimi, spicy tuna rolls, salted grouper, or pan roasted Chilean sea bass, why should humanity care about the extinction of these species? We are destroying a food chain system kept in balance by evolution through millennia. There will be no big fish to eat the medium fish. And too many medium fish to eat all the small fish. And then there is no one to eat the really small organisms: the plankton, the algae, etc.
The result, slime: shorthand for the increasingly frequent appearance of dead zones, red tides, and jellyfish that, when they die out, sink to the bottom of the ocean to mix with dissolved oxygen while they rot. Nothing can live in these oxygen-depleted waters, except… bacteria. So it’s like we are getting rid of the complex, sophisticated organisms that took millions and millions of years to develop.
And… replacing them with the most basic ones. Not the wisest of evolutionary strategists, are we?
Green Forum Oceans
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In the US and Canada, warming trends have led to earlier spring activity of insects. Down the road, entomologists predict that many species of insects may thrive on a warmer planet, and populations may explode. This is because research shows that insects that are adapted to warmer climates have faster population growth rates. Insect species generally have short life cycles, fast and prolific reproduction and rapid mobility, thus warming can readily result in massive increases in populations.
Insects have a number of responses to warming. Some species may avoid warmer temperatures by moving to cooler regions. Others may adapt to warmer climates by changing their biochemistry or their behavior. Of course, some insects may not adapt at all and disappear, but those that can adapt will thrive in warmer environments. In general, insects are expected to benefit most in mid and high latitudes. For example, in Alaska and Siberia, longer summers are already producing demographic explosions in defoliating and wood-eating insects that have led to the devastation of thousands of forest acres and millions of dollars in damage. In the future, it is certain that other groups of insects, locusts, and many others will cause even more significant losses for crops across the globe.
The research on weeds and climate change is a little more complicated. Some weeds are not expected to thrive with higher CO2 levels. These are weeds that belong to the C4 plant groups that typically do well under lower CO2 conditions. However, some of the most invasive weeds belong to the C3 plant groups. These include Canada thistle, star thistle, quackgrass, lambsquarter, and spotted knapweed. In addition, the use of herbicides to control weeds is potentially problematic at high CO2 levels. Experiments suggest that certain weeds become tolerant to chemicals such as Roundup at high CO2 concentrations.
Biofuels are fuels that derive their energy from biological carbon fixation via photosynthesis. Biofuel sources include a whole variety of plants such as corn, sugar cane, soybeans, sunflowers, maize as well as aquatic algae. The most common compounds used to make fuels are sugars, starch and vegetable oil. A wide variety of fuel types are included under the biofuel umbrella including bioalcohol (most often known as bioethanol), biodiesel, vegetable oil, and solid biofuel. Biofuels were recently considered a vital part of the world's future energy portfolio, and the most compelling argument for their production in the US was energy independence and the low of cost production. Recently, however, traditional biofuels have fallen somewhat out of favor, partly as a result of environmental and ethical concerns, and partly due to the surge of natural gas production.
Biofuels are a very complicated and constantly evolving issue as research on them intensifies and the global energy portfolio changes. Research is being directed at fuel production, for example, the development of fuels that produce the most energy and the least land area to grow. However, the key ethical issue is that the production of biofuels uses land that could also be used to grow crops to feed people. In Brazil, which is the world's second-largest producer of bioethanol, large agribusinesses are devoted to its production. However, subsistence farmers often make more money producing biofuels than crops for food, and this has led to a loss in land area for producing crops for consumption. In addition, deforestation to develop acreage for biofuel production helps to accelerate climate change. Finally, the use of agricultural land to produce biofuels has the potential to drive up the price of food.
These ethical issues are forcing the biofuel industry as well as governments around the world to invest in research into fuels that are ethically acceptable. If biofuels are to be an accepted part of our energy future, fuel sources must be developed that require less land area and less water per unit of energy. Alternatively, fuel such as cellulosic ethanol can be produced from crops or waste products that cannot be consumed; other potential fuel sources include aquatic algae and agricultural or human waste.
The following video describes the advantages and disadvantages of biofuels.
Agriculture in developed countries is less likely to be vulnerable to climate change than in developing nations. In both places, the impact will depend on the nature of the climate changes, as well as the ability of agriculture to adapt through technological advances and changing food demand. For example, the management of water resources (see Module 8) will be critical for agriculture in arid and sub-arid environments facing increasing drought. Advanced soil management and crop rotations can also help maintain healthy soil conditions. In the following, we describe a menu of adaptation strategies that have the potential to maintain and increase food production over the coming decades.
All of these approaches have been tested and yield positive results. However, their implementation will require decisions by governments as well as substantial investment. Such investment is most challenging in under-developed nations, where policies will need to be conducive to promoting family-run farms. Nevertheless, consideration of these approaches must increase for nations to attempt to feed their citizens in the face of population increase and climate change.
Food security refers to a wide range of factors that affect the supply of food in sufficient quantities to keep populations nourished. As we have seen, a number of scenarios related to climate change have the potential to disrupt that supply. The most drastic food supply issues derive from extreme events such as natural disasters, political unrest, as well as climate change. For example, floods and heat waves can drastically reduce the supply of food. Currently, estimates suggest that more than 1 billion people are estimated to lack sufficient dietary energy availability, and at least twice that number suffer micronutrient deficiencies.
A key component of availability of food is the price. Recently, in the US, food prices have increased significantly. This situation has been part of a global increase in the price of food, driven in part by weather events such as the prolonged drought in Australia, and floods in the Midwest and parts of Southeast Asia. This increase has led to demonstrations and rioting in more than 14 countries. The situation is particularly bad in Haiti, where citizens have eaten mud cakes just to survive, and hunger and starvation constantly have the potential to cause anarchy.
Food prices are controlled by many other factors besides climate change; for example, currency fluctuations, import and export policy, energy costs, as well as population growth. In the future, climate change and population growth are likely to cause major food security problems. Solutions to the problem must include a combination of concerted efforts to protect people all over the world who are facing hunger and starvation, changes to agricultural practices discussed previously, as well as action to reduce greenhouse gases.
As we have seen, biofuels have the potential to cause major food security issues. Ethanol produced from corn requires a lot of crops compared to other biofuel sources. In fact, one gas tank’s worth of ethanol fuel requires the same amount of corn that could feed one person for an entire year. Thus, competition for corn between food suppliers and energy producers has the potential to increase corn process drastically and potentially lead to shortages. This has led many to question the ethics of using corn as a source of fuel. Subsidies for biofuel production by farmers in the US and Europe are therefore extremely controversial.
One of the most difficult problems facing agriculture is that the industry itself is a major contributor to greenhouse gases. A considerable amount of energy is used up producing fertilizers, running the factories that convert crops into packaged food, and transporting the food to market. Currently, agricultural activities around the world are responsible for 12% of greenhouse gas emissions, actually more like 30% if the impact of deforestation and the production of nitrogen fertilizers are included. Because more fertilizer and more deforestation will be required to feed the world’s growing populations, this number is set to increase.
So, where is all of this headed? It's very hard to predict. Food, like water, is so vital for human livelihood, and climate change is almost certain to cause shortages in some regions of the planet. The likelihood, therefore, is for intensifying conflict in these parts of the globe in the future.
In this module, you should have mastered the following concepts:
You should have read the contents of this module carefully, completed and submitted any labs, the Yellowdig Entry and Reply and taken the Module Quiz. If you have not done so already, please do so before moving on to the next module. Incomplete assignments will negatively impact your final grade.
Links
[1] https://www.youtube.com/channel/UCU1QB1a5XJa_nTHD2lzr7Ew
[2] https://www.nasa.gov/topics/earth/features/ndvi_locusts.html
[3] https://commons.wikimedia.org/wiki/User:Cmglee
[4] http://en.wikipedia.org/wiki/Day_of_Seven_Billion
[5] http://creativecommons.org/licenses/by-sa/3.0/
[6] https://www.youtube.com/channel/UCpVm7bg6pXKo1Pr6k5kxG9A?feature=emb_ch_name_ex
[7] http://en.wikipedia.org/wiki/File:Darfur_refugee_camp_in_Chad.jpg
[8] https://creativecommons.org/licenses/by-sa/3.0/
[9] http://www.flickr.com/photos/un_photo/4421127032/sizes/o/
[10] https://creativecommons.org/licenses/by-nc-nd/2.0/
[11] http://www.nairaland.com/582396/biafra-nigerian-civil-war-pictures/1
[12] https://www.youtube.com/channel/UCIUYbdQt-ll9ICPE3vXUCgA
[13] http://documents.worldbank.org/curated/en/606251468324545952/pdf/520610WP0Agrui1round0note101PUBLIC1.pdf
[14] https://www.flickr.com/photos/dmahendra/
[15] http://www.flickr.com/photos/dmahendra/3743846699/
[16] https://creativecommons.org/licenses/by-sa/2.0/
[17] https://ciat.cgiar.org/
[18] https://www.flickr.com/photos/pagedooley/
[19] https://www.flickr.com/photos/pagedooley/2641336835/sizes/o/
[20] https://creativecommons.org/licenses/by/2.0/
[21] https://en.wikipedia.org/wiki/User:Paulkondratuk3194
[22] https://commons.wikimedia.org/wiki/File:Irrigation1.jpg#file
[23] https://creativecommons.org/licenses/by-sa/3.0
[24] https://en.wikipedia.org/wiki/Arthur_Rothstein
[25] https://en.wikipedia.org/wiki/Farm_Security_Administration
[26] https://en.wikipedia.org/wiki/File:Farmer_walking_in_dust_storm_Cimarron_County_Oklahoma2.jpg#/media/File:Farmer_walking_in_dust_storm_Cimarron_County_Oklahoma2.jpg
[27] https://www.youtube.com/channel/UClzCn8DxRSCuMFv_WfzkcrQ?feature=emb_ch_name_ex
[28] http://Bitsofscience.org
[29] https://www3.epa.gov/
[30] https://creativecommons.org/licenses/by/4.0/
[31] https://www.un.org/en/
[32] https://nca2009.globalchange.gov/projected-temperature-change/index.html#footnote3_3crj4pl
[33] https://nca2009.globalchange.gov/projected-change-north-american-precipitation-2080-2099/index.html
[34] http://www.flickr.com/photos/hamed/
[35] http://www.flickr.com/photos/jantik/111670098/sizes/z/
[36] https://www.flickr.com/photos/nickyfern/404443201/sizes/z/
[37] http://en.wikipedia.org/wiki/File:Chilean_purse_seine.jpg
[38] http://creativecommons.org/licenses/by-sa/3.0/us/
[39] https://www.flickr.com/photos/48722974@N07/
[40] https://www.flickr.com/photos/48722974@N07/4523955644/sizes/z/
[41] http://creativecommons.org/licenses/by/2.0/
[42] https://www.youtube.com/channel/UC6JvI7uKCP7BFM5TafNctkA?feature=emb_ch_name_ex
[43] https://www.flickr.com/photos/47108884@N07/5478682616/sizes/z/
[44] http://creativecommons.org/licenses/by-sa/2.0/
[45] https://ofrf.org/staff/mark-schonbeck/
[46] https://www.flickr.com/photos/argonne/
[47] http://www.flickr.com/photos/argonne/3812650188/sizes/z/
[48] http://creativecommons.org/licenses/by-nc-sa/2.0/
[49] https://www.flickr.com/photos/siftnz/
[50] http://www.flickr.com/photos/siftnz/4169699511/sizes/z/
[51] https://www.youtube.com/watch?v=xL9F7OS5Uww
[52] https://www.youtube.com/channel/UC86dbj-lbDks_hZ5gRKL49Q
[53] http://www.flickr.com/photos/jeffcouturier/
[54] https://www.flickr.com/photos/richie_in_london/2520063950
[55] https://www.flickr.com/people/68824346@N02
[56] https://commons.wikimedia.org/wiki/File:Agricultural_Fields,_Wadi_As-Sirhan_Basin,_Saudi_Arabia_-_NASA_Earth_Observatory.jpg#/media/File:Agricultural_Fields,_Wadi_As-Sirhan_Basin,_Saudi_Arabia_-_NASA_Earth_Observatory.jpg
[57] https://creativecommons.org/licenses/by/2.0
[58] http://www.flickr.com/photos/bytemarks/
[59] http://www.flickr.com/photos/bytemarks/5210687107/in/photostream/
[60] https://www.flickr.com/photos/eu_echo/
[61] https://www.flickr.com/photos/69583224@N05/8022566649/
[62] http://www.flickr.com/photos/crossroads_foundation/
[63] https://commons.wikimedia.org/wiki/User:Jashuah
[64] http://en.wikipedia.org/wiki/File:FAO_Food_Price_Index.png
[65] https://creativecommons.org/licenses/by-sa/3.0/us/
[66] http://www.flickr.com/photos/zedworks/
[67] http://www.flickr.com/photos/zedworks/2940260897/in/photostream/