Deforestation and Climate Change



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Deforestation and Climate Change

Phillip Larson, Ben Mancheski, Andrew Rooyakkers, & Aaron Schaufenbuel




Many environmental processes affect the delicate world we live in today, but how many people realize the severity of damage being caused to our fragile environment? Numerous human-induced environmental problems are prevalent within our world today, and one that will be affecting us more in the near future is deforestation. According to the Dictionary of Geography (1999), deforestation is defined as “the deliberate clearance of forested land by cutting or burning. It can have a major impact on surface water flows, channel hydrographs and soil erosion as the interception layer of the canopy and the soil binding properties of the roots are removed” (p. 62). Countless numbers of acclaimed scientists all agree that deforestation is also causing the delicate climate of earth to change from its previous norms. To begin, what exactly is deforestation and how does the scientific data help to illustrate its effects on the environment?

Deforestation, as previously stated, is the clearing of forested land, and it is caused mainly through agricultural practices, cattle ranching, and commercial logging. Agricultural deforestation is caused by shifting cultivation and permanent agriculture. The first, shifting cultivation has three sub-categories which are traditional shifting cultivation, short-rotation cultivation, and encroaching cultivation (Grainger, 49).

Traditional shifting agriculture, or slash and burn, is the burning of trees in order to release nutrients into the soil for it to become more fertile. In traditional farming, regeneration periods are long, approximately 15-20 years, and it has one major drawback; it typically supports less than 20 people per square kilometer. This causes families to often move from one area to another, clearing trees as they go.

Short-rotation cultivation also is a major cause of deforestation. In comparison with traditional shifting agriculture, short-rotation agriculture employs much faster fallow periods (Grainger, 51). Fallow periods are times when a deforested parcel of land is regenerated. When fallow periods are short, regeneration areas become “fallow forests,” or areas with very bushy, adolescent trees (Richards, 27). These trees are then harvested and the family lives off that parcel for a short period of time.

The third type of cultivation that is another player in the deforestation dilemma is encroaching cultivation or “shifting cultivation by necessity.” This type of deforestation is caused when people in heavily wooded areas spread off the main roads, clear land, and instigate agricultural practices. When the land becomes infertile and has little yield the family moves on and begins the process once again. In Brazil, for example, this is a major problem because 42% of the land is owned by 1% of the people. Thus, many people have to clear forested areas near the main roads and establish their own residence (Grainger, 51).

The second main type of agriculture that causes deforestation is permanent agriculture. Permanent agriculture occurs when the same crops are grown in successive years on the same plot of land (Maser, 222). The reason deforestation is so prevalent through this type of cultivation is because many soils cannot grow good crops in successive years. Only alluvial and volcanic soils can successfully grow the same crop numerous years in a row. Alluvial soils are those soils which are washed down from mountains and form fan-like features at its base (Grainger, 54). This type of agriculture has five sub-types which include staple food crops, fish farming, government resettlement schemes, cattle ranching, and finally tree crop and other plantations.

The first subtype, staple food crops, involves permanent clearing of the land and planting crops such as rice, maize, and cassava (cassava is the source of tapioca). Staple food crops typically involve flooded conditions which reduce soil erosion as well as soil acidity.

Secondly, trees are also being cleared at an alarming rate through fish farming. Along the coasts of Ecuador, for example, estuaries and coastal areas are being converted to rice paddies and shallow ponds to breed shrimp (Grainger, 56). These estuaries and coastal areas are being enlarged by the clearing of trees and removing the soils, thus making the ponds much larger and more profitable. Shrimp is the second leading export of Ecuador, next to petroleum, so shrimp farms are quite important to its economy.

Next, in Brazil and India for example, deforestation is happening through government resettlement schemes. Government resettlement plans involve moving people from overcrowded areas to regions with minimal people and high soil fertility, like tropical rain forests. In Brazil, 72% of the population lives on 29% of the land, which leads to overcrowding. The government then moves families into new villages (Richards, 17). Each village has fifty houses, one school, one medical and social center, general store and low cost housing which is payable over a twenty year period. These resettlement plans call for the clearing of the rainforest in order to build these small villages and their supply roads. Seventeen years after the program was initiated, eleven percent of the Amazonian forest was cleared. This resulted in 1.6 million hectares of clearance.


Another major cause of deforestation through permanent agriculture is cattle ranching and the clearance of land for cattle pastures. In tropical regions, law states that ranchers must retain half their land as forested areas, thus resulting in the decline of deforestation on a local scale (Grainger, 59). This however is often avoided through selling the forested areas to another rancher who clears half the land and this continues until there is virtually no land left on the once forested plot.

Other causes of deforestation include mining, hydro electric plants, urban expansion, and cultivation of illegal drugs. Mines cause deforestation through the building of the roads leading to the extraction site. Hydro electric dams, such as the Tucurú Dam in the Amazon region had a reservoir built that was 2000 square kilometers. Also, the cultivation of illegal drugs is creating deforestation as well. In 1987, Peru had over 200,000 hectares (480,000 acres) of coca plantations, resulting in the further clearance of trees.

Deforestation is also greatly affected by commercial logging in tropical areas. Many countries use commercial logging to help alleviate their debt (Richards, 211). This is done by charging a high price for the wood, when it actually cost the government very little to extract. This is evident in the United States for example, because after the European colonization approximately 297 million acres of trees were deforested prior to 1909 (Grainger, 97). This built awareness of deforestation. Roosevelt made this statement regarding deforestation: “Our country…is only at the beginning of its growth. Unless the forests of the United States can be made ready to meet the vast demands which the growth will inevitably bring, commercial disaster, that means disaster to the whole country, is inevitable. The railroads must have ties…the miner must have timber…the farmer must have timber…the stockman must have fence posts. If the present rate of forest destruction is allowed to continue, with nothing to offset it, a timber famine in the future is inevitable.” By 1910, Pinochet was convinced that the country had already “crossed the verge of a timber famine so severe that its blighting effect will be felt in every household on the land.” The famine was the direct result of a “suicidal policy of forest destruction which the people of the United States have allowed themselves to pursue” (Richards, 212).

Deforestation is socially significant due to the rapid rate of population growth presently in the world. According to the Population Reference Bureau, around the year 2050, the population of the world will be around 9.3 billion people. Because of this new measures will have to be taken in order to ensure the survival of the human race. With 9 billion people, there will have to be increasingly more clearance of forests to build houses, raise cattle, and produce agriculture for food. By then the tropical rainforests may not even be in existence due to urban expansionism. At the present time, we are not affected significantly, but in years to come, the consequences of deforestation will become a pressing issue.

Now how exactly is deforestation affecting the climate of the world? Four possibilities have been discovered, each having their own adverse effects on the environment. Though these climate changes are small on a regional scale, they are large on a global scale due to the fragility of the environment. The first climatic change is the increase in solar radiation reflected from Earth due to the decrease in vegetation cover. This could lead to a slight cooling of the Earth due to the decrease in absorption from the decreasing amount of vegetation cover. Also, less evapo-transpiration could lead to a warming effect on the climate due to the decrease in water loss from plants. This could be quite evident in the Amazon region where approximately ½ of all rainfall comes from evapo-transpiration (Grainger,163). Another climatic change that may be experienced is the change in rainfall due to the change in wind caused by the removal of many trees in one specific area. The fourth possible climatic effect is that moist mountain climates may become dry. This is thought possible because fog often forms on the sides of mountains and condenses onto vegetation, and in turn brings water to the plants and ground. Without the vegetation for the fog to condense onto, certain mountain habitats may actually become significantly drier (Maser, 217).

Deforestation is primarily occurring in developing countries where urban expansionism is becoming an increasing problem for the environment, or in areas such as the tropical rainforest where the abundance of trees is overwhelming. Deforestation is not occurring in the United States nearly as much as in other areas because we have the money to pay other countries to exacerbate their natural resources in order for ours to be spared. Deforestation is not presently affecting people in radical ways, but in the future it will effect the environment quite drastically. In Wisconsin, clearing of trees occurred due to the Fox River and paper mills. Paper mills were first introduced here because the Fox River provided easy means for transporting the lumber.

When looking at the debate over Global Warming the question arises as to how much we as humans truly affect the change in climate. An important first step in understanding how deforestation, as that being our main topic, greenhouse gases and other such catalysts affect the climate change we must first look at the natural systems that have existed for millions, the entire history of the planet which has exsisted 4.5 billion years. This is a fundamental point to realize so that an educated comparison between the previous cycles and the current trend can be made.

The first thing one must realize in looking at the current warming trend is that there have been previous periods in the Earth’s history of both extensive warming and cooling. These trends often occur over thousands of years and have resulted in various glacial (ice-ages) and inter-glacial periods. The last such ice age was known as the Pleistocene which consisted of various periods of retreat and advance and spanned from 2 million years ago until ten thousand years ago. This glacial period is easily recognizable and easily studied due to the fact that it occurred so recently in geologic time. Much of the terrain we see today in Wisconsin is evidence of this well preserved geologic past. But, this recent Ice age is only one of at least “a half-dozen” ice ages that have occurred in the history of our planet (Montgomery, 209). Following each of the Ice-Ages has also been evidence of warming trends in which global temperatures rose greatly. The reasons believed for these climatic changes are various and far ranging, but in hopes of greater understanding of the situation, we will discuss several of the natural cycles and events that are believed to have lead to previous periods of global warming.

The cyclical variations in the Earth’s orbit and its inclination from the sun are believed to play a vital role in natural climate change. The concept that must be realized here is that the amount of energy received from solar radiation is directly influenced by the angle of the sun’s rays as they hit the earth. The angle at which the rays hit is due to the Earth’s inclination towards the sun, this means the degree at which the Earth’s axis tilts towards or away from the sun. A Milutin Milankovitch, a Serbian mathematician, was able to theorize that the Earth “wobbled” in cycles of 21,000, 41,000, and 100,000 years. When this was studied more closely it was found that “cycles of cooling and warming determined from marine sediments are 23,000, 42,000, and 100,000 years, thus closely matching the times predicted by Milankovitch.” (Plummer, 306, 2001)Orbit to a lesser extent can affect the amount of energy received due to pure distance from one object to the next and in-turn affects the climate of the Earth as a whole (Plummer, 306, 2001).

Another theory has been suggested that naturally occurring cyclical changes in the atmosphere have also greatly influenced climate changes of the past. The most recognized theory is that carbon dioxide plays the most important role in atmospherical changes. This is where the “greenhouse effect” becomes important. As more carbon dioxide appears in the atmosphere the less heat energy can be allowed to escape from the Earth. This then creates a warming affect somewhat similar to that of a greenhouse. It is believed that this continues until the carbon dioxide in the atmosphere decreases. The main theory regarding its decrease is that “when vegetation is more abundant, there is less carbon dioxide in the atmosphere. The cooling this causes results in an ice-age and much of the Earth’s vegetation dies, releasing carbon dioxide back into the atmosphere” which begins another warming trend (Plummer, 307, 2001).

Another consideration must be made to volcanic activity. Major volcanic eruptions have been known to drastically change climatic conditions. The eruption of the Indonesian volcano, Karkatoa, in 1883 is probably the most notable in recent history. After its eruption worldwide temperature dropped 2 degrees Celsius, and other such eruptions can and would have caused drastic change such as this. It is believed that the SO2 and volcanic particulates are blown across the Earth by high atmospheric winds. This in turn blocks much of the solar energy that would be allowed to reach the surface.

The last main cyclical change that will be discussed here is the changes in ocean currents and sea water circulation. The freedom of ocean currents to mix is believed to play an important role in this. For example, “according to one hypothesis, a glacial episode begins when Atlantic water circulates freely with Arctic Ocean water. At present the warmer waters of the Atlantic Ocean cannot mix freely with water in the Arctic” (Plummer, 307, 2001). This results in the Arctic Ocean staying frozen for large portions of the year. “Continental glaciation begins, according to this hypothesis, when warmer Atlantic water flows through a shallow channel between Greenland and Canada. This would keep the Arctic Ocean from completely freezing over during the winter.” The result would be large amounts of precipitation being deposited over the continental land to the far north. Large glaciers would grow and spread as long as this is the case. Sea-level would recede greatly in this situation and eventually “drop below the floor of the shallow channel…shutting off the supply of warm Atlantic waters to the Arctic Ocean.” Thus allowing for the Arctic to freeze again and shut off the huge supply of moisture for precipitation (Plummer 307).

There are several other mechanisms that could affect climate change such as a more polar position of the continents and sliding of the West Antarctic Ice Sheet but the processes mentioned earlier are accepted to a much greater extent. Another important thing to realize is that it is often not just one of these processes acting alone. It is readily accepted that several of these actions working together would most likely result in global climate changes. Although these changes naturally occur and the evidence shows that these warming and cooling trends exist, none of these account for the magnitude of change that we are seeing today. Human activities have taken a naturally occurring process and accelerated beyond what the Earth systems can control. Deforestation among many other factors play a vital role in the process we have created and this will be discussed in greater detail in what is to follow.

Human induced deforestation can have a real tangible impact. There have been many proven arguments to support this claim. This deforestation is driven by capitalism. Whether it is harvesting the trees directly or deforestation from military forces, capitalism is the culprit (Jorgenson). Yet capitalism is spreading at a dangerous rate (Wallerstein). There is talk of the gross world product to double to some $80 trillion dollars within the next 20 years (Kovel)

One study from the Journal of Climate used a coupled numerical model of the global atmosphere and biosphere (Center for Ocean-Land- Atmosphere GCM) to assess the effects of Amazonian deforestation on the regional and global climate. It found that when the Amazonian tropical forests were replaced by degraded grass (pasture) in the model, there was a significant increase in the mean surface temperature (about 2.5°C) and a decrease in the annual evapo-transpiration (30% reduction), precipitation (25% reduction), and runoff (20% reduction) in the region (Nobre,Carlos A). These figures speak for themselves about the effects that deforestation can have on a local environment. If there was to be mass deforestation, the numbers might be even higher than those of a test on a local system.

CO2 concentrations in earths atmosphere are becoming are foreseeable problem.



Examinations of land-use changes to increase or decrease CO2 concentrations in the atmosphere over the next century should be given consideration. In a study in the Journal of Global Change Biology, it makes simple but robust calculations of the maximum impact of such changes. Historical land-use changes, mostly deforestation, and fossil fuel emissions have caused an increase in atmospheric concentration of CO2 of 90 ppm between the pre-industrial era and year 2000. The projected range of CO2 concentrations in 2100, under a range of emissions scenarios developed for the IPCC, is 170 ppm above 2000 levels. This range is mostly due to different assumptions regarding fossil fuel emissions. If all of the carbon so far released by land-use changes could be restored to the terrestrial biosphere, atmospheric CO2 concentration at the end of the century would be about 40 ppm less than it would be if no such intervention had occurred. Conversely, complete global deforestation over the same time frame would increase atmospheric concentrations by about 130 ppm. These are extreme assumptions; the maximum feasible reforestation and afforestation activities over the next 50 years would result in a reduction in CO2 concentration of about 15 ppm by the end of the century (House, Joanna I).

It was thought that replanting the trees would cancel out the effects deforestation has on climate change. A study by the Journal of Global Climate Change has shown that this might not necessarily be the case. While it may help somewhat, the following study, on a series of ponderosa pine (Pinius ponderosa var. Laws.) stands ranging from 9 to> 300 years in central Oregon, USA, biological measurements were used to estimate carbon storage in vegetation and soil pools, net primary productivity (NPP) and net ecosystem productivity (NEP) to examine variation with stand age. Measurements were made on plots representing four age classes with three replications: initiation (I, 9 years), young (Y, 56 years), mature (M, 95 years), and old (O, 190 years) stands typical of the forest type in the region. Net ecosystem productivity was lowest in the I stands ( g C m yr), moderate in Y stands (118 g C m yr), highest in M stands (170 g C m yr), and low in the O stands (35 g C m yr). Net primary productivity followed similar trends, but did not decline as much in the O stands. The ratio of fine root to foliage carbon was highest in the I stands, which is likely necessary for establishment in the semiarid environment, where forests are subject to drought during the growing season (300 mm precipitation per year). Carbon storage in live mass was the highest in the O stands (mean 17.6 kg C m). Total ecosystem carbon storage and the fraction of ecosystem carbon in aboveground wood mass increased rapidly until 150 years, and did not decline in older stands. Forest inventory data on 950 ponderosa pine plots in Oregon show that the greatest proportion of plots exist in stands  100 years old, indicating that a majority of stands are approaching maximum carbon storage and net carbon uptake. The data suggests that NEP averages  70 g C m year for ponderosa pine forests in Oregon. About 85% of the total carbon storage in biomass on the survey plots exists in stands greater than 100 years, which has implications for managing forests for carbon sequestration (Law, B.E.).

In summary for human induced deforestation and climate change, it has been shown that:

(A) Mass deforestation of Amazon regions could increase in the mean surface temperature in that area about 2.5°C and decrease the annual evapo-transpiration (30% reduction), precipitation (25% reduction), and runoff (20% reduction) in the region

(B) There has been an increase in atmospheric concentration of CO2 of 90 ppm between the pre-industrial era and year 2000. The projected range of CO2 concentrations in 2100, under a range of emissions scenarios developed for the IPCC, is 170 ppm above 2000 levels.

(C) Managing forests to help control greenhouse gases can be complicated. If the forests are cut down again before they grow to their optimum carbon storage potential, they might not prove to be as helpful to counter-balance deforestation as once was thought.

When all of these points are tied together, it is easy to realize that human induced deforestation is a problem that will only become more pronounced in the future.

While there is an amount of natural causes for deforestation, we have ways we could cut down the human induced deforestation that occurs. The current problem stems not only from our need for wood, but with the fact that capitalism has become a global social system. The rules of capitalism dictate that it is more profitable to just cut down trees then to cut down trees and plant new trees to replenish the desecrated forests. This leads to mass deforestation with little forestation re-growth. A couple of ways of preventing such mass deforestation shown in this paper are: social reform, mass population protest, technology and regulation.

Social reform could be a solution of fixing the problem of deforestation. The current form of deforestation has been caused by the social system of capitalism that has spread globally. However, capitalism has proven to be one of the most mutually beneficial social systems in history. Even if the world was to regress to a hunter gather social system, the hunter gather social system used slash and burn as a common technique (wikipedia.org). This crude form of mass deforestation is thought to help create huge prairies in the U.S. This vast amount of deforestation can lead to erosion and other forms of environmental degradation. It is almost inconceivable that the capitalist system will relinquish control to another social system in the near future. The population can influence the government through popular protest which does have real results. This will be considered in more detail further on.

Technologies that are coming out might be able to help prevent deforestation on such a grand scale. We have developed a dependency on a lot of other, some artificial, resources that have taken the place of wood. Unfortunately, creating these resources can cause severe environmental degradation as well. One example of these resources is the metals that are used in constructing structures. To dig up these metals, great amount of environmental degradation takes place. The only way we can eventually stop environmental degradation is through the populace rallying to stop such great amounts of degradation through regulation.

One possibility of decrease in deforestation is through technology so advanced that it can create resources with almost no environmental degradation. This kind of technology is strictly theoretical, but possible. Advancing technology is encouraged though capitalism. In capitalism, you want to curb the market to make the greatest amount of profit you can. This is why a great deal of money spent by corporations is on research and development. This could eventually advance technology to the point where almost no human induced degradation will take place.

Regulation is one of the best ways we could help prevent deforestation. This is to say is governments regulated how many trees a company can deforest, vast improvements would be seen. Possibly a law that forces companies to replant new trees and limit corporations to only cut down the trees that they farm would be a good form of regulation. Banning deforestation in certain countries might be a good idea to save wildlife and allow the climate to renew itself where it is damaged. However, this type of action will not come easily. This is due to the corporations giving huge amount of money to government officials to help them get into office. The politicians will then take a special interest and look after what those corporations need done. This means that money is power in the current governmental setup of most capitalist nations. Unfortunately, since corporations use up the earth resources to make a profit, the trend of corporations “buying” candidates is generally very harmful to the environment. It this specific case, deforestation is the problem.

While there are almost endless possibilities that could help reduce deforestation, there already have been several steps taken to reduce deforestation. A few of the actions being taken are: Forest replacement program, non-profit organizations and wildlife / national park reserves.

Currently, there are many programs that offer monetary incentive to plant new trees. Depending on the location, these incentives are offered through corporations, states and even international organizations and governments (www.rfmu.org). This agreement works for individuals, organizations, governments and corporations. Unfortunately, it is still unprofitable to plant mass amounts of trees. With our current form of society, the idea to pay people for planting new trees sounds like a great idea. However, it is still unlikely someone would be able to make a living though planting trees. So, only those who would be interested in tree planting tend to be the environmentalists who are not doing it for the money but to help renew the environment.

Buying Rainforest trees is something that is being brought up in schools all around the world. While a child might only be able to but an acre or two of rainforest trees, the fact that there are non-profit organizations trying to preserve the world’s forests is something that has helped slowed deforestation. One company alone has purchased over 62 square miles of Amazon forests (www.ecologyfund.com).

Creating environmental reserves has become slightly more of a priority in some nations. This has been due to the fierce intensity of the environmentalists. Most governments are reluctant to give up resources such as vast amounts of land. Environmental reserves also require large sums of money to establish which governments are usually unwilling to part with due to the lack to direct and instant benefits. For instance, at the “Earth Summit” which took place at Rio de Janeiro in 1992, the G-7 countries pledged $1.2 billion to establish to establish the Pilot Program to Conserve the Brazilian Rain Forest (PPG7). (Linden) According the World Bank, PPG7’s goal was to “maximize the environmental benefits of Brazil’s rain forests consistent with Brazil’s development goals, through the implementation of a sustainable development approach that will contribute to a continuing reduction of the rate of deforestation.” (World Bank) However, in the 10 years following the Earth Summit, only $120 million had been disbursed. (Linden) Even after an environmental reserve has been created, if there is a great amount of a needed resource discovered there, it can be handed over to the corporations. A recent example of this would be the Alaska wildlife reserve that has now been given over to oil drilling companies (USA Today). So, while an environmental reserve might only delay the deforestation, it is helping the environment in many ways.

In the end, the problem may be rooted in capitalism or even in human desires or maybe just lack of education. American society today (for example) values cars, large homes, electronics and other such things (in other parts of the world, large families which lead to expanding population should be added to this list as well.). While it is no doubt that we (Americans) value our health and well-being, the lack of these due to the climatic changes because of deforestation is something that we have not experienced and therefore do not understand. While there is mounting scientific evidence that the climate is changing due to rising CO2 levels, which in tern may be partially caused by deforestation, the general population does not yet realize the effect it is beginning to have. Unless this connection is made and the general population sees a solid link, they will continue to value material things more than a bunch of trees and deforestation will continue.



The climate is slowly changing and this may partially be due to deforestation. We need to preserve what forests are left and allow them to reestablish themselves in order to protect ourselves from whatever impacts rising global temperatures may have. This will not be done unless it becomes a priority for the people of the world. It is a world-wide issue.






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