Key Points

• The idea that we are entering a new geological epoch, the Anthropocene, is gaining currency. As you read this chapter about human impacts, are you inclined to agree with this claim?

• In Western culture, the dominant way of thinking about humans and nature has typically involved an anthropocentric (human-centered) worldview.

• Our discussion of the earth’s current state raises a provocative question that will resurface in various forms in later chapters: Is a global disaster looming or will a different way of thinking about humans and the environment, human ingenuity, and technology solve our problems

• Small, often insignificant, changes to the environment can have major impacts if they are repeated enough. Arable and pastoral activities can lead, over time, to major environmental problems.

• Technological developments related to energy demands continually change the environment. 3. The lifestyles promoted by technological advances also work to change the environment.

• Increasing human populations are a threat to the environment.

• Increasing connections between different regions of the globe mean that human activities that used to have merely local or regional consequences are now more likely to be global in their impact. The most obvious example is global warming

• Through a combination of our large and growing population, our advancing technologies, and our improving living standards, we are changing the global ecosystem in many and varied ways, often with negative consequences. The powerful idea of the Anthropocene epoch suggests that we need to think and act differently from the past.

• Some of these ways are fairly easy to predict, at least in general terms, while others are likely unanticipated.

• Our global environmental future is uncertain, as evidenced by the multitude of contradictory reports that include results and forecasts that sometimes flow from preconceived outcomes.

• Because the authors of some research assume never-ending progress while other authors assume inevitable downfall, the best message is to read and think about environmental issues both thoughtfully and critically

• Humans have an impact on land, air, and water to survive

• In the past, impacts have been slight since technologies were limited and populations were small

  • The few environmental changes brought about by humans were temporary and restricted to a local scale

• Now, most environmental impacts are numerous, relatively permanent, and significant on a global scale

• The environmental impact is harsh enough that scientists contend that we no longer live in the Holocene

  • The recent geological epoch that began at the end of the most recent Ice Age

  • We have transitioned into the Anthropocene epoch

• Anthropocene means we have become a force of nature transforming the planet on a geological scale

• In 2011, a leading scientist suggested that coral reefs will be the first ecosystem entirely eliminated by human activity (by 2100)

• “The future of our planet is at least partly in our hands” - Anthropocene

  • Humans are causing forests to disappear

  • Desert environments are expanding in range

  • Rivers and lakes are drying up

  • Climate is slowly but surely making a drastic change

• Remote sensing and GIS collect and analyze human impacts

A Global Perspective

• “Everything is related to something else”

  • One cannot change an aspect of nature without directly or indirectly affecting others

• Human activity in any single area has the potential to affect all other areas

• Harnessing the energy and producing food has changed our environment

  • The changing environment may threaten human survival

• Systems and ecology are valuable concepts for human survival

Systems, Ecology, & Ecosystems

• Open and Closed Systems

  • Open

    • Interact with elements outside the system

    • Necessitating the study of inputs and outputs of energy and matter

  • Closed

    • Lacks inputs and outputs

    • Less common

• Relationships between a system’s parts or between a system and external elements are described as a feedback

  • Positive feedback reinforces some change

  • Negative feedback counters some change

• Ecology is the study of organisms in their homes

• The concept of an ecosystem integrates systems and ecology

  • Developed by English botanist A.G. Tansley in 1935

• Ecosystems can be identified on a wide range of scales

• The global ecosystem is the home of all life on earth

  • AKA the ecosphere or biosphere

  • A thin shell of air, water, and soil

• Ecosystems can be identified with the larger ecosphere

• Any self-sustaining collection of living organisms and their environment is an ecosystem

  • The ecosystem concept refers to distinct groupings of things and the relationships between them

• Three basic parts of the ecosystem are the atmosphere, hydrosphere, and the lithosphere

• The global ecosystem has one key input: the Sun

  • The source of energy that warms the earth

  • Provides energy for photosynthesis

  • Powers the water cycle to provide fresh water

• Our global ecosystem relies on the cycling of matter and the flow of energy

• Energy flows through the system because of the second law of thermodynamics

  • Energy quality cannot be recycled

• The circular pathways of the chemical biogeochemical cycle

• Our global ecosystem (every ecosystem) is dynamic

• A cause of ecosystem change is the human population

  • Any human change to an ecosystem is usually a simplification

  • A simplified ecosystem usually is vulnerable

• Our use of energy and high valuation of technology affects how we live inside ecosystems

Energy and Technology

• Humans have basic physiological needs for food and drink

  • We have a host of culturally based wants that appear to have no upper limit

• Needs and wants are satisfied largely as a result of humans’ using their energy to harness other forms of energy

• The more successfully we can utilize other energy, the more easily we can fulfill our needs and affect the environment

• We continue to become aware of using other energy sources through the development of new technology

• All forms of technology represent ways of converting energy into useful forms

• An important technological advance was the human use of fire

  • Used to convert inedible into an edible form for human use

• By domesticating plants, humans gained control over a natural energy converter

  • The plants that convert solar energy into organic material via photosynthesis

• In domesticating animals, humans took control over another natural converter

  • The animals that change one form of chemical energy into another form usable by humans

• The domestication of plants and animals is referred to as the agricultural revolution

  • Example of how humans have used technology to tap new energy sources

• New plants and animals were domesticated

• New tools and techniques were invented

• Three new energy converters were developed to utilize the energy in water and wind

  • The Water Mill

  • The Windmill

  • The Sailing Craft

• The Industrial Revolution led to humans using inanimate converters on a large scale to tap into new energy sources

  • Coal, oil, nuclear power, and electricity

• Energy sources such as coal and oil are not “new”

  • They are fossil fuels formed from ancient organic matter

  • Non-renewable

• We are using these resources in ways that are often harmful to our ecosystem

Natural Resources and Human Values

• Humans continually evaluate physical environments

  • As human culture (technology) changes, so do evaluations

• Something becomes a resource only if humans perceive it as useful

  • Technologically useful

  • Socially useful

  • Politically useful

• Different groups may disagree on what is considered a resource

  • Potential farm or building land VS. valuable landscape

• Geographers have divided resources into two types

  • Stock Resources

    • Includes all minerals and land are essentially fixed

    • Take a long time to form (by human standards)

  • Renewable Resources

    • E.g. air and water

    • Constantly forming

    • Continuing availability depends on how we manage the resources

  • For both resources, there may be a need for conservation

Renewable Energy Sources

• Globally, fossil fuels comprise 87% of global energy consumption

  • Renewable sources account for the remaining 13%

• In less developed parts of the world, biomass sources are an important energy source

• The International Energy Authority (IEA) predicts an approximate 50% rise in global energy demand by 2030

• We are unaware of when non-renewable energy sources will run out

  • Despite the demand increasing all the time

  • New reserves are being discovered

  • New technologies are being developed to make other known reserves profitable to exploit

• Human progress has always been tied to increasing energy use

  • The use of fire → agricultural domestication → Industrial Revolution → use of fossil fuels

The Need for Renewable Energy

• Current major technological challenges are decreasing reliance on non-renewable fossil fuels and finding new energy sources

  • Reasons to find different ways

    • Global warming

    • Political reasons (pressure by voters increasingly aware of environmental issues)

    • Need for national economies to be self-sufficient in energy

    • Need to diversify to reduce dependence on specific energy sources

    • Oil, natural gas, and coal become more expensive as supplies become scarcer

• Even those with uncomfortable with environmental arguments acknowledge such concerns

  • Conservative pro-globalization American scholar Thomas Friedman (2008) in Hot, Flat, and Crowded calls for a transformation of energy systems

    • Move away from fossil fuels

    • Less use of electricity

    • Requirements that power companies buy energy from cleaner sources (Federal government intervention including a new tax regime)

• The UN’s Intergovernmental Panel on Climate Change (IPCC) stated there needs to be a massive shift from fossil fuels to renewable energy sources

  • Natural gas was seen as a crucial bridge to this change

• Currently, renewable energy sources are typically tapped on a relatively local scale

  • The main potential sources are water, sun, wind, and geothermal energy

  • Nuclear power can also be considered renewable

• Some crops are being used to produce biofuels as an alternative to gasoline

Hydropower

• The global output of hydroelectric power is increasing annually

  • Most countries rely significantly on hydroelectric power

• This resource is generated by extracting energy from moving water

  • The principal technology involves damming rivers

• Hydroelectric power is very inexpensive → creates no waste/pollution

• More dams have been constructed in parts of the less developed world

  • With the financial support of the World Bank

• Serious damage to the environment can be made from these constructions

  • Between 1 and 2 million people were displaced as 13 cities, 140 towns, and 1,350 villagers were submerged by the Yangtze River and dam

  • Evidence of the brutal crushing of protests and officials pocketing funds intended for resettlement projects revealed further misery

  • It is feared the reservoir may become a giant cesspool filled with sediment washed down from surrounding deforested mountains

• Series of dams are ongoing Asian projects expected to lift much of the population out of poverty

• Generating power through tidal and wave motion is not yet well developed

  • Locations of potential production limited

• A tidal and wave energy project that will supply all the electricity needs for the 3,500 inhabitants of the Scottish Isle of Islay is scheduled for completion in 2020

Nuclear Power

• There are more than 400 nuclear reactors in the world

  • Most use the basic nuclear fission process

  • Future reactors are likely to use the more efficient “fast breed” process

• Nuclear power does not pollute but the residue from nuclear power is extremely polluting and long-lasting

• This type of power has not been deemed a safe and inexpensive energy source

• The cost may be a real issue for expansion

  • A power station being built on the island of Olkiluoto in western Finland was scheduled to open in 2008 but was delayed until 2012

  • Partly due to the cost doubling

• US power companies tend not to favor nuclear precisely because of such concerns

• Increased use of nuclear power is likely despite several serious accidents

  • 2011 nuclear power plant failures in Japan were caused by an earthquake and subsequence tsunami

• Figures such as George Monbiot argued against the conventional environmentalist position that opposed nuclear power primarily because of its possibility of major accidents

• The argument in favor was twofold

  • Major accidents did not have devastating consequences

  • Nuclear power is needed as a partial replacement for fossil fuels

Solar Power

• New technologies are being developed to reduce costs

• Spanish and German companies are installing large-scale solar power plants in North Africa

  • Requires power transmission over long distances

• Solar panels in private homes and businesses are attractive to individuals

• The prospects for solar power production at reasonable costs seem positive

Wind Power

• Wind turbines can be used individually but are more typically grouped in wind farms

• Denmark is a leader in wind farm technology

• In Britain, the preferred renewable source is wind

• Wind farm technology is clean and renewable but there are some negatives

  • Sites are often seen as blighting the landscape

    • Located in areas of natural beauty

    • When sited in close proximity to human populations

  • Causes health problems related to the low-frequency sound emitted

  • Environmentalists are torn between the need for renewable energy and the need to preserve natural landscapes

  • Wind power can be unreliable because wind speed varies

    • No way to store surplus electricity produced when winds are strong

Geothermal Energy

• The heat from the earth is both clean and renewable

• The upper three meters of the earth’s surface is about 10-16 celsius

• Some locations contain hot rocks underground that heat water to produce steam

  • Frequently released as geysers

• Heat pumps can access the earth’s resources to both heat and cool buildings

• A few kilometers deep, temperatures increase to about 250 celsius

  • The technologies to tap this resource are not yet available

• There are geothermal power stations accessing heat sources close to the surface in several countries

• The one Canadian location where geothermal energy is being actively pursued is Meager Mountain, a volcanic region in British Columbia

Biofuels

• Increasing use of crops to produce biofuels

  • Alternative to gasoline

• Countries such as Brazil and Canada are converting agricultural products to alcohol that can be blended with gasoline

  • Government regulations in Brazil require that all gasoline sold to be mixed with at least 20% ethanol

  • Ethanol will provide 10% of the world’s gasoline by 2025

• Biofuels might be a problem rather than a solution to climate change

• A 2009 report commissioned by the International Council for Science concluded that farming biofuel crops release enough nitrous oxide to negate the benefits of reduced carbon dioxide emissions

• It is widely accepted that using crops to produce biofuels instead of using them for eating contributed to the 2007 world food price crisis

The Future for Renewables?

• Major oil companies are investing heavily in renewable energy sources

  • BP announced its intent to spend $8 billion over 10 years on the development of such sources

• A strong argument for national governments to promote alternatives to fossil fuels

• Sweden has established a goal of weaning itself off oil by about 2020

  • Through the use of other renewable energy sources

• Other countries are less ambitious but share the same goal

• Optimism that in the twenty-first century that renewable sources could supply 80% of global energy needs by 2050 (theoretically)

  • Governments would need to actively pursue a full range of renewable technologies

• Absence of a framework to can inform discussions of comparative costs and externalities

  • The costs that occur outside the market, such as pollution

Environmental Ethics

Western Environmental Concern before 1900

• Evidence to suggest that we are causing damage (perhaps irreparable) to our environment

• Concerns about the consequences of human activities were raised by the ancient Greeks

  • Plato noted the detrimental effects

    • Agricultural activities on soil

• Geographers were most interested in the earth as a home for humans made by God and the land as a cause of human activity (before the 18th century)

  • Teleology and environmental determinism

• The Europeans’ general failure to appreciate natural resources/Other cultures recognizes the necessity of protection

• European colonization was environmentally destructive (18th century)

• The general question of human impact on the land first received scholarly attention from Buffon in discussions of the contrasts between settled and unsettled areas and human domestication of plants and animals

  • Buffon believed that humans inhabit the earth in order to transform it

• Malthus established the terms of the present debate by focusing attention on the relationship between available resources and the number of people

• Humboldt explicitly identified lower water levels in lakes as human impacts

  • Caused by deforestation for the purpose of agricultural activities

• The earliest systematic work on human impacts was done by G.P Marsh

  • American geographer and congressman

  • “His Man and Nature, or Physical Geography as Modified by Human Action” (1864, revised editions in 1874/1885)

• The late-nineteenth-century Western world heavily involved colonial expansion

  • People only became concerned about environmental change when it had impacts on human economic interests

The Current Debate: Origins

• Human impacts on ecosystems came in the 1960s with the publication of Rachel Carson’s Silent Spring

  • Reveals the dangers associated with indiscriminate use of pesticides

  • A seminal academic work, Man’s Role in Changing the Face of the Earth (Thomas et al) had come to the same conclusion

• Increasing pressure from advocates of wilderness preservation and new scientific research about worsening air pollution

• Two popular explanations for the environmental crisis

  • The Judeo-Christian belief that humans had been placed on earth to subjugate nature

    • Too simplistic

    • Ignores the complexity of Christian attitudes

  • The failings of capitalism

    • One aspect of an ideological approach

    • Stresses the links between different parts of the world

• Our awareness of environmental impacts outside the capitalist world economy is sound

  • In Eastern Europe and the former Soviet Union prior to the major political changes that began in 1989

The Current Debate: Political Overtones

• Environmental issues entered the political arena in the early 1970s with the creation in the United States of the Environmental Protection Agency

• The first international meeting on the subject (the human environment) was held in Stockholm in 1972

• By 1980, the more developed world became increasingly aware of environmental and related food supply issues in the less developed world

  • Food shortages in India

  • Droughts in the Sahel region of Africa

  • The 1984 leak of methyl isocyanate from a pesticide plant in Bhopal, India killed as many as 10,000 and disabled up to 20,000

  • The 1986 nuclear disaster in Chernobyl

  • The 1985 discovery of a seasonal ozone hole under Antarctica

  • Recognition of both the rapidity and the consequences of tropical rainforest removal

• By the late 1980s, the environment was on the national agenda of many countries

• At the national level, green political parties first appeared in West Germany in 1979 and were present in most countries in the more developed world by 1990

• Many countries have some form of a green plan

  • An encyclopedic survey of the Canadian environment is available as part of Canada’s Green Plan (Environment Canada, 1991)

• International agreement is the best way to solve those environmental problems that transcend national boundaries

  • Some of which have global impacts

• Calls for the creation of international institutions and policies

• Most governments agree on the need for international policies, but many are unwilling to sacrifice their sovereignty

• Major international developments include the 1987 Montreal Protocol

  • Aimed at the reduction and eventual elimination of chlorofluorocarbons

    • One cause of global warming

The Current Debate: 3 Contentious Issues

• Relationships between the environment and the economy

  • Usually argued that market forces are unlikely to solve environmental problems

  • Market-based decisions rarely consider environmental factors as equal to or above the need to make a profit

  • Increasing evidence suggests that economic growth leads to a reduction of environmental problems

    • As long as growth is accompanied by good governance

  • The richer a country is and the better it is governed, the more it invests in environmental protection

    • Cleaning water supplies

    • Reducing pollution

    • Improving sanitation

• Environmental problems are increasingly affecting relationships between countries

  • Not only because of the international application of human impacts but because environmentalists are anxious to impose their standards on other countries

    • Especially those in North America

  • Payment is one solution

  • The 1987 Montreal Protocol included a fund to assist those countries most likely to suffer economically as a result of the agreement

  • International disapproval

  • Trade policies are among the few weapons available to one national government to another to persuade and amend its environmental behavior

• The behavior of individuals as group members

  • The eco-philosopher Arne Naess argued that humans need to develop a new eccentric worldview

    • Recognize connections

    • With worth and not against nature

    • A central goal of human activity is the preservation of ecosystems

  • This idea is in stark contrast to the anthropocentric notion that humans are the source of all value and that land exists for human use

    • Plus the misconception that energy and other resources are unlimited

  • Deep Ecology, introduced by Naess in 1979, is a term sometimes used to describe this viewpoint

• These concepts have informed many of the ideas of contemporary green movements

Human Impacts on Vegetation

• Modification of plant cover results in changing soils, climates, geomorphic processes, and water

• Europe, Asia, and the former USSR were the first regions to experience any considerable impact

• It is only relatively recently that the tropical and subtropical areas of Central and South America have been subjected to significant deforestation

• In Europe, large-scale deforestation occurred from about the tenth century

  • By the eighteenth century, the continent was a largely agricultural region with few remnants of the once-dominant forest

• Cleared land represented progress and the triumph of technology

• Europeans confronted different environments when moving overseas → Eastern North America was densely wooded

• The forest was a symbol of nature’s domination over humans

  • Settlers stripped trees from their land → oppressive

• Deforestation in Ontario proceeded apace as humans established their dominance over the land

• By the 1860s, settlers were becoming aware of the disadvantages of deforestation, but the damage was already done

• Remote sensing is a versatile and effective tool for monitoring forestry operations

• In Canada, Landsat and other imagery allow forest managers to collect data on forest inventory, depletion, and regenerations

  • Such data are invaluable in accurate mapping

Fire

• Modern humans and their predecessors, Homo erectus, used fire deliberately to modify the environment

• Initially, vegetation removal probably resulted in increased animal numbers and greater mobility for human hunters

• Fire offered security, a social setting at night, and movement to colder areas

• For later agriculturalists, a fire was a key method of clearing land for agriculture and improving grazing areas

  • Fire continues to serve these and similar functions

• Deforestation by fire or other means has been prompted largely by the need to clear land for agricultural activities both pastoral and arable

• Deliberate burning and the natural fires that are much more common have drastically modified vegetation cover

• Fire has played a major role in creating some vegetation systems and has been affected all such systems except tropical rainforests

  • savannas, mid-latitude grasslands, and Mediterranean scrublands

• Areas significantly affected by fire typically possess a considerable species variety

Plant Domestication

• Domestication is a process whereby a plant is modified in order to fulfill a specific human desire

• Once domesticated, a plan this permanently different from the original

• Domestication is an ongoing process and an important part of agricultural research

• The labeling and removal of plants that are not domesticated with weeds are associated with plant domestication

• Human activity contributes to human domestication

• Early domesticates included wheat, barley, oats, and potato forms

• It is thought that many fruits and nut species were first domesticated in an extensive forested area in the mountainous landscape of Central Asia

  • In recent years, this area has been subject to extensive deforestation because of overgrazing and other human activities

  • Concern that the loss of original wild specific in this biological Eden might threaten the future of these foods (climate change uncertainties)

A Great Reversal?

• Without human activity, forests would cover most of the earth’s land surface

• Large-scale deforestation accompanies the rise of the Chinese, Mediterranean, and Western European civilization

• Forests are able to grow by spreading outwards and by becoming denser

• Evidence from a major 2011 report suggests that forest density is increasing in many parts of the world after several decades of a decline

  • A change labeled the Great Reversal by the report authors

    • Rautiainen et al., 2011

• Forest density is thickening in 25 of 68 countries that together account for 72% of global forests

• The increases are uneven but evident in all areas studied

• Even in tropical rain forests, there is evidence that denser forests are at least partially compensating for a decline areal extent

• This dramatic finding has positive implications for carbon capture → climate change

• The 2010 Canadian agreement to protect 2/3 of the country’s forest from unsustainable logging

  • This protected zone extends across Canada from the Pacific to the Atlantic

Tropical Rain Forest Removal

• Human removal of tropical rainforests continues to be of major concern

• Deforestation is presently concentrated in the tropical areas of the world

• Tropical forests typically grow on much poorer soils that are unable to sustain the permanent agriculture now practiced in temperate areas

• Tropical rainforests play a major role in the health of our global ecosystem

• The present rate of depletion and the loss to date are both open to dispute

• Remote sensing using Landsat and other satellite data permits some objective assessment of clearance rates

• 12% loss of Brazilian rainforest was shown to be about twice the actual loss

• Still uncertainties about the details of rainforest removal

  • The FAO recognized in 2008 that it is difficult to demonstrate convincingly that deforestation is occurring

  • Estimates derived from satellite imagery in 2005 suggest annual rates of 6000 square miles due to selective cutting and a similar reduction due to clear-cutting

• The more developed areas are a leading cause of deforestation because of their enormous appetite for tropical timber and inexpensive beef production

• Poor people in the less developed world use cleared land for subsistence farming

  • Such farming is only possible for a few years because of cultivation techniques that rapidly deplete already poor soils of key nutrients

• Cattle ranching also becomes less profitable because rainforest soil supports grazing for only a few short years

• Countries experiencing rainforest clearance might view such activity as a means of reducing population pressure elsewhere

• Rainforest removal has two principal ecological consequences

  • A major cause of species extinction because the rainforests are home to at least 50% of all species

    • From a strictly utilitarian viewpoint, many tropical forest species are important to humans as foods, medicines, sources of fibers, and petroleum substitutes

  • Global warming

    • Carbon is stored in trees and when burning occurs it is transferred to the atmosphere as carbon dioxide

    • Soil is a source of carbon dioxide, methane, and nitrous oxide

      • All released into the atmosphere as a result of forest removal and farming

  • Each of these gases contributes to the greenhouse effect

Desertification

• Land deterioration caused by climate change and/or human activities in semi-arid and arid areas

• The significance of desertification lies not just in the clearing of vegetation but also in the consequences of clearing

  • Includes soil erosion by wind and water and possible alterations of the water cycle

• A 2007 UN report estimated that 2 billion people live in drylands susceptible to desertification in sub-Saharan Africa and Central Asia

  • As many as 50 million are in danger of being driven from their homes by about 2017

• Deserts are natural phenomena, but desertification is the expansion of desert areas

• Human causes are complex but typically involve vegetation removal as a result of overgrazing, fuel gathering, intensive cultivation, waterlogging, and salinization of irrigated lands

• Population pressure and/or poor land management are influences

• No clear single definition of desertification

• Desertification is caused by population pressure, inappropriate human activity, human conflict, and drought periods

• Many human causes are placed on local people by the introduction of capitalist imperatives into traditional farming systems

• The technology to combat desertification is available

  • The will to use it is rare

• A major international effort to combat desertification, the 1977 UN Plan of Action failed for two reasons

  • Technical solutions were applied to areas where the key causes were economic, social, and political

    • These underlying causes were not addressed

  • Local populations were not involved in the search for solutions

• Led by 2004 Nobel Peace Prize winner Wangari Maathai, he initiated the Kenyan Green Belt Movement

  • A tree-planting scheme that focused on the value of working on a community level (especially with women)

  • The central goal is to reclaim land lost to desert and to guarantee future fertility

  • Specific objectives include conserving water, increasing agricultural yields, limiting soil erosion, and increasing wood supplies

• The ideas of working on a local level and involving women are crucial

• Reclaiming land is important to local people

  • Direct involvement makes the exercise more meaningful

  • Women are increasingly aware of future needs

• Tree-planting to combat desertification is far from a panacea

  • Regardless, still positive development

• Other parts of the world are adopting strategies of this Kenyan movement

  • Planting trees while women plant crops around trees to improve yields

• Areas subject to desertification are home to poor people who often are unable to adopt appropriate remedies and lack political influence

  • A proper solution requires that the dryland ecosystems be treated as a whole

    • Land management is needed

• Population pressures must be reduced

• Land needs to be more equitably distributed

• Greater security of land tenure is required

• Global warming must be combatted

Human Impacts on Animals

• Animal domestication serves many purposes

  • Providing foods such as meat, milk, furs, fur fibers, and skins

• Animals have frequently been moved from place to place

  • Deliberately and accidentally

    • European rabbit to Australia - drastic ecological consequences

    • Rabbits spread rapidly across the non-tropical parts of the continent prompting a series of unrelenting devasting rabbit plagues

  • Rabbits consume vegetation needed by sheep and remain a problem despite the introduction of the disease myxomatosis and rabbit-proof fences

• A 2014 report suggested that human activities have caused populations of mammals, birds, reptiles, amphibians, and fish to decline by an average of 52% since 1970 (WWF, 2014)

• Human extinctions have increased as human numbers and levels of technology have

• It is possible that humans have caused species extinction since 200,000 BCE although evidence is uncertain

• Hunting populations have caused extinctions

• All moa species have become extinct after Europeans arrived in New Zealand

• Much evidence to suggest that animal extinctions in North America coincided with human arrival

• The 1859 publication of Darwin’s On the Origin of Species helped to place the extinction of plant and animal species in context and was followed by protectionist legislation in several of the British colonial areas

• When natural habitats are removed, extinction follows

  • This is one major component of a major threat to biodiversity

Biodiversity Loss

• E.O. Wilson, today’s best known Darwinian thinker, believes the earth is entering a new evolutionary era involving the greatest mass extinction since the end of the Mesozoic era 65 mil. years ago

• Humans are the cause of the current extinction phase

  • Species around the world are dying off as humans remove or destabilize their environments

• This loss of biodiversity is irreversible by any reasonable human standards of time

• Future generations are certain to live in a world that is biologically impoverished

• The rate of biodiversity loss is difficult to measure

  • Suggestions ranging from 100 to 10000 times normal rates as recorded in the fossil record

• A 2008 report by the WWF and related organizations concluded that biodiversity had plummeted by 1/3 between 1970 and 2005

• Most commentators explain biodiversity loss by reference to population growth and increasing consumption of energy and resources

• With more people around the world aspiring to the lifestyle of the affluent minority, the human ecological footprint is outgrowing the resources needed to support it

• Wilson extends this argument in a more controversial direction to suggest that the impulse towards environmental destruction is innate, hard-wired into us

  • Clearing forests and killing animals is instinctual for humans

• Evidence of biodiversity loss is compelling

Human Impacts on Land, Soil, Air, and Water

• Humans are geomorphic agents who change land and affect soil

• The earlier account of desertification is an impact on both vegetation and soil

• Industrial activities add substances to the atmosphere that can cause harm to people and to environments

• We use and pollute water, a valuable and threatened resource

Land

• Most human activities create landforms

• Excavation of resources such as common rocks, minerals, and metals has major impacts

  • Changing ecosystems

  • Lowering land surfaces

  • Flooding

  • Building waste heaps

  • Creating toxic wastes

  • Leaving scenic scars

• When we modify river channels, sand dunes are affected

  • Coastal erosion and coastal deposition also occur

• Degradation and loss of arable land are occurring throughout the world as a result of population increases, industrialization, and improper agricultural practices

• Reported that the average annual loss of farmland in China between 1857 and 1980 was 2.5 million acres

• About 40% of the world’s agricultural land is seriously degraded

  • Latin America is the most impoverished at 75%

• Canada’s exploitation of Alberta oil sands began in the 1990s

  • Prompted by technological advances that reduced costs and resulted in significant environmental damage

• The oil sands are a mixture of sand, water, and heavy crude oil

• Extracting the oil is difficult, expensive, and requires large amounts of natural gas and water

• The water is drawn from the Athabasca River and consequently affects the water levels and the health of communities downstream

  • Cannot be reused and ends up in tailing ponds with other waste

  • In April 2008, about 1600 migratory waterfowl returning north landed on what was perceived as a lake but died on contact with an oil slick on top of the tailings pond

Soil

• Soil is susceptible to abuse

  • Humans use and abuse soil extensively

• Agricultural activities have the greatest impact on soil through erosion and chemical changes

• Humans increase the salinity (salt content) of soil through irrigation

  • Negative effect on plant growth

• Humans increase the laterite content of soil by removing vegetation

  • Laterite is iron present in tropical soils and is essentially hostile to agriculture

• Soil erosion is associated with deforestation and agriculture

• Forests protect soil from runoff and roots bind soil

• The best-known example of human-induced soil erosion is the “Dust Bowl” in 1930s North American latitude grasslands

• Low-rainfall years, overgrazing, and inappropriate cultivation procedures associated with wheat farming

• The resulting “black blizzards” led many people to leave the prairies

Air

• Pollution related specifically to smoke-producing industries in more developed countries has been significantly reduced

  • But by no means eliminated

• Many large cities throughout the world suffer the problem of chemical smog largely as a result of automobile emissions

• An important atmospheric concern is the ozone layer

  • Ozone is a form of oxygen that occurs naturally in the cool upper atmosphere

  • Ozone serves as a protective sunscreen for the earth by absorbing the ultraviolet solar radiation that can cause skin cancer, cataracts, and weakening of the human immune system

• Ozone depletion was first recognized in 1985 by scientists with the British Antarctic Survey

  • An ozone hole over Antarctica appeared to be about half the size of Canada

  • The principal culprits were CFCs and some greenhouse gases

  • CFCs exemplify the devastating environmental impact of many efforts to satisfy human demands through the use of technology

• CFCs were not even synthesized until the late 1920s when they represented a remarkable advance

• CFCs are ideal as coolants because they vaporize at low temperatures and serve well as insulators

• CFCs are easy and inexpensive to produce, hence their widespread use since World War II as coolants in refrigerators, propellant gases in spray cans, and ingredients in a wide range of plastic foams

• As CFCs rise into the atmosphere, chemical reactions occur and ozone is destroyed

• Recognition of CFC’s impact on the atmosphere prompted 24 countries to gather in Montreal in 1987 and agree to reduce CFC production by 35% by 1999

  • Most environmental experts argued that this target was inadequate

  • A 1990 London agreement set the goal of eliminating CFC production by the year 2000

  • Neither goal was achieved

• UN studies have concluded that depletion of the ozone layer peaked by 2005 and that recovery was evident by 2014

Water

• Water is an essential ingredient of all life

• Rather than carefully safeguarding water quantity and quality, the public causes shortages and continually contaminate it

• The two issues of scarcity and contamination dominate our consideration of the human impact on water

The Global Water Cycle

• The three principal paths of the water cycle are precipitation, evaporation, and vapor transport

• Total annual global precipitation is estimated at 496,000 km cubed

  • About 385,000 km cubed falls over oceans and cannot be easily used

• Water returns to the atmosphere via evaporation from the oceans and from inland waters and land as well as by transpiration from plants

  • Some of the precipitation that falls on land is transported to oceans via surface runoff or groundwater flow and some water evaporated from the oceans is transported by atmospheric currents and subsequently falls as precipitation over land

• This much water is available this year globally, but this figure is reduced by 27,000 km cubed lost as flood runoff to the oceans and by another 5,000 km cubed flowing into the oceans in unpopulated areas

• Only about 9,000 km cubed are readily available for human use

  • This amount of water is possibly enough for 20 billion people

• Some states have a plentiful amount and others have an inadequate amount

• Where water is abundant, it is treated as though it were virtually free, and where it is scarce, it is a precious resource

• The average US citizen annually consumes 70 times more water than the average Ghana citizen

  • Through combined household, industrial, and agricultural uses

Using Water

• Agriculture consumes 73% of global water supplies, often highly inefficiently

• Industry consumes about 10% of global supplies

• Basic human needs are the remaining factor using water quantity

• Shortages are common in many areas, some continuous and some periodic

• Bahrain, for example, has virtually no fresh water and relies on the desalinization of seawater

• Groundwater depletion is common in the US, China, and India, and water levels have fallen in both Lake Baikal and the Aral Sea

• In the early twenty-first century, Australia experienced a 10-year drought that devastated agricultural landscapes

  • More recent periods of drought in Brazil and South Africa have meant there has been insufficient water to generate hydroelectricity

• Many of the world’s great rivers flow through major grain-growing regions and no longer reach the sea

• These regional problems do not mean that there is, or soon will be, a global water shortage

  • Humans only use about 9% of the water that flows through the global water cycle

  • However, all other life on earth also uses water

• Human use of water is growing significantly because of increasing population numbers, improved living standards, and climate change

  • Most of the addition to the world population occurs in the cities of less developed countries, and urban dwellers use more water than rural dwellers do

• Improved living standards typically involve a shift in diet from vegetarian to meat-eating

• Growing 1 kg of wheat uses about 1,000 liters of water while producing 1 kg of beef requires 15,000 liters

Polluting Water

• Organic waste (from humans, plants, and animals) is biodegradable but can still cause major problems in the form of oxygen depletion in rivers and lakes and in the form of water contamination

• Much industrial waste is not easily degraded and is a major cause of deteriorating water quality

• Pollutants enter the water via pipes from industrial plants, diffuse sources, and the atmosphere (acid rain)

• Both inland waters and oceans are suffering the consequences of pollution

• Satellite evidence suggests that Lake Chad is disappearing because of drought and irrigation

• A notorious example of pollution is the toxic chemical waste in the waters at Love Canal in the US

  • An explosion at a petrochemical plant near Harbin, China, in 2005 released toxic pollutants into a major river, resulting in water being shut off to almost 4 million residents for five days

• Acid rain is a general consequence of urban and industrial activities that release large quantities of sulfur and nitrogen oxides into the atmosphere

• Acid rain is a difficult issue because pollution may occur far away from its source

• The effects of acid rain are not entirely clear, but there is no doubt about the negative impacts on some aquatic ecosystems

• One of the most severe problems involved in reducing water pollution is the difficulty of securing the necessary international co-operation

• Efforts to combat acid rain, particularly in Europe, require cooperation among more countries

• International agreement is essential to combat ocean pollution

• Many states exploit oceans but no state is prepared to assume responsibility for the effects of human activities

• Estimates suggest that only 3% of the world’s oceans remain undamaged

  • Overfishing and climate change are the main causes of damage

• More than 50% of the world’s population lives close to the sea

  • Most of the world’s ocean fish are taken from coastal waters

• Water quality in the oceans is seriously endangered and many ocean ecosystems have been damaged

• News reports often refer to dead zones, areas close to land that are starved of oxygen because fertilizer flows down rivers into the sea and results in the loss of fish and underwater vegetation

• Remote sensing enables objective assessments of water pollution

  • Images of the Mediterranean Sea show a marked contrast between the northern shore

  • Heavily polluted by water from major European rivers and coastal towns

• Remote sensing permits effective monitoring of oil spills

  • As in the Exxon Valdez incident off the Alaskan coast in 1989

• We do not know enough about the consequences of our activities, but we do know that restoring the quality of ocean water is likely to be more difficult than is the case with surface inland water

• The public need institutions and regulations to enable the long-term interests of all users to take precedence over the short-term interests of individual users

Human Impacts on Climate

• The concept of interrelations is heavily demonstrated in a consideration of human impacts on climate

• Scientists and environmentalists feel that our most damaging impacts of all are on global climate

• In our discussions of other human impacts, we are confronted with two general areas of uncertainty

  • The role played by humans

    • As opposed to natural physical factors

  • The extent of any human-induced change

  • What is certain is that humans are causing climate change

The Natural Greenhouse Effect

• Temperatures on the earth’s surface result from a balance between incoming solar radiation and loss of energy from the earth to space

• The presence of an atmosphere results in the average surface temperature is about 15 degrees Celsius or 60 degrees Fahrenheit

• Half of the outgoing radiation from reaching space is absorbed and some bounces back to earth

  • This is called the natural “greenhouse” effect

  • Not related to human activity but to the presence of water vapor and other gases in the atmosphere

• These greenhouse gases are only a fraction of the atmosphere

  • Nitrogen and oxygen make up 99.9% of it

• We are increasing the greenhouse effect by adding CO2 and other similar gases

Human-Induced Global Warming

• Human additions to the natural greenhouse effect are the product of our increasing population numbers and advancing technology

  • Results of fossil fuel use, increased fertilizer use, increased animal husbandry, and deforestation

• Until recently, much carbon was stored in the earth in the form of coal, oil, and natural gas

• Burning these resources releases CO2, water vapor, SO2, and other gases into the atmosphere

  • Burning wood also adds CO2 into the atmosphere

• Soil contains large quantities of organic carbon in the form of humus and agricultural activity speeds up the process by which this carbon adds CO2 to the atmosphere

• Estimates suggest that the concentration of CO2 in the atmosphere has increased from 260 parts per million 200 years ago to 440 ppm in 2015 and might be up to 550 in 2030

  • This level is now higher than at any time in the past 650,000 years

• The agricultural activity also adds CH4 and N2O to the atmosphere

• CH4 is increasing both as a result of paddy rice cultivation and a large number of flatulent farm animals

  • Growing crops such as corn and canola releases N2O

• It is possible that deforestation is resulting from the spread of agriculture through much of Europe and China about 5,000 years ago initiated warming comparable to that evident since the Industrial Revolution

• Ruddiman suggests that the spread of early agriculture prevented the onset of a period of much colder temperatures

• Human-induced global warming is raising the average temperature of the earth

• The fifth report of the UN’s authoritative IPCC noted that global temperatures have increased .9 Celsius in the past 100 years

  • Predicted further rise of between 1.4 Celsius and 2.6 Celsius by 2050 and up to 4.8 Celsius by 2100

• Human-induced global warming has also caused the global sea level to rise by 20 cm in about the last hundred years

  • An additional 45–82 cm increase is predicted by 2100

  • Up to 15% of Egypt’s arable land would be at risk

  • Many coastal cities would be below sea level

• Even before sea levels rise substantially, many coastal areas would be in danger because of storm surges

• The Netherlands has successfully adapted to a situation where much of its current area is already almost 4 meters (13 feet) below sea level

  • Levees and dikes

  • Venice is pursuing a similar strategy

    • Constructing a flexible seawall to protect the city against Adriatic storms

• One estimate places the cost to protect such major areas, not including coastal margins, at approximately US$300 billion

• There is an alternative to adaption → moving away from threatened areas

  • Hardly an option for many people in the less developed world

  • Culturally and economically unthinkable for many in the more developed world

Responding to Human-Induced Global Warming

• The principal response to global warming has been an effort to implement policies that will reduce the emission of greenhouse gases

• The UN-sponsors Kyoto Protocol established goals that, if met, were expected to slow the rate of global warming

  • This legally binding agreement to cut greenhouse gas emissions was reached in 1997 by about 150 countries

  • Only came into force in early 2005 with most participating countries agreeing to reduce emissions by a specific percentage

• The US never ratified the agreement, principally because legislators saw it as unfair that neither China nor India was required to cut emissions during the first phase

  • Especially significant because the US and China are major emitters

• Germany and Britain are judged to have responded positively

  • About 10% reduction but failed to meet targets

  • Canada agreed to cut emissions by 6% from the 1990 level, but by 2006 the emissions increased by 21.3%

• The Conservative government formally withdrew from the protocol arguing instead for an alternative voluntary approach to emission reductions

  • The decision highlights the close links between environmental action and political ideology

• Discussions concerning the details of human-caused global warming tend to be compromised by many national governments’ perceived need to focus on economic growth

• Progress on Kyoto has been assessed during UN conferences on climate change - held on a regular basis

• Their meetings hold limited successes

  • Many remaining details about Kyoto have been finalized

    • Including what is to happen if countries fail to meet targets

  • The Kyoto Protocol has been extended to 2020

  • All participants agreed to talk about ta possible UN climate pact

    • Include countries that have not signed up for Kyoto

      • Most importantly, the US participation

  • Participants agreed to promote carbon capture and sequestration technologies

  • A fund has been set up to help less developed countries cope with climate change

• The perceived failure of many of these meetings has revealed major flaws in existing policy

  • Notably the inability to agree on plausible policies to reduce emissions after the Kyoto agreement expires

• A separate international agreement was reached in mid-2005

• The US, China, India, South Korea, Japan, and Australia agreed to reduce emissions

  • Pact received criticism because it is non-binding

  • A feature of this agreement is the emphasis on tackling emissions through new technologies rather than reductions in economic growth

• Some believe these agreements are not the best route to that

• Victor noted that it is not sufficient to merely lower emission levels as they need to be close to zero

• Any reductions resulting from current policies are difficult to predict, which means setting qualitative goals is not very helpful

• Countries should adopt specific policies relating to energy research and development

  • Policies should be based on bottom-up initiatives on national, regional, and global scales

• Another option is to do nothing on the grounds that there might be positive consequences of global warming

  • The melting of Arctic ice might open up the Northwest Passage

    • Significantly reducing the sailing distance between Europe and Asia

    • This would eventually bring to the fore acrimonious international conflict regarding sovereignty in the Far North

  • The melting of Arctic ice might also mean that drilling for oil in the region will be more economically feasible

    • A circumstance prompting further interest in issues of Arctic sovereignty

• Another possible advantage is that the growing season might be extended in some areas

• The general consensus, however, is that the probably negative consequences of global warming significantly outweigh any possible advantages

Acknowledging Uncertainty

• Uncertainties involved in predicting either the magnitude or the consequences of the human-induced greenhouse effect

• There is considerable uncertainty about the regional consequences of global warming

  • A reflection of the basic ecological fact that all things are related

• Scientists feel confident in the prediction as warming occurs, the earth’s polar regions will be the most seriously affected

• By the late 1990s, it was clear that warming was underway and not all the evidence to this effect came from scientific sources

• In northern Canada, Inuit elders and hunters reported that glaciers were receding and coastlines eroding, the fall freeze was arriving later, and the winters were becoming less severe

• Clear evidence of warming in lower latitudes is less clear, agreed that the next several decades will see a poleward…

  • The retreat of cold areas

  • A corresponding expansion of forests and agricultural areas

  • Changes in the distribution of arid areas

  • Rising sea levels as the ice caps melt

• Scientific evidence suggests that the higher precipitation and related melting of snow and ice in northern areas are likely to accompany global warming

  • This will lead to increased river discharge into the Arctic and North Atlantic Oceans

  • Substantially lower temperatures in Northwest Europe

• Contrary to the established scientific consensus, it is claimed that some glaciers in the Himalayas are advancing rather than retreating

  • The deciding factor is not climate change

    • The amount of surface debris

• Danis scientists show concerns about Arctic ice reaching a tipping point that will prompt a rapid melt of remaining ice misplacement

• Scientific understanding is always subject to evaluation and possible change

  • Do not be swayed to overturn conventional scientific understanding

The Point of No Return?

• James Lovelock, the originator of the Gaia concept, sees [global warming] as inevitable but argues that our intelligence will allow us to cope

• James Hansen, a leading US researcher on human-caused climate change, argues it will be impossible to avoid climate change

• The 2014 IPCC report argued that averting catastrophe is possible and affordable

  • The key is to abandon our dependence on dirty fossil fuels

  • Make much greater use of renewable energy sources

• Natural gas should play an important role in the transition of lesser fossil fuel dependence

Earth’s Vital Signs

• Our current impacts on ecosystems are greater than ever

• Impacts are increasing as a general result of the growth of population and technology

• Debates continue regarding the present condition of the environment and the probably future scenario

Apocalypse Now, Deferred, or Never?

• Many different opinions about the impact of human activities on the environment

• Catastrophists

  • View the present situation and future prospects in negative terms

  • An opinion articulated by Kaplan

• Cornucopians

  • Believe the gravity of current problems has been greatly exaggerated

  • Human ingenuity and technology will overcome the moderate problems

  • Simon and Kahn

  • A broad and complex debate

Responding to Uncertainty

• Continually being addressed by geographers and other environmental scientists

• Three general responses to these challenges

  • We can attempt to develop new technologies to counter our deleterious impacts. But there are perhaps some simple changes we might make that will have positive consequences.

    • Eating less meat will reduce methane emissions from animals and was advocated by the un climate chief in 2008. Transforming dark urban surfaces into white will increase the reflection of sunlight and reduce warming.

  • We can acknowledge that environmental impacts are inevitable and emphasize our need to adapt to such changes.

    • Adaptation might involve new population movement, water-supply systems, and coastal defenses.

  • The third response involves the conservation of resources and the prevention of harmful impacts: recognize the likelihood of significant negative consequences and to take immediate action designed to mitigate the anticipated consequences.

    • Conservation refers generally to any form of environmental protection.

    • Prevention involves limiting the increase of greenhouse gases, reducing the use of certain materials, and reusing and recycling.

    • Recycling often makes sense economically as well as environmentally.

• Prevention is central to many current moves to protect environments

• It can be argued that economic systems do not properly award the efficient use of resources

• The physical environment has been seen as irrelevant in the final economic accounting

  • Only recently have we begun to understand that price and value are not equal

• How do we assign a monetary value to a wilderness landscape?

  • Assert that certain ecosystems or landscapes are sufficiently distinct as to merit protection or preservation

• The largest protected ecosystem today is Antarctica

  • Other protected landscapes include wilderness regions

    • Canada’s national and provincial parks

• To improve the health of Earth, solutions are needed at all spatial and social scales

Sustainability and Sustainable Development

• We are transforming the earth in unintended ways

• We need to manage the earth along appropriate pathways

  • Requires us to understand what kind of earth we want

  • Reach consensus

  • Find an appropriate balance between the values of economic development and conservation

• People in different areas, different circumstances, different value systems

  • Imperative that a balance be established

• The relationship between humanity and land is such that environment and economics must both be central concerns

• The term sustainability was introduced in the late 1970s to refer to the idea that our way of life could not continue indefinitely

  • Based on the ever-increasing consumption of resources

  • We need to find a more sustainable way of life

• It is difficult to argue against the desirability of sustainability

• Considerable disagreement as to what changes were needed to achieve the desired state

• Sustainable development

  • Loosely defined as development that accounts for social, and economic concerns

  • The term was introduced by Our Common Future, the World Commission on Environment and Development’s influential 1987 report

• The report defined sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”

• The concept of sustainability can be explained by reference to the systems concept

• The earth can be regarded as a closed system

  • Although energy enters and leaves the system, matter only circulates within it

  • This type of system can reach a state of dynamic equilibrium

    • On that involves optimal energy flow and matter cycling in a way that the systems do not collapse

• Sustainable development would represent a similar state of dynamic equilibrium

• The idea of sustainable development became a key focus at the UN Conference on Environment and Development held in Rio de Janerio in 1992

• The essence of sustainable development is the attempt to blend sustainability and development into one process

  • Often seen as opposites

• To limit damage to the environment, it may be necessary to limit growth

• Suggesting that rich countries should strive for sustainability by limiting their own growth, while poor countries, which have not reached an adequate level of economic development and should have a chance to do so

• How do we move towards a sustainable world where environmental changes are in accord with sound ecological principles?

  • FOUR PRINCIPALS

    • We need to recognize that humans are a part of nature. To destroy nature is to destroy ourselves.

    • We need to account for environmental costs in all our economic activities.

    • We need to understand that all humans deserve to achieve acceptable living standards. A world with poor people cannot be a peaceful world.

    • We need to be aware that even apparently small local impacts can have global consequences. This is one of the basic themes of ecology— “think globally, act locally”—and it becomes ever more obvious as globalization processes unfold.

• Vast differences between acknowledging the need for a new attitude, seeing it adopted globally, and finally, putting it into practice

• The dilemma facing humans today was expressed forcefully some years ago

  • “To continue with the trial and error procedures of the past means to risk irreparable damage to [our] habitat. To accept responsibility for full environmental control means to anticipate change and decide in which direction to go”

• Clean air acts, environmental impact assessments, and environment ministries are now standard in many countries

• Environmental issues are increasingly recognized as relevant at all levels, from individuals to governments

  • Not equally the case for all countries

Conclusion

• Everything is related to everything else

• One cannot change one aspect of nature without directly or indirectly affecting other aspects