1.5: Environment and Sustainability

Introduction

The study of environmental science is interdisciplinary. It is important to understand how and why the environmental movement started, and to know the historical contributions many individuals have made.

Our society and planet will continue to face many environmental problems. Global climate change, habitat alteration, deforestation, the many forms of pollution, and food production are just a few of the myriad issues challenging the conservation of the environment. We all need to take ownership of the environmental issues and promote solutions to these problems.

The ideas of social justice, sustainable development, and sustainability are all integral to environmental science. Keep these in mind throughout the course!

Important Terms throughout the Course

Conservationist: someone who advocates or practices the sensible and careful use of natural resources
Preservationist: someone who advocates allowing some land and some creatures to exist without significant human interference
Environmentalist: someone who is concerned about the impact of people on environmental quality
Ecologist: a scientist who studies the relationships between organisms and their environments.

Taking The Long View: Sustainability in Evolutionary and Ecological Perspective

Of the different forms of life that have inhabited the Earth in its three to four-billion-year history, 99.9% are now extinct. Against this backdrop, the human enterprise with its roughly 200,000-year history barely merits attention. As the American novelist Mark Twain once remarked, if our planet’s history were to be compared to the Eiffel Tower, human history would be a mere smear on the very tip of the tower. But while modern humans (Homo sapiens) might be insignificant in geologic time, we are by no means insignificant in terms of our recent planetary impact. A 1986 study estimated that 40% of the product of terrestrial plant photosynthesis — the basis of the food chain for most animal and bird life — was being appropriated by humans for their use. More recent studies estimate that 25% of photosynthesis on continental shelves (coastal areas) is ultimately being used to satisfy human demand. Human appropriation of such natural resources is having a profound impact on the wide diversity of other species that also depend on them.

Evolution normally generates new lifeforms at a rate that outstrips the extinction of other species, resulting in strong biological diversity. However, scientists have evidence that, for the first time in known evolutionary history, another species — Homo sapiens — has upset this balance to the point that the rate of species extinction is now estimated to be 10,000 times the rate of species renewal. Human beings, just one species among millions, are crowding out the other species we share the planet with. Evidence of human interference with the natural world is visible in practically every ecosystem, from pollutants in the stratosphere to the artificially altered courses of most river systems on the planet. It is argued that ever since we abandoned nomadic, gatherer-hunter ways of life for settled societies some 12,000 years ago, humans have continually manipulated their natural world to meet their needs. While this observation is correct, the rate, scale, and nature of human-induced global change — particularly in the post-industrial period — are unprecedented in the history of life on Earth.

There are three primary reasons for this:

Firstly, the mechanization of both industry and agriculture in the last century vastly improved labor productivity, enabling the creation of goods and services. Since then, scientific advances and technological innovations — powered by ever-increasing inputs of fossil fuels and their derivatives — have revolutionized every industry and created many new ones. The subsequent development of Western consumer culture and the satisfaction of the accompanying disposable mentality have generated material flows of an unprecedented scale. The Wuppertal Institute estimates that humans are now responsible for moving more matter across the planet than all natural processes (earthquakes, storms, etc.) combined.

Secondly, the sheer size of the human population is unprecedented. Every passing year adds another 90 million people to the planet. Even though environmental impacts vary significantly between countries (and within them), the exponential growth in human numbers, coupled with rising material expectations in a world of limited resources, has catapulted the issue of distribution to the forefront. Global inequalities in resource consumption and purchasing power mark the clearest dividing line between the haves and the have-nots. It has become apparent that current patterns of production and consumption are unsustainable for a global population projected to reach 12 billion by 2050. If ecological crises and rising social conflict are to be countered, the present rates of over-consumption by a rich minority and under-consumption by a large majority will have to be brought into balance.

Thirdly, it is not only the rate and scale of change, but also the nature of that change, that are unprecedented. Human inventiveness has introduced chemicals and materials into the environment that either do not occur naturally at all or do not occur in the ratios in which we have introduced them. These persistent chemical pollutants are believed to be causing alterations in the environment, the effects of which are only slowly manifesting themselves, and the full scale of which is beyond calculation. CFCs and PCBs are but two examples of the approximately 100,000 chemicals currently in global circulation. (Between 500 and 1,000 new chemicals are being added to this list annually.) The majority of these chemicals have not been tested for their toxicity to humans and other life forms, let alone for their effects when combined with other chemicals. These issues are now the subject of special UN and other intergovernmental working groups.

The Development of Sustainability as an Idea

Our Common Future (1987), the report of the World Commission on Environment and Development, is widely credited with having popularized the concept of sustainable development. It defines sustainable development in the following ways…

• …development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
• … sustainable development is not a fixed state of harmony, but rather a process of change in which the exploitation of resources, the orientation of technological development, and institutional change are made consistent with future as well as present needs.

The concept of sustainability, however, can be traced back much farther to the oral histories of indigenous cultures. For example, the principle of intergenerational equity is captured in the Inuit saying, ‘We do not inherit the Earth from our parents, we borrow it from our children.’ The Native American ‘Law of the Seventh Generation’ is another illustration. According to this, before any major action was undertaken, its potential consequences for the seventh generation had to be considered. For a species that is currently only 6,000 generations old and whose current political decision-makers operate on time scales of months or a few years at most, the thought that other human cultures have based their decision-making systems on time scales of many decades seems wise but, unfortunately, inconceivable in the current political climate.

Environmental Equity

While much progress is being made to improve resource efficiency, far less is being made to improve resource distribution. Currently, just one-fifth of the global population is consuming three-quarters of the earth’s resources (Figure \(\PageIndex{1}\)). If the remaining four-fifths were to exercise their right to grow to the level of the rich minority, it would result in ecological devastation. So far, global income inequality and limited purchasing power have prevented poorer countries from reaching the standard of living (and also resource consumption/waste emissions) of the industrialized countries.

Countries such as the so-called BRIC countries of Brazil, Russia, India, and China (along with others like Malaysia) are, however, catching up fast. In such a situation, global consumption of resources and energy needs to be drastically reduced so that it can be sustained by future generations. But who will do the reducing? Poorer nations want to produce and consume more. Yet so do richer countries: their economies demand ever greater consumption-based expansion. Such stalemates have prevented any meaningful progress towards equitable and sustainable resource distribution at the international level. These issues of fairness and distributional justice remain unresolved.

Concepts in Environmental Science

The ecological footprint (EF), developed by Canadian ecologist and planner William Rees, is basically an accounting tool that uses land as the unit of measurement to assess per capita consumption, production, and discharge needs. It starts from the assumption that every category of energy and material consumption and waste discharge requires the productive or absorptive capacity of a finite area of land or water. If we add up all the land requirements for all categories of consumption and waste discharge by a defined population, the total area represents the Ecological Footprint of that population on Earth, whether or not this area coincides with the population’s home region.

Land is used as the unit of measurement for the simple reason that, according to Rees, “Land area not only captures planet Earth’s finiteness, it can also be seen as a proxy for numerous essential life support functions from gas exchange to nutrient recycling … land supports photosynthesis, the energy conduit for the web of life. Photosynthesis sustains all important food chains and maintains the structural integrity of ecosystems.”

What does the ecological footprint tell us? Ecological footprint analysis can tell us, in a vivid, ready-to-grasp manner, how much of the Earth’s environmental functions are required to support human activities. It also makes visible the extent to which consumer lifestyles and behaviors are ecologically sustainable, calculated that the ecological footprint of the average American is – conservatively – 5.1 hectares (or around 2.2 football fields) per capita of productive land. With roughly 7.4 billion hectares of Earth's total surface area of 51 billion hectares available for human consumption, if the current global population were to adopt the consumer lifestyle of Americans, we would need two additional planets to produce the resources, absorb the wastes, and provide general life-support functions.

The precautionary principle is an important concept in environmental sustainability. A 1998 consensus statement characterized the precautionary principle this way: “when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically”. For example, if a new pesticide is developed, the precautionary principle would dictate that we presume, for the sake of safety, that the chemical may have potential negative consequences for the environment and/or human health, even if such consequences have not yet been proven. In other words, it is best to proceed cautiously in the face of incomplete knowledge about something’s potential harm.

Some Indicators of Global Environmental Stress

Below are just some of the indicators of global environmental stress. Each of these, and others, will be covered in more detail throughout this text, as well as possible solutions.

Atmosphere 

The Intergovernmental Panel on Climate Change has established that human activities are having a discernible influence on the global climate. CO₂ emissions in most industrialized countries have risen over the past few years, and countries generally failed to stabilize their greenhouse gas emissions at 1990 levels by 2000, as required by the Climate Change Convention.

Biodiversity

Biodiversity is increasingly threatened by development, which destroys or degrades natural habitats, and by pollution from various sources. The first comprehensive global assessment of biodiversity estimated the total number of species at close to 14 million and found that between 1% and 11% of the world’s species may be threatened with extinction each decade. Coastal ecosystems, which host a very large proportion of marine species, are at great risk, with perhaps 33% of the world’s coasts at high potential risk of degradation and another 17% at moderate risk.

Forests

Deforestation remains a main issue. 1 million hectares of forest were lost every year in the decade 1980-1990. The largest losses of forest area are occurring in tropical moist deciduous forests, the zone best suited to human settlement and agriculture. Recent estimates suggest that nearly two-thirds of tropical deforestation is due to farmers clearing land for agriculture. There is increasing concern about the decline in forest quality associated with intensive use of forests and unregulated access.

Soil

As much as 10% of the earth’s vegetated surface is now at least moderately degraded. Trends in soil quality and management of irrigated land raise serious questions about longer-term sustainability. It is estimated that about 20% of the world’s 250 million hectares of irrigated land are already degraded to the point where crop production is seriously reduced.

Fresh Water

Some 20% of the world’s population lacks access to safe water, and 50% lacks access to safe sanitation. If current trends in water use persist, two-thirds of the world’s population could be living in countries experiencing moderate or high water stress by 2025.

Marine fisheries

25% of the world’s marine fisheries are being fished at their maximum level of productivity, and 35% are overfished (yields are declining). To maintain current per capita fish consumption, global fish harvests must increase; much of this increase might come from aquaculture, which is a known source of water pollution, wetland loss, and mangrove destruction.

Toxic chemicals

More than 100,000 chemicals are now in commercial use, and their potential impacts on human health and ecological function represent largely unknown risks. Persistent organic pollutants are now so widely distributed by air and ocean currents that they are found in the tissues of people and wildlife everywhere; they are of particular concern because of their high levels of toxicity and persistence in the environment.

Hazardous wastes

Pollution from heavy metals, especially from their use in industry and mining, is also creating serious health consequences in many parts of the world. Incidents and accidents involving uncontrolled radioactive sources continue to increase, and particular risks are posed by the legacy of contaminated areas left from military activities involving nuclear materials.

Waste

Domestic and industrial waste production continues to increase worldwide, both in absolute and per capita terms. In the developed world, per capita waste generation has increased threefold over the past 20 years; in developing countries, it is highly likely to double over the next decade. The level of awareness regarding the health and environmental impacts of inadequate waste disposal remains rather poor; poor sanitation and waste management infrastructure is still one of the principal causes of death and disability for the urban poor.