Introduction
In recent times, the environment has emerged as a major area of concern worldwide. Pollution in particular is perceived as a serious threat in the industrialized countries, where the quality of life had hitherto been measured mainly in terms of growth in material output. Meanwhile, natural resource degradation is becoming a serious impediment to economic development and the alleviation of poverty in the developing world.
Mankind’s relationship with the environment has gone through several stages, starting with primitive times in which human beings lived in a stage of symbiosis with nature, followed by a period of increasing mastery over nature up to the industrial age, culminating in the rapid material-intensive growth pattern of the twentieth century which resulted in many adverse impacts on natural resources. The initial reaction to such environmental damage was a reactive approach characterized by increased clean-up activities. In recent decades, mankind’s attitude towards the environment has evolved to encompass the more proactive design of projects and policies that help anticipate and avoid environmental degradation. The world is currently exploring the concept of sustainable development an approach that will permit continuing improvements in the present quality of life with a lower enhanced stock of natural resources and other assets.
It is useful to recall here that the environmental assets that we seek to protect, provide three main types of services to human society – and the consequences of the degradation of all these functions must be incorporated in to the decision-making process. First, the environment is a source of essential raw materials and inputs that support human activities. Second, the environment serves as a sink which absorbs and recycles (normally at little or no cost to society) the waste products of economic activity. Finally, the environment provides irreplaceable life support functions (like the stratospheric ozone layer that filters out harmful ultraviolet rays), without which living organisms would cease to exist, at least in their present condition.
Role of Environmental Economics
Environmental economics facilitates the efficient use of natural resources (both mineral and biological), as well as manmade capital and human resources – an objective which is a vital prerequisite for sustainable development. Special attention is paid to the key role of environmental economics in helping value environmental and natural resources in to the conventional calculus of economic decision-making. More generally, the identification of sustainable development options requires:
· Good understanding of the physical, biological and social impacts of human activities;
· Improved estimates of the economic value of damage of the environment, to improve the design of policies and projects, and to arrive at environmentally sound investment decisions; and
· Development of policies tools and strengthening of human resources and institutions to implement viable strategies and manage natural resources on a sustainable basis.
Linking Economics and Environment
Environmental economics plays a key role in identifying efficient natural resource management options that facilitate sustainable development. It is an essential bridge between the traditional techniques of decision-making and the emerging more environmentally sensitive approach. Environmental economics helps us incorporate ecological concerns in to the conventional framework of human society.
Various economic sectors (such as energy, industry, agriculture, transport, etc.) exist within each country. Finally, each sector consists of different subsectors, projects and local schemes.
Unfortunately, the analysis of the environment cannot be carried out readily using the above socioeconomic structuring
A holistic environmental analysis would seek to study a physical or ecological system in its entirety. Complications arise because such natural systems tend to cut across the decision-making structure of human society. For example, a forest ecosystem (like the Amazon) could span several countries, and also interact with many different economic sectors within each country.
The causes of environmental degradation arise from human activity (ignoring natural disasters and other events of non-human origin). The physical (including biological and social) effects of socioeconomic decisions on the environment must then be traced through to the left side. The techniques of environmental assessment (EA) have been developed to facilitate this difficult analysis. For example, deforestation of a primary moist tropical forest may be caused by hydroelectric dams (energy sector policy), roads (transport sector policy), land clearing encouraged by land-tax incentives (fiscal policy), and so on. Disentangling and prioritizing these multiple causes (right side) and their impacts (left side) will involve a complex EA exercise.
Meanwhile, the usual decision-making process relies on techno-engineering, financial and economic analyses of projects and policies. In particular, we note that conventional economic analysis has been well developed over the past several decades, and uses techniques including project evaluation/cost-benefit analysis (CBA), sectoral/regional studies, multi sectoral macroeconomic analysis, and international economic analysis (finance, trade, etc.) at the various hierarchic levels.
Environmental economics plays its bridging role, by mapping the EA results onto the framework of conventional economic analysis. Once again, a variety of environmental economic techniques including economic valuation of environmental impacts (at the local/project level), integrated resource management (at the sector/regional level), environmental macroeconomic analysis and environmental accounting (at the economy wide, multi sector level), and global/transnational environmental economic analysis (at the international level), facilitate this process of incorporating environmental issues in to traditional decision making. We note that there is considerable overlap among the analytical techniques described above, and therefore this conceptual categorization should not be interpreted too rigidly.
Once the foregoing steps are completed, projects and policies must be redesigned to reduce their environmental impacts and shift the development process towards a more sustainable path. Clearly, the formulation and implementation of such policies is itself a difficult task. In the deforestation example described earlier, the decision makers who wish to protect this single ecosystem are likely to face problems in coordinating policies in a large number of disparate and (usually) non-cooperating ministries and line institutions (i.e., energy, transport, agriculture, industry, finance, forestry, etc.).
Climate Change
The term, climate, is generally used to connote a complex natural phenomenon comprising such variables as air temperature and humidity, wind, and precipitation. Although the climate remains fairly stable on the human time scale of decades or centuries, it fluctuates continuously over thousands or millions of years and is affected by a large number of variables (Cunningham et al., 1999: 195). There have been perceptible changes in the climate all over the world, particularly in the last two decades or so. The climate change and its adverse impacts on the environment, human health and the economy have recently risen to the top of economic and political agenda in various national and international forums and meetings on environment.
As some of the climatic changes are attributable to human activities and therefore change in human behavior can be an important instrument of minimizing the extent of those changes in the climate which have harmful effects. The most important climatic changes that have come to the fore recently and that are harmful include acid rain, global warming, and depletion of stratospheric ozone shield or layer. Besides, such climatic aberrations as floods, droughts, cyclones, and tsunamis also cause serious damage to humans and have adverse effects on local, regional and global climate.
The Earth’s atmosphere keeps the planet warm. Without the warming cover of natural greenhouse gases, mainly carbon dioxide (CO2) and water vapour, life could not exist on Earth. Through the release of greenhouse gases such as CO2, methane, CFCs and N2O caused by human activities, our climate will change. How fast and where exactly, is still controversial, but there is consensus in the scientific community that the consequences may be serious:
· the expected rise in sea levels may threaten islands and nations with low coast lines;
· changes in rainfall levels and patterns may affect natural vegetation, agriculture and forestry;
· the loss of biodiversity may be accelerated if climate zones move so fast that species (e.g. in rain forests) cannot follow them;
· weather anomalies such as hurricanes may occur more frequently, causing immense damage to humans and their property, and to nature.
· Not all possible consequences are fully understood. For example, it is very uncertain:
· to what extent greenhouse gas-induced disturbances of the ocean-atmosphere equilibrium contribute to altered global circulation patterns such as the El Niño phenomenon;
· whether the gulf stream, Europe’s central heating, could change its direction and/or intensity, thus leading to a drastic cooling of Europe’s climate;
Global Warming
According to the National Academy of Sciences, the Earth’s surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. In 1980, the mean global temperature was 15.18oC; is increased to 15.38oC in 1990, 15.39oC in 1995 and 16.04oC in 2005. In fact in the northern hemisphere, 2005 is likely to go down as the warmest year ever recorded with an increase in the mean global temperature of the order of + 0.6.5oC. Increasing concentrations of greenhouse gases are likely to accelerate the rate of climate change. Scientists expect that the average global surface temperature could rise 0.6-2.5°C in the next fifty years, and 1.4 – 5.8°C in the next century, with significant regional variations. Evaporation will increase as the climate warms, which will increase average global precipitation. Soil moisture is likely to decline in many regions, and intense rainstorms are likely to become more frequent (http://www.epa.gov/ozone/intpol/index.html).
Global warming refers to the rising average temperature of Earth’s atmosphere and oceans and its projected continuation. In the last 100 years, Earth’s average surface temperature increased by about 0.8 °C (1.4 °F) with about two thirds of the increase occurring over just the last three decades. Warming of the climate system is unequivocal, and scientists are more than 90% certain most of it is caused by increasing concentrations of greenhouse gases produced by human activities such as deforestation and burning fossil fuels. These findings are recognized by the national science academies of all the major industrialized countries.
Climate model projections are summarized in the 2007 Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC). They indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C (2 to 5.2 °F) for their lowest emissions scenario and 2.4 to 6.4 °C (4.3 to 11.5 °F) for their highest. The ranges of these estimates arise from the use of models with differing sensitivity to greenhouse gas concentrations.
An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, and a probable expansion of subtropical deserts. Warming is expected to be strongest in the Arctic and would be associated with continuing retreat of glaciers, permafrost and sea ice. Other likely effects of the warming include more frequent occurrence of extreme weather events including heat waves, droughts and heavy rainfall events, species extinctions due to shifting temperature regimes, and changes in agricultural yields. Warming and related changes will vary from region to region around the globe, with projections being more robust in some areas than others. The limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world. Hence, the ecosystem services upon which human livelihoods depend would not be preserved.
Proposed responses to global warming include mitigation to reduce emissions, adaptation to the effects of global warming, and geo engineering to remove greenhouse gases from the atmosphere or reflect incoming solar radiation back to space. The primary international effort to prevent dangerous anthropogenic climate change (“mitigation”) is coordinated by the 194-nation UNFCCC. The Kyoto Protocol is their only legally binding emissions agreement and only limits emissions through the year 2012. Afghanistan and the USA are the only nations in the UNFCCC that have not ratified the original protocol and several others have refused to extend the emissions limits beyond 2012. Nonetheless, in the 2010 Cancun Agreements, member nations agreed that urgent action is needed to limit global warming to no more than 2.0 °C (3.6 °F) above pre-industrial levels. Current scientific evidence, however, suggests that 2°C is the “threshold between ‘dangerous’ and ‘extremely dangerous’ climate change”, that this much warming is possible during the lifetimes of people living today.
Acid Rain
The acid rain adversely affects plants, fishes and birds and corrodes metals and building materials. The effects of aid rain have been recorded in parts of the United States, the erstwhile Federal Republic of Germany, Czechoslovakia, the Netherlands, Switzerland, Australia, Yugoslavia and elsewhere. It is also becoming a significant problem in Japan and China and in Southeast Asia. Rain with a pH of 4.5 and below has been reported in many Chinese cities. Sulphur dioxide emissions were reported in 1979 to have nearly tripled in India since the early 1960s, making them only slightly less than the then-current emissions from the Federal Republic of Germany (http://www.geocities.com/narilily/acidrain.html).
Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of carbon dioxide, sulfur dioxide and nitrogen oxides which react with the water molecules in the atmosphere to produce acids. Governments have made efforts since the 1970s to reduce the release of sulfur dioxide into the atmosphere with positive results. Nitrogen oxides can also be produced naturally by lightning strikes and sulfur dioxide is produced by volcanic eruptions. The chemicals in acid rain can cause paint to peel, corrosion of steel structures such as bridges, and erosion of stone statues.
Ozone Layer Depletion
Global warming has several adverse effects on human health, and agricultural production. It leads to increase in heat-related diseases and deaths. Besides, it also indirectly affects human health due to higher incidence of malaria, dengue, yellow fever and viral encephalitis caused by expansion of mosquitoes and other disease carriers to warm areas. Adverse effect on agricultural production is due to droughts and increased incidence of pests, causing shortage of food.
Within the stratosphere, a concentration of ozone molecules makes up the ozone layer. Around 90% of the ozone is within the ozone layer. The ozone layer could be thought of as Earth’s sunglasses, protecting life on the surface from the harmful glare of the sun’s strongest ultraviolet rays, which can cause skin cancer and other maladies. The stratospheric ozone layer filters ultraviolet (UV) radiation from the sun. As the ozone layer is depleted, more ultraviolet radiation reaches the earth’s surface (Raven et al.,1998: 471-75). There are reports of large ozone holes opening over Antarctica, allowing dangerous UV rays through to Earth’s surface. Indeed, the 2005 ozone hole was one of the biggest ever, spanning 25 million sq km in area, nearly the size of North America. While the ozone hole over Antarctica continues to open wide, the ozone layer around the rest of the planet seems to be on the mend (Source: http://www.sciencedaily.com/releases/2006/05/060527093645.htm). Over-exposure to UV rays may cause several health hazards for humans. Skin cancer is the most widely known. In addition, over-exposure to UV rays can also cause cataracts.
Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth’s stratosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone over Earth’s polar regions. The latter phenomenon is referred to as the ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar tropospheric ozone depletion events.
The details of polar ozone hole formation differ from that of mid-latitude thinning, but the most important process in both is catalytic destruction of ozone by atomic halogens. The main source of these halogen atoms in the stratosphere is photodissociation of man-made halocarbon refrigerants (CFCs, freons, halons). These compounds are transported into the stratosphere after being emitted at the surface. Both types of ozone depletion were observed to increase as emissions of halo-carbons increased.
CFCs and other contributory substances are referred to as ozone-depleting substances (ODS). Since the ozone layer prevents most harmful UVB wavelengths (280–315 nm) of ultraviolet light (UV light) from passing through the Earth’s atmosphere, observed and projected decreases in ozone have generated worldwide concern leading to adoption of the Montreal Protocol that bans the production of CFCs, halons, and other ozone-depleting chemicals such as carbon tetrachloride and trichloroethane. It is suspected that a variety of biological consequences such as increases in skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean’s photic zone may result from the increased UV exposure due to ozone depletion.
Nuclear Accidents & Holocaust
A nuclear and radiation accident is defined by the International Atomic Energy Agency as “an event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, large radioactivity release to the environment, or reactor core melt.” The prime example of a “major nuclear accident” is one in which a reactor core is damaged and large amounts of radiation are released, such as in the Chernobyl Disaster in 1986.
The impact of nuclear accidents has been a topic of debate practically since the first nuclear reactors were constructed. It has also been a key factor in public concern about nuclear facilities. Some technical measures to reduce the risk of accidents or to minimize the amount of radioactivity released to the environment have been adopted. Despite the use of such measures, “there have been many accidents with varying impacts as well near misses and incidents.
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere. As a result, the average surface temperature is higher than it would be if direct heating by solar radiation were the only warming mechanism.
Solar radiation at the high frequencies of visible light passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.
The existence of the greenhouse effect was argued for by Joseph Fourier in 1824. The argument and the evidence was further strengthened by Claude Pouillet in 1827 and 1838, and definitively proved experimentally by John Tyndall in 1859, and more fully quantified by Svante Arrhenius in 1896.
If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3°C. However, since the Earth reflects about 30% (or 28%) of the incoming sunlight, the planet’s effective temperature (the temperature of a blackbody that would emit the same amount of radiation) is about −18 or −19°C, about 33°C below the actual surface temperature of about 14°C or 15°C. The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect. Earth’s natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing of forests, have greatly intensified the natural greenhouse effect, causing global warming.
