1.1 – The Nature of Environmental Threats
Most of our economic and social activities are supported by services provided by the natural environment. We extract from it natural resources, such as fresh water, minerals and energy and discharge waste residuals into it. The natural environment is important to our well being as we enjoy amenities like fresh air and water and view beautiful natural sceneries.
However facing problems of global warming, ozone depletion and exhaustion of natural resources and their impacts, such as the loss of biodiversity and the weakening of resilience capacity, it becomes increasingly important to argue “whether the global economic system can continue to grow without undermining the natural systems which are its ultimate foundation” (Perman et al., 2003). More then ever, our society need to put the environment high on the agenda, whether our concern of the environment originates from a belief that the environment has a certain intrinsic value or purely is intended to serve as an economic resource base or waste sink. The limits to the resource capacity of our natural environment as well as to the assimilative capacity to absorb waste are obvious. Exceeding these limits will cause global, regional and local environmental changes that are sometimes irreversible and as a consequence will have long-term effects on the global economy and the quality of life around the globe.
The sustainability problem
The question on how to sustain global economic development over generations within natural and social limits is called the sustainability problem. The sustainability problem has been recognized by the international community and since the publication of the famous Brundlandt report “Our Comming Future’, many studies have been undertaken to address its issues in more detail. Roughly speaking sustainability is the achievement of current economic and social targets without compromising future generations to do so, or to speak with the Brundlandt report: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs …. “ (WCED, 1987) As figure 1.1 shows, sustainability implies the implication of three sectors: planet (environment sustainability), people (social sustainability) and profit or prosperity (economic sustainability).
The challenge of achieving sustainable development is to make decisions while considering these three interests simultaneously. Finding this balance for a specific case is a complex assignment and is determined by a lot of (local) variables. According to the Brundlandt report, it would also involve a transformation in our economy and society including the alleviation of poverty. To further illustrate the interdependence of planet and profit, the next paragraph describes a model to quantify the environmental impacts from economic activities.
Environmental impact of economic activities
The environmental impact of economic activities can be qualified by extractions from and insertions into the environment, expressed by the IPAT identity. In terms of mass or volume, environmental impact is determined by multiplying numbers of population (P), affluence (A) and technology (T). Technology is defined as the use of materials, resource consumption and waste generation per unit production (expressed in mass of volume), while affluence is economic growth in developed and developing countries per capita (expressed in monetary terms). An increase in population or of one of the other variables will then lead to an increase in environmental impact. The IPAT identity is a materials based reference for environmental impact in terms of mass or volume and is useful to get a glance about what drives the sizes of the economy’s impacts on the environment. The following paragraph explains how materials do impact the environment. More information on the IPAT identity and calculations are available in Perman et al. (2003), pp. 28-33
The nature of environmental threats
The origin of environmental problems could be traced back to materials that in one way or the other have an adverse effect on the environment. As mentioned earlier, technology is one of its main drivers. Technology refers to both resource consumption and waste generation and is crucial to the understanding of environmental impact in physical terms. Resource consumption are material extractions from the environment and resource problems arise when the current use of natural capital threatens future availability. Waste generation and disposal can be looked at in terms of insertions into the environment. The flow of waste residuals is defined as pollution.
Pollution problems and their impacts are characterized by (Graedel and Howard-Grenville, 2005):
• Environmental impact potential of materials
• Spatial scale of impact
• Damage potential (severity of hazards)
• Degree of exposure
• Remediation and reversibility time
• Quantity of materials used (throughput)
It is obvious that pollution also has adverse effects on the future availability of natural resources. For example, when heavy metals at high concentration are leaching from landfills to groundwater resources, the surrounding watersystem may get disturbed in such a way that it becomes unsuitable for drinking water purposes any more. This illustrates the understanding that pollution occurs when waste disposal exceeds the assimilative capacity of the environment and also that when this occurs, it reduces the assimilative capacity of the system itself.
In addition to material insertions and extractions, the nature of pollution problems is determined by the spatial scale of the impact. Environmental threats occur at different scales. Some pollutants can have global impact, while other pollutants cause damages in the vicinity of their source. Current global environmental threats are caused by pollutants that are locally emitted but have global effects on ecosystems and economies. These effects include sea level rise, desertification, a loss of biodiversity. From the perspective of resources, the exhaustion of natural resources, such as tropical rain forests, minerals and fresh water sources have global scarcity effects and impact regional and local ecosystems and economies as well. A current global environmental threat that is of special importance in this course, is the problem of climate change, but also ozone depletion and exhaustion of natural resources are important. Sections 1.7 and 1.8 discuss regional and local environmental threats