Environmental Challenges for the Next Century: from Urban Pollution to Global Change



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Environmental Challenges for the Next Century:

from Urban Pollution to Global Change


Outline of remarks by Mario J. Molina

Human beings started altering the surface of the planet a long time ago, at least since they began to establish settled communities and developed an agriculture that required plowing, irrigation and the clearing of forests. However, it is only in the past few decades that we have come to recognize the global nature of the impact of human activity on the environment. Of course, it is also in this century that there has been enormous technological progress and economic growth in many parts of the world. The quality of life has increased in many ways - for example, the average life expectancy has more than doubled in the past 50 years alone! On the other hand, we now understand the environmental impact of this progress enough to know that we must change our view of the world - and we must adopt new ways of thinking so that we can expect a sustainable future for humankind.

Sustainable development involves economic, social, and environmental issues -- economic growth coupled to protection of the environment. The challenge of sustainable development is to find ways to meet the needs of the people for better lives without destroying the resources upon which future progress depends.

The Meaning of Sustainable Development

What type of development is sustainable? A working definition is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs”   (adopted in the Brundtland report, “Our Common Future”, World Commission on Environment and Development, 1987). A problem with this definition is that the “needs” are not well defined. On the other hand, common sense allows us to recognize practices which are not sustainable, e.g. accumulation of toxic wastes, degradation of land, depletion of fisheries, etc. I agree on this matter with my MIT colleague Robert Solow (Nobel laureate in economics), who has stated that a series of imperfect steps to improve current practices is preferable to an interminable debate about the perfect formulation of sustainable development.

Our knowledge is far from perfect also from a scientific point of view, and much remains to be learned to enable intelligent decisions concerning the connections between environmental effects and sustainable development. Consider, for example, ecological systems: they are in general capable of functioning under stress, but beyond a certain threshold their operation may be seriously impaired, or else they may readjust and function in a very different mode, often with significant changes in the ecological balance between species. Thus, a key question is the resilience of ecological systems, which is a measure of their capacity to absorb disturbances before they change or flip to a different mode of operation; and yet very little research has been carried out on this topic. Furthermore, even from the perspective of physics and chemistry alone, the Earth’s environment is extremely complex. Much progress has been made, for example, in our understanding of the climate system, but reliable predictions of the impact of human activities on climate are not yet feasible, and continued research in a variety of scientific fields connected with this system is imperative. Nevertheless, we know enough to be aware that current world-wide energy consumption practices may well lead to unacceptable changes in the Earth’s climate.

Local vs. Global Concerns

The trend towards globalization and competitiveness in our world is relentless. Economic growth for industrialized countries involves trade and investments in countries with lower GDP per capita. Is it acceptable to invest and build factories in the less developed country, taking advantage of their lower environmental protection standards? It is often assumed that the poorer countries cannot afford environmental protection, that pollution is a necessary consequence of the early stages of economic development. There are, however, many examples which show that the preservation of environmental quality is not a luxury, but a necessity; in the long run it is cheaper to anticipate and prevent pollution than to fix it  prevention is better than cure.

I will address next several aspects of sustainable development, stressing the environmental component and using examples taken from my own field of expertise, which is atmospheric chemistry: the examples involve urban air pollution in Mexico City; CFCs and ozone depletion, and climate change. There are, of course, other environmental issues which are also highly relevant, such as water pollution, solid waste disposal, degradation of land, etc.

Global Environmental Issues

For global environmental issues the concept of sustainability involves the health of the entire planet. Consider the CFC - ozone depletion issue: it is now clear that continued release of industrial CFCs would lead to unacceptable risks stemming from increased ultraviolet radiation reaching the Earth’s surface. The international community was willing to accept regulations (phase out of CFCs through the “Montreal Protocol on Substances that Deplete the Ozone Layer”) that involve a current cost in order to prevent a future damage. If, however, the cost associated with the environmental damage is taken into account (i.e., if the economic externalities are internalized), a case can be made that it is more costly not to regulate. It is also a question of long term damage versus short term benefit. The dilemma is how to compute future costs: is the application of “discount rates” to future costs acceptable? If so, at what rate? On the other hand, with the CFC issue we are already seeing effects at present (depletion of ozone and formation of the ozone hole) from actions taken in the past (release of CFCs a decade ago); hence, preventive action is relatively easily justified. It is more difficult to call for changes in the way society functions if the immediate cost is large and if the damage is not yet entirely clear, as is the case with climate change caused by the greenhouse effect.



Urban and Regional Air Pollution

For urban and regional air quality issues, the geographical scale of the problem needs to be taken into account. As is the case with global issues, some of the environmental degradation might occur well beyond the location where the pollutants are emitted. In fact, many of the problems that are now surfacing on a regional scale appeared first inside cities. One example is the formation of a sulfuric acid haze from the combustion of sulfur-rich coal: it was the origin of London’s “killer fog” of the 1950’s, and is now clearly a problem affecting large regions of the Northern Hemisphere. Fortunately, the atmosphere has a cleansing mechanism   rain and clouds   to remove the haze; otherwise it would eventually accumulate in large regions reaching levels that would approach those of London’s killer fog . Unfortunately, the atmospheric cleansing process itself is not harmless: it leads to acid rain, which may damage a variety of ecosystems.

Another example of a regional environmental problem that first appeared in cities is the air quality problem: the chemistry of large portions of the lower atmosphere is now being affected by human activities such as the combustion of fossil fuels. These activities generate nitrogen oxides and volatile organic compounds, the ingredients of “photochemical smog”, which consists of ozone, particulates and other pollutants. It is not only the combustion of fossil fuels, but also the burning of agricultural waste products and forests that leads to air pollution, as was vividly demonstrated last year in Southeast Asia. Note that firewood is still used as a heating fuel in urban settings in many developing countries; and, ironically, backyard trash incinerators were once common in the US. There were about 300,000 units in the Los Angeles area in the 1950s, but they were banned in 1958 because of their contribution to smog formation, in spite of significant public opposition at that time.

The urban air pollution issue has turned in recent decades from a local to a regional problem, and is now beginning to reach global proportions because it occurs so often and in so many places. It should be added to stratospheric ozone depletion and to the greenhouse effect as a significant global environmental issue.



Equity and Environmental Protection

There is also an important connection in the policy arena between urban pollution and global environmental problems, a connection related to the inequity in the distribution of economic resources – “the rich vs. poor" dilemma. In this respect there is an important precedent: the Multilateral Fund of the Montreal Protocol, financed by the industrialized countries, was established in order to facilitate the transition to non-polluting, CFC-free technologies in developing countries. These countries rightly pointed out that a large fraction of the ozone-depleting compounds found in the environment had been emitted by the industrialized countries, with a cheaper   but more polluting   technology. But the formation of the Multilateral Fund provided a powerful incentive for developing countries to sign the Montreal Protocol.

In the case of urban smog, in many cities the contribution to air pollution comes predominantly from older cars; new automobiles fitted with “state-of-the-art” emission control devices generate about 20 times less pollutants than the older cars. Policy makers face the dilemma that allowing only newer, less polluting automobiles discriminates against the poor. The solution, however, should not be to allow increasing numbers of cheap but polluting automobiles; rather, it should be to provide clean and efficient public transportation, and to subsidize, if at all, the acquisition of cleaner automobiles by people with scarce economic resources. These types of measures end up costing less if one considers medium and long time scales, and if one takes into account the environmental costs, e.g. the effects on health and on the quality of life. Of course, other issues such as traffic congestion also need to be taken into consideration.

Integrated Solutions to Local and Global Environmental Issues

The solution to global environmental problems such as the greenhouse effect and regional to global atmospheric pollution can be facilitated by taking an approach to these problems that integrates them with urban air quality. In many countries the main contribution to emissions of greenhouse gases and photochemical ozone precursors originates in their large cities, and such countries are likely to pay more attention to these local issues. Both the greenhouse effect and photochemical air pollution are consequences of the burning of fossil fuels and other organic matter. However, the existing research agenda on global change issues is dominated by the perspective from industrialized countries, with little connection to urban pollution problems.



Precautionary Principle

We know that there are large uncertainties in the climate change issue, so one might argue that there is no need to do something about energy today, such as a carbon tax, or carbon dioxide (CO2) caps. On the one hand, we can justify this need with the precautionary principle   we need to have an “insurance policy." On the other hand, it is clear that if we consider population growth, if we consider economic growth in developing countries, and if we consider their undeniable goal of achieving a higher standard of living for their average citizens, we must conclude that the historical patterns of consumption of energy and of natural resources that have been characteristic of the industrialized countries up to the present should not be used as models for developing countries. And, of course, the industrialized countries have to change as well.

In this context the uncertainty about potential environmental damage is not large. We cannot go on much longer assuming that there is no charge to use the environment to dispose of unwanted waste. Environmental costs must be internalized somehow into the main stream economy. And even in the face of uncertainty, society should take reasonable actions to avert risks where the potential harm to human health or the environment is thought to be serious or irreparable. For example, policy-makers cannot wait to respond to the risks posed by climate change until all scientific uncertainties have been resolved. Instead, they must consider these uncertainties in the context that climate-induced environmental changes cannot be reversed quickly, if at all, because of the long time scales associated with the climate system. Addressing this problem will require the development of more energy efficient technologies, and of alternative, cleaner energy sources.

Information and Community Involvement

Creating a better future depends on the knowledge and involvement of people of all sectors of life. Citizens must have access to high-quality education that enables them to understand the interdependence of economic prosperity, environmental quality and social equity, so that they can participate in decisions that affect their lives.

While some global problems such as greenhouse gases must be addressed via international agreements, ultimately the solutions for sustainability must come at the local ecosystem and community level. The key to success is local leadership and local institutions, working together towards a common goal.

Education and Development of Human Resources

Another important component of sustainable development is education and the development of human resources. To achieve sustainable development, it is essential to develop a solid scientific knowledge of the physics, chemistry and biology which form part of the Earth’s system; this knowledge is also essential to understand the ways in which human activities affects this system. Furthermore, the technical, economic and social issues related to the preservation of environmental quality are becoming increasingly more complicated, and the formulation of satisfactory solutions to the problems associated with these issues require highly qualified personnel   scientists, engineers, economists, etc. Such personnel must be familiar with the local environment, as well as with the local economic and social issues, but should also have a global perspective of these problems.



Investment in Research & Development

Investments in science and technology are essential to improve basic knowledge and the innovations in processes and techniques needed to understand, anticipate and mitigate the emerging environmental threats. As stated earlier, it is sound policy to anticipate future problems as a means to prevent rather than simply to respond to environmental threats. These investments would have substantial returns for the health, economic prosperity, security, and well-being of all citizens. Market incentives and the power of the consumers can lead to significant improvements in environmental protection at less cost.



Environmental Challenges for Hong Kong

What do these ideas imply for a commercial city such as Hong Kong? There is increasing concern that the quality of life in Hong Kong is deteriorating as the result of environmental problems, as is the case with many other large cities. One problem involves pollution in the city itself, which can be minimized by putting in place appropriate control strategies, e.g., introduce and enforce regulations leading to clean and efficient energy use in the transportation sector and in industry; provide incentives to produce materials with very little waste by-products, etc. A second problem involves pollution which affects the city, but which is generated from across the border, on a regional scale. And, a third problem consists of environmental degradation occurring across the border, caused by activities conducted inside the city. Thus, it is no longer practical to consider in isolation environmental quality inside large cities; environmental effects related to cities and the economic consequences of such effects are becoming more and more globalized, as is the case with the economy itself. To the extent that environmental agreements, regulations, standards, incentives, etc. that apply across the border can be affected by the government and businesses of Hong Kong, it is beneficial to actively participate in the formulation of such agreements to insure sustainability, and hence, long term economic advantages. On the other hand, Hong Kong needs to lead by example by first setting high environmental protection standards for itself.

Hong Kong’s rate of spending on research and development is rather low by world standards (~0.1 % of GDP, compared to 2.88 for Japan, 2.44 for US, 1.80 for Taiwan and 1.18 for Singapore). In the book “Make by Hong Kong” (edited by S. Berger and R. Lester), the MIT based research team recommends that both government and private firms increase the rate of investment in R&D. In addition, it recommends upgrading Hong Kong’s human resources by attuning university education in the sciences and engineering more closely to the needs of the local economy and industry.

I am pleased to learn that the Planning, Environment and Lands Bureau of Hong Kong is committed to creating a clean and healthy environment for Hong Kong and has commissioned a study on sustainable development of Hong Kong for the next century. In my opinion, the preservation of the environment is bound to become an increasingly more pressing issue as a consequence of population growth, globalization, and other such forces. Hence, businesses, industries, cities and countries which are aggressively investing at present in environmental protection will be the ones having a competitive edge in the 21st century.







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