Two opposing approaches to environmental ethics became evident as the field emerged. The approach that sees the environment only in terms of what in the environment can benefit humans is called the anthropocentric approach. The nonanthropocentric approach, conversely, considers the intrinsic value in every part of the environment, from the oceans to bacteria. But there are many variations in both of these main approaches, as each seeks to expand or limit its scope for reasons of practicality and common sense. For instance, as J. Baird Callicott points out, a strictly anthropocentric view holds that humans alone are morally valuable because only they possess the property of rationalism, and they are the only inhabitants of the environment that do. However, if we follow the logic of such a point of view, infants, for example, would have no moral value and thus not merit our consideration or protection. Anthropocentrism must therefore "lower the bar" of moral consideration such that it includes groups like the one just cited.
On the other hand, an ecocentric approach that requires us to give moral consideration to every living thing on the planet would be too broad to be of any practical value, since inevitably certain human requirements will come into conflict with some parts of the environment. If mosquitoes carry diseases that kill humans (malaria, for instance), it is not practical nor would it be acceptable to claim that we should not try to eradicate the disease-carrying mosquitoes, because they deserve the same moral consideration as humans.
It is interesting to note that there are times when both approaches would arrive at the same conclusion regarding the moral justification (or lack thereof) for a certain action on the environment. In light of what we now know about dichlorodiphenyl trichloroethane (DDT), its use would be wrong from an ecocentric point of view because it causes massive damage to many different species. From an anthropocentric point of view, the damage that DDT contamination causes in humans, both physically and through destruction of the beneficial parts of their environment, would make its use unjustified.
Nonetheless, DDT, although it is banned in developed countries, was still being manufactured by China and Mexico, as late as 1999, and exported to developing countries. It is mainly used to control malaria, for which scientists claim there is no economically feasible alternative, and was formerly employed to protect crops imported by the United States (though this has not been the case since 1986). Is the use of DDT to control malaria justified, in the absence of feasible alternatives? What about the protection of crops? For people living in poverty, healthy crops that can be exported mean a better life—a desirable outcome. But the environmental damage to the region that is sprayed, including its human population, is as bad as it has always been. Furthermore, importing sprayed crops reintroduces DDT into our environment. Even the anthropocentric views that strictly consider human benefits vs. risks would agree that the latter use of DDT is morally unjustified, but can the same be said about its use to control malaria? Approximately one million people die each year as a result of this disease. The problem here is not scientific—alternative control methods exist. Therefore, it seems that the only morally justified action would be to make the alternative available at a reasonable price, so that neither the environment nor the people who survive the malaria suffer the consequences of exposure to DDT.
As environmental ethics matured and expanded, so did the questions it raised. Who is responsible for the cost of cleaning up hazardous waste? Or for the harm an old dump site caused when the chemicals there leaked? What if at the time the site was created, the company dumping wastes at that location only suspected this action would present a problem in the future, but had no concrete evidence of this? A holistic view (neither anthropocentric nor ecocentric) would say that the morally correct course of action would be to err on the side of caution. The precautionary principle, as it is known, places the burden of proof on the entity trying to promote the action it says would be beneficial—for example, the DDT manufacturer—since an action cannot be reversed once it is taken. At that point, one can only control the damage, if it occurs. Another area environmental ethics expanded into is distributive justice, which calls for everyone involved in a process or decision to receive their due consideration. Distributive justice is important in siting a hazardous waste disposal site, for instance. Currently, these sites often end up in low-income or politically powerless areas, where the local population has no adequate representation. Distributive justice seeks to remedy this kind of discrimination.
Environmental ethics became the basis for many political movements with sometimes contradictory ideas, but the many successful campaigns associated with such movements improved our lives by protecting the environment and reducing pollution. However, in light of the fact that the overall global picture is not improving where the environment is concerned, it would appear beneficial to all of us to adopt personal environmental ethics and live by them day to day.