Scholars and decision-makers - once terrified by Malthusian dystopia of a "population bomb" - are more sanguine now. Advances in agricultural technology eradicated hunger even in teeming places like India and China. And then there is old idea of progress: birth rates tend to decline with higher education levels and growing incomes. Family planning has had resounding successes in places as diverse as Thailand, China, and western Africa.

In near past, fecundity used to compensate for infant mortality. As latter declined - so did former. Children are means of production in many destitute countries. Hence inordinately large families of past - a form of insurance against economic outcomes of inevitable demise of some of one's off-spring.

Yet, despite these trends, world's populace is augmented by 80 million people annually. All of them are born to younger inhabitants of more penurious corners of Earth. There were only 1 billion people alive in 1804. The number doubled a century later.

But our last billion - sixth - required only 12 fertile years. The entire population of Germany is added every half a decade to both India and China. Clearly, Mankind's growth is out of control, as affirmed in 1994 Cairo International Conference on Population and Development.

Dozens of millions of people regularly starve - many of them to death. In only one corner of Earth - southern Africa - food aid is sole subsistence of entire countries. More than 18 million people in Zambia, Malawi, and Angola survived on charitable donations in 1992. More than 10 million expect same this year, among them emaciated denizens of erstwhile food exporter, Zimbabwe.

According to Medecins Sans Frontiere, AIDS kills 3 million people a year, Tuberculosis another 2 million. Malaria decimates 2 people every minute. More than 14 million people fall prey to parasitic and infectious diseases every year - 90% of them in developing countries.

Millions emigrate every year in search of a better life. These massive shifts are facilitated by modern modes of transportation. But, despite these tectonic relocations - and despite famine, disease, and war, classic Malthusian regulatory mechanisms - depletion of natural resources - from arable land to water - is undeniable and gargantuan.

Our pressing environmental issues - global warming, water stress, salinization, desertification, deforestation, pollution, loss of biological diversity - and our ominous social ills - crime at forefront - are traceable to one, politically incorrect, truth:

There are too many of us. We are way too numerous. The population load is unsustainable. We, survivors, would be better off if others were to perish. Should population growth continue unabated - we are all doomed.

Doomed to what?

At other extreme are religious literalists who regard Man as crown of creation with complete dominion over nature and right to exploit its resources unreservedly. Similar, veiled, sentiments can be found among scientists. The Anthropic Principle, for instance, promoted by many outstanding physicists, claims that nature of Universe is preordained to accommodate sentient beings - namely, us humans.

Industrialists, politicians and economists have only recently begun paying lip service to sustainable development and to environmental costs of their policies. Thus, in a way, they bridge abyss - at least verbally - between these two diametrically opposed forms of fundamentalism. Still, essential dissimilarities between schools notwithstanding, dualism of Man vs. Nature is universally acknowledged.

Modern physics - notably Copenhagen interpretation of quantum mechanics - has abandoned classic split between (typically human) observer and (usually inanimate) observed. Environmentalists, in contrast, have embraced this discarded worldview wholeheartedly. To them, Man is active agent operating upon a distinct reactive or passive substrate - i.e., Nature. But, though intuitively compelling, it is a false dichotomy.

Man is, by definition, a part of Nature. His tools are natural. He interacts with other elements of Nature and modifies it - but so do all other species. Arguably, bacteria and insects exert on Nature far more influence with farther reaching consequences than Man has ever done.

Still, "Law of Minimum" - that there is a limit to human population growth and that this barrier is related to biotic and abiotic variables of environment - is undisputed. Whatever debate there is veers between two strands of this Malthusian Weltanschauung: utilitarian (a.k.a. anthropocentric, shallow, or technocentric) and ethical (alternatively termed biocentric, deep, or ecocentric).

First, Utilitarians.

Economists, for instance, tend to discuss costs and benefits of environmental policies. Activists, on other hand, demand that Mankind consider "rights" of other beings and of nature as a whole in determining a least harmful course of action.

Utilitarians regard nature as a set of exhaustible and scarce resources and deal with their optimal allocation from a human point of view. Yet, they usually fail to incorporate intangibles such as beauty of a sunset or liberating sensation of open spaces.

"Green" accounting - adjusting national accounts to reflect environmental data - is still in its unpromising infancy. It is complicated by fact that ecosystems do not respect man-made borders and by stubborn refusal of many ecological variables to succumb to numbers. To complicate things further, different nations weigh environmental problems disparately.

Despite recent attempts, such as Environmental Sustainability Index (ESI) produced by World Economic Forum (WEF), no one knows how to define and quantify elusive concepts such as "sustainable development". Even costs of replacing or repairing depleted resources and natural assets are difficult to determine.