The momentous subject of chlorofluorocarbons (CFCs) and their effect on The Biosphere's stratospheric ozone shield is treated rather generally but in sufficient depth where necessary in three main sections dealing with (i) scientific background and current status of ongoing investigation, (ii) the major technological uses of CFCs and available or foreseeable alternatives to them, and (iii) the policy status and regulatory activity involving present or proposed future restrictions in CFC emissions.

It being unlikely that life, at least as we know it, would have developed on Earth without an ozone layer in the stratosphere to ‘filter off’ harmful ultraviolet rays from solar radiation, the prospect of continuing manufacture in developing countries of its destroyers is highly alarming, especially as these destructive CFCs may take more than a decade from emission to reach the levels around 40 km altitude at which they do the most harm.

Research over the past century has shown that the rates and magnitudes of climatic change constitute a continuum. Changes have now been identified in the climatic record that range in duration from interannual through decades and centuries to the multi-millennial time-scale. Examples range from the drought years of the 1930 and 1970 decades to the ponderous comings and goings of the ice-ages. More recently it has become clear that some changes can be quite rapid. In recent decades great progress has been made in identifying the causes of climatic variation.

The present understanding of the causes of climatic change emphasizes continental drift (or ‘plate tectonics’) at the million-years' scale, with pulses of plate movement producing significant bursts of volcanic activity that may act on the millennial or century scale. At the multi-millennial scale there is growing agreement that the variations in irradiance of the Earth, resulting from slow changes in the Sun-Earth geometry (the so-called Milankovitch variations), exercise the operative control on the timing of ice-ages and interglacials. At the decadal and interannual scales there is less agreement; but there is at least a body of research which suggests that significant volcanic activity is a contributing factor. There is considerable agreement—but little direct evidence—that anthropogenic causes such as increased carbon dioxide and other Man-made or-enhanced trace gases in the atmosphere, will be important in the coming decades.

Cultural responses might be expected to differ across this continuum. To assess the expected response to a climatic variation, one must know at least the shape of the response surface.

There is probably a critical threshold combination of climatic change magnitude and duration. Human cultures seem to be adapted to frequently-occurring short ‘aberrations’ from the expected climate. Some evidence indicates, on the other hand, that relatively small changes of climates (of the order of a century in duration) have been associated over the past 8,000 years with cultural changes that proved large enough to lead to different names being assigned in perhaps half of the cultural termini identified. A climate model which includes the effect of volcanic aerosols, suggests that most of the climatic changes associated with these globally synchronous cultural termini are related to peaks of volcanic activity. Some apparently catastrophic events have been recognized in this connection.

There remains the problem of assessing, in realistic terms, the impact of large-magnitude climatic variations on modern human societies. Of particular concern is the effect of climatic events associated with very large-scale short-term insertions of aerosols into the atmosphere. It is likely that non-equilibrium models of the atmosphere, with specified sea-surface temperatures, would give realistic results if refined to the degree that they could replicate events of lesser magnitude which have occurred in the past century. At present there appear to be no models in which the formulation of the radiative effect of aerosols or gases gives a good match with observed radiative effects. It seems that much more research, including field experiments, will be needed if science is to supply reliable advice to society on the nature of coming climatic changes.

Human activities in Nigeria are not evenly distributed on the land surface, owing to marked differences in climatic, geological, demographic, and cultural, factors in different areas of Nigeria. The use of land is designed to optimize resources for diverse interest-groups, thus causing pressures to be exerted on the land in varied degrees. Because land-uses are neither influenced by capabilities of existing resources nor based on effective land-use policy, the economic development of land is not conducive to conservation of the environment. Indeed, the attempt to maximize the use of resources constitutes a serious impediment to future development, as most lands are either destroyed or rendered marginal for primary production.

However, the best use to which land can be put is ultimately largely a political matter, and this is influenced by socio-economic factors at work in a given environment. Unfortunately, when the use of land is not in harmony with ecological approaches to development, the soils commonly depreciate to counter-productive levels. This is why, when land uses are in opposition, they pose serious questions regarding the extent to which they can adequately sustain life. There is plenty of evidence that the rate of forest depletion in the country may increase in relation to population increase, which is why, without adequate measures being taken, constraints in land-use could lead to shortened fallow periods, reduced crop-yields, overgrazing, indiscriminate burning of vegetation, excessive hunting, poor techniques of mineral exploitation, and application of unconserving agro-technical practices for food production.

In the face of the above problems, however, adoption of alley cropping by smallholder farmers, establishment of woodlots for fuel-wood production in the vicinity of large towns, planting of timber trees in the periphery of cocoa and oil palm plantations, private-sector participation in reafforestation, and rehabilitation of mined areas with suitable vegetational forms, are some of the strategies that can reduce the rate of forest depletion in the country.

As tropical forest cover is eliminated, there appear to be—despite earlier supposition to the contrary—a number of significant repercussions for climatic regimes, whether at local, regional, or even global, levels. These are manifested through disruptions of hydrological systems and precipitation patterns, through changes in albedo and associated evapotranspiration rates, and through contributions to the ‘greenhouse effect’. Certain of these processes are well established scientifically, whereas others remain speculative pending urgently-needed research.

This exploratory paper reviews some of the ecological linkages at work in the above super-serious circumstances. Further, it assesses the profound consequences that may arise for major development sectors such as agriculture, energy, and human settlements. It concludes with a short appraisal of some policy responses available, though here again choices for adoption should be based on the results of far more scientific research and allied investigation than has yet resulted in reliable knowledge.

Throughout their existence, civilized peoples have been turning their environment into desert. The causes of desertification are well known—overgrazing, the felling of trees for fuel, and bad agricultural practices. Their effects are apparent in disasters such as the Sahel drought and recent famines in Ethiopia, the Sudan, and elsewhere. The population explosion enhances the extent of the environmental degradation. More agricultural land is currently being lost through salinization and waterlogging than is being created by new irrigation schemes, but this is only part of a problem that faces all tropical third-world countries and for which multinational organizations and the affluent nations of temperate regions are, regrettably and often unknowingly, largely responsible.

Because the poorer countries receive, for their agricultural products, cash of which the market value does not take into account the cost to the environment of overexploiting the land, they are apparently doomed to a vicious circle of increasing poverty, deprivation, and famine. Yet it is not beyond the abilities of civilization to devise a viable scheme, based upon sound ecological principles, by which the quality of life of desert peoples could be immeasurably improved. Instead of trying to change the land to make it conform to present economic and political expectations, development should be adapted to exploit the potentialities of the environment as it exists. Such a scheme, profiting from the diversity of microenvironments that occur in desert regions, would encompass multiple land-use and the development of numerous small agricultural and other projects—rather than the large-scale schemes hitherto initiated in fragile environments, and which have so often led to large-scale disaster. By adopting it, the world would simultaneously be made both more stable and more productive for the benefit of all its inhabitants.

Four grassland types at Cherrapunji, in northeastern India, namely the Osbeckia, Arundinella, Ischaemum, and Eragrostiella, types, were studied for soil nutrient losses through their hydrology and related soil-fertility changes. Losses through water and the consequent soil-fertility depletion were shown to be related to the frequency of the burn to which these grasslands are subjected. The Ischaemum type, with regular burning at 2-years' intervals, was the most adversely affected, compared with the Osbeckia type, which had not been burnt for the past 6 years.

In all the grassland types which were studied, the losses through water were high during the early part of the monsoon period, owing to the poor vegetation cover at that time. A desertified site with the Eragrostiella type of grassland had the lowest soil-fertility level, and had losses through removal in water that far exceeded the prevailing soil-nutrient level.

Fire can help in stabilizing the seral grassland vegetation if the soil is sufficiently deep and the frequency of the burn is not too great. On the other hand, too frequent perturbations by fire are apt to result in a desertified landscape that is difficult to restore.

The environment and natural resources of Estonia (area 45,000 km2, population c. 1.5 million) are described: Estonia is a flat country of which 40% is forested (managed on a sustained-yield basis), 20% is covered by peat bogs (widely cut for agricultural purposes and fuel), and 22% is under cultivation, often on drained land (largely growing grain for livestock). Rich deposits of oil-shale (used for fuel, etc.) and phosphorite (used for fertilizer, etc.) are exploited, especially in the north-east. Both of these resources are to a large extent strip-mined, causing enormous local surface disruption and more widespread water and air pollution— especially so in the case of the phosphorite extraction. Estonia has, however, recently been able to prevent a planned expansion of phosphorite exploitation.

About 3% of Estonia is set aside as Nature reserves, including some wetlands of international importance. Environmental protection is an important item on Estonia's agenda; the prognosis is quite favourable, not only because of a commendable population density, but also in large part (as there is considerable evidence to suggest) because the population has a keenly-developed Nature ethic of long standing.

The concept of The Biosphere as the integrated living and life-supporting system comprising the peripheral envelope of planet Earth together with its surrounding atmosphere so far down, and up, as any form of life exists naturally, stems from the writings of V.I. Vernadsky in the 1920s but has only emerged and become widely accepted in the latest decades. Yet it is quite one of the largest and most important entities with which humans have to deal, being, moreover, the only natural habitat and life-support of Mankind and Nature and, as such, needful of safeguarding and healthful maintenance.

No other meaning than the above should be attached to the term Biosphere, the importance of which concept and actuality being such that it should be far more widely known than is currently the case — to which end a small conference was held in 1987 and a larger one is contemplated in 1990 on the theme of Threats to The Biosphere and Imperative Countermeasures.

Other activities on behalf of The Biosphere include the ‘Johnny Biosphere’ media campaign of Dr John R. Vallentyne, those of The World Campaign for The Biosphere and its sponsoring World Council For The Biosphere, and the newly-established [International] Vernadsky Foundation which it is hoped will have, as one of its main objectives, the fostering of due reverence for life in its full Biospheral context.

As this paper demonstrates, the Philippines is undergoing much environmental degradation—mainly in the form of deforestation, soil erosion, disruption of hydrological systems, over-exploitation of fisheries, destruction of coral reefs, and extinction of species. These problems are accentuated by the pressures of a large, fast-growing and impoverished population; and they may shortly start to be aggravated yet more by climatic change in the wake of the global ‘greenhouse effect’. Moreover, and as this paper further makes plain, the environmental degradation leads to adverse economic consequences that are pervasive and profound—as may be expected in a country where several salient sectors of development are dependent upon the natural-resource base. In the long run, indeed, environmental degradation could well preclude the Philippines' prospects for sustainable development.