Sustainable development requires that resources are used as conservationally and as optimally as possible in order to maintain an adequate resource-base for future generations. It is not an easily-defined concept, nor is there any single way of achieving it. It does, however, focus on the environment, as this provides the resource-base that supports all society. Among the recently-evolved scientific developments, biotechnology has many applications that can improve resource-use. It involves the manipulation of organisms to undertake specific processes and includes genetic manipulation or ‘engineering’.

In an environmental context, biotechnology has its greatest contribution to make in agriculture — especially by improving crop-yields. It offers opportunities to design crops for specific environments and to make crops more efficient producers of food-energy than otherwise. Biotechnology can thus manipulate primary energy-flows; it can also reduce fossil-fuel energy inputs into agricultural systems. It could also contribute to the mitigation of environmental problems such as deforestation and soil erosion. Both food- and fuel-energy resources are key components of sustainability. Sources produced biotechnologically, e.g. SCPs and biomass fuels, can supplement those produced conventionally.

Resource recovery and recycling, and hazardous-waste disposal, are other environmentally-beneficial facets of biotechnology. These are equally pertinent to sustainable development because they extend the resource-base. In this context, biotechnology constitutes a vehicle for the improved manipulation of biogeochemical cycles.

There are, however, potentially significant drawbacks in the use of biotechnology. These focus on technology transfer between the Developed and Developing World; this is economic and political, and relates to intellectual property rights, etc. Environmentally, the disadvantages concern the potential creation of ‘ecological ogres’ which could generate ecological disasters. Moreover, biotechnology relies heavily on the availability of a sustainable genepool, i.e. on biodiversity; indeed the two are interdependent. The high rates of extinction of plant and animal species that are currently occurring are thus limiting biotechnological opportunities for the future.

Large-scale forest conversion in Brazil, primarily to cattle pasture, contributes significantly to the global anthropogenic emission of CO2 into the atmosphere. An alternative land-use, namely extractive reserves for forest residents, may serve as one means of using Amazonian forests sustainably and of maintaining carbon in living matter rather than adding it to that in the atmosphere.

In the Seringal (former rubber estate) Porongaba (6,800 ha) of the Chico Mendes Extractive Reserve, Acre, Brazil, primary forest still covers more than 90% of the area. Total biomass in primary forest is estimated at 426 tons per ha, equivalent to 213 t C per ha. Rubber tappers effectively maintain about 60,000 tons of carbon per household (family unit) in forest biomass and thus out of the atmosphere. Deforestation of primary forest was less than 0.6% per yr — much less than rates of natural disturbances for other neotropical forests.

Slash-and-burn agriculture in the Seringal Porongaba releases carbon at a gross rate of some 200 t C per yr per household. Net releases are much less, as regrowth forests absorb carbon at rates of about 9 t C per ha per yr. The net areal flux of carbon to the atmosphere from land-use in Seringal is much less than one ton of carbon per ha per yr, which is equivalent to less than 0.3% per yr of the carbon stock in forest biomass. If Seringal Porongaba is typical of the three million hectares in extractive reserves in Brazilian Amazonia, then these reserves are calculated to retain 0.6 Gigatons of carbon in the terrestrial biota.

Adverse changes in income patterns for rubber tappers could lead to abandonment of extractive reserves or increased deforestation within them. Diversification and improvement of income from non-timber forest products are needed to maintain rubber tappers in extractive reserves. Most beneficiaries of carbon storage in these and other reserves live outside Brazil; devising means of recompensation for these benefits is a challenge for the global society.

An experiment to study the effects of habitat fragmentation on biological diversity was commenced in an Eucalyptus forest, in February 1985, at Wog Wog in southeastern New South Wales, Australia. The two hypotheses which are being tested are (1) that habitat fragmentation reduces biological diversity, and (2) that the reduction in diversity is fragment-size dependent.

The experimental design consists of three fragment-sizes replicated six times. The sizes are 0.25 ha, 0.875 ha, and 3.062 ha, the two larger ones being progressively c. 3.5 times the size of the smaller ones. Four replicates (12 fragments) were retained as Eucalyptus forest when the surrounding land was cleared for a softwood (Pinus radiata) plantation. Two replicates (six fragments) are controls in an adjacent State Forest.

The sampling is stratified into slopes, drainage lines, and inner and outer zones, with samples replicated twice in each stratum. Thus, there are two outer slope and two outer drainage-line sample sites, and two inner slope and two inner drainage-line sample sites. This gives 144 permanent sample sites within the Eucalyptus forest.

Following the experimental treatment, a further 44 permanent sample sites were established between the fragments. Aranae, Phalangida, Formicidae, Scorpionidae, Diplopoda, Coleoptera, and vascular plants, are the main groups of organisms involved in the experiment. Mosses and liverworts, breeding birds, small ground-mammals, skinks, and bats, are also being monitored.

Monitoring commenced in February 1985. The experimental treatment, i.e. forest fragmentation, took place during 1987. Two years after the treatment there were still no experimental results, because of the inherent delays in sorting and identifying the arthropods, and in establishing and managing the very large database involved. However, the analysis of some pre-treatment data is used to assess the experimental design. This analysis demonstrates the importance of adequate replication in ecological field experiments.

We are optimistic about the ability of our social institutions to respond to the challenges of environmental degradation, but recognize that (a) restoring environmental quality to a world inclined towards rapidly-increasing consumption of resources and generation of wastes will require profound institutional changes, and (b) environmental challenges cannot be separated from the global-scale issue of achieving an equitable distribution of resources. Conventional economics practically ignores environmental consequences, and is inadequate to the challenge of environmental restoration. A new way of ‘doing business’ is called for.

Three industries — energy, agriculture, and automobiles — have a responsibility to become the avant garde of global environmentalism, owing to the large toll which they exact in resource utilization and pollution, and for the almost universal role that each of these industries plays in the planet's diverse societies. In order to effect changes of an appropriate magnitude, these industries will need to reorient their priorities and goals — as will the institutions with which they routinely interact, including governments, research and development, and financial institutions.

Genuine or American mahogany is obtained from trees of the genus Swietenia (S. mahagoni, S. macrophylla, and S. humilis), and is one of the premier timbers of international commerce. The trade in mahogany commenced almost five centuries ago with S. mahagoni from the Caribbean; but following ‘commercial’ extinction of this resource, trade became centred on mahogany populations in South and Central America (S. macrophylla). The trade in mahogany is predominantly from primary forests, and has led to population and genetic resource declines — particularly in the Caribbean and Central America. More recently, there have been an increasing number of ‘commercial’ extinctions in South America. As the resource declines, pressures mount to accelerate the illegal extraction of mahogany from National Parks and lands reserved for indigenous (‘Indian’) peoples. Inability to control this trade threatens mahogany populations and genetic resources throughout its range, at the same time adversely affecting the livelihoods of indigenous peoples in the process.

Mahogany often regenerates poorly following logging operations that are conducted using current management practices, and further research is required to determine the optimum biological and economic conditions for in situ silviculture. Attempts to cultivate mahogany in plantations have met with little success in the Americas, due mainly to effects of the shoot-borer (Hypsipyla grandella), a moth larva that damages terminal shoots, so leading to excessive branching and reduced timber value (Figs 3 and 4). The success of mahogany plantations in the neotropics will require the development of an integrated pest-management system, perhaps involving the incorporation of pestresistant genotypes within agro-forestry or mixed plantation systems.

It is vital that appropriate silvicultural and trade practices are adopted to ensure sustainable mahogany extraction, while at the same time conserving an adequate population and genetic resource-base. To this end, effective trade monitoring and resource-regulation measures must be introduced to assist in controlling illegal trade and to encourage a scientifically managed, sustainable, utilization of mahogany. Two of the three mahogany species, S. humilis and S. mahagoni, have been listed in Appendix II of the Convention on International Trade in Endangered Species (CITES). The third and only other recognized species of Swietenia, S. macrophylla, should also be considered for listing in CITES Appendix II, thereby benefiting from the international trade-monitoring and resource regulation requirements consequent upon such listing.

This article examines, through a molecular perspective, the ‘ozone-friendly’ refrigerants R-134a and R-123 vis-à-vis R-12 and R-11, which are targeted to be phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer, Final Act (1987). It appears that the molecular weight, size parameter, and dipole moment, of R-134a and R-123, may induce a pronounced effect on the chemical equilibrium of ice particles in the polar stratospheric clouds and subsequently influence the photochemical reactions therein.

Non-polar, high-molecular-weight perfluoropropane (R-218), could be a better substitute for R-12, while R-134, which is a non-polar HFC of the ethane family, could also be a candidate although its molecular weight is lower than that of R-12. The search for a good substitute for R-11, however, must continue.

Examined here is the impact exerted by the military sector of human society on national parks and other protected natural areas. Disruption during wartime, both by regular and by insurgent armed forces, results largely from the collateral effects of their operations and weapons as well as from illegal logging, hunting, fishing, and pillaging. Disruption during peacetime results largely from training exercises and poaching.

A number of actions are suggested to mitigate the military impact on protected natural areas, among them: enhanced environmental education and training (in both the civil and military sectors), greater local participation in the management of protected natural areas, creation of greater respect for an expanded system of demilitarized World Natural Heritage Sites, and especially the nurturing among all peoples of a greater respect for Nature.

In reviewing the results of our analyses of European temperature and precipitation data, we see patterns that are similar to those discovered in our prior studies of the United States and the British Isles: precipitation begins to increase at about the time that Northern Hemispheric SO2 emissions began their rapid ascension, while prior upward trends of surface-air temperature are dramatically truncated.

We also find that surface-air temperature trends of different localities over the past three-and-a-half decades are closely tied to the amount of aerosol sulphates in the atmosphere above them. The wide range and thrust of these several observations, along with their theoretical expectation, provides strong support for the premise that anthropo-generated climate change is indeed occurring in Europe, but that it may well be SO2-induced rather than CO2-induced.