Background
Environment is the sum of all external conditions affecting the life, development and survival of man and other living things. Our environment is the thin covering of our planet (earth) called the biosphere. The biosphere includes the atmosphere (air), hydrosphere (water bodies) and lithosphere (rock, the crust of the earth). There are variety and frequency of different ecosystems in the biosphere. An ecosystem is a community of interdependent plants, animals and other organisms together with the non-living components of the environment. It may be on soil surface or water body.

The environment is our life-support system. It provides goods and services for our well-being. These include:

(a)     Nature as a source of resources used in economic processes:

(i) Renewable resource: a resource that can renew itself (or be renewed) at a constant level by recycling

(e.g. water) or can propagate itself or be propagated (e.g. plants, animals, biological diversity and genetic diversity).

(ii) Non-renewable resource: a resource whose consumption necessarily involves its depletion (e.g. mineral deposits).

(b)     The amenity function of nature e.g. enjoyment of scenery, landscapes, unpolluted
air and other natural surroundings, and maintenance of favourable weather conditions.

(c)     Capacity to serve as sinks for pollution arising from human activities. The
ecosystem’s failure to absorb pollutants may directly affect humans by causing illness or death. The indirect effects include fish poisoning resulting from water pollution, crop failure due to land degradation and reduced property value due to corrosion arising from air-borne pollutants.

The carrying capacity of an ecosystem is the capacity to support healthy organisms while maintaining its productivity, adaptability, and renewal capability. Any human impacts that cause the capacity to be exceeded would deteriorate the quality of the life-support system.

Principles of a Sustainable Society

Human activities have negatively impacted on the bio-physical environment, impaired public health and compromised the ability of ecosystems to provide goods and services.
The World Conservation Strategy published in 1980 called for a sustainable development if people are to achieve a life of dignity and if the welfare of present and future generations is to be assured. The World Commission on Environment and Development (WCED), in its 1987 report (Our Common Future), advanced our understanding of global interdependence and the environment. It also endorsed the concept of sustainable development. The WCED defined sustainable development as ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’.

Our Civilisations are at risk because we are misusing natural resources, disturbing natural systems and pressing the earth to the limits of its capacity. We need a kind of development that provides real improvements in the quality of human life while living within the carrying capacity of the earth’s resources. This is called sustainable development. Living sustainably or building a sustainable society requires the adoption of the ethic for sustainable development at the individual, community, national and international levels.

The principles of a sustainable society are inter-related and mutually supporting. Of the nine principles set out below, the first provides the ethical basis for the others. The next four give the criteria to be met in building a sustainable society; and the last four define the roles of individual, community, national and international governments in achieving sustainable living. The principles are adopted from a framework of strategy for sustainable living published in 1990 by the International Union for Conservation of Nature and Natural Resources (IUCN) / United Nations Environment Programme (UNEP) / World Wide Fund for Nature (WWF).

The Principles are:
1) Respect and care for the community of life: This principle recognizes the inter dependence of human communities and the duty of care for other people and other forms of life, now and in the future. This implies that development should not be at the expense of other groups or later generations. And that we should aim to spread the benefits and costs of resource use and environmental conservation among different communities and interest groups, among the poor and the affluent, and between our generation and future generations.

The principle also proposes morally-compelling strategies to guide human conduct, as set out below:

i)    Every form of life warrants respect independently of its worth to people, and human development should not threaten the integrity of nature or the survival of other species. People should treat all creatures with care and respect, and protect them from cruelty, avoidable suffering and unnecessary killing.

ii)    Every person should take responsibility for his or her impacts on the environment. People should conserve ecological processes and biodiversity, and use any resource frugally and efficiently, ensuring that renewable resources are used in a sustainable manner.

2) Improve the quality of human life: This principle emphasizes that development has to be both people-centred and conservation based. It views development as a process which improves the quality
of human life. It proposes that development is real if it makes humans live better in the following respects:

i)    A long, healthy and fulfilling life;

ii)    Access to education and other resources needed for a decent standard of living;

iii)    Political freedom, guaranteed human rights, and freedom from violence.

3) Conserve the Earth’s vitality and diversity: The principle emphasizes that development will only succeed if it maintains the productivity, resilience and variety of ecosystems in the biosphere. Conservation-based development requires us to:

i)    Conserve life-support systems: These are the ecological processes that shape climate, cleanse air and water, regulate water flow, recycle essential elements, create and regenerate soil, and keep the planet earth fit for life.

ii)    Conserve biological diversity: It is the total variety of genetic strains, species and ecosystems. This includes species of plants, animals and other organisms. Biological diversity should be conserved because all species deserve respect irrespective of their use to humanity. The diversity of nature is a source of beauty, enjoyment, understanding and knowledge. It is the source of all biological wealth (food and raw materials); and genetic materials for agriculture, medicine and other industries.

iii)    Conserve renewable resources: They are the base of all economies. They include soil, water;  products we harvest from the wild such as timber, nuts, medicinal plants, fish and the meat and skin of wild animals; domesticated species raised by agriculture, aquaculture and siviculture; and ecological systems such as those of rangelands, forests and waters. The renewable resources will perpetually renew themselves if they are used sustainably.

4)    Minimize the depletion of non-renewable resources: Mineral resources and fossil fuel such as oil, gas and coal are effectively non-renewable. However, their ‘life’ can be extended, for example, by recycling    , using renewable substitutes where possible, etc.

5)    Keep within the Earth’s carrying capacity: There are finite limits to the “carrying capacity” of the earth’s ecosystems – i.e. impacts that the biosphere can withstand without dangerous deterioration. The limits vary from one region to another, and the impacts depend on human activities and use of resources. Sustainability will be impossible if human activities and exploitation of resources exceed the carrying capacity of the earth. It is important to ensure a substantial safety margin between our total impact and our estimate of what the earth can withstand.

6)    Change personal attitudes and practices: Poverty has been identified as a major factor which forces people to live unsustainably. People will do things that will help them to survive for the present, even though they know they are creating problems for the future. Conversely, more affluent groups and countries live unsustainably because of lack of concern or disincentives to discourage wasteful consumption. To achieve sustainability people must re-examine their values and change personal attitudes and practices which are contrary to the ethic for living sustainably. Society must promote values that support the new ethic and discourage those that are incompatible with sustainable living. Appropriate information on the new ethic must be disseminated through formal and informal educational systems.

7)    Enable Communities to care for their own Environments: Communities and citizens’ groups constitute a powerful and effective force for enhancing sustainability in the local communities. Properly mandated, empowered and informed, communities can take an active role in decisions that affect their environments and create and / or promote a securely-based sustainable society. The process by which communities organise themselves to work for sustainability in their own communities, and in a manner that also satisfy their social and economic needs has been termed Primary Environmental Care (PEC).

8)    Provide a National Framework for Integrating Development and Conservation: All societies need a framework of law and institution, and consistent economic and social policies to promote and enforce the ethic for sustainable living. This should include environmental impact assessment law  and regulations & standards for controlling pollution and other negative impacts of development.

9)    Create a Global Alliance: Global Sustainability can only be achieved by collective actions of all nations.  Global and shared resources, especially the atmosphere and oceans can only be managed with the co-operation of all nations. Many great river systems are also shared between several states. Global warming and ozone depletion have also been accepted as environmental problems that require international law. It is not just enough to think globally and act locally now. We must act globally as well.

Conclusion
The nine principles stated above reflect values and duties. They are specific on the duty of care for other people and of respect and care for nature. Contrarily. Nigeria is one of the major sources of oil & gas related atmospheric pollution, which contributes significantly to global warming and also poses a threat to local ecology and public health. There is need for the Nigerian government to build practical strategies for sustainable living and empowerment of local citizens around these principles. This would go a long way in addressing the genuine concern of oil- communities of the Niger Delta region. The Niger Delta communities have for the past fifty (50) years been bearing the agony of environmental devastation to sustain our mono-product economy based on petroleum.