The natural environment is in a constant state of motion, it is dynamic. Human beings are part of that dynamism of nature. Nature has a tendency towards achieving a balance and this is an inherent tendency which means left alone nature would achieve a balance.
Secondly nature has an inherent capacity to absorb change. Part of that change arises from the impact of human activity on nature, essentially because humans are part of nature, then humans are part of the dynamism of nature, human will also influence this motion. Human activity with respect to nature is legitimate, it is perfectly natural, environmental management is not based on the theory of zero impact on nature because nature can absorb impact from humans and other aspect. The reality is that human impact on nature has a tendency now to destabilise the natural balance and that destabilization of the natural balance is what we refer to as environmental degradation or pollution.
Human impact on nature tends to destabilise nature because of advance in technology which has meant that the capacity of humans to impact on nature has changed in scope and character. A good example is that humans are not content just to have basic things, they want more and have the capacity to build bigger for example houses and so on. Humans are even attempting to create new forms of nature through technology like bio-technology
Secondly human beings are adventurous, they have limited knowledge about natural processes and therefore often humans cannot predict the impact of their activities on nature but because of the constant experiments that humans carryon in respect to nature, quite often there are impacts which are not observed until the damage has occurred. The case of the Nile Perch is introduced in Lake Victoria without realising it will eliminate all other fishes. Limitations of human knowledge are important aspect.
Human acquisitiveness which is that humans on the whole are not content to live from day to day, they want to stock for the future so they acquire, most animals have a meal a day and assume that the next meal will be available when they wake up but not so humans, humans stock and the result is that they do not allow nature to recover its balance because of this tendency of planning ahead.
Because of the tendency by humans to destabilize natural balance, it becomes necessary to put into place measures for regulating human conduct which impact on the environment. Left to themselves, the human instinct is very much towards self-aggrandizement, it is this behaviour which tends to mean that the logic that human behaviour will destabilize the environment might be appreciated academically but in reality nobody thinks about it. In economic terms it is referred to as the tragedy of the commons (the phrase is inherited from British economist called Harding who wrote about commons which refers to a common area, Harding described his observation with regards to a traditional community who rely on the commons for grazing, the cows are owned individually but the grazing area is held in common and the result is that everyone has the urge to maximise the use of the commons like adding the numbers of cows grazing at the commons or sending them earlier before others, the result is that the commons is degraded but no one restrains themselves because everyone thinks the neighbour will get the better of them) this is why left to themselves, humans will degrade the environment because the environment is common to everybody and the benefit to be had from exploiting the environment is individual and so each person has the temptation to appropriate more and more components of the environment. It becomes necessary to introduce standards to regulate human behaviour.
Environmental Law is thus defined as norms which regulate human conduct in order to ensure that the impact of human conduct does not destabilize natural balance. This law is more about human behaviour.
In determining environmental degradation there is a tendency to think in subjective terms which essentially means that we define environmental law qualitatively or subjective e.g. this air is polluted. Qualitative perceptions are problematic in the context of enforcement. The Penal Code has a provision that makes it an offence for vehicles to emit dark smoke, it is a misdemeanour, dark smoke is clearly an environmental pollutant and the problem is how to prove that dark smoke was emitted. So the way in which we utilise concept of environmental degradation is by introducing objective standards.
A standard is an objective indicator of environmental degradation or pollution and standards are expressed numerically in terms of numbers. For instance one will say that 10mg/litre of chlorine, one may say that anything above 10 is pollution and below is not. In dealing with environmental offences one needs a numerical representation.