By Rowland Benjamin

It is common knowledge that humans continue to have a large impact on the environment. The combination of an exponentially growing population, escalating use of the Earth’s resources and the human desire to modify rather than adapt to our surroundings, may seriously challenge the assimilative capacity of our natural systems to recover from such stress. Up to one half of the Earth’s terrestrial environment has already been altered from its natural state through human activity. Over time, two conflicting facts have become clear: that we continue to degrade the environment and that we rely on the functioning of its processes for both our economic and physical survival.

The focus on environmental issues has increased in both organisations and the wider community, particularly in the latter half of last century and various attempts to improve its state have been initiated throughout the world. Yet our mitigative efforts are being outweighed by counter-productive, destructive activities such as our reliance on fossil fuels and the ever-extending city boundaries. There has been an increase in recent years in the number of issues which require urgent attention from the global community in order to ensure that the environment is accessible to future generations.

Issues/Problems

Climate change/Global warming

Greenhouse gases are the waste from burning fossil fuels and agricultural activities. The main gases are carbon dioxide, methane, nitrogen oxides and halocarbons. Humans are producing them in such large quantities that they are building up in the atmosphere. The concentration of greenhouse gases in the atmosphere has been increasing since the industrial revolution, but in recent years this has caused a measured warming of the planet.

The ramifications of the alteration of the greenhouse effect on Earth are widely disputed. However, it is anticipated that if the current levels of emissions continue, this will cause an increase in the average global temperature of up to 2.5 deg C by 2050. The consequences of this will be a melting of the polar ice caps which will cause the sea level to rise by about 20 centimetres.

Small increases in the Earth’s temperature can also result in changes to the weather patterns, such the amount and distribution of rainfall, cloud distribution, wind patterns, and ocean currents. Rising ocean levels will cause the loss of coastal ecosystems, such as mangroves and coral reefs, and the loss of small islands. Climate change will alter the species composition of some ecosystems and completely destroy others.

Loss of biodiversity

Biodiversity is under an ever increasing threat from human activity. Over the past 25 years, we have triggered the extinction of one quarter of all life on Earth and one third may be extinct by 2025. The destruction or modification of habitats and the introduction of invasive species are the main causes. Over-hunting and pollution are also contributing factors. Global warming and UV radiation from ozone layer damage will also result in a loss of biodiversity with the destruction of many integral ecosystems.

There is the possibility of over 50 million species currently inhabiting the Earth but only about 2 million of these have been identified. With this lack of information and identification, it is impossible to know the exact consequences of these extinctions. It is important to preserve as many species as possible since it is not yet known which could be potentially useful as food sources, medicines, materials and genetic stocks.

Land and soil degradation

A layer of soil less than a metre deep supports all terrestrial plant and animal life and agricultural production on this planet. Our land is a finite, fragile and non-renewable resource. It aids in the preservation of biodiversity, the regulation of the hydrological cycle, carbon storage and recycling and is the basis for human settlement and transport activities.

Human activities contributing to global land degradation include overgrazing, deforestation, agricultural mismanagement, fuel wood consumption, industrial expansion and urbanisation.

The degradation of land and soil resources is a threat to the security of the global food market. As the irreversible damage to land continues and the amount of land available for farming diminishes, our ability to supply the planet with food will be tested. Land degradation in developing countries continues to worsen as people are forced on to marginal land and the governments provide no economic or political support to encourage appropriate agricultural practices. Excessive use of fertilisers and other chemicals degrades the soil and can leach into rivers and groundwater. Inappropriately designed irrigation systems lead to waterlogging and the salinisation or alkalisation of the soil.

Air pollution

Air pollution has increased dramatically in the past 25 years, with many countries becoming more industrialised and urbanised. This has caused many environmental and health problems to develop. Ground-level ozone, smog and fine particulates have emerged as major health risks, triggering or exacerbating respiratory and cardiac problems, especially in children, the elderly and asthmatics. Environmental problems that require urgent action are urban air pollution, acid rain (especially in Europe and North America and more recently China), contamination by toxic chemicals, depletion of the stratospheric ozone layer and changes in global climate. The World Health Organisation lists 6 ‘classic’ air pollutants – CO, lead, nitrogen dioxide (NO2), suspended particulate matter (SPM), SO2 and tropospheric ozone (O3). The major source of these air pollutants is the burning of fossil fuels and biomass.

Addressing air pollution is a notable victory but needs continuing vigilance. Taller chimneys solved the problem of intense localised pollution only to create problems at a distance from the source. The pollution is transferred to other parts of the country or to neighbouring countries, thus transferring the problem. This is becoming more and more evident worldwide with many countries getting their neighbours' pollution after it travels long distances, such as the west coast of the USA, registering problematic levels of pollution which originates in Asia about once a year.

Forest degradation and deforestation

Forests are the largest and most complex ecosystem. They contain over 90% of the Earth’s species. Forests provide many goods and services ranging from wood, non-wood products and recreational areas, to the conservation of soil and biodiversity, and participate in the global carbon and hydrological cycles. An area of tropical forest the size of Britain is cut down or burned each year. This rate of deforestation exceeds the rate of new plantings by more than ten to one.

Forests play an integral role in the reduction of greenhouse gases. Plants absorb and store carbon dioxide, the main cause of global warming, and a loss of large amounts of plants leads to an increase in greenhouse gases. Deforestation also leads to soil erosion. Globally, approximately 24 billion tonnes of topsoil is lost to erosion each year. The eroded topsoil can cause pollution of water and air supplies which then leads to other environmental and health problems.

One of the main reasons why forest degradation and deforestation is still a major problem globally is because of the conflicting interests in managing forests. On the one hand, there is the importance of the environmental conservation of this significant and delicate ecosystem. And, on the other hand, there is the priority of economic development in many countries. Clearing of the forest allows for an increase in the amount of land available for development and the harvesting of products is important to local economies. While there is an increase in productivity in the short term, the possibility of long term sustainability is all but completely gone.

Freshwater stress and scarcity

The over-exploitation of the freshwater resources which are the basis for domestic and agricultural supplies has given rise to more and more countries facing the problems of water stress and scarcity. Today, over one third of the global population lives in an area that has been classified as being with moderate to high water stress. This is when water consumption is more than 10% of the available renewable freshwater resources of the area. There are three main factors that lead to an increase in the water demand of an area. These are an increase in the population, the development of industry and the expansion of irrigated agriculture.

The impact of decreasing freshwater on the environment is quite significant, especially in developing countries. Marshes and wetlands are eliminated with the water and there is also an alteration of water flow in rivers and streams and the possibility of contamination of water sources with industrial and human waste. In regards to health, there are currently over 1.2 billion people who have no access to clean drinking water and 2.4 billion have no access to sanitation services. This has led to between 3 and 5 million people dying annually from water related diseases.

Degradation and pollution of coastal and marine environments

Coastal and marine environments are some of the most sensitive ecosystems on Earth. The degradation and pollution of these environments has not only continued but intensified over the last decade. There has been an increase in the deposition of nitrogen, which has led to an increase in eutrophication, and the introduction of exotic species also affects both marine and coastal environments through competition with native species. There are countless fisheries that have collapsed and others are on the verge, due to the ever increasing exploitation and depletion of wild fish stocks caused by a 240% increase in the consumption of fish since 1960.

The current threats to the coastal and marine environments are marine pollution, the over-exploitation of living marine resources and coastal habitat loss, through physical alteration and destruction. These threats are caused by a variety of pressures, mainly an increasing population, urbanisation and the development of industry and tourism in the areas. The main pollutant globally, by volume, is coastal sewage discharges which have increased dramatically in the last 30 years. There is also the problem of human induced alterations to sediment flow. While deltas, mangroves, beaches and other coastal habitats can be sustained by an increase to the supply of sediment, others, such as coral reefs and seagrass beds, may be smothered and deprived of light, causing the loss of some extremely important ecosystems. Non-biodegradable litter which is dumped into the marine environment is also a threat, with it becoming entangled or ingested by marine organisms.

Genetic engineering

Genetic engineering is the transfer of genes from one organism to another and is a relatively new problem. There are many issues that need to be dealt with before genetically engineered organisms can be successfully integrated into ecosystems. There is the possibility of unintended change in the modified organisms along with the threat of unintended gene transfer, even over long distances. There is also the possibility of unknown environmental or health disasters. Additionally, developed countries may alter a crop so that they can grow it more successfully to the detriment of developing countries who export the same crop. There is also the possibility that developing countries may become reliant on private corporations to supply them with genetically modified seeds.

On the other hand, there is the potential for enormous benefits for medicine and agriculture. Reduced pesticide use and less damage to vegetation, land and freshwater resources are just a few of the other benefits of genetic engineering. The Cartagena Protocol on biosafety is the only international instrument that deals exclusively with genetically modified organisms, although there are others that cover other issues and contain small elements on biosafety.

Radioactive and hazardous wastes

Since 1960, 200,000 tonnes of spent fuel has been produced around the world. Every year 10,000 tonnes are added to the stockpile. This waste can come from a number of sources. Industry, electricity generation and the military contribute to the growing piles of radioactive and hazardous waste. Growing disarmament means some countries are dumping weapons (e.g. mustard agent) into oceans. However, most radioactive and hazardous waste is buried, which adds to the radioactivity in the environment that in turn spreads throughout the world. This radioactivity can have immediate and lasting effects on the health of all organisms and any alterations can become hereditary.

The major problem with radioactive and hazardous waste is the pressure that developed countries put on developing countries to accept shipments of these wastes. This transfers the problem to countries without the resources to ensure that the waste is disposed of appropriately. The Basel Convention controls the transfer of radioactive and hazardous waste but it will take time, government support, and resources to ensure that there is no transfer of hazardous waste to developing countries. The Convention also encourages environmentally sound management through an integrated life-cycle approach.

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