The fact that the worldwide human ecosystem is threatened by grave imbalances in productivity and within the distribution of products and services – as evidenced by the very fact that an outsized proportion of the human population lives in poverty, which a widening gap exists between those that enjoy economic and technological development and people who don’t.
Consequently, a good range of environmental problems has emerged; those problems include anthropogenic global climate change (‘global warming’), the depletion of stratospheric ozone (the ‘ozone hole’), the acidification of surface waters (‘acid rain’), the destruction of tropical forests, the depletion and extinction of species, and therefore the precipitous decline of biodiversity. Yet, while all of those problems have physical (environmental) manifestations, their causes – and their potential solutions – are invariably bound up with human attitudes, beliefs, values, needs, desires, expectations, and behaviors. Thus the symptoms of the environmental crisis can’t be regarded purely as physical problems requiring solutions by environmental ‘specialists’; instead, they’re intrinsically human problems and that they are intimately associated with the question of what it means to be human.
Main features of the environmental crisis
At now, a really brief overview of the environmental crisis could also be helpful. it’s important to emphasize that a good range of views about the character and severity of the present environmental crisis exists, and a few of the problems are highly controversial. Nevertheless, there’s broad agreement that the environmental crisis encompasses the subsequent main issues.
Anthropogenic global climate change thanks to pollution of the atmosphere by greenhouse gases (and other contaminants) is now considered one of the main global environmental issues. It occurs largely as a result of the combustion of fossil fuels, emissions from agriculture and pastoralism, and land-use changes that accompany the destruction, clearance, and burning of forests. global climate change already has observable ecological and social effects, and its projected impacts could potentially end in profound changes in global mean surface temperature, sea level, ocean circulation, precipitation patterns, climatic zones, species distributions, and ecosystem function.
Stratospheric ozone depletion:
The depletion of stratospheric ozone thanks to the pollution of the atmosphere by halocarbons (such as chlorofluorocarbons, or CFCs) is another serious environmental issue. it’s a big concern because the shortage of protective ozone at high altitudes leads to increased levels of harmful solar ultraviolet (UV-B) radiation reaching the surface, causing a variety of health-related and ecological impacts.
Degraded air quality:
Other sorts of pollution also are significant, particularly at regional and native scales, as they’ll seriously degrade air quality; worldwide, approximately one billion people inhabit areas – mainly industrial cities – where unhealthy levels of pollution occur. Many air pollutants are liable for the degradation of air quality, but some key pollutants include particulate (such as soot), tropospheric ozone, oxides of nitrogen, oxides of sulfur, lead and various aromatic compounds (such as benzene). Many air pollutants may cause or aggravate respiratory and cardiovascular illnesses; some are known carcinogens; and a few can cause damage to vegetation and, in turn, produce a variety of ecological effects.
Degraded water quality:
Similarly, water quality is often seriously degraded by contamination with pollutants, giving rise to a variety of health-related and ecological effects (such because of the degradation of coral reefs). a serious source of pollution is that the terrestrial run-off to inshore waters that happens in many coastal locations; such run-off may contain significantly elevated levels of nitrogen and phosphorus from agricultural land and from human settlements. Many other human activities cause pollution, including mining and industrial processes, which can create toxic effluent. Oil spills, accumulation of plastics and therefore the bioaccumulation of persistent organic chemicals are a number of the opposite causes of great degradation of the marine environment.
Scarcity of freshwater:
Besides the pollution of freshwater sources, there is a spread of other reasons for the scarcity of water for drinking in many parts of the planet – many of which are associated with poor water resource management practices. as an example, the over-abstraction of water from rivers leads to water shortages and problems of salinization downstream. Irrigation practices can also be liable for the depletion of local water sources and therefore the salinization of irrigated land.
Land contamination occurs as a result of chemical or radioactive pollution, especially by long-lived (persistent) chemical species that enter the soil. Land contamination may cause profound ecological effects and it presents severe constraints to development since contaminated land must typically be rehabilitated before it’s safe to use for agriculture, construction or recreation.
It’s been estimated that around half the world’s mature forests are cleared by humans. Deforestation occurs for a spread of reasons, but the bulk of deforestation now occurs when tropical forests are cleared for agriculture and pastoralism; other reasons include the destruction of trees for charcoal production and therefore the selective logging of forests for timber. Whilst tropical forests cover only around 6% of the surface, they’re an important part of the worldwide ecosystem and of the biosphere: they assist to manage climate; they protect soils from erosion; and that they provide habitats for a huge number of plant and animal species. One estimate suggests that around 90% of the world’s species are found in tropical forests (Park 2001).
Soil erosion and degradation:
Concerns about erosion, soil degradation and therefore the problem of desertification became acute. In part, these concerns are supported the historical experiences of dramatic erosion and transport in New World countries including the USA (during the ‘Dust Bowl’ of the 1930s) and Australia. Whilst analyses of the issues of erosion and degradation became more sophisticated, recently, it’s clear that these problems still have important consequences for agricultural and pastoral productivity also as for the functioning of natural ecosystems.
Land-use change and habitat loss:
these issues overlap with others, like deforestation, but they’re broader and include the clearance of forest for agriculture and pastoralism, the transformation of land during urban growth, the event of latest infrastructure (such as roads), the drainage of wetlands, and therefore the destruction and removal of coastal mangrove forests.
Many plant and animal species are threatened with extinction, thanks to the spread of disease, the destruction and degradation of their habitats, and direct exploitation. In 1999, UNEP (1999) estimated that one-quarter of the world’s mammal species and around one-tenth of the world’s bird species faced a big risk of total extinction. Threats to biodiversity aren’t confined to terrestrial ecosystems; serious concerns are raised about the longer term of marine and coastal wildlife species as a result of the pollution, over-exploitation and acidification of ocean and seas.