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Understanding global warming and its underlying crisis

Unit 1 The Earth System and its Components 1. Awareness of this environmental crisis has grown since the 1970s, partly as a result of the prominence given to major so-called 'environmental' disasters such as the Sahelian droughts of the 1970s and 1980s and the nuclear accident at Chernobyl in 1986.

  • Coral bleaching, for example, has occurred in nearly all tropical coral-growing regions and is unambiguously related to increased temperatures e;
  • The graph also shows the often-used power relationships e;
  • It is important to emphasise that a wide range of views about the nature and severity of the current environmental crisis exists, and some of the issues are highly controversial;
  • It is also highest immediately after the emission of each gas and decreases thereafter;
  • Their likely occurrence is often linked to cumulative warming.

Yet, while all of these problems have physical environmental manifestations, their causes - and their potential solutions - are invariably bound up with human attitudes, beliefs, values, needs, desires, expectations, and behaviours. Thus the symptoms of the environmental crisis cannot be regarded purely as physical problems requiring solutions by environmental 'specialists'; instead, they are intrinsically human problems and they are intimately related to the question of what it means to be human.

Main features of the environmental crisis At this point, a very brief overview of the environmental crisis may be helpful. It is important to emphasise that a wide range of views about the nature and severity of the current environmental crisis exists, and some of the issues are highly controversial.

Nevertheless, there is broad agreement that the environmental crisis encompasses the following main issues.

  • Yet, while all of these problems have physical environmental manifestations, their causes - and their potential solutions - are invariably bound up with human attitudes, beliefs, values, needs, desires, expectations, and behaviours;
  • In part, these concerns are based on the historical experiences of dramatic soil erosion and transport in New World countries including the USA during the 'Dust Bowl' of the 1930s and Australia;
  • It is a significant concern because the lack of protective ozone at high altitudes results in increased levels of harmful solar ultraviolet UV-B radiation reaching the earth's surface, causing a range of health-related and ecological impacts;
  • Achieving the first one billion of human population took most of human history, whilst the most recent increase of one billion was achieved in little more than a decade.

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. Climate change already has observable ecological and social effects, and its projected impacts could potentially result in profound changes in global mean surface temperature, sea level, ocean circulation, precipitation patterns, climatic zones, species distributions and ecosystem function.

It is a significant concern because the lack of protective ozone at high altitudes results in increased levels of harmful solar ultraviolet UV-B radiation reaching the earth's surface, causing a range of health-related and ecological impacts. Many air pollutants are responsible for the degradation of air quality, but some key pollutants include particulate matter such as soottropospheric ozone, oxides of nitrogen, oxides of sulphur, lead and various aromatic compounds such as benzene.

Many air pollutants may cause or aggravate respiratory and cardiovascular illnesses; some are known carcinogens; and some can cause damage to vegetation and, in turn, produce a range of ecological effects.

  • That would mean that current projections for up to a 4;
  • Shorter calculation intervals could be used, in principle, but extra emission units would then affect both the starting and end points for calculating rates of change, leading to complex and sometimes counter-intuitive consequences;
  • Some impacts, most notably sea-level rise, are not functions of the temperature in future years, but of the cumulative warming leading up to those years Vermeer and Rahmstorf 2009;
  • These kinds of impacts are;
  • All three perturbations are then normalized to calculate relative perturbations, Q, as:

A major source of water pollution is the terrestrial run-off to inshore waters that occurs 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 lead to water pollution, including mining and industrial processes, which may create toxic effluent. Oil spills, accumulation of plastics and the bioaccumulation of persistent organic chemicals are some of the other causes of serious degradation of the marine environment.

Scarcity of fresh water: For instance, the over-abstraction of water from rivers results in water shortages and problems of salinisation downstream.

Irrigation practices may also be responsible for the depletion of local water sources and the salinisation of irrigated land. Vast differences in water security exist at the global scale, reflecting both demand for fresh water and the scale of public and private investment in water supplies, treatment and distribution. Land contamination may cause profound ecological effects and it presents severe constraints to development, since contaminated land must typically be rehabilitated before it is safe to use for agriculture, construction or recreation.

Deforestation occurs for a variety of reasons, but the majority of deforestation now occurs when tropical forests are cleared for agriculture and pastoralism; other reasons include the destruction of trees for charcoal production and the selective logging of forests for timber. Soil erosion and degradation: In part, these concerns are based on the historical experiences of dramatic soil erosion and transport in New World countries including the USA during the 'Dust Bowl' of the 1930s and Australia.

Climate-change impact potentials as an alternative to global warming potentials

Whilst analyses of the problems of soil erosion and degradation have become more sophisticated, recently, it is clear that these problems continue to have important consequences for agricultural and pastoral productivity as well as for the functioning of natural ecosystems. Land use change and habitat loss: The impact of land use change on forest and grassland environments is depicted in 1.

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 significant risk of total extinction. Threats to biodiversity are not confined to terrestrial ecosystems; serious concerns have been raised about the future of marine and coastal wildlife species as a result of the pollution, over-exploitation and acidification of ocean and seas.

They encompass a range of economic, social, political and technological issues. Achieving understanding global warming and its underlying crisis first one billion of human population took most of human history, whilst the most recent increase of one billion was achieved in little more than a decade. However, recent declines in the rate of growth of population have occurred in many parts of the world, and in some countries populations are now declining.

The total human population was around 5. The increasing human population inevitably places greater demands on the natural environment - for habitat, resources and waste assimilation - although the extent to which the human 'population explosion' is driving environmental degradation is a complex and controversial question.

Significant differences exist in cultural attitudes to the issues of human population size and the rate of population growth. Urbanisation is often associated with a range of social and environmental problems including overcrowding, congestion, pollution, public health issues, shortages of water for drinking, and inadequate sanitation.

Urbanisation is also related to another issue: Vast differences in patterns of income, production and consumption are evident at all spatial scales, and those patterns are reflected in distinctive patterns of environmental impact although in some cases environmental impacts are 'exported', as in the case of radioactive waste that is generated in one country before being transported to another for processing or disposal.

However, the average values conceal enormous differences in the distribution and quality of food, and the lack understanding global warming and its underlying crisis food security remains a profound challenge in many parts of the world.

1.4 The environmental crisis

Debates about food production raise important environmental issues such as the use of genetically modified GM and genetically engineered GE seeds and produce.

Large differences occur in the responses of human societies to diseases, reflecting vast inequalities in health care spending and in funding for pharmaceutical and medical research.

  1. As far as possible, categorise those issues according to a spatial scale; b time scale; and c the prospects for finding effective technological or policy solutions.
  2. Natural variations in sunlight and ocean currents; concentrations of particles in the air, manmade and otherwise; and even plain old weather variations can speed the warming up or slow it down, even as the underlying temperature trend continues upward. For cumulative-warming impacts, however, the greatest marginal impact of CH4 additions also occurs at the end of the assessment period.
  3. It is a significant concern because the lack of protective ozone at high altitudes results in increased levels of harmful solar ultraviolet UV-B radiation reaching the earth's surface, causing a range of health-related and ecological impacts.
  4. Nevertheless, there is broad agreement that the environmental crisis encompasses the following main issues.

Peak oil and energy security: Some estimates suggest that peak oil will occur - or has already occurred - early in the 21st century, with the implication that alternative energy sources will need to be developed in sufficient time to serve as a substitute for oil. For instance, the use of depleted uranium munitions causes significant land contamination, whilst the effects of the displacement of large numbers of people from zones of conflict can exert pressures on adjacent ecosystems.

Why Global Warming Slowed in the 2000’s: Another Possible Explanation

Displacement of people does not occur only in response to violence; globally, the effects of climate change are projected to result in the displacement of as many as 500 million environmental refugees. Natural disasters Whilst not necessarily part of the environmental crisis, human populations are also faced with ongoing threats due to the occurrence of natural disasters such as earthquakes, landslides, floods, tsunamis and wildfires. Yet whilst these hazards may be natural in origin, it is important to acknowledge that human vulnerability to natural disasters is generally increasing, not least because human populations and settlements are growing in many marginal and dangerous areas, such as floodplains.

Hence unsustainable practices - such as the construction of settlements on floodplains, or the intensive cultivation of marginal hill slope lands - may greatly increase the impacts of natural disasters on human societies and economies. The causes of the environmental crisis The causes of the environmental crisis have been the subject of considerable debate.

However, in general, its main causes are now acknowledged to be: List the main issues that comprise the environmental crisis. As far as possible, categorise those issues according to a spatial scale; b time scale; and c the prospects for finding effective technological or policy solutions.