The atmosphere is a mixture of different gases, particles and aerosols collectively known as air which envelops the Earth. It provides various functions, not least the ability to sustain life. Indeed, its protection is at the very heart of sustainable development as all living organisms affect and are affected by the atmosphere. Threats to the atmosphere are the result of a large number of human activities occurring on a range of spatial scales from very local indoor air pollution to urban, regional, hemispheric and global pollution. Also, changes in atmospheric composition due to anthropogenic emissions of greenhouse gases and aerosols may lead to a global climate change with very significant implications for socio-economic activities.
Atmosphere Composition. The remainder, less than 0.1%, contains many small but important trace gases, including water vapor, carbon dioxide, and ozone. All of these trace gases have important effects on the earth's climate. The atmosphere can be divided into vertical layers determined by the way temperature changes with height. The layer closest to the surface is the troposphere, which contains over 80% of the atmospheric mass and nearly all the water vapor. The next layer, the stratosphere, contains most of the atmosphere's ozone, which absorbs high energy radiation from the sun and makes life on the surface possible. Above the stratosphere there are two layers: the mesosphere and thermosphere. They include regions of charged atoms and molecules, or ions. The ionosphere is the region to radio communications.
Oxygen, upon which all animal life depends, probably built up as excess emissions from plants that produce it as a waste product during photosynthesis. Human activities may be affecting the levels of some important atmospheric components, particularly carbon dioxide and ozone.
Atmosphere and Sustainable Development
The changes in the composition of the atmosphere are resulted from decades of emissions or the reaction products of emissions of both human and natural origin. A more comprehensive understanding of the global geosphere and biosphere is required to understand several impacts. In fact, some pollutants, such as persistent organic pollutants (POPs), can result in adverse environmental impacts at locations far from the source. In some cases the effects can persist for many decades and perhaps millenniums, even after corrective measures are implemented. A growing problem is the current relationship between improvements in living standards and increasing emissions to the atmosphere. Thus, more effective policy decisions are required so that actions can be taken early enough to avoid environmental harm that may be irreversible.
Measures and Indicators
Indicators and tools
CO2 Calculator is a tool to to find out what your carbon footprint is and how you can make some simple changes to help tackle climate change.
GHG concentration European Environment Agency
J.E. Frantsen, T. Mathiesen, J. Rau, J. Terävä, P. Björnstedt, B. Henkel, "Effects of Gas Atmosphere and Surface Quality on Rouging of Three Stainless in WFI" (2003).
Air Quality Research (AQRB) - Environment Canada
Atmosphere/Air Pollution: Best Practices, Lessons Learnt and Case Studies By UN Cooperative, Report of the UN Issues Management Group (IMG) of EMG (2006).
Global Environment Outlook: environment for development, State-and-Trends of the Environment: 1987–2007, United Nations Environment Programme (UNEP)
Millennium Assessment Reports, Millennium Ecosystem Assessment
Protection of the Atmosphere,United Nation Commission on Sustainable Development
WMO Global Atmosphere Watch (GAW) - Strategic Plan: 2008 – 2015, World Meteorological Organisation N.172
Find more information in the statistics and atmosphere.