ATMOSPHERIC ENIVORNMENT

• The atmosphere plays a vital role in maintaining the heat balance on the earth by absorbing the IR radiation received from the sun and re-emitted by the earth
• Greenhouse effect


  Phenomenon that keeps the earth warm enough to sustain life
• The air is a combination of gaseous elements that have a remarkable uniformity in terms of their contribution to the totality of life
• Oxygen (O2) supports life on earth, nitrogen (N2) is an essential macro-nutrient for plants, and carbon (IV) oxide (CO2) is essential for photosynthetic activity of plants
• The atmosphere is a carrier of water from the ocean to land, which is vital for the hydrological cycle
• Any major disturbance in the composition of the atmosphere resulting from anthropogenic activities may lead to disastrous consequences or may even endanger the survival of life on earth
• The three main gaseous elements in the atmosphere below 100 km

  • Nitrogen (N2) - 78.09%
  • Oxygen (O2) - 20.95%
  • Argon (Ar) - 0.93%
• Trace gases


  Gases that exist in small quantities, measured in parts per million by volume (ppmv), parts per billion by volume (ppbv) or microgram per cubic meter (μgm-3)
• If the concentrations of trace compounds or other pollutants are increased due to human activities and bioaccumulate over time, it becomes hazardous to life
• Layers of the atmosphere

  • Troposphere
  • Stratosphere
  • Mesosphere
  • Thermosphere
  • Exosphere
• Troposphere


  • Contains 75% of the atmosphere's mass, temperature and pressure drops with increasing altitude
• Stratosphere


  • Lies directly above the troposphere, extends from about 15 km above the earth's surface
• Mesosphere


  • Directly above the stratosphere, extending from 50 to 80 km above the Earth's surface, very rarefied atmosphere
• Thermosphere


  • Extends from 80 km above the Earth's surface to outer space, temperature is hot and may be as high as thousands of degrees
• Exosphere


  • The final layer, gradually gets thinner as it reaches into the vacuum of space at around 700 km above the earth's surface
• When analysing markets, a range of assumptions are made about the rationality of economic agents involved in the transactions
• The Wealth of Nations was written

  1776
• Rational


  (in classical economic theory) economic agents are able to consider the outcome of their choices and recognise the net benefits of each one
• Rational agents will select the choice which presents the highest benefits
• Consumers act rationally by


  Maximising their utility
• Producers act rationally by


  Selling goods/services in a way that maximises their profits
• Workers act rationally by


  Balancing welfare at work with consideration of both pay and benefits
• Governments act rationally by


  Placing the interests of the people they serve first in order to maximise their welfare
• Rationality in classical economic theory is a flawed assumption as people usually don't act rationally
• Marginal utility


  The additional utility (satisfaction) gained from the consumption of an additional product
• If you add up marginal utility for each unit you get total utility
• Burning can equally be viewed as emission of combustion products that includes greenhouse gases into the atmosphere and the loss of biomass useful as valuable material resource
• The extent of biomass burning generally in Africa and particularly in Nigeria coupled with the complexity of the reactions involved; alongside its health implications constitute an important motivation to view it as a global problem deserving priority attention and careful multisided investigation because air has no boundary i.e. it is transboundary
• Burning vegetation releases large amounts of particulates (solid carbon combustion particles) and gases, including greenhouse gases that helps warm the Earth
• Greenhouse gases may lead to an increased warming of the Earth or human-initiated global climate change
• Studies suggest that biomass burning has increased on a global scale over the last 100 years, and computer calculations indicate that a hotter Earth resulting from global warming will lead to more frequent and larger fires
• Biomass burning particulates impact climate and can also affect human health when they are inhaled, causing respiratory problems
• Biomass burning, once believed to be a tropical phenomenon, has been demonstrated by satellite imagery to also be a regular feature of the world's boreal forests
• Recent estimates indicate that almost all biomass burning is human-initiated and that it is increasing with time
• With the formation of greenhouse and chemically active gases as direct combustion products and a longer-term enhancement of biogenic emissions of gases, biomass burning may be a significant driver for global change
• The historic data indicate that biomass burning has increased with time and that the production of greenhouse gases from biomass burning has increased with time
• The bulk of biomass burning worldwide may be significantly reduced
• Policy options for mitigating biomass burning

  • Marketing of timber as a resource
  • Improved productivity of existing agricultural lands to reduce the need for conversions of forests to agricultural lands
  • Animal grazing could be replaced by stall feeding in tropical savannas grasslands
  • Incorporate crop wastes into the soil, instead of burning, as is the present practice throughout the world
  • Use crop wastes as fuel for household heating and cooking rather than cutting down and destroying forests for fuel as is presently done
• Cooking and heating with solid fuels such as cow dung, wood agricultural residuals, coal is about the largest source of indoor air pollution globally
• When used in cooking stoves, these fuels emit substantial amounts of pollutants including respirable particles, carbon-monoxide, nitrogen, sulphur oxides and benzene