Climatic Change

Climate Change

Meaning and Nature of Climate Change

Climatic change refers to large scale alteration in the normal cycle of weather over pronounced time or duration.  This change or alteration is expressed in the irregularities (anomalies) of the cycle or regimes of major elements such as rainfall, solar radiation, temperature, pressure patterns and all-other elements otherwise called climate controls.

Causes of Climate Change

Climate change may be caused by natural phenomena, as well as human activities.

Natural Causes

1. Volcanic Eruption: Natural incidents of climate change may be derived from volcanic eruption such as the 1972 eruption which took place in Kenya (East Africa).  The volcanic materials and dust particles which were hauled (carried) over long distances led to significant impact in the weather of such areas.  It was reported that a pronounced dry spell occurred in the religions which were covered by the effects of these volcanic materials.

• Change in Earth’s Orbital Plane: It has been said that the path along which the earth revolves round the sun is elliptical (irregular) equally, the angle of inclination of the earth axis to the plane of elliptic also tilts or wobbles leading to a shift in the Equinoctial angle (equatorial plane) in relation to the sun.  Such a tilt may result in pronounced aphelion or perihelion for the earth environment.

Man-Made Causes of Climatic Change

Human activities have been responsible for the incidence of large scale climate change phenomena.  Important causes of climate change include the following, among others:

• Deforestation
• Atmospheric pollution
• Ozone layer depletion
• Increased green house effect
• Increased urbanization

1. Deforestation

Different activities engaged in by man leads to reduction in the forest areas.  The climatic impact of deforestation is first seen in the overall disruption of the global and regional ecological balance.  This means that the energy cycles in the flow of moisture (water) carbon, nitrogen and other element will be adversely affected.

• Atmospheric pollution

Atmospheric pollution is derived from many anthropogenic source in addition to some natural sources (already explained).  Industrial pollution of different kinds contribute to large quantities of emission of carbon dioxide and other green house gases to the atmosphere.

• Ozone Layer Depletion

Ozone layer is a layer of tri-molecular oxygen (O³) in the stratosphere called stratospheric ozone layer.  It functions as a screen (interceptor) of excess short wave ultra-violet rays to the lower layers.

Under normal conditions, the amount of insolation is effectively regulated by this layer.  The ozone layer has been discovered to be perforated (destroyed) in some parts, and so is producing what is called ozone hole.  Climatically, it is called atmospheric window.  The incidence f atmospheric window produces opportunity for increased insolation.

• Increased Green house Effect

This phenomenon has been discussed previously in connection with atmospheric pollution effect on climate.  Increased house effect is derived from increased production of carbon dioxide from sources deforestation, industries and agricultural activities.  The more the concentration of the principal greenhouse gases (CO₂, SO₂, NO₂, CH₄, etc.)  The higher the temperature of the lower troposphere. 

• Increased Urbanization

Effect of urbanization on climate change has been recognized.  Urban development produces large-scale changes in the character of the land.  Vegetation clearance and the introduction of new landscape features in the form of `tarmacked surface (tarred roads) concrete surfaces, open air surfaces have been carried out to investigate the existence of urban micro climate and the findings are that the temperature, rainfall, humidity and pressure system in the inner city are different from the surrounding rural areas.

Consequences of Climate Change

Climate change has far reaching consequence on the ecosystem as well as human welfare.

Examples of these consequences include:

• Sea level rise and flooding of continental water.
• Melting glacier
• Biodiversity loss
• Wide spread incidence of diseases
• Proliferation of disease vectors
• Poor productivity in agriculture
• Others: (Displacement of Isotherms)

1. Sea-level Rise

Climate change or the global warming type will cause the melting of glaciers and continental ice sheets.  The glacial melted water from the glacier will add to the existing level of the oceans thereby causing a rise in the level of the sea.

• Melting Glaciers

This point has been discussed in connection with sea-rise above.  There are several implications of the incidence of melting glaciers and the sheets.

First, this will result in the transformation of the ecosystems in such location.  Life forms like polar bears and other creatures will be threatened.

Melting ice may spell doom for mankind in the long run because it will cause excessive rainfall and flooding which may drown continental upland regions in different parts of the world.  This means large scale danger to human settlements both in the hinterland and as well as coastal and island locations.  The flood incidence envisaged by this incidence of glacial melt will be akin (close) to the biblical “Noah’s flood”

• Disease Vectors

Global warming caused by rising temperature levels will provide Favourable conditions for proliferation of disease vectors.

• Agricultural Productivity

Agricultural productivity will be adversely affected in some regions while in others it may be favoured.  For example, increased rainfall caused by temperature rise will work in favour of arid and high latitude areas while for the equatorial and tropical areas, it will generally be disfavored.  Poor productivity in agriculture in some regions will lead to emergence of food crisis.

• Shift in Isotherms

It has been predicted that climatic changes will likely result in the pole ward shift of the isotherms. This implies equatorial belts will shift northwards by about ten degrees (10^o) and correspondingly, other belts will undergo pole ward advance such that temperate belts will move pole wards in a pole ward shift.  This could lead to widespread dislocation of ecosystem across regions.

Solutions to Climate Changes

Incidence of environmental or climate change can be mitigated or addressed using a variety of measures which include reforestation, reduction in carbon emission levels through improved energy efficiency, introduction of clean development mechanisms, innovation in agriculture, population control, improved forest management, sustainable use of resources to ensure availability in the present generation and legislation and measurement of climate impact on society.

Improving Energy Efficiency

This requires changes in the techniques/technologies of production.  Energy-efficient technologies may result in reduction of the amount of carbon dioxide emitted to the atmosphere which will in turn reduce green house effect and global warming.

Clean Development Mechanisms (CDM)

Clean development mechanisms involves the use of energy sources that are pollution free. For example, the use of solar energy power, hydro-power, wind power and other energy sources that will contribute zero emission to the atmosphere.  The alternative energy sources will cause the reduction in CO₂ and green house emissions.

Agricultural Innovation

Innovation in agriculture requires a wide range of approaches to be adopted to achieve environmentally friendly practices.  This may involve adoption of methods like intensive cultivation involving better methods of soil management, employing the method of mixed farming, reducing over grazing and adopting the method of livestock ranching among others.

Such innovations will reduce deforestation as well as curb overgrazing of areas.

Population Control Measures

Measures of population control are diverse but they all aim at reducing exponential (spiraling) growth of population.  It has been recognized that the greatest enemy of the environment is increased population.

Improved Forestry Management

Improved forestry Management will involve adoption of different strategies aimed at curbing excessive exploitation of forest resources.

For instances, introduction of other sources of domestic fuel supply may cut down aggressive exploitation of wood for fuel from the forests.  The use of kerosene, gas and other energy sources will divert attention from dependence on fuel wood.

Legislative Measures

This involves enacting laws to protect the environment from unwanted destruction.  Legislation may come in the form of principles, guidelines, protocols, treaties and declarations all aimed at regulating and controlling the use of environmental resources in a more sustainable way.