Global Warming and Climate Change
This is a main global environmental concern presently, with profound implications for the way the world generates and consumes energy. It is now an accepted reality which global warming is taking place due to the enhanced Greenhouse Effect.
Energy related human activities are leading to excessive concentration of greenhouse gases (GHGs) such as carbon dioxide, water vapour, methane, nitrous oxide, chlorofluorocarbons (CFC), ozone, halons and Peroxyacetylnitrate (PAN) in the Earth's atmosphere. These gases trap the heat reflected from the Earth's surface and do not permit it to escape into space. This increases the temperature of the atmosphere. In trace amounts, gases like CO2 make the Earth warm sufficient to sustain life. This is the natural greenhouse effect. In excessive amounts, these gases can be extremely harmful as you will learn in this section.
The Greenhouse Effect is enhanced because of human habitations and several human activities particularly in the industrialized countries. More than two- thirds of the world GHG emissions originate from the energy sector in processes such as energy production and energy end-use in several sectors such as industry, transport, agriculture, power sector, etc. Other sources involve activities in residential and commercial areas.
Figure: Human Activity Related Annual GHG Emissions (sector-wise) in 2000 AD
Energy production technologies such as thermal power plants and the combustion of fuels in several activities like heating, cooking, transport, industries and etc., add greenhouse gases to the environment. It is now well established in which the increasing greenhouse gases will cause the Earth to warm so fast that we might not be able to adapt to the resulting changes.
It is predictable in which the global temperature will increase through another 1.5 to 4.5°C sometime in this century if we do not take drastic measures. Some scientists have begun referring to global warming as global heating - this is meant to be a wake up call for the world!