Quality Tale - News on Technology: Global Warming

Global warming (also known as the greenhouse effect) is the term describing the gradual warming of the atmosphere due to the build up of certain gases - principally carbon dioxide (CO2) but also Methane (CH4), Nitrous Oxide (N2O), Hydorfl jorocarbons (HFCs), Perfluorocarbons (PFC), Sulphur hexafluoride (SF6) and some ozone depleting gases. These gases are transparent to incoming solar radiation but reflect back a proportion of the resulting heat radiation from the earth. The Earth's total carbon balance is determined by the store of carbon in plants, the oceans, held in reserves of fossil fuels and the amount of carbon dioxide in the atmosphere. So the burning of fossil fuels affects the balance in one way by releasing more carbon dioxide. Deforestation also affects the balance because trees absorb carbon dioxide during photosynthesis. Over the last hundred years there has been a 25% increase in the amount of carbon dioxide in the atmosphere.

There is much scientific uncertainty around the rate at which global warming is occurring and whether the resulting climatic changes will be offset by other factors. However, there is currently a consensus that global mean surface temperatures are projected to rise between 1.4 and 5.8 degrees centigrade by 2100. Global mean sea levels are expected to rise by 9 to 88 cm flooding low lying coastal areas. This may also lead to:

- changes in rainfall patterns increasing the threat of floods in many regions; climate becoming more variable with greater threat of extreme weather events, such as intense storms and heat waves.

- changes in agricultural productivity as patterns of climate shift and change in different regions.

- increased risk of abrupt and large scale events, for instance the weakening or complete shut down of the ocean thermohaline circulation (such as Gulf Stream), or the collapse of Greenland and West Antarctic ice sheets. The likelihood of such devastation effects occurring in the next hundred years is remote, it increases with the rate and scale of global warming.

The effects of climate change can already be observed, for instance, in earlier flowering of plants and egg-laying in birds.

The climate system is very complex and he scientists still need to improve their understanding of the extent, timing and impacts of climate change.

Global warming is a particularly difficult issue to control as it is closely linked with the use of energy for industrial processes and with the destruction of habitat to make way for development. However, in 1992 an agreement was drawn up at the United Nations Conference on Environment and Development (known as the Rio Earth Summit). This took form of United Nations Framework Convention on Climate Change. Ninety countries signed the International Agreement on Climate Change, which commits developed countries to stabilising emissions of carbon dioxide and other greenhouse gases not covered by the Montreal protocol by 1995 and reducing them to the 1990 level by 2000. Unfortunately, it is unlikely that most of the signatories will succeed in reaching their target. The target in itself is insufficient to stabilise global temperatures.

This event was followed by he Kyoto Protocol dated 11.12.1997, in which the developed countries (also called Annex 1 countries) committed themselves to specific targets in reducing the net emissions of greenhouse gases not covered by the Montreal Protocol (see Depletion of Ozone Layer). The parties committed to reduce the emissions of such gases at least five percent below the 1990 levels. The commitments to reduction of emissions by the parties vary from 92% to 94% of base levels. Some countries committed to certain specific limits varying between 100% to 110% of the base year level.

The protocol requires countries to establish systems for monitoring of anthropogenic emissions of listed green house gases from the listed sources and removal of such gases by sinks (forests).

The greenhouse gases covered include:

- Carbon dioxide (CO2),
- Methane (CH4),
- Nitrous Oxide (N20),
- Hydorfluorocarbons (HFCs),
- Perfluorocarbons (PFC),
- Sulphur hexafluoride (SF6)

In order to minimize the costs of reductions of emissions in developed countries and also to stimulate. reductions in other countries (also called non-annex 1 countries), two market based mechanisms were established:

- Clean Developed Mechanism (CDM) in which developed countries can "buy", reductions in developing countries

- Joint Implementation (JI) in which developed countries "buy" reductions from other developed countries.

The protocol has to be ratified. by the parties representing not less than 55% of total carbon dioxide emissions in 1990 before it will enter into force. Most unfortunately the current refusal to ratify the protocol by USA and Russian Federation made it virtually impossible, for USA represents 36.1% and Russian Federation 17.4% of base year emissions.

Even if the Kyoto Protocol does not enter into force, the European Union (EU), Japan, Canada and other countries are taking actions to reduce their emissions. In Europe, for example, the EU Emissions Trading Scheme (EU ETS) makes reductions mandatory for more than 17,000 facilities starting in 2005.

Friday, March 20, 2009

Global Warming - Need To Think

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