> The Greenhouse Effect
> Environmental Policies
dijous, 4 de març de 2004
The Catalan Government's Advisory Council for Sustainable Development has drawn up a report on climate change in the Principality of Catalonia, which predicts an average temperature increase of approximately 3.5º C by the end of the 21st century. The report also confirms that the 1990's was the warmest decade on record.
This increase in the temperature on land will have various consequences, such as a rise in sea level, with a subsequent risk of flooding, and the earlier arrival of spring, which would affect the ecosystems.
Moreover, a few days ago there was news of another report written by the U.S. Defence Department, the Pentagon, which warns of the risk of a climactic catastrophe that may lead to global military conflicts because of the scarcity of sources of energy and basic resources such as food and water. This report, which was supposed to be secret, was discovered by the British newspaper The Observer.
Both these reports testify to the importance of predicting climate change, which is of increasing concern to people and institutions around the world. We shall now go on to discuss the causes and consequences of this climate change.
The Greenhouse Effect
+ The pollutant gases cause an increase in the Earth's temperature.
Thanks to the warming energy of the Sun, the average temperature on the Earth's surface is approximately 15º C, and this is ideal for there to be life on Earth. This temperature remains more or less constant because part of the solar energy, which reaches us in the form of infrared rays, is reflected towards the Earth by a set of gases, thereby preventing it from going back up into Space. Carbon dioxide, methane, ozone and water vapour are some of the gases that allow this phenomenon, known as the greenhouse effect, to occur it is absolutely necessary to stop our planet from freezing. The problem comes when man uncontrollably emits pollutant gases into the atmosphere, causing an increase in the greenhouse effect and, consequently, an increase in the Earth's temperature.
This continued increase in temperature could have various consequences, some of them very severe, both from an environmental and an economic point of view. One of them would be the thinning of glaciers on mountaintops and at the polar ice-caps, which would in turn cause a rise in the sea level and therefore flooding. Another would have the opposite effect: the desertification of some areas of the planet because of more severe droughts. There might also be a spread of diseases that are typical of the tropics to areas with a temperate climate, or there could be major changes to our ecosystems, with the risk that various animal and plant species become extinct.
Because of all the above, for several years now there has been a debate on the measures to adopt in order to remedy this gradual warming of the planet. The starting point was in 1992, the year of the Earth Summit in Rio de Janeiro, at which the United Nations Framework Convention on Climate Change was approved, with the aim of stabilising pollutant gas emissions. Five years later, in 1997, thirty-eight states committed themselves to reducing the emission of greenhouse gases, under the Kyoto Protocol. Today, the number of states that are signatories to this protocol has grown to eighty-four, and they make up 44.2 % of the total emissions. Unfortunately, there are still states that have not ratified it, such as the United States, the most polluting country in the world.
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