Climate and atmospheric scientists that hand in reports to the Intergovernmental Panel on Climate Change (IPCC) say that we are already experiencing man-made global warming effects and there is a fear of the warming escalating out of control.
Scientists discern climate change in tree rings, coral reefs and in gas bubbles from ice-cores taken in Antarctica or in Greenland. The ice-cores show that the world has not experienced this degree of warming in many thousands of years. The three warmest years on record have been measured from 1998; the 19 warmest years are from the year 1980. The Earth has most likely never in its history warmed as rapidly as it is at this moment and during the last 30 years – when changes on the sun and aerosol from volcanic eruptions should have cooled the atmosphere. Rather, the Earth is getting warmer and warmer and investigation into the heat capacity of the oceans show that more global warming is expected.
We, human beings, are responsible for those changes by burning enormous amounts of fossil fuels, oil and natural gas. We release billions of tons of carbon dioxide into the atmosphere each year, but the changes really first began when agriculture started in Mesopotamia around 8000 years ago.
If the present emission of gases continues, the amount of carbon dioxide in the atmosphere will double during this century from pre-industrial levels. That will most likely result in an increase of global mean temperature from around 2°C to 5°C. There will certainly be significant warming, but how significant depends on factors and feedback loops involving melting of ice, ocean temperature, water vapour in the atmosphere, clouds and changes in vegetation.
As natural habitats and ecosystems are damaged, the biodiversity of life is threatened. Most species cannot adjust fast enough to adapt to such drastic climatic changes. Some scientists, therefore, simply assert that there is an ongoing mass-extinction of many species taking place today and that the rate of extinction will increase when the full impact of climate change hits the planet.
The heat expansion of the ocean waters due to global warming along with increasing volume due to melting land ice will most likely cause the sea levels of the world to rise. Human impact could cause a large scale melting of the Greenland ice cap and at the same time parts of the west Antarctic, ice mass could melt. This kind of melting would cause, at a minimum, 6 meters rise in sea levels, enough for the ocean to inundate land where billions of people live.
Temperatures could become even more scorching if it were not for the sulfuric aerosol and ash emitted from industry and from volcanic eruptions into the stratosphere where the aerosol has a cooling effect. Forests and the ocean also absorb around half of the carbon dioxide we release into the atmosphere. But it seems that the Earth cannot absorb more CO2, at least its concentration is constantly rising in the atmosphere. Recent research indicates that peat marshes and forests that used to bind carbon dioxide are really slowly becoming carbon emitters instead of being carbon sinks.
The main greenhouse gases are carbon dioxide, water vapour, methane, and chemicals such as SF6 that can stay for thousands of years in the atmosphere. Carbon dioxide is formed by burning fossil fuels in industry and by burning vegetation and forests. Methane is released from ruminants, marshes from the permafrost areas of the northern hemisphere that are melting because of the warming climate. Some of the greenhouse gases like CFC-gases are totally man-made.
Ways of combating climate change:
- Technical solutions – polluting less
- Technical solutions – removing CO2 from the atmosphere
- Changed lifestyle – consuming less and less burning of oil and fossil fuels
- Education – educating about climate change
Ingibjörg Elsa Björnsdóttir „Hnötturinn“, Náttúran.is: Oct. 28, 2012 URL: http://www.nature.is/d/2007/06/26/hnotturinn/ [Skoðað:April 23, 2021]Efni má nota eða vitna í samkvæmt almennum venjum sé heimilda getið með slóð eða fullri tilvitnun hér að ofan.
skrifað: June 26, 2007
breytt: May 21, 2014