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Difference between revisions of "Climate change"
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|See also the Climate change category.|
for subtopics, how-tos, project pages, designs, organization pages and more.
Climate changeW is a significant and lasting change in the Earth's climate over an extended period. In this article we discuss the impact of a rise in the average temperature of the Earth's atmosphere and oceans from the 19th century to the present.  Climate change is expected to have far greater negative effects on developing countries than on developed countries due to numerous factors including exposure to extreme weather and infrastructure considerations.
- 1 The science of climate change
- 2 Uncertainties in the impact of global warming
- 3 natural change in climate
- 4 Climate change mitigation
- 5 Climate change chain reactions
- 6 Climate Change on the Ocean
- 7 Notes
- 8 See also
- 9 Interwiki links
- 10 External Links
The science of climate change
Although the existence of the greenhouse effect has been largely understood since 1896, there are still a tiny minority of scientists who remain critical of specifics written in some reports of the IPCCW and other organisations. These so-called climate change skepticsW are generally misinformed or are deliberately attempting to create doubt and uncertainty about the science.
Certain politicians, lobbyists and economists refer to disinformation from climate change 'skeptics' for their own advantage, portraying an image that climate change does not exist, poses but a minor problem, or may even be beneficial so as to be able to prevent action to reduce greenhouse gases (mostly resulting from the burning of fossil fuels). The GWPF in the UK is an example of a political lobbying group, which is secretly funded by fossil fuel interests.Guardian article on the secret funding of the GWPF
Uncertainties in the impact of global warming
Although climate change itself has been proven, there are some remaining uncertainties in predicting the effects. The IPCC is highly confident that impacts will increase as greenhouse gases and associated positve feedback effects kick in (methane release from melting permafrost), though their severity and the timescales may differ to some extent:
- changing weather patterns (greater or fewer precipitation on specific areas, the weather is also expected to be much more radical). This will negatively affect farming
- natural disasters (ie mud slides, hurricanes, ...) are expected to occur much more frequently. Death toll in 2003 = 150000 people 
- Sea-level rise will contaminate a very large percentage of the agricultural fields with sea salt and make them no longer suitable for continued food production. In addition, many low-lying islands and coastlines will need to be abandoned, forcing many people to move.
natural change in climate
The term "climate change" is often used to describe the impact of human-caused pollution on the earth's climate. It is important to understand, that climate change is also caused by natural phenomenons.
History of Ice Ages The earth is subject to large fluctuations. The biggest fluctuations are ices age, which drop the earth's surface temperatur and cover parts of the surfice in ice. There are only 5 know ice ages to date, that have lastet from 30 million up to 300 million years. The most recent one is "Quaternary", which started about 2.5 million years ago and is still lasting. In between ice ages, the poles are not covered by glaciers and the temperatur is higher. The climate is quite stable in these periods, however during ice ages strong variations occur. These variation are called glacial (cold) and interglacial (hot) periods. Glacials and interglacials alternate every 5,000-15,000 years. The current interglacial period started 14,000 years ago.
Climate change mitigation
Several options are available to reduce the impacts of a changing climate. Most of these (the most efficient ones) are lifestyle changes (i.e. stop the burning of fossil fuels, stop eating meat etc.) and can be put in place today. We also do not need to wait for any specific technology to became available. Rather, the essential technology is already here today. Politicians often portray a different picture but it is not based in reality. Selected options include:
- Reduce the release of greenhouse gasesW (GHG's) into the atmosphere (ie through energy efficiency, ...)
- Prevent carbon dioxide from being released into the atmosphere (ie through carbon capture and storage (CCS), biochar, ...). With Carbon sequestration/CCS, after combusting a fuel, the CO2 is stored in a cavity underground.
- Remove carbon dioxide from the atmosphere, e.g. through geo-engineering ocean fertilisation, planting extra trees, ...
- Shield some of the atmosphere from the sun or reflect a proportion of sunlight back into space (ie by painting roads, parkings and roofs white, spraying sulfate aerosols into the stratosphere, ...)
- Climate change mitigation: build heat tolerant houses (passive solar with suitable insulation), flood control barriers, ...
- Grin and bear it: put up with the inconveniences and the expected loss of biodiversity and increases in certain types of natural disasters and wait for extinction.
The IPCC already considers a 2°C temperature rise is inevitable. In addition, it also advises the use of most other measures, yet stays critical of geoengineering options, due to the dangers involved.
Climate change chain reactions
The change in temperature and weather has a huge impact on wildlife which can become dangerous if the change stays the same.Even the minor change of temperature can lead to earlier hatching of insects or melting of snow which protects snow rabbits from their natural hunters.These effects cause problems like insect overpopulation or too less surviving rabbits to reproduce sustainably.The insects are dangerous because they consume crops and other plans and in huge amounts they are even able to consume a whole field of possible food.Because this problem is getting bigger and even endangers species and if it goeas on like this many species will die out and even our own food capacity may shrink exponentionally.
Climate Change on the Ocean
Earth is called the blue planet because approximately 72 percent of it are covered by oceans. The oceans influence the weather on local to global scales, while changes in climate can fundamentally alter many properties of the oceans.
Ocean conveyor system
The thermohaline circulation also called the great ocean conveyor belt or global ocean conveyor belt, is a large scale ocean circulation that distributes vast quantities of heat and moisture around on a planetary scale.
Gulf stream has the length of 10000 km. It is one of the largest and fastest ocean current on earth. At 2 [math]m/s[/math], it brings 100 000 000 [math]m\lt sup\gt 3\lt /sup\gt /s[/math] towards Europe.
Sea level rise
As water gets warmer, it takes up more space. Each drop of water only expands by a little bit, but when you multiply this expansion over the entire depth of the ocean, it all adds up and causes sea level to rise. But that's not the only cause of the rise of sea level. The rise of sea level also caused by the melting of glaciers and polar ice caps and ice loss from Greenland and West Antarctica.
Ocean acidification is the ongoing decrease on ocean pH cause by human CO2 Emission. Ocean pH has decreased by about 30% already and if we continue emitting CO2 at the same rate by 2100 ocean acidity will increase by about 150%, a rate that has not been experienced for at least 400,000 years. Such a monumental alteration in basic ocean chemistry is likely to have wide implications for ocean life, especially for those organisms that require calcium carbonate to build shells or skeletons.
- http://earthobservatory.nasa.gov/Features/Water/images/precipitation_intensity_map.png Precipitation changes
- One solution is to grow less fragile crops, ie more resistant to changes in watering
- 150000 people killed by global warming upto 2003
- Sea level rise: 2m rise expected by 2100 A.D., 6,5m by 2200 A.D.
- Earth under water documentary
- Note: this direct temperature reduction does not reduce carbon levels, so ocean acidification from higher carbon dioxide is still a problem
- Renewable energy
- Incentives for sustainability
- Sea level rise
- Measures to stop global warming