Is Global warming Natural or Man-made?

However, is all the information that we receive from the public, environmental groups, the media, government and scientists reliable?

The greenhouse effect – A natural Cause –The Science

For a start global warming increases with an increase in the level of the heat absorbing gases. Our earth atmosphere is like a filter. It absorbs some of the ultraviolet light and visible light but reflects the others. The 50 % of radiation that does get through gets to the earth’s surface and warms it up then it gets reflected back in to space in the form of infrared radiation. Greenhouse effect is the when the infrared radiation is unable to leave the atmosphere. Radiation from the earth’s surface varies in wavelength with temperature. These are the greenhouse gases and, in order of importance, water vapor, carbon dioxide, methane and nitrous oxide. Each greenhouse gas gets absorbed at certain wavelength range. When the molecules absorb radiation it vibrates causing it to emit infrared radiation in all directions into the atmosphere and earth’s surface. This leads to increased temperature. This contributes to climate change. This is a natural cause. I have illustrated a picture showing what happens in the greenhouse effect:

Continental drifts, volcanoes and ocean currents also contribute to the earth’s global warming.

Global warming- Man made – The Science

In 2007 many scientists said that global warming was caused by humans. Many of this was caused by combustion of carbon based fossil fuels. These gases are also part of the greenhouse gas family, for example carbon dioxide, methane and nitrous oxide. All of these are emitted. All these gases contribute towards to the atmosphere’s layer. These are permeable to ultraviolet light, but are not to infrared radiation. As more and more fossil fuels are burned the atmosphere layer will get thicker and thicker. All this warms the atmosphere up, this is called global warming. If we reduce deforestation and conserve fossil fuels we will have more chance of infrared radiation going out of the atmosphere. We cannot prevent the atmospheric layer from absorbing in visible and light radiation. Below I have shown a picture showing man made contribution towards global warming:

Chlorofluorocarbons, I personally think that this causes an awful lot of damage. The CFC’s trap heat and also make the protective ozone layer thin. This will accelerate the process of climate change.  According to CFCs absorb 20,000 times as much heat; however as however international decisions have been taken to decrease CFC emissions and help stabilize CFC levels in the air.

We need radiation from the sun. The Greenhouse effect is definitely real because of the fact that it keeps the Earth warm, whereas if there was no greenhouse effect it will be 30 degrees colder, which will be extremely cold for the existing life on earth.

Evidence

The evidence for scientists blaming human activities for global warming has been provided by supercomputers. These are computer climate models, based on different amounts of carbon dioxide in the atmosphere; produce the same changes as have been observed in the real world. These models show short to medium impacts on the increase of global warming. The models show the increase in warmth but no what the cause is.

The daily mail in 2007 - many experts said that global warming was a natural cycle. They thought it was due to a natural 1,500 year cycle. 2007 was the highest record for global warming. At that time many scientists said that climate was more likely to be part of a cycle of warming and cooling which happened every 1500 years they said.

In 2007 a climate physicist called Fred Singer, thought that the slighter warmer climate with the carbon dioxide in many ways was beneficial rather than damaging. Economic studies showed him that modest warming and higher Co2 levels was going to increase GNP and also raise the standards of living. He thought it will improve agriculture and forestry. He knew that Co2 was a plant food and it was vital for the growth of various crops and trees. He said that climate had been changing clinically for the last million years and had shown a huge variation over geological time. He also stated that humans had adapted, and will carry on doing so.

In 2008 some experts doubted the data supporting the global warming theory. The exact temperature records only went back few hundred years, this was only a short term trend, and nothing could have predicted using this. They tried measuring sea levels but it was too hard on a planetary scale.

Jim pinto, an environmentalist, in 2010 wrote a balanced argument on manmade and natural causes. He said that 18,000 years ago the earth emerged from the ice age. There has been a variation of temperature over millions of year’s history.  His solution was to reduce human effects through emissions. He also said to not spend the national budget trying to stop or reverse the natural process.

On both sides of the argument, the data is misintertpresnted or misused. Politicians on the other hand just provide a cause to support man made global warming. It is not the job of politicians to sort the fact and opinion about global warming.

So what is the answer is global warming man made or natural?

Above I have my scientific theories of various manmade and natural contributions to global warming. I also gathered information from sources and noted down some strong evidences. I am now going to sum everything up and give my final opinion.

Evaluation

Many natural activities have been scrutinized in the past by a minority of scientists; many others including the (IPCC) are blaming humans for the cause of global warming. Many people have been affected by global warming, for example hurricanes are cause by the warm water from the seas. Many oceans and seas absorb a lot of radiation, which makes the water warm. I do agree that this has been a problem with the natural activities, but humans should also be guilty for this. If there had been less fossil fuels burned, less deforestation and less CFC’s, we could have kept the edge of the atmosphere very thin. If we did have, we would have been able to reflect more infrared radiation out of our atmosphere. We have to bear in mind that natural activities have been happening since earth was created, there could have not been a sudden plunge in warming in the world.

Bibliography

1.  - undated

2.  - 21st November 2009.

3.  - 21st December 2009.

4.  

5. Collins GCSE science Revision Guide --- Page 24 – showing greenhouse gases.

6. Image showing atmospheric radiation – Google images

7. Image showing man made causes – Google images

8. Image showing temperature increase – from NASA website.