It has long been known that greenhouse gases contribute to global warming. In 1827, Jean-Baptiste Fourier suggested that greenhouse gases kept the earth warmer, whilst in 1938 an Engineer, Guy Stewart Callendar predicted that doubling the concentration of carbon dioxide from fossil fuel burning would lead to a global increase of 2 °C, with the poles warming more.
This was a remarkable prediction, since it is exactly on course to what we observe today! Calendar's predictions were later confirmed by several independent but more detailed studies in the 1970s, including one by an elite group of ex-military physicist's dubbed the 'Jason's'. By the 1990s professional climate scientists armed with an extensive range of measurements and calculations had removed all reasonable doubt that human activity was causing global warming. Even scientists in the oil industry agreed with them.
So only as the evidence became undeniable did the fossil fuel businesses realise they might have confront the growing political pressure to reduce global warming. As a consequence, they employed a host of public relations experts, many who had successfully delayed regulations against the tobacco sector, to weave a web of misinformation using a variety of unscrupulous media and various 'junk science' websites. Their methods were not based on physical science but psychology by targeting uneducated and scientifically illiterate people using tried and tested methods of persuasion. This included peer pressure, misrepresentation, over-simplistic arguments, reiteration of falsehoods, attacks on individuals and groups, and claimed threats on personal liberty and wealth.
The main object was not to win, but provide the impression of an informed 'debate' and to cast 'sufficient doubt' on climate science by spreading confusion and uncertainty. This would allow these businesses to fight a delaying action to avoid regulation, and thereby impose an enormous cost to future society. This highly co-ordinated campaign has lately been supplemented by attacks on the climate scientists themselves using misleading cherry picked extracts from stolen Emails attempting to implicate them in fraud. Yet what a close examination of these documents reveal is a genuine but frustrated profession who are constantly being misquoted, misrepresented and attacked by media savvy and politically motivated groups.
Whilst more than 97% of scientists who are active publishers in the field of climate change accept the reality of AGW (anthropogenic or human induced global warming), a very small number of climate scientists and non-specialists lured by money from the fossil fuel lobby were successfully recruited into the Climate Denial camp. Their names often appear in petitions, mixed with fake identities and even the decreased, to make it appear as if there is a substantial proportion of scientists which oppose the AGW consensus.
The Scientific Reality:
A large number of studies using a variety of direct and proxy measurements of historical temperature and greenhouse gas concentrations further support AGW. Combining these tell us that the present world climate has probably never been warmer over the last one to two thousand years than at present and possibly for as long as 100,000 years. More importantly it shows that there has been an unprecedented warming over the last hundred years and in particular the last thirty. The probability that this change has occurred naturally just as we have released vast quantities of greenhouse gases into the atmosphere is very unlikely even if we ignore the more direct evidence from satellites and calculations. As all other reasonable influences have been extensively studied and discounted, we can be assured beyond reasonable doubt that the current bout of global warming is mainly caused by the release of greenhouse gases from fossil fuel burning.
However, greenhouse gases are not the only influence on temperature, there are other man made and natural causes at work, some which cause cooling as well as heating, and to determine the precise effect of each, these need be isolated. To do this requires the use of more detailed models that have been produced compared and scrutinised by some of the world's finest climate scientists.
Climate models combine all this data together and confirm the common sense notion based on temperature trends and satellite measurements that greenhouse gases are mainly responsible for the current surge in global warming and will continue to cause substantial further increases unless they are substantially reduced. However, although the basics behind global warming are firmly established and is well supported by observations, science of this type always throws up odd anomalies. This provides opportunities for Deniers to misrepresent and undermine the conclusions reached by the substantial majority of scientists on what must be the most studied and scrutinised phenomenon in mankind's history.
In addition to the reduction in sea ice area in recent years there has been substantial thinning of the ice, and there was probably less volume of ice in September 2009 than in any previous year in recorded history. In fact the Arctic sea ice is on course for disappearing completely within a few decades during the summer months.
Be aware that the information from the Intergovernmental panel on Climate Change (IPCC) will usually be out of date by the time it is published, and it is always conservatively written due to political pressure. In the last report they had to tone down statements about climate feedback effects that should have been emphasised. This is itself worrying since the worst case scenarios are by far the most costly and disruptive and should be entered into the overall cost benefit equation. It is akin to your insurance company not allowing for the possibility of your house burning down because it is unlikely to happen! No wonder the IPCC have been accused of corruption for not being alarmist enough! It seems they are stuck between a 'Rock and Hard Place'.
The US military provide a useful independent view on global warming and are far less reticent about these issues. In their report 'National Security and the threat of Climate Change', they include a section on 'abrupt climate change' not addressed by the IPCC scenarios which include the possibility of the rapid increase of sea level due to the break-up of glaciers caused by these feedback effects.
Based on all this evidence, one might think any Climate Denier would have to be very sure before challenging the established view, yet they resort to a variety of unscrupulous techniques ranging from distortion to outright lies. This demonstrates either their naivety or callousness of their ideology.
Unless rapid action is taken to circumvent the onset of irreversible warming it will be impossible to stop the large-scale loss of habitat and large-scale land loss resulting in human migration, substantial economic cost and political turmoil in the long term. In view of the need to find alternative energy sources as well, the argument for concerted action to prevent global warming is indisputable.
The common myths and answers to global warming questions are widely available from reputable sources but are simply ignored by climate Deniers because their purpose is not to inform but confuse and mislead. Don't be swindled by them or allow their own ignorance or selfish motives destroy opportunities for future generations.
Denierism unlike other lunatic conspiracy theories such as the 'faked moon landing' would be amusing if it wasn't so dangerous, irresponsible and selfish if not down right criminal. This is something that cannot be easily reversed. Once the Arctic sea ice melts in summer, the sunlight is absorbed onto the darker surface of the water, this warms the surface further. Also when the land permafrost melts, masses of the potent greenhouse gas methane will be released. Both these lead to what climate scientists call a positive feedback effect, a rapid increase in global temperature which cannot be subsequently controlled by reducing greenhouse gases. AGW isn't just a theory predicted by models, this effect can be experimentally observed in the laboratory and a large number of sensors and instruments rely on the same principles to function. Moreover, satellites have measured a significant decrease in outgoing radiation at the wavelength bands associated with the main greenhouse gases as their concentrations have increased. This provides direct experimental evidence of the greenhouse effect in the atmosphere and removes any doubt that the increase in greenhouse gases MUST be having some effect.