Global Warming - the Greenhouse Gas Illusion? Earth Is Set to Cool Writes Julian Hodge Lecturer Prof Beenstock
Byline: Julian Hodge
Greenhouse gas theory predicts that if the level of atmospheric concentrations of greenhouse gases increases, global temperature rises because it is more difficult for the heat of the sun to escape the earth's atmosphere.
A key greenhouse gas is carbon dioxide, which is primarily influenced by carbon emissions due to energy production.
Although many climatologists disagree, it has become an accepted fact that carbon emissions threaten to r se global temperature during the 21st century by 3-4 degrees C after increasing by about 0.7 degrees during the 20th century.
Greenhouse gas theory was the driving force behind the Kyoto Accords, the EU decision to limit carbon emissions, and the recent Copenhagen conference on climate change.
President Obama's decision to take the greenhouse effect seriously has given the greenhouse scare a major political boost.
In the mid-1970s climatologists predicted a new ice age following the fall in global temperature in the 1950s and 1960s. Now they are predicting the opposite following the increase in temperature in the 1970s and 1980s.
Recent evidence shows that since the early 1990s global temperature has stabilised once more. Maybe climatologists will change their minds yet again.
My main contention is not that climatologists are prone to change their minds, but that they make poor statisticians.
They are particularly poor at analysing trending data, such as global temperature, solar irradiance and atmospheric greenhouse gases.
Their main mistake has been to fall into what statisticians call the 'spurious correlation trap'. Just because two variables happen to trend together and are therefore correlated does not necessarily mean that they are causally related.
There are after all many variables that tend to increase or decrease over time, and are consequently even highly correlated, but in fact are completely independent.
The absolute correlation between GDP in the UK and the flow of water in the River Jordan exceeds 0.8, but this is obviously spurious. The world is full of such spurious correlations.
In recent research I show that the correlation between carbon emissions and global temperature is yet another example of spurious correlation.
It is not that greenhouse gases have no effect on global temperature. …