Global warming is a popular buzz-word among politicians and the media and an issue that we are constantly being reminded of. However if you have read up on the subject further in your own time, then you might have also heard other murmurs – that global warming is in fact not a man-made event at all, and that it is rather just a natural cycle that the planet is going through and that it has occurred before. In fact some researchers claim that the effects of the cycle are not entirely negative and that it is in some ways a positive effect. So what are we to believe?
The belief among some researchers is that the cycle occurs regularly (though estimates as to the length of the cycle vary between 1,500 and 40,000) and has done so for the last million years. Allegedly while this will lead to various negative effects, it is still nonetheless preferable to the cold phases of cycle which have historically killed around twice as many people as the hotter periods. Previous examples of these ‘cold’ periods in history were the ‘dark ages’ and the ‘little ice age’ – both of which brought storms, famine and plagues.
Of course it is also believed that global warming has occurred before, the most recent previous case being between 1850 and 1940. Paintings from a point in the middle ages that featured bluer skies are meanwhile seen as evidence for the ‘Medieval Warming’. These same global warming ‘sceptics’ have also been quoted as claiming that the current global warming has also been blown out of proportion – that the damage to corals and wildlife has been exaggerated and that there have actually been fewer storms and droughts.
This evidence seems to suggest a shorter (roughly 1,500 year) cycle. This is believed partly to be due to a ‘wobble’ in the Earth’s rotation that brings the planet further and closer to the sun over thousands of rotations. However other evidence suggests a longer cycle such as the existence of the Cretaceous Period – a prehistoric time on Earth when the temperature was far hotter than today and this could be due in part to changes in solar activity.
Man made causes are referred to as ‘anthropogenic’. Models for global warming that predict a continual rise in the temperature are based on more recent data and do not address the causes of the warming.
So does this mean that global warming is a natural and inevitable cycle? Does this suggest we are being overly cautious and overly worried? Of course this is a subject of much debate, but the reality remains that regardless of the natural causes of global warming, by unleashing CO2 into the atmosphere and destroying the trees and plant life that could otherwise convert it back to oxygen, means that we are undoubtedly further contributing to this change and according to some scientists anthropogenic causes outweigh the natural causes.
And this is something worth bearing in mind – partly the reason that the planet cooled down again following the Cretaceous period was that the CO2 in the atmosphere was eventually buried and transformed into fossil fuels such as oil and coal. The very same fossil fuels we are now burning in high quantities. And regardless of how much of global warming is man-made, it certainly doesn’t hurt to stop contributing more to it and to allow the planet to take its natural course uninterrupted.