The idea of the "tipping point" is fashionable, cogent and attractive. It is a concept that applies in many walks of life. But like any compelling concept, it is sometimes applied inappropriately.
The climate alarmists are warning of a tipping point in the Earth’s climate. Unless we take urgent action to halt carbon emissions and to mitigate global warming, they say, terrible consequences will follow. Earth’s ice-caps will disappear. The Gulf Stream will stop. The tundra and the perma-frost will melt, releasing vast amounts of methane and CO2. We shall create a positive feed-back loop. We shall face an unstoppable, self-reinforcing, exponential rise in global temperatures which will threaten the very survival of mankind.
The alarmists are behaving as if 2008 were Year Zero. If we had no history of the Earth’s climate, no basis on which to judge, then there might indeed be some grounds for considering scientific theories and fanciful speculation of this kind. But the world is four and a half billion years old. We have a good knowledge of climate history, and they should pay attention to it. The very modest warming we have seen over the last 150 years is entirely within the normal range of variation, and perfectly consistent with well-established cyclical climate patterns over the last ten thousand years. We see warmer and cooler periods every 1200 years or so. We had the Roman Optimum, followed by a cool period in the Dark Ages, then the Medieval Warm Period, followed by the little Ice Age, and now we are moving to a 21st-century Optimum. There is no reason to invoke special pleading and human activity to explain a perfectly natural phenomenon.
The world is cooler now than it was during the Holocene Optima, the
Roman Optimum or the Mediaeval Warm period. There was no run-away
warming then: there will be none now. The world was much warmer than
today, for extended periods, over geological time, but there was no
tipping-point, no runaway heating, no global holocaust. Nor is today’s
level of atmospheric CO2 particularly high by geological standards. At
one point CO2 levels were higher than today’s. Much higher. Indeed
they were over ten times higher. Was there run-away global warming?
There was not. In fact the exceptionally high CO2 level occurred
during an extended Ice Age.
Viewed against climate history, we can see climate alarmism for the modish claptrap that it is.
That is not to say that there can never be a tipping point in the
world’s climate. In fact the record shows repeated tipping points.
Few people realise it, but for a million years the world has been
locked in an Ice Age, punctuated every hundred thousand years or so by
inter-glacial periods of relative warmth. The reasons for this
cyclicity are not perfectly understood, but it seems to be driven
primarily by astronomical cycles. And the changeover from Ice Age to
inter-glacial seems to happen rather suddenly, over a relatively short
period. This is indeed a tipping point. The current inter-glacial,
which has contained the whole history of human civilisation from the
earliest cities of the fertile crescent, has lasted about ten or twelve
thousand years. And that is typically the length of an inter-glacial.
So unless human activity has put an end to astronomical cycles, the
next tipping point will herald not runaway warming, but runaway cooling
(and let’s hope we have nuclear fusion on line by then, or we’ll be
So you can stop worrying about global warming. Worry instead about a mile of ice over Edinburgh.
FREE CLIMATE CHANGE DVD
Roger Helmer has just published a DVD entitled "Straight Talking on
Climate Change". He argues that climate alarmism is misplaced,
pointing out that the world has cooled in the last ten years (and
cooled sharply in 2007); that increases in atmospheric CO2 from current
levels will have a trivial impact on climate; and that the policies
proposed to mitigate climate change and cut emissions will certainly
cause vast economic damage, but will have little impact at all on
climate. The DVD is available free of charge from his UK office at
Boswell House, 9 Prospect Court, Courteenhall Road, Blisworth,
Northamptonshire, NN7 3DG. Or e-mail firstname.lastname@example.org.