Idiot’s Guide To Global COOLING Not Warming
Some weekend trivia for readers.
The earth was much hotter 1,000-2,000 years ago and even hotter during the Cretaceous period some 100 million years ago when dinosaurs were at their peak.
The atmospheric carbon dioxide level, due to volcanic activity (greenhouse effect), was so high that forests extended to the Arctic. Even then, they had sudden ice ages that scientists are trying to explain today.
Humanity had our own mini Ice Age just 300-400 years ago – The Maunder Minimum 1645-1710 which coincided with a protracted period of very low level of sun spot activity and another less severe Dalton Minimum, occurred during the period 1790–1830.
So, what is all this about ?
I am just tired of hearing my son blame everything so easily on global warming and CFCs as they are taught in school. It seems to stem of an overinflated sense of self importance these days where humans think civilisation is in the centre of the universe when homo sapiens just emerged about 100,000 years ago and civilisation started proper perhaps 50,000 to 12,000 years B.C (disputable).
Anyhow, I have been quite keen on this topic since reading about the scandal of environmental findings years back and recently, when the scientists are unable to give a conclusive estimate of the rise in sea levels.
You see, it is not just the study of one science but a dozen or more branches of science like astro physics, paleoclimatology, geophysics and paleomagnetism (these are the easy ones I can pronounce), to get the big picture and my personal understanding is patchy and fragmented but I will give it go for this chance to rant.
There are 2 issues here which is not quite right but I grouped sun spots and sun activity under geomagnetic reversals.
1. The Milankovitch theory which describes the collective effects of changes in the Earth’s movements upon its climate.
– the shape of the Earth’s Orbit around the Sun (100,000 year est. cycle)
– the Earth’s Tilt when orbiting (41,000 year est. cycle)
– the Earth’s Precession i.e. trend of the orbit (26,000 year est. cycle)
A simple visualisation would be a hula hoop orbit with a gentle hula within the hula that is not quite circular as we would like to think. The asymmetrical motion means we have only the same orbit every 100,000 years or so, as the tilt comes a full cycle every 41,000 years and so it goes. This magnetic pull is outside our control.
As all these affect the intensity of sunlight hitting the Earth’s surface, thus ice ages occur.
2. Geomagnetic Reversals in the Earth and the Sun
Every now and then, the Earth’s magnetic poles reverse, completely and incompletely, briefly and for extended periods. The last one occured 41,000 years ago and lasted for about 250 years, the entire process taking 440 years.
Because the Earth is one giant electromagnet is due to its molten core and the convection currents running through it (flux), it is possible for the field to be disrupted and altered through its orbit as well as external factors such as meteor impacts and internally when the mantle of the Earth is disrupted.
The magnetic field surrounding Earth is important in shielding the Earth from harmful UV radiation and bombardment of particles from the Sun. Weakening the field leads to an imbalance which has been hypothesised to have caused the extinction of species.
Interesting fact : The magnetic North Pole has been shifting towards Siberia at a pace of 40 km per year and should reach there within the next half century. http://news.nationalgeographic.com/news/2009/12/091224-north-pole-magnetic-russia-earth-core/
The Sun reverses its polarity more regularly in 11 year cycles during which sun spot activity affects Earth’s temperature. Sun spots are still not fully understood but besides the effect of polar reversals, longer term trends in sun spots have a direct impact on Earth’s temperatures. The 2 mini ice ages we have on record have been found to directly correlate to diminished sun spot activity.
We do, however, have a problem that is puzzling scientists.
“Scientists know that irregularities in the Earth’s orbit, which occur every 23,000, 41,000, and 100,000 years, affect global climate cycles. Those deviations can nudge the northern hemisphere farther from the sun, causing ice to remain through the summer and auguring a new ice age, like the one that ended 10,000 years ago in North America. But starting in the late Pliocene era, some three million years ago, evidence of the 23,000-year cycle of climate change disappeared from the climate record.”
Yes, we do have cause for concern even if we cannot change the Sun.
Because small as we may be, we have the ability to affect big things. Our part in the environment can affect the magnetic fields and I say that because this fracking business and the obsession with shale oil and gas does disrupt the Earth’s mantle which results in temperature shifts deep in the ground which could possibly affect the current flow within the Earth’s core in the years to come.
Why ? Because deep in the oceans is a huge store of heat which has a delayed effect on our global temperatures. Some argue that this store of heat is unrelated to puny human efforts but I often wonder if large scale fracking and shale extraction could affect the inner temperatures to the extent that it disrupts the magnetic flux in the core ?
More reading on the impact of ocean currents : http://www.21stcenturysciencetech.com/articles/ocean.html
As it is, we are experiencing 6 times the number of earthquakes than we are used to 40 years ago which is also a questionable statistic because perhaps monitoring has not been as vigilant then ? Still a rather scary statistic for me.
Every little thing counts, I suppose. The internet and social media age has done its part in spreading widespread ignorance amongst the young that humans are all that matter.
What will I tell my boy ?
It is not true but plastic bags, CFCs and everything the books say do matter. We freak out over earthquakes and tsunamis and the melting poles and start looking to apportion blame but the dinosaurs did it for millions of years before us and lived for millions of years too, for that matter – there was numerous ice ages within the 170 million years that they existed, dying out just 60 million years ago. I bet they complained like hell then for the ice ages occured every 20-40 thousand years.
Yet it is horrific that we are expending all the oil on Earth formed by all the dead dinosaurs and plants in just a matter of 50 years ? (so I read from the Primary 6 textbook)
You know what I think ?
It is overpopulation and not global warming that is our problem and that is topic for next week in addition to another topic on the next most sustainable but controversial energy source.