Cosmic Cycles, not Carbon Dioxide, Control Climate
Those who think the political war on carbon will cool the globe or keep climate stable need to study climate history.
Temperatures on Earth dance to a cyclic rhythm every hour, every day,
every month, every season, every year, and to every beat of the
sun-spot and glacial cycles.
The daily solar cycle causes continual changes in temperature for
every spot on Earth. It produces the frosts at dawn, the mid-day heat
and the cooling at sunset. It is regulated by rotation of the Earth.
Superimposed on the daily solar cycle is the monthly lunar cycle,
driven by the orbit of the Moon around the Earth. These two cycles
interact to produce variations in atmospheric pressure and tides, and
currents in the oceans and the atmosphere. These are the daily weather
makers.
The yearly seasonal cycle is caused as the tilted axis of Earth’s
rotation affects the intensity of solar energy received by each
hemisphere. This produces spring, summer, autumn and winter for every
spot on Earth.
Then there is the 22 year sun-spot cycle, which correlates with
cycles of floods and droughts. Sunspot cycles are indicators of solar
activity which causes periods of global warming and cooling.
Earth’s climate is also disrupted periodically by the effects of
changing winds, ocean hot spots and submarine volcanism that produce the
El Nino Southern Oscillation.
The least recognised but most dangerous climate cycle is the glacial
cycle. We live in the Holocene Epoch, the latest brief warm phase of the
Pleistocene Ice Age. The climate history of the Holocene, and its
predecessor the Eemian, are well documented in ice core logs and other
records in the rocks. Each cycle consists of a glacial age of about
80,000 years followed by a warmer age of about 20,000 years, with peak
warming occurring over about 12,000 years. Our modern warm era commenced
12,000 years ago, so it is probably nearing its end.
There have been eight warm eras separated by long glacial winters
over the last 800,000 years of the Pleistocene. In every beat of this
cycle, the vast ice sheets melt, sea levels rise dramatically, coral
reefs and coastal settlements are drowned, and forests and animals
re-colonise the higher land released from the ice. Warm climate animals
such as hippos, water buffaloes and elephants got as far north as
Germany in the last warm era. Then suddenly the ice returned, covering
the northern hemisphere as far south as Chicago and London, destroying
the forests, lowering the seas, stranding the relocated coral reefs and
eliminating unprepared species. (Some dopey grizzly bears got stranded
in the Arctic Ice and the most enterprising of them survived to evolve
into white grizzlies now called polar bears.)
This regular repetition of natural climate change is partially
explained by the Milankovitch cycles relating to changes in Earth’s
precession, orbit and tilt. These drive variations in solar energy
received by Earth and have the greatest temperature effect on the large
land masses of the Northern Hemisphere.
On an even longer time scale, oscillation of the solar system through
the plane of the Galaxy seems to trigger magnetic reversals and violent
spasms of volcanism, crustal movements glaciation and species
extinction. Earth is never still for long.
What about the role of carbon dioxide in climate? Al Gore did a great
job to dramatise the recurring glacial cycles in his widely acclaimed
work of science fiction. But he missed two inconvenient truths.
First, ice cores show that in the glacial spring-time the temperature rose BEFORE the CO2 levels rose. Therefore the rising CO2 cannot be a CAUSE of the warming – it is a RESULT of CO2 being expelled from the warming oceans.
Second, at the top of every summer-time in the glacial cycle, the
high levels of CO2 in the atmosphere were unable to prevent the cooling
into the next cycle of ice.
We are already in the autumn of the current glacial cycle and nothing
man can do will change that. Global temperatures today are lower than
they were in Roman and Medieval times. They will still fluctuate with
the effects of daily, lunar, yearly and sun-spot cycles, but the
long-term trend of maximum and minimum temperatures will continue
drifting downwards. Once summer temperatures in places like Siberia are
unable to melt last winter’s snow, the already growing glaciers will
join to form ice sheets and Earth will once again be gripped by another
long Glacial Winter.
The transition from Greenhouse Earth to Icehouse Earth always occurs
suddenly. Once our verdant greenhouse is gone, life of Earth will never
be the same again.
The warm days, seasons, years and epochs have never been a deadly
threat to life on Earth. Frost, snow, hail and ice are the killers. If
our descendants do not have the energy, resources and wisdom to keep
their people warm and fed through the coming glacial epoch, humans may
follow our Neanderthal cousins who perished in the last glacial winter,
just 20,000 years ago.
It is a wonder of the modern era that people who cannot accurately
forecast next weekend’s weather claim they can regulate the temperature
of the whole globe by bashing industry and taxing carbon.
There is NO evidence in climate history that carbon dioxide has a
detectable effect on global temperatures. However if our continued use
of cheap reliable hydro-carbon energy does slightly delay the onset of
the next glacial winter, we and all life on Earth should count ourselves
extremely lucky.
