Energy limitations to population.
Most of the world's energy is
produced from fossil fuels. The rate at which carbon dioxide
is being added to the atmosphere is likely to double the carbon dioxide
content within the next century. This is the most benign estimate..
A Global warming of between 2 and 6 °C is predicted for a such an increase.
This is thought likely to cause an even larger temperature increase in
latitudes away from the equator.
Such a rise in temperature is likely to be accompanied
by more serious chaotic changes in the ecosystem - rises in sea level,
destruction of coastal habitats, desertification of the savanna, extinction
of plant and animal species, and of much that man depends on for survival.
We have reached a critical point.
Our reliance on carbon combustion is limited, not by the availability of
coal or oil reserves but by the atmosphere’s ability to cope with the
Carbon above our head.
Carbon Dioxide level
For every person on this planet,
there are 130 metric tons of carbon (mainly in the form of carbon dioxide)
in the atmosphere. At the moment, the average person's energy
usage (transport, and industrial production, as well as the direct consumption
of electricity) amounts to some 1.2 kilowatts. Most of this
is produced by the combustion of carbon based fuels, and contributes 1.1
metric tons to the atmospheric carbon every year.
Methane, another carbon greenhouse gas, has been
shown to be significantly less important than carbon dioxide.
With just the current CO2 production and no significant
increase in carbon absorbing vegetation - we can see a doubling
in about 100 years.
Some climatologists would argue that increase
in the phitoplankton of the worlds oceans will provide the necessary sink.
However, evidence from continuous records of the atmospheric CO2 at Mauna
Loa, Hawaii in the Pacific show:
1). At the current rate of increase, a concentration
of twice the pre-industrial revolution level (from 280ppmv to 560ppmv) will be reached
in 100 years.
2). The rate of increase is indeed accelerating,
and is consistent with a doubling every twenty five years.
Also, the historical record of world carbon dioxide
output shows it clearly doubling every twenty five years. With increasing
population and spreading technology, the worlds energy consumption will
increase rapidly. The world as a whole is likely to reach the UK’s
per capita energy consumption within fifty years. If
the whole world now consumed energy at the rate that we do in the UK, we
would see climatic catastrophe in twenty five years - even less with the
consumption rate of the USA. The climatic change has only been
held restrained up till now by the low energy consumption of the underdeveloped
Currently, the average energy consumption per
person on this planet is 1.2 kilowatts. This includes heating,
lighting, and transport, as well as electric power (its fraction accounting for
three times its electrical power value in fossil fuel burning).
We can’t go safely beyond this level without
using renewable energy. The richest viable, safe, non-polluting
alternative is solar power, much of which will need to be in the form of
electric power. With 1% of the land surface covered with photovoltaic
cells of current efficiency of 17% we could gather 6 kilowatts per person on this
The future solution?
Solar cell design is improving, new materials
which would be cheaper to manufacture are being discovered.
Production has increased and prices have reduced. We have already
passed the point where the energy generated by a solar panel, even in the
latitude of the UK, will generate enough electricity in its lifetime to
pay for its manufacturing cost. It has been estimated that
even in the UK, we could meet all our energy needs merely by cladding all
our buildings with photovoltaic cells.
Unfortunately, there is very little financial
investment in photovoltaic production or integration into architecture.
The worldwide investment in PV production plants is now of the order of
£3.5 billion. This is about 12 times what it was a decade ago
when this website started. This produces 3.5 Gigawatts of peak generating
capacity per year. In forty years we need to reach a target
of 25,000 Gigawatts. This will require six thousand times
the current annual production at 3 Gigaawatts per year.
This will require an investment of some 40 billion pounds per annum over
twenty five years. A huge, but achievable budget.
We cannot afford to wait around.
All the signs are that we need to act now. Improvement in the
efficiency and durability of systems will indeed strike the core economics,
but without practical experience now, we will not tackle these improvements
Area of PV cells compared to Australia
The above map shows the area of PV cells of current
efficiency (10%) required to supply ALL the WORLDS current energy requirements
(electrical/transport/heating!). The RED area shows the area required if the
efficiency approached 100%.
Richard Monkhouse.- 1999,
updated Aug 2008