From Dr John Littler
Sir, - The Revd Michael Roberts's letter (
8 August) included a welcome plea for careful assessment of the
validity of quoted sources of information. I venture, therefore, to
question some of his statements.
He is amazed at the recommendation that fossil fuels should stay
in the ground. The most obvious justification for this
recommendation is that carbon-balance studies show that the earth
(i.e. the ocean) is absorbing and storing, each year, only
approximately a quarter of what we push into the atmosphere by
burning fossil fuels. The amount absorbed by the sea is already
dangerously acidifying the water, and that which remains in the
atmosphere causes global warming (as explained by Arrhenius in
1896).
He is stunned to find the statement that "Oil is the principal
source of nitrogen for fertilisers." This is, of course, indeed
erroneous; but the slightly more elaborate statement that "Oil is
the principal source of energy used to convert atmospheric nitrogen
to fertilisers" expresses accurately the problem that without large
use of fossil energy current agricultural production cannot be
maintained.
He is also misleading on the question of fracking. Methane,
wherever it comes from, burns to provide energy while producing
approximately half the carbon dioxide that would be produced if
coal were used. So far, so good; but, unfortunately, any methane
that escapes to the atmosphere is 20 times more effective than
carbon dioxide in producing global warming, in spite of its
eventual destruction in the atmosphere.
Taking these figures together, a methane-drilling and
distribution system that loses only five per cent of the gas by
leaks is no better than a coal system. So the ques- tion whether
methane is a cleaner source of energy depends, critically, on how
carefully it is handled.
Reliable information, in a comprehensible form, can be found at
Professor David McKay's site www.withouthotair.com.
The geopolitical issues of the rest of this century will not be
the ownership of oil or gas fields, but the control of desert
territories where large amounts of solar energy can be
captured.
JOHN LITTLER
18 Hillside Road
Portishead BS20 8EW