Nature has proved to be much more successful in removing excess carbon monoxide from atmosphere
THE fear of being choked to death by a
smog of atmospheric carbon monoxide
(co) has prevailed ever since the beginning of the industrial revolution (New
Scientist, Vol 151, No 2045). The study
of co gas is important because the
levels of its emission are much more
than that of any other pollutant. Also,
high emission of co could use up the
available hydroxyradicals (free radicals), consequently reducing the ability
of this chemical to oxidise and remove
other pollutants like sulphur dioxide
and methane. It is also the main
cause of global warming and ozone
depletion.
Studies conducted by Patricia Martineria and colleagues at the laboratory
of Glaciology and Geophysics of the
Environment in Saint Martin d'Heres,
France, show that nature has been more
efficient than expected in removing
excess co from the atmosphere. There
has not been any significant increase in
global concentration of co during the
industrial era although activities like the burning of coal and wood have doubled from one billon tonnes to 2.7 billion tonnes a year.
Estimates done in the '80s show that
concentration of the gas in the
atmosphere was only one-third the
level present today and there has been
a regular six per cent rise every
year, thereby suggesting the positive
role played by nature. But lately, scientists had to rework the idea that there
is a firm link between the growing
number of co emission sources and
the rising concentration of the gas in
the air.
It was found that co level in atmosphere dropped by more then 10 per cent
between 19.90-1993. This erratic rise
after 80's and fall between 1990-93 in
concentration has still not been understood. Seeing this, some scientists have
started assuming that all this sudden rise
and fall may be linked to the impact of
eruption of Mt Pinatubo in 199 1. But
this forced researchers to assume that
their extrapolation of concentrations
based on data restricted to the past 40
years is faulty; which is, again, not possible since nature does play an efficient
role in converting co to C02. The
extrapolation suggested that concentrations of co in the northern hemisphere
had risen from around 40 parts per billion (ppb) in the pre-industrial era to
around 120 ppb today. But Martineria
reported that the concentration of co in
the atmosphere in the year 1802 was 92
ppb and thereafter it slowly rose to 110
ppb in 1947 (see graph). In Antarctica
the concentration has remained constant, that is, 60 ppb for about 50 years,
thus suggesting the efficient role played
by nature.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.