Tuesday, July 28, 2009

isramart : CO2 implicated in mass extinction of life

Isramart news:
I WRITE to support and expand on Peter Burgess’ letter (July 3) and his useful cost saving suggestions to help reduce carbon dioxide (CO2) emissions.

Although historic global temperatures can only be estimated it is clear that temperatures have been higher, and much lower, than they are today.

Global temperatures rise and fall in complex, multiple and not fully understood interacting cycles (sunspots, Earth’s orbit, etc) and there are other driving factors (plate tectonics, Earth’s atmospheric composition and reflectivity, etc).

It is generally accepted that our planet should now be into a mini (approximately 30 year) cycle of global cooling, but that is manifestly not the case.

The main reason for this countering of the natural global temperature cycles is that levels of ‘greenhouse’ gases in the atmosphere, notably CO2, have been rising dramatically since the start of the Industrial Revolution and are now higher than they have been for at least the last 900,000 years.

Amongst other factors, melting ice-caps and glaciers will reduce Earth’s reflectivity and cause further temperature increases – which will release additional greenhouse gases by unlocking methane (a very potent greenhouse gas) in permafrost and undersea deposits.

Other processes, such as a decreasing ability of oceans to absorb CO2 have already been observed in the Atlantic Ocean. These elements increase the amount of greenhouse gases in the atmosphere, causing further climate change.

Such vicious circles have occurred in the distant past and CO2 is implicated in four of the five mass extinctions of life on Earth: Ordovician, Late Devonian, Permian-Triassic and Triassic-Jurassic.

Palaeontologist Peter Ward has written a book ‘Under a Green Sky’ telling us about global warming, the mass extinctions of the past, and what they can tell us about our future.

As well as Peter Burgess’ suggestions, readers can find more energy (and cost) saving ideas at www.Energysavingtrust.org.uk and, locally, at www.actingtogether.co.uk where residents can find practical steps we can take in the community.