Welcome to our late spring 2012 edition of the Newsletter, and the Group blog.We are including an article by Donald Howells, who now lives in retirement in Richards Castle, having been chair of the Portsmouth Humanist Group and great contributor to their regular newsletter, which I believe was called ‘Hemlock’, which does suggest a distinctive sense of humour.
Donald talks about his wakening to the reality of evolution, helped by visits to the wonderful Natural History Museum in Kensington as a child. Similarly, I remember visits to the Natural History and Science museums in London as a child (I was born in Fareham), but this was about three decades after Donald – in the 1960s. Whether this influenced my subsequent beliefs I’ve no idea, but they are a great place to take children, and I still enjoy the odd visit as an adult.
Donald ends his article with a proviso about possible ways humanity could destroy the planet, and that reminded me to mention what I think may be a very important book I’ve just finished, called the Medea Hypothesis, by Peter Ward. Mr Ward is a planetary scientist employed by NASA and so writes with some authority, in this case about the Earth, past and future. His choice of Medea is interesting – for those who know their Greek mythology, you will probably recognise her as the wife of Jason, who infamously killed her own children, exasperated by the behaviour of her husband (not that that’s a good enough excuse).
Peter Ward deliberately sets himself against the popular Gaia hypothesis of life on Earth – which broadly assumes that the total Earth flora & fauna act as a self- regulating mechanism to produce optimum conditions for life. I’ve always personally thought this smacked of wishful thinking, but Mr Ward systematically goes through the 4 billion years of life on Earth to date and points out that several of the mass extinction events were almost certainly provoked by life itself – starting with the mass production of oxygen by the blue-green algae, and going through a couple of ‘snowball Earth’ epochs, and stagnant ocean periods. Looking forward, I was surprised to read that he thinks life on Earth only has another 100 to 500 million years to run (only, because the Sun won’t explode for another 5 billion years). The mechanism of failure he postulates is an unusual one, bearing in mind our current concerns on global warming – the loss of atmospheric carbon dioxide, which will lead to the loss of plant life, as we know it. Plate tectonics and weathering all have a part, but plant life itself will cause its own downfall, using up residual atmospheric carbon dioxide until it reaches the deadly 100 ppm minimum for trees, 10 ppm minimum for grasses – so we’ll go through a period of loss of forests, or perhaps replacement with bamboo, before the end.
The book is not all doom and gloom, though, as Peter Ward sees humanity as the living planet’s saviour – we must engineer on a grand scale to balance the atmosphere and prevent an ‘early’ demise of life as we know it here. That task will start by having to deal with the consequences of the temporary blip of increased carbon dioxide we are currently experiencing – which will lead to loss of the Greenland and, eventually, Antarctic ice sheets through global warming (almost inevitable, he believes) over the next few hundred years. As the seas rise and we lose coastal cities and rich low lying farming land, we will have to make sure that the new land opened up in Greenland and Antarctica is suitable for farming – preventing the inevitable inland lakes (formed by land depressed from the weight of ice) from becoming ‘contaminated’ by seawater. The carbon dioxide rise will only be temporary, in geological terms, and it will steadily decline over the millennia unless we also engineer stability in the atmosphere. Fascinating stuff – and I believe it could be a critical message for future generations. It is also hopeful – humanity can save the planet. That should cheer us up.
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