When I was a boy growing up in London during the 1960’s, there was an overiding fear which affected everyone – the fear of Nuclear War. Young people were especially depressed about this subject and some even felt it a waste of time to bring babies into such a dark world. My parents had joined the Civil Defense force which meant they had access to the gory details of just what damage a 1 Megaton H-bomb dropped on central London would cause. Millions would die and those that survived would face a bleak future with no infrastructure and the risk of radiation poisoning. This was a very real fear because scientists knew and could measure exactly the effect of a single nuclear explosion. As the nuclear arms race between the West and the Soviet Union continued the world moved through an extremely dangerous period. To understand the times , one should read Neville Shute’s book – “On the Beach”. Eventually, all out nuclear war was supposedly deterred by the MAD strategy – Mutually Assured Destruction. However, the world stopped during the Cuba missile crisis which was probably the closest the world has been to a mass extinction. Since the Cold War ended people’s fears about nuclear weapons have evaporated, and today no-one worries excessively about Doomsday. Instead a fear is growing on the same scale about so-called “Climate Change” as a result of increased CO2 concentration in the Earth’s atmosphere. Is this fear genuinely of the same scale ? I would argue no it isn’t for the following reasons:
1. Nuclear War is an immediate man-made disaster of inconceivable consequences. All-out war could also provoke a nuclear winter by creating dust clouds in the upper atmosphere to block the sun’s energy. Just such an effect happens with a massive volcanic eruption such as Mount Pinatubu – 1% cooling and earlier Tombora eruptions cooled the earth for 2 years.
2. Climate Change is a symptom, but it is not a cause. Its effects are anyway only noticeable over periods of a century. There are many other symptoms of man’s impact: species extinction, land change, air pollution, overfishing etc. The world’s surface is already incomparably changed due to man’s activity. The root cause of all these symptoms is over- population of humanity on the earth. The rest of nature suffers far more from land change, farming, and fishing than from the current increase in CO2. You only need to look at the countryside anywhere in the world from a plane – even in Ethiopia or in Burma.
Man has dramatically changed the natural environment on the majority of the earth’s surface. Human activity also changes the climate through changes to the land environment, through deforestation, and through actual heating (cities, transport etc.) Human energy production is currently about 0.01% of total radiant energy from the sun. This may not sound much, but at night and in cities the effect is easily measurable. So why is Climate Change the only issue that clouds world fears ? Is it perhaps that various interest groups and indeed we ourselves seek and therefore find simplistic slogans and one track solutions. Let’s consider Carbon. All the carbon that is now being released by burning fossil fuels was once in the atmosphere. The oil and coal was buried during an intense explosion of plants and forests during the carboniferous period. Chalk and limestone are the result of buried sea organisms and river erosion over millions of years. This does not mean that burning it is a good thing – but it does imply that the climate has always changed. Man is definitely accelerating this trend, but the impact on the rest of nature and on other species of man’s activity is far more rapid and destructive than climate change. It is naive to think that reducing carbon emissions per capita by half will solve the problem, when the population will anyway double by the end of the century. This whole issue has become political and the science debate has degenerated turning towards absolutism.
Let’s consider ice ages: It was not too long ago that the big scare was that man would trigger a new Ice Age. Over the last 100,0000 year the natural climatic state of the earth has been Ice Ages. That means that Northern Europe and North America were encased in ice. Interglacial periods were rare warm times. What causes Ice Ages? The most likely causes are astronomical variations in details of the earth’s orbit round the sun. Every 100,000 years the eliptical orbit elongates. Every 40,000 years there is a wobble of the axis of the earth with respect to the sun. This causes a reduction in radiant energy from the sun which is then thought to trigger Ice Ages in the Northern Hemisphere. Most land mass is located in the Northern Hemisphere and the oceans have a less stabilising effect on temperature. For the last million years the earth has been dominated by Ice Ages. They normally last about 100,000 years with a briefer interglacial period of around 15,000 years. It seems that humans moved out of Africa during the last Ice Age to populate the rest of the Earth. Probably the Sahara desert was grassland and evidence of humans living in the Sahara has been found. Sea levels were much lower than at present because so much water was stored in ice on the Northern continents. This enabled humans to walk across much smaller water barriers, including North America. The current warm period began about 15,000 years ago, but it is really only the last 10,000 years that temperatures have been as warm as today. This also seems to correspond to the development of farming and early civilisations. The next Ice Age should begin sometime within the next 10,000 years triggered for astronomical reasons. However, whether Man’s impact on land usage and/or CO2 emission will have any effect on this is debateable – I suspect not. Although I haven’t seen Al Gore’s film, I believe he uses ice core derived graphs of temperature change during recent ice ages correlated with falls and rises in CO2 as proof that CO2 drives the climate. I think it is actually completely the other way round – the climate (and life) drives the CO2 concentration in the atmosphere. Why ? – because during an Ice Age the oceans absorb much more CO2 due to blooms in plankton over larger areas (that’s why whales feed in the Antarctic/Arctic). In fact the CO2 graph he used lags behind the temperature graph in time implying it is an effect and not a cause. This doesn’t mean that man-induced CO2 increases won’t affect the future climate – it will, it really just means that Al Gore took the argument too far. Perhaps the English judge who banned its showing in schools was right.
This week the UN Conference on climate change took place in Bali. A thousand delegates flew in from all corners of the earth and spent 2 solid weeks in Bali seemingly only to draft a resolution to agree to continue talks for a new treaty in 2009. During the “heated” process EU delegates “threatened” to boycott the US sponsored conference in Hawaii! Luckily for them a last minute compromise was met so that these important talks may continue in other exotic places.