Tuesday 20 January 2009

Global Warming is a fact

A letter in the Bracknell Standard of 15 January accepts that global warming is a fact but claims that human beings are not to blame for the sharp rise in temperature (one degree centigrade in the last 100 years including a half degree rise in the last 30 years, an increase far greater than anything in the known past). Unfortunately all the scientific evidence shows that it is the burning of fossil fuels in increasing amounts over the last 150 years that has caused this huge risk to the continuance of human life as we know it on the planet. The result is now a carbon dioxide level in our atmosphere of 387 parts per million compared with the range of 180 to 280 before 1860, as shown from to ice cores going back 800,000 years.

Science tells us that the earth’s temperature should in fact be cooling as the cyclical changes in the planet’s movement (angle of obliquity, precession, the shape of our orbit around the sun, the Milankovitch cycles) show we should be moving slowly towards a colder period. The fact that the atmosphere is getting warmer (and the many resulting effects) is down to the burning of fossil fuels. There is no other scientific explanation. The Earth’s atmosphere is highly complex and its delicate balance has been disturbed.

We know the effect this has already had. The warmer atmosphere has caused an increased number of killer storms. Diseases from Africa are moving north as the bugs thrive in our warmer climate (blue tongue disease arrived here for the first time in 2007, malaria is following and there is disease in UK bee population – bees are needed to pollinate crops). Our wildlife is changing as the seasons alter. Water shortages in some parts of the world (e.g. Australia) are caused by rainstorms being fewer in number but torrential when they come. They also cause flooding. Hot temperatures mean less efficient food production leading to higher prices. We are using more fossil-fuel energy to keep cool in summer. Expansion of warmer seas and the melting of glaciers and icecaps will cause rising sea levels which will mean some cities and low land going under water.

Unfortunately it takes time for the temperature of the atmosphere to catch up with the greenhouse gases we humans have put there so far. So even if we use no more gas or oil, the temperature will still rise by a further half a degree centigrade in the next fifty years. To avoid runaway climate change, we must start now to cut back our carbon emissions. It will make a difference if we all help in lots of tiny ways and not build a third runway at Heathrow.

On another point, your correspondent claims that the holes in the earth’s ozone layer were reduced by nature. In fact it was the international banning of CFCs at the Montreal conference which was responsible for protecting the planet over that issue. Now the politicians must have another international meeting to stop the risk of runaway global warming immediately, not by 2050.

But politicians in Westminster have a short term goal of winning the next election. They ignore the long term peril of the human race. They ignore the threat that increased warming will to lead to such catastrophes as the melting of the permafrost. This could release into the air a maximum of 900 gigatonnes of carbon currently held inside the rotting frozen Arctic soil. This is more than is in our atmosphere already. If even a small proportion is released, runaway global warming will mean our grandchildren will not live normal lives.

The climate is like being in a cage with an angry tiger that the human race is permanently poking with a stick; a very bad idea.


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David Young is the Green Party General Election candidate for Bracknell.