OBJECTION: The climate changes naturally in cycles Ė it always has.
ANSWER: True; due to changes in the strength of the sun, ocean cycles, volcanic activity and other causes. But it doesnít follow that we canít change it too! Our emissions have been described as ďthe largest uncontrolled scientific experiment in historyĒ.
OBJECTION: Itís the sun which is causing global warming.
ANSWER: Researchers advise that the sunís irradiance increased during the first half of the 20th century (and caused warming) but has been constant since (apart from the 11-year sunspot cycle) and that the background temperature increase, espcially since 1975 can only be explained by our carbon emissions.
OBJECTION: It was as warm or warmer in Britain during the Mediaeval Warm Period.
ANSWER: Researchers disagree on this. But even if it were warmer (due to natural causes), there is now much more greenhouse gas in the atmosphere and fast increasing. This has the potential to increase warming substantially and in a short timescale.
OBJECTION: Greenhouse gas is only a very tiny part of the atmosphere.
ANSWER: True - the science was established 150 years ago that it is these trace gases which trap the heat!
OBJECTION: Water vapour is a greenhouse gas and is much more abundant than the carbon-based gases.
ANSWER: True Ė but water vapour acts to amplify the warming of the carbon-based gases, the amount in the atmosphere depending on temperature. We canít control water vapour.
OBJECTION: But we want some warming in Britain!
ANSWER: The concern is about the average warming globally; this is believed to make the climate systems more volatile and result in increased extreme weather. Most of us may still be OK but people in many parts of the world are suffering badly.
OBJECTION: But we need to consume energy to live.
ANSWER: After meeting our basic needs, there is enormous scope for moderation.
OBJECTION: There is no proof that human activity is the main cause of climate change.
ANSWER: True, but the majority of researchers believe that it is, so letís not gamble with the wellbeing of other people and of future generations. There may never be cause-and-effect proof. After all, temperature rises from human-produced emissions, similar to current predictions, were foreseen as long ago as the 1890s (by Arrhenius).
OBJECTION: Not all climate scientists agree that climate change is mainly caused by our emissions.
ANSWER: The large majority do. Most of the prominent sceptics belong to organisations which receive funding from oil and mining companies Ė this is well documented, as are their attempts to spread doubt about the science, some assisted by ex-tobacco industry PR experts.
OBJECTION: But during the 1970s, we were being warned that another ice age was due!
ANSWER: This was because there had been a slight global cooling between approx. 1945 and 1965. This is believed to have been due to the amount of sulphur particle pollution in the atmosphere from fossil fuel burning Ė sulphur particles reflect the sun and have a cooling effect. But carbon emissions have greatly increased since that time. Also, the sulphur falls out after a time, whereas carbon emissions remain for many years and accumulate.
Current estimates of the onset of an ice age are several thousand years away - warming due to our emissions is probably here now and is expected to increase rapidly during the next few decades!
OBJECTION: This is doom-mongering!
ANSWER: But people are suffering now! And the risks are too great to be ignored.
OBJECTION: I canít make any difference.
ANSWER: Edmund Burke stated 200 years ago: "Nobody made a greater mistake than he who did nothing because he could only do a little". Itís a matter of principle and moral responsibility to try. More and more people are now doing their bit to reduce their energy consumption and helping to increase the inertia. World governments and large businesses too are taking the problem more seriously Ė we must all work together.
OBJECTION: Itís too late already.
ANSWER: It may be, but climate predictions are uncertain and nobody really knows for sure just what will happen or when. We should make every effort to reduce emissions in the hope that life will be tolerable and survivable for future generations.