THE Gazette has published another letter from R Quirk complaining about the climate change activist Greta Thunberg, who is accused of “fostering mass hysteria” about the future of planet Earth (Letters, March 12, 'What Greta doesnt' realise').

Mr Quirk points out that many have benefited from the products of the Industrial Revolution, which has been based on the exploitation of fossil fuels. Quite so, but that is no reason to ignore the possible downsides.

All Ms Thunberg has done is to read and think about the abundant scientific evidence for human-made global warming, assembled by numerous climate experts. Mr Quirk does not seem to have done this, relying instead on the false “information” that can be found on the many internet climate denial sites. This latest letter includes one of the common examples, which is to do with how much atmospheric CO2 is due to human activities.

Mr Quirk claims humans are responsible for only five per cent of the total atmospheric CO2, a common falsehood perpetrated by climate deniers. It is based on the fact natural processes (gas release from the oceans, vegetation and plant litter decomposition, and volcanic activity) transfer about 200 billion tonnes of carbon to the atmosphere each year, while human activities contribute about 10 billion tonnes.

But as most school students will tell you, these inputs to the atmosphere are only part of the carbon cycle. Other natural processes (ocean uptake, plant growth and rock weathering) absorb about 200 billion tonnes of carbon from the atmosphere each year. Thus, the natural processes are roughly in balance, and the only net addition to the atmosphere is by humans. In this way, since about 1800 we have increased atmospheric CO2 by about 50 per cent. This is scientific fact, and it’s not that difficult to understand.

I suggest Mr Quirk spends less time writing bad-tempered letters based on unscientific falsehoods, and more time reading proper scientific literature, like Greta does.

Ed Tipping