PRESIDENT Trump has acted against the Paris treaty. The United States no longer accepts the pressing need to stop burning fossil fuel (such as coal and natural gas) for electrical power generation.We should take note.

Wind power needs low-cost fossil fuel backup like the gas power recently provided by Peterhead.

It is very likely that in the near future it will become commonly accepted that our economically damaging attempts to stop climate change by focusing on cutting back on carbon dioxide emissions from coal and gas power stations was a waste of time.

The role of humans in climate change is not settled, as some would have us believe.

There is a slow realisation by climate scientists that humans, by becoming the dominant species, have attained dominance over much of the natural carbon dioxide cycle. We may have had this power over the carbon cycle since the first large-scale agriculture caused a major pollution of the sea which seems to contain a major part of the natural servo control system (based on calcium carbonate) which controls how much carbon dioxide remains in the atmosphere; this amount seems from a study of geology to be allowed to go very much higher than its present or possible near-future values, but since this natural servo feedback control system is essential for plant and animal life we need to seriously consider how we might, by inappropriate agricultural intoxication of the sea, seriously have put this essential-for-life support system at risk.

Evidence that we are re-setting a major marine carbon cycle control system lies in the fact that the Earth's human population is very exactly correlated with the amount of carbon dioxide in the atmosphere. This effect seems to have been in place from before the industrial revolution. This kind of ultra-exact correlation cannot be accounted for from any kind of direct atmospheric input of carbon dioxide from fossil fuel combustion.

The lack of an effect of the 2009 global economic downturn (where fossil fuel use was down) but the human population dependent rate of increase on atmospheric carbon dioxide was unchanged supports this theory.

David Grant,

Ashbank Cottage, 2A High Street, New Deer, Aberdeenshire.