The question that has to be continuously asked – is the science on climate change sound enough to justify Ireland facing into an enormous ongoing diminution of our agricultural potential?

What caused me to pause in my certainty was a lecture given last week in Dublin by the retired professor of atmospheric sciences at the Massachusetts Institute of Technology (MIT), Richard Lindzen. MIT is one of the leading scientific institutes in the world and if scientists who have reached that stage of achievement in their career are making serious points, then in my view we have a duty to at least listen and try and assess the arguments.

There were two basic strands to the discussion.

The key point for me was the statement that methane produced by cattle and sheep and nitrous oxide produced in tillage operations have very little role in whatever global warming is taking place. The point was made that naturally occurring water vapour in the atmosphere is thousands of times more plentiful than these gases and its greenhouse effect vastly outweighs any additional effect they could have.

If accepted as scientific fact, this assertion has the most basic implications for Ireland or at least for our agriculture. It would mean that we could and should continue to increase our livestock numbers subject only to the carrying capacity of our land and the availability of profitable markets.

The other was the assertion that while CO2 levels are certainly increasing and some warming of the earth is likely to result, the observed warming is small compared with climate model projections and, as carbon dioxide is essential for photosynthesis and plant production, the increased levels of CO2 may in fact be beneficial and helping to produce the record levels of grain output we have seen over the last number of years. There were a number of interesting historical parallels given on the whole role of CO2 and why alarm is unjustified, including the mention that from 1950 to 1980, the worry was that we were about to enter a new ice age.

It is difficult in this whole climate change debate to establish who are impartial scientific analysts and those who see the whole subject as a means of furthering their own financial or career wellbeing.

There is due to be another lecture soon by a professor from Princeton, another world-leading centre of science. That will be listened to with interest.