Ice Age & Climate Change was the hot topical of member Pete Lewis’s talk for this month’s Teignmouth Mens Probus Club.

It is only in recent times that our scientific advancements are beginning to bring together an understanding of the environment for sustaining life on our planet earth.

Our environment is influenced by several cycles of events each with peculiar time periods.

Our Sun cycle of 22 years, the sustainer of all life, also varies in distance earth’s elliptical phase of 10,000 years bring hotter and colder influences. Sun spots and their radiation particles also have a strong influence. The way the earth rotates (wind patterns) and tilts its axis (41,000 year cycle) as it circles our sun changes the effect of the sun’s power creating periods of heat and cold (our 4 seasons etc). Our atmosphere created over billions of years is ever changing, protecting us from many of the sun’s ill effects (and benefits) has its cycle too. The relationship of land and sea masses also has influence as does water vapour levels in the atmosphere.

Our ‘science’ only really started in 1659 with the start of climate recording. Then the isolation of Carbon Dioxide (CO2) by Joseph Black in 1757 and the ‘discovery’ of oxygen by Joseph Priestley in 1774.

The moment of realisation that all these things had a bearing on our environment kicked off during Queen Victoria's era about 1840’s when glaciation and the ‘ice ages’ were identified. Unification of climate standards only happened in 1914 and the ‘cycles’ theory and ‘finding’ the jet stream winds in 1923/4.

Mankind can only gain an understanding of things it can’t control (Sun, Earth part of solar system) but that which humans can do is recognise the effect humanity has on our world and to mitigate its impact on our own wellbeing. We now have a better understanding of ‘greenhouse gasses’ and the great impact CO2 has, is of great importance upon the weather cycle.

In the ice-age cycle (the Pre-Cumbrian lasted for 2½ million-ish years.) we are going downhill towards the next but in the CO2 cycle we are exponentially increasing which is overriding the cooling cycle.

Not so long ago we celebrated ‘Frost Fairs’ held on the solid frozen Thames 1680’s, in 1536 (Henry VIII) & 1564 (QE1) & between 1715  to 1788 then suddenly stopped in 1813/14. Recent study has shown a direct relationship with high sunspot activity as with the current phenomena with the aura borealis sightings so far south presently.

Pete explained how CO2 levels cycle affected our wellbeing. Too little - 150 ppm (part per million) and all plant life on earth stops and life forms die at 40,000 ppm. The level during the ice-age was 180ppm, Pre-industrial agricultural was 280 ppm and presently about 400 ppm and increasing. Optimum CO2 levels for plant growth in green house controlled environment is 1200ppm. We now understand the effect on mankind as CO2 levels increase. Whatever we do in GB, only influences 0.88% of world output of ‘man made’ CO2 so influencing world action is important (particularly China and India at 40%). Any major volcanic eruption causes a serious setback too, yet offset by plant photosynthesis absorbing about 50% of natural output. Methane is a miniscule contributor compared to CO2.

The message is that mankind must attempt to reduce its own generated impact to preserve a balance within our Troposphere in which we live (and it is the first 70km above sea level).

Rick Purnell, Press Officer