In coming weeks, I shall write about a range of climate change issues but thought it would be helpful to start by outlining the science behind it.
We get our warmth from the sun’s short wave heat rays entering the atmosphere.
The heat has to find some way to escape, otherwise the planet would totally overheat.
Some bounces straight back into outer space from polar ice caps and glaciers, some becomes embedded in the sea and some goes into the ground.
The latter emerges in a long wave form, rising up to escape into space.
As the long wave heat passes through the atmosphere it is partially captured by atmospheric molecules.
Carbon dioxide, methane and nitrous oxide hold heat more than the average gases.
As a result of increasing these greenhouse gases in the atmosphere, more heat has been held, with the consequence our global temperature has, on average, increased by 1°C over the past 150 years - and continues to rise.
This may not seem like much but it destabilises the planetary weather balance, causing more violent weather.
It is causing the permafrost to melt, releasing more greenhouse gases and some of the polar ice caps are melting, reducing reflection of the sun’s rays.
Peat is drying and forest fires are increasing, both delivering additional greenhouse gases into the atmosphere. This spiralling effect is known as feedback loops. Sadly, even if we stopped producing carbon dioxide today, these loops would continue to warm the atmosphere for some time.
Earth has been in relative stability for 11,500 years. However, over its 4.5 billion-year history, the planet has undergone many dramatic changes. We do not always know why these happen and we do not know the limits of the planet’s tolerance before it tips into a new and perhaps more dangerous environment.
We know a possible consequence of passing through a critical threshold will be a dramatic rise in sea levels. While the science is not exact as to when these ‘tipping points’ occur, and the consequences of passing through the threshold are not fully known, this lack of precision should not be confused with the almost unanimous scientific certainty that global warming will cause serious consequences for human lives and livelihoods.