Portsmouth Climate Action Network

Interesting page:
http://www.portsmouthcan.co.uk/whats-man-made-climate-change.html

But haven't we known about green house gases for a few decades and not done anything about it?

The movie Soylent Green in 1973 showed the earth in a pretty sorry state with global warming caused by emissions.

We've actually known about greenhouse gases for a couple of Centuries, not decades! This is not 'new' science. Our understanding of just how potent these greenhouse gases can be and the impact they can have on our natural processes is relatively new. But, researchers are currently trying to pinpoint the impacts on the polar regions.

That's why this year has been designated 'International Polar Year' (http://www.ipy.org/). Many of the world's climate scientists are focussing their efforts on understanding better the impact of global warming in those areas. We should have much better data available this time next year. Maybe it'll be good news...

Thats interesting.
When is the earliest record of knowledge of green house gases?
Who first discovered the phenomenon.

I suppose i meant public popular awareness of green house gases is a recent thing.

As far as I'm aware, the 'greenhouse gas' theory goes back to Baron Jean Baptiste Joseph Fourier (1768 - 1830). Although primarily a mathematician, his contribution to the understanding of climate came about through the realisation that, as he climbed, two things happened. It got colder and the air got thinner. Putting these together, he termed the ability of the air itself to trap heat as 'the greenhouse effect'. He published this work in 1824 and the term 'greenhouse effect' has been in common usage since then.

John Tyndall (1820 - 1893) took up Fourier's theory and set out to prove it. Using some fancy equipment (which he himself invented) he was able to show that there were certain gases at low concentrations that are highly effective at trapping heat. Interestingly, he tried all the main gases in air first (like nitrogen and oxygen) but they were transparent to heat. Only then did he try water vapour, carbon dioxide, ozone and nitrous oxide. He published this work in the 1850s and the 'greenhouse gases' became a useful catchphrase for all these.

In relation to the public usage of these words, that's a question for a sociologist! Every earth and environmental science student will be familiar with these phrases but it only takes the media to catch onto something for it to become a household name overnight!