Science must end climate confusion January 27, 2010

There has been a lot of “news” in the papers about Science “Lies” with regard to Climate Change.

Richard Betts from the Met Office tries to clear things up a little here.

One of things scientists are being critised for is a lack of evidence, but for Scientists the evidence is what we get “after” the experiment… if we waited that long it might be too late. So we’re stuck with predicting (the thing we do before we try the experiment, but we use our best knowledge to get the best prediction).

A lot has been said of warm periods in the past… e.g. growing vines in Britain and even Greenland in Roman times.

This is a graph of temperatures for the last 1000 years… Since we only have reliable measurements from 1850 the rest are reconstructed from articles of the conditions then, dates of harvest, types of snow in ice cores, from the width of tree growth rings, etc

Black – actual measured temperatures
Redder – reconstructed from newer items
Bluer – reconstructed from older items

This graph shows the  last 150 years – the time since the “Industrial Revolution” when we started burning fossil fuels in larger amounts.

Graphs taken from Wikipedia article “Temperature record of the past 1000 years“

We can see from these graphs that the last few years have been warmer globally. In fact the 20 warmest years recorded all happened since 1983 – with the all the years from 2001 being in the top 10!

So – what do we make of it all. Firstly we need to remember a few things.

• The Scientists are making predictions of an upwards trend of Global (not local) Warming – generally increasing global temperatures.
• That an upwards trend does not stop the odd Cold Winter or even a downwards year and that local cold spells might not matter globally.
• Carbon Dioxide, methane and other gases in the air do trap Infrared (heat) in the Greenhouse effect as it reflects from the Earths surface
• The natural amount of CO2 in the atmosphere is so small we call it a “Trace Gas” – so even a tiny increase is a significant change – it went up 0.6% in 2007!
• The Scientists keep revising their predictions as more evidence arrives.
• The Scientists will not 100% “know” if they are “right” until the “experiment” is done – so after it has happened! Can we really wait that long?
• Most Science that is published has been checked (peer-review) before it is published in specialist journals – so scientists often refer to the work of other scientists in the assumption it is correct.
• But, just because there is a Scientific consensus, that does not mean they are all right – it only took one Einstein to show the rest they were wrong.
• Newspapers are written by journalist who try to give both sides an equal voice, even when one has more evidence than the other – fair and balanced is not always correct and truthful.

So – what do you think?

Mr G