Friday, 2 January 2009

Global warming vs. climate change

John over at "Kona - a pedestrian view" writes about his confusion on global warming, and I agree with him, it's a confused press release that probably reports the research inaccurately and leaves several details out. The article he comments on claims that the Earth had a warm atmosphere with freezing temperatures. That's nonsense of course, and I suspect it's down to lazy reporting.

Although I'm no expert on atmospheric science, I do know what effect CO2 has in the atmosphere as it affects infrared astronomy. It is a particularly efficient absorber of infrared radiation which is why it's such an important molecule in climate research - it lets sunlight reach the Earth's surface, but the infrared radiation that's then re-emitted from the surface is absorbed by CO2 and hence the atmosphere is warmed. Not such a bad thing really because without "greenhouse" gases such as CO2 the planet would be uninhabitable. Of course, too much of a good thing can be bad.

This is one of the main reasons I despise the term "global warming". Although it may be correct in a global term - the more greenhouse gases we have in the the atmosphere the more likely it is to become warmer - there are enough studies to show that some areas will become colder, some will become dryer, some wetter and some may not notice a thing at all. On the whole though, the Earth's temperature will rise, unless of course we get more clouds which reflect sunlight and etc. etc. - you get the message.

"Climate change" is a much better and more accurate term and I wish it had been used earlier. I have noticed that the term is becoming used a little more often than it used to and hopefully that's because people are becoming a little more educated about the environment. I'm fed up , for instance, listening to the more loony talk shows that have everyone calling in saying it's the coldest day in 30 years here, so what's all this nonsense about global warming?

As for my own experience with science press releases, well, I rarely believe much that's written in them and always prefer to go to the source if possible. I have actually been (un)fortunate enough to be named in the odd press release, one or two on the BBC website as well would you believe, but I'll never forget the first one.

The initial release said that our group had rediscovered a star that had been been lost for sixty years. Well, the truth was that the group had made a chemistry/physics discovery that shed light on a problem about something called the "diffuse interstellar bands" (DIBs) - astronomical spectroscopic features that today are still not definitely identified, so we don't know what molecules in space are causing them. The first DIBs were discovered about 60 years before the press release was written...

Although it would have been a great discovery, unfortunately we never did find a lost star.

By the way, happy new year everyone. The last one sucked and this one surely can't be worse.


Diane said...

I don't know much about science of climate change but I do agree totally that 2008 sucked. Here's to a much better 2009!

You have forsaken my blog lately, my friend. Don't make me come out to Hawaii and give you the what for in person. Ummmm... wait... forget I said that... forsake away. I'm booking my flight now ;)

Anonymous said...

Hi Tom,

I left a comment on John's blog on my take on that article. I agree with you - the reporter screwed up. Have a look at this article from the Press Association which seems to have more informed and careful science correspondents.

The main point I get from reading it is that the increased levels of CO2 and ice is just a coincidence and the inference is that the large amount of CO2 was not sufficient to warm an Earth which was essentially covered by ice (2nd sentence). Ice reflects the Sun's radiation efficiently and so the Earth doesn't absorb enough of it to re-radiate the IR for the CO2 to absorb.

That was my understanding of it. But I must be missing something as I do have a problem with this sentence which is actually attributed to the scientist: "...the Earth, ... was once hot on the outside, surrounding a cold, icy surface".

The terms "hot" and "cold" really need to be quantified.


John Powell said...

I get that the increased CO2/ice age combination was an anomaly. What I don't get, and resent, was turning the story into another global warming scare story. ("Such glaciation could happen again if global warming is not curbed, the university's school of geography, earth and environmental sciences warned.")I'm basically pro-environmentalism, but I don't like feeling like I'm being played.