One of the worrying aspects about climate change is the melting ice in the Arctic, but not because all that melted ice would cause a rise in sea levels.

In fact, about 90% of the ice is below sea level, and as water expands when frozen, by around 9%, it is quite possible that the Arctic melting would have zero impact on sea levels.

However, ice is also very reflective and a lot of solar energy hitting the earth is reflected back into space by the Arctic ice. No ice, and all that heat gets absorbed by the sea, warming it – and in turn causing sea volumes to expand and sea levels to rise.

So, how about increasing the amount of the earth’s surface that reflects the solar radiation? It’s something I have occasionally pondered about, but lacked the resources/skills to work out the maths.

Some boffins have also thought about similar ideas – such as seeding clouds over oceans or even more brazenly, putting mirrors in space.

Now another report appears on my mailing list – where some boffins have actually looked at what would happen if you liberally splashed white paint on the roofs of city buildings.

Asphalt roads, tar roofs, and other artificial surfaces absorb heat from the Sun, creating an urban heat island effect that can raise temperatures on average by 2-5 degrees Fahrenheit (about 1-3 degrees Celsius) or more compared to rural areas. White roofs would reflect some of that heat back into space and cool temperatures, much as wearing a white shirt on a sunny day can be cooler than wearing a dark shirt.

Their simulations, based on an idealized view of different types of cities around the world, indicate that, if every roof were entirely painted white, the urban heat island effect could be reduced by 33 percent.

I was reminded of the issue today though, as someone has had an accident outside the flat and most of the road is now covered in whitewash. I wonder what the impact would be if every road was also covered in whitewash – presuming one can be developed that lasts more than a few days.

I am as it happens, quite a fan of green roofs, where the tops of buildings are given over to garden spaces for the residents or shrub-land for the local wildlife and it is a pity that so few new buildings in London are thus designed.

Obviously, the Gherkin might have a bit of a problem!

A heads up that the Prince Charles Cinema in Leicester Square is showing archive films of London in the 1950s as part of a free event later this month.

The official fluff reads:

Take a trip back in time to see 1950s London through rare and original archive film. Reminisce about life as used to be in the capital and remember the events that shaped the 1950s; from the lights returning to the post-war Piccadilly Circus and the Festival of Britain; to the last presentation of debutantes and the coming of motorways.

Anyone who went to see the B&W films in Trafalgar square recently, or with a general interest in London history will probably find this of interest.

You can reserve up to 4 free tickets at the Archive Film Shop website.

Pathé News has also been making its archive easier to view – and some of my personal selection is here.

Found an interesting report on my science RSS feeds this morning, which ties in with something which tends to irritate me slightly about how the media runs with “scare stories”.

We all tend to focus on big one-off events, but in doing so tend to ignore the smaller more frequent events which have a bigger overal impact.

For example, if a multiple car accident occurs, the media will be all over it – but the death rate in the accident would actually not be noticeably higher than the daily average for road culls in the UK – which is about 10 deaths per day.

What is it about 10 deaths in one place which makes it more newsworthy than 10 deaths dotted around the country?

Are the other 10 people not worthy of our attention?

Obviously, if the media reported the news based on statistical impact – then every newspaper front page would proclaim the deaths of dozens of people every single day – a “Baby P” every week (yes, they actually are quite regular events), etc.

OK – Joseph Fritzel is an exception

Anyhow, in the release I read, statistician Professor David Spiegelhalter claimed that the number of murders in London last year was not out of the ordinary and followed a predictable pattern. Spiegelhalter’s report, published today in Significance, the magazine of the Royal Statistical Society, argues that shocking headline numbers are not as surprising as one might think.

The study, which looked at the pattern of murders between April 2004 and March 2007, also shows that on around 64% of days we can expect there to be no murders at all. Each year the London Metropolitan Police record around 170 homicides and there has been little change over the last five years.

You can read the full press release (warning – the study was funded by the government, so caveat emptor may apply) at AlphaGalileo

I’m joking – although frankly, I wouldn’t rule it out. Anyhow, enjoy this outstanding picture from the members of the b3ta photoshopping website.

The Day After Today – from b3ta productions.

Sitting at home, and what should go past the flat, but an iceberg with a polar bear on top of it.

After having a WTF moment and grabbing the photo, I am now wondering where in the “Dummies Guide to Climate Change” did it mention icebergs in the River Thames.

Alternatively, it could be a publicity stunt for someone too shy to put a brandname on the iceberg (or the bear’s fur?)