Ascension : Met Office Weather Report
Submitted by The Islander (Met Office) 17.12.2009 (Article Archived on 31.12.2009)

Statistics for the week ending Monday 14th December 2009

Statistics for the week ending Monday 14^th December 2009

	Max (Celsius)	Min (Celsius)	Rainfall (mm)
AIRHEAD	28.9	22.2	Trace
TRAVELLERS	30.1	20.0	0.1
RESIDENCY	24.0	18.4	1.7
GEORGETOWN	30.9	22.1	Trace
ST. HELENA	22.5	16.2	8.4
FALKLANDS	18.3	2.1	Trace
UK (Brize Norton)	11.1	-0.9	11.5

UK: A long spell of unsettled, windy & wet weather came to an end Thursday as high pressure developed over Britain. However this brought cooler weather with some fog and frost.

Falklands: At last some vaguely summer weather, though there was a slight ground frost Saturday.

Ascension: The end of the more cloudy season seams to have arrived.

St Helena: Mostly fine and dry, showers early in the week.

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Climate Change

With the recent “Climate” talks in Copenhagen there are a lot of articles on TV and in the press about “Global Warming”, or more accurately “Climate Change”. The problem with Climate Change, though it is real and in general the trend is for a warming world, it is not that simple. Sea levels are and will continue to rise. While the changing weather patterns could mean some parts of the world may even get a little cooler as weather patterns shift, some parts may become drier while others get wetter. If you are lucky you may live in a part of the world where there is not much change at all. Of course there are so many variables and unknowns in the system that truly accurate predictions from year to year and place to place are extremely difficult, thus leaving the field open for the sceptics to bring to the fore there favourite theories on, “it’s all down to sunspots” etc.

The orbit of the earth around the sun and the variation in heat output of the sun do change over time and these cycles almost certainly do affect the climate. However there is no doubt, and hard science, to the fact that carbon dioxide and methane are “greenhouse gasses” and these are steadily increasing. Over the last hundred years or so atmospheric CO2 levels have increased from around 280ppm to 387ppm now. This increase in greenhouse gasses, having begun with the industrial revolution and widespread agriculture, continues on an increasing curve as not only are there a lot more people in the world, by and large we all enjoy a much more affluent lifestyle than not so many years ago.

These may be low risk, but there are some scary scenarios that Climate Change could throw at us. - They have happened before.

Rising air and sea temperatures cause melting of perma-frost in the Arctic and this releases methane, which is a much more effective greenhouse gas than carbon dioxide. Under the sea, around the fringes of many continents, there are also large reserves of clathrates, or gas hydrates, which are a form of methane and water ice in a stable “crystallised” state. If rising sea temperatures should interfere with this then further methane could be released very rapidly. Let’s just say there is an awful lot of methane out there. This could cause very rapid warming.

Of course we could go the other way, at least in some parts of the world. The polar regions are by and large warmer than they could be, as the tropics are cooler. This is because vast amounts of heat are transported north and south from tropical regions towards the poles via the atmospheric and ocean circulation. One key driver of the ocean circulation starts in the North Atlantic off Greenland. Here there is a delicate balance between sea surface temperature and salinity which causes the surface water to sink and generate a deep ocean current that eventually moves all the way south in the deep Atlantic, through the Indian Ocean and into the Pacific. This in turn draws warm water northwards as the “North Atlantic Drift”. It is this that keeps Europe in particular relatively warm. If warming of the oceans and the release of large amounts of fresh water from the Greenland Icecap should upset this balance then the North Atlantic drift could weaken or move further south. Then every Christmas in the UK may be white!

What can we do? Largely it’s all down to energy use, and from what source that energy is derived. Whether it’s the heating and cooling of our homes or the things we buy and use. We have to wean ourselves off fossil fuels; after all they will not last forever anyway, so going on as we are only delays the inevitable. Let us hope that the politicians can agree targets to cut carbon emissions.

What can we do on Ascension? Well perhaps encourage more use of wind or solar power, though it all costs in the short term. Recycle and re-use if possible, though that cool beer this evening beckons, and yes sadly the bottle will end up in the landfill!

Compiled by  Chill       

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