Thursday, 14 March 2013

Twenty Three and a Half Degrees

My bicycle leans on our back wall at much the same angle as planet Earth leans on space --  a distinctly casual, street-corner 23.5 degrees, or thereabouts.  That crucial tilt of our planet's axis from the vertical explains pretty much everything about climate, varying day length, and seasons, or so I was taught at school.  The angle of inclination of my bike, as far as I know, has no effect on the Earth's climate.

Or...  Does it?  That bike spends a lot more time leaning against that wall than it should.  And, although I walk whenever I can when I feel like it, I drive to work much more often than I should.  It seems that, by letting that bike lounge around all day, I'm doing my bit to screw things up, climate-wise.

Now, we all need to be reminded, constantly, of the way our small choices add up to big consequences.  If only so that we cannot claim, as the sea-level rises and the forests burn, that no-one ever told us it could have been otherwise.  Moralists are annoying, of course.  Everyone accepts the truth that over-fondness for biscuits will lead to weight gain, but no-one likes to be told that the overweight are, morally, second-class citizens.  The morally-trim are annoying, in the same way thin or young or good-looking people are annoying, because they are a walking critique of and rebuke to the rest of us.

What we need is facts, and arguments backed by well-researched figures, not holier-than-thou finger-wagging.  Enter my old friend, Science Man.  I've talked about Andy before (for example, here and here).  He's my go-to man when I have a scientific or environmental conundrum, particularly one that involves the use of numbers, a language I do not speak.

For example, I was exercised by the way so many homes now have central-heating systems operated by a condensing boiler. On a cold morning you see vast plumes of water vapour belching from every house's boiler vent, like traction engines getting up steam.  Surely Britain would soon be disappearing under a veiling smog of boiler-generated cloud-cover?  Apparently not:
"Don't worry  about the water vapour. Whenever you burn a carbon based fuel you get carbon dioxide and water. The only difference with a condensing boiler is that some of the latent heat that was used, inadvertently, to turn this water into steam is recovered and so doesn't go to waste. So, an ordinary boiler will also be emitting steam but you don't see it because it hasn't been condensed. Plus because the ordinary boiler is less efficient there'll actually be more water vapour emitted than from a condensing boiler."
Reassuring, simply put, and (to the best of my limited knowledge) correct.

So, if, like me, you need your eco-conscience to be pricked by evidence and convincing arguments, and don't like to be hectored with trendentious assertions, you may welcome the advent of Andy's blog, Seven Billion to One.  However, if you find fault with his reasoning and reckoning there, take it up with him, not me.  As I say, I don't speak numbers.  Or ride a bike as often as I should.


Zouk Delors said...

On yer bike, Mike!

I suspect you have misquoted Andy here, since anyone who did any chemistry at all knows that water (H2O) is formed by oxidation (let's just say burning) of hydrogen (H), and although most fuels (except pure hydrogen, of course, which powers a new generation of motor vehicles) only contain hydrogen in chemical combination with carbon (C) - eg "natural gas" (CH4), nevertheless charcoal for instance, an eminently and (almost) exclusively carbon-based fuel, contains none to speak of.

The vapour you see pouring out is, I believe, that part of the combustion steam which escapes condensation in the boiler (which condensate is run off as liquid water) and is ejected with the carbon dioxide as exhaust, only to condense on meeting the cold outdoor air, creating the visible colloid you perceive.

Also, "vertical" means along a straight line originating at the Earth's centre of gravity (the line along which an object dropped from a height falls to earth). The 23.5 degree tilt of the Earth is from the perpendicular to the imaginary line between the centres of Earth and Sun.

In other words, in Space, not only can nobody hear you scream, but also nobody can tell you which way is up.

Mike C. said...

Well, good to get that sorted out (again).