Monday, September 14, 2009

More on CO2

CO2 properties

It is a sign of the prevailing climate of ignorance that the public has been led to believe that carbon dioxide is a ‘pollutant’

There are certainly plenty of harmful pollutants in the atmosphere (e.g. particulates, and nitrogen and sulphur oxides), and local and regional measures are needed to combat such emissions.

But while carbon particles (soot) are a pollutant, CO2 is not – it is a benign, nontoxic gas that is food for plants, a vital ingredient of photosynthesis and therefore of the food chain, and essential to life on earth.

It has been called the ‘molecule of life’.

As a greenhouse gas, CO2 traps heat by absorbing and reemitting infrared radiation emitted from or reflected by the earth’s surface.

Other greenhouse gases include methane and nitrous oxides, but by far the most important one is water vapour.

The pre-industrial concentration of CO2 in the atmosphere is said to have been about 280 parts per million by volume (ppmv), whereas the current concentration is 385 ppm – i.e. just under four hundredths of 1% of the atmosphere.

By contrast, the concentration of water vapour in the air ranges from 0 to 5% by volume, with an average value of about 1%.

Water vapour and clouds are responsible for about 90% of the greenhouse effect.

This is not just due to water vapour’s higher concentration, but also because it is far more efficient than CO2 at absorbing infrared (IR) radiation, as the following diagram shows.

Fig. 7.1 The top panel shows the incoming solar radiation in red, and outgoing radiation in blue, the rest being absorbed or scattered. The lower panels show the wavelengths of the radiation absorbed by the main greenhouse gases. CO2 absorbs infrared radiation in only three narrow bands of frequencies, and only the one corresponding to a wavelength of 15 micrometres (µm) has much significance. Even if the atmosphere consisted of nothing but CO2, it would still only be able to absorb no more than 8%, and perhaps as little as 4%, of the heat radiating from the earth.
Where the grey shading extends to the top of a panel, it indicates that the energy at that wavelength is fully absorbed. This means that adding more of the gas in question will not absorb any more energy as that wavelength is fully saturated. Parts of the CO2 spectrum are already fully saturated, and adding more CO2 will result in ever diminishing effects as more of the available wavelengths become saturated. (

As atmospheric CO2 increases, plants grow faster, and are also able to grow under drier conditions since leaves transpire less, i.e. lose less water.

Commercial growers deliberately increase CO2 levels in agricultural greenhouses to between 700 and 1000 ppm to raise productivity and improve the water efficiency of food crops.

The increase in atmospheric CO2 since the beginning of industrialization is said to have increased the average plant growth rate by about 15%.

Experiments indicate that if the present atmospheric CO2 concentration were to increase by about 300 ppm, the productivity of earth’s herbaceous plants would rise by around 30% while the productivity of its woody plants would rise by around 50% (Idso & Idso, 2007).

Increases in both water temperature and atmospheric CO2 enhance marine biological productivity, leading to increased production of dimethylsulfide and various iodocarbons.

These are known to be instrumental in creating more, brighter, and longer-lasting clouds, which reflect more incoming solar radiation back to space (Idso & Idso, 2007).

This negative (mitigating) feedback is one of the factors contributing to the self-regulation of the earth’s climate and biosphere.

CO2 and temperature

CO2’s current atmospheric concentration is close to the lowest level during the past half a billion years.

Back in the Eocene, when many of our plant families evolved, the concentration was five times higher than today.

About 450 million years ago CO2 concentrations were more than 10 times present levels, yet the earth was in the throes of a severe ice age.

David Pratt

So when you read or see Hanson, Mann and others talking about this subject at Copenhagen in a few weeks time wonder why they are manipulating the evidence in the way they are

What we do understand clearly though is that their stories fly in the face of scientific evidence

So how can so few bullshit so many?



The need to sustain fear

The need to sustain anxiety levels

Vested interests

.........................And the little boy cried the Emperor is naked

Are we all really so gullible today that we cannot think for ourselves?

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