Global Warming - Misconceptions

There is a very strong scientific agreement in the scientific community that global warming is happening and that it is a result of man's activities in releasing carbon into the atmosphere that was locked away for millions of years in fossil fuels.

The evidence that the earth is warming is overwhelming

There will always be people who argue the opposite to any idea and they are vital to avoid blind adherence to what may turn out to be incorrect and to encourage further investigation and refinement of ideas.

There comes a point however where an alternative idea becomes something only considered by the occasional maverick (and don't mavericks love the idea of being a maverick?) and then just becomes something that isn't considered seriously any more.

There is also the fact that many of the articles that doubt global warming are sponsored by the oil and related industries.

Many who doubt mans influence on global warming by releasing carbon dioxide from fossil fuels are driven by a dislike of taxes that are being raised by politicians as a result. Arguments frequently start with not wanting to pay tax and end up with deciding global warming is not happening.

That part of the atmosphere known as the stratosphere is 50km thick (the atmosphere goes beyond this to 690m, the edge of the "thermosphere" and beyond, but this will do for now).

0.0382% of this is a layer works out at 19.2m thick if all the CO₂ was collected in a single layer (that's over 62 feet).

To try and put it in some kind of context, compare this to the ozone layer. The ozone above our heads protects us from ultra violet rays from the sun, without it life on earth as we know it would be impossible (the immediate effects would be appalling sunburn on overcast days).

If the ozone above our heads were collected together in a continuous layer it would be about 3mm thick (1/8th of an inch). Hard to believe? but true, by comparison 0.0382% at 19.2m is a huge thick duvet.

Global warming models differ as to the exact effects of where and to what extent temperatures will change, but they all have one thing in common - that the effect of global warming is not uniform.

Different parts of the world react in different ways and one of them is that in the early stages (where we are now) the temperature in some parts of the world will actually fall or at least remain stable which is what is being observed. Eventually as warming advances, then most or all parts of the world will rise in temperature, though again - not at a uniform rate.

The areas that benefit however will be greatly outweighed by the parts of the earth that become too hot and dry to inhabit and by coastal towns and cities, including some of the worlds greatest cities that may be flooded and so have to be abandoned.

Hundreds of millions of people could suffer from global warming, the winners will be a small proportion by comparison.

from: http://volcanoes.usgs.gov/Hazards/Wh...as/volgas.html

"Comparison of CO2 emissions from volcanoes vs. human activities.

Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO₂ into the atmosphere every year (Gerlach, 1999, 1992). This estimate includes both subaerial and submarine volcanoes, about in equal amounts.

Emissions of CO₂ by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 22 billion tonnes per year (24 billion tons) [ ( Marland, et al., 1998) - The reference gives the amount of released carbon (C), rather than CO₂.].

Human activities release more than 150 times the amount of CO₂ emitted by volcanoes."

The hole in the ozone layer is a different problem with different causes to global warming.

The atmosphere consists of a VAST amount of air, so even billions of tons of CO₂ doesn't push the actual portion up that much. Unfortunately though CO₂ is incredibly effective at being a greenhouse gas and so tiny amounts make big differences. The figure in the air is around 0.04%. There's also the fact that the oceans have been absorbing a lot of the CO₂ produced, so all of that extra produced is not actually in the atmosphere.

The amount of carbon dioxide in the air has increased in the last 150 years:

It has been doing so since the industrial revolution and is currently outside of any observed natural cycle:

The above two diagrams are used courtesy of Robert A. Rohde  Global warming Art
 

How much carbon dioxide is released by a car?

1g of octane takes 3.5g of oxygen to burn it fully. This is 1 molecule of octane and 12.5 molecules of oxygen. This produces just over 3g of CO₂ and 1.42g of water, respectively 8 and 9 molecules of each.

This is the counter-intuitive part in that 1g of a tangible substance (petrol - octane - an easily visible liquid) is producing more than 3g of CO₂ an invisible, odourless, colourless gas. But the science all adds up correctly.

It means that for a petrol (gasoline) car, the mass of CO₂ emitted is 3 times the mass of petrol burnt!

Worth thinking about next time you're standing by the pump as all the fuel goes flooding into the tank, 50L of petrol weighs about 37kg, this is the equivalent of 111kg of carbon dioxide being released per tank full.

If we take a car that emits a rather frugal 135g/km of CO₂ emission, we can work backwards from the figure of  of CO₂ and assuming perfect combustion of octane (mostly what petrol is C₈H₁₈), this figure is equivalent to 59 miles per gallon, which is actually pretty optimistic!

Water vapour may add to the effects of global warming by adding to the earth's heat retentive blanket in a positive feedback effect. More carbon dioxide means warmer temperatures, means more water vapour in the air, means warmer temperatures. Water vapour alone is not the reason for global warming and certainly not the starting point.

Of course that does mean that it has been released, but it's cutting down on the amount a little at least.

The carbon dioxide that fizzes your drinks up today could have come from burning fuel, yeast that were busy making beer or some chemical process that releases it as a by-product.

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This carbon came from the food we ate and is a part of the natural carbon cycle whereby plants and animals are balanced. It does not contribute to global warming as it will be recycled when it is taken in by a plant for photosynthesis.

The problem with carbon dioxide and global warming comes from carbon released from fossil fuels where the carbon has lain locked up in a carbon-sink for many millions of years and is now released into the atmosphere. If we didn't burn fossil fuels (or make cement) then mankind would pretty much carbon-neutral - as we were before the industrial revolution.