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Global Warming... But!


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Want some good reading?

Take a touch of humour, add some genetic science and nanotechnology. Steep with conspiracy and stir in murder and despair. Season with romance between three people in a secret location. Garnish with morality.

The result is 'A Vested Interest', a novel series by John and Shelia Chapman. John is the author of this post. Check out their website at http://www.avestedinterest.info

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Global Warming... BUT!

For the last few years there's been a lot of talk about Global Warming. It now seems to be accepted as a 'fact' and pretty well everyone wants 'them' to do something about it. But is it a 'fact'? There are still those who deny it just as there are some who deny smoking is harmful. Well I'm convinced about the harm smoking does but is Global Warming a threat to us? This article sets out to clear up some of the issues.

First we need to be clear about what we mean by Global Warming. It's no use defining it as a process where the Earth is going to get hotter - that happens from night to day and from winter to summer. So here is my definition of Global Warming:

Global warming is the process where man made changes to the environment make the Earth hotter than it would be without those man made changes.

There - that definition rules out natural changes we have no control of such as the Sun getting hotter, volcanoes, earthquakes and the orbit of the planet each of which do make the Earth hotter or colder. We just need to look at the changes we've made and figure out if they are warming the planet. Except it isn't quite that simple.

To make a start we need to look at natural changes and understand how they affect the Earth's temperature. Here's a table of what I found. Pretty well all of this can be regarded as being facts rather than speculation:

Change Timescale How it affects the Earth
Sunspot cycle (Schwabe cycle) 9-12 years. Averages 11 years varies the heat from the sun by 0.07% or 1.3 Watts per square metre. Radiation is highest when sunspots are at maximum. The effect is great enough to affect the price of crops. Last minimum was April 2008 and the next maximum is expected 2013.
Changes in Sun activity - See below: varies with an average of 205 years Currently at an all time high with the start of a decline expected about 2040
Solar activity Long term solar cycles Numerous

Cycles have been discovered of:
87 years (Gleissberg cycle - warming from 1986 to 2030)
105 years (Suess cycle - cooling from 2002 to 2107)
131 years
210 years
232 years (warming from 1898 to 2038)
385 years
504 years
805 years
2,241 years
2,300 years (Hallstatt cycle)
6000 years

Eccentricity of the Earth's orbit 413,000 years Varies from a value of 0.005 (nearly circular) to 0.058 (elliptical) Currently at 0.0167 and the difference between closest approach to the Sun (perihelion) and furthest distance (aphelion) is only 5.1 million km. This difference is equivalent to about a 6.8% change in incoming solar radiation. Perihelion presently occurs around 3 January, while aphelion is around 4 July.
Tilt of Earth's axis 41,000 years The greater the tilt the less solar radiation received at the poles in winter and the warmer the summer. Varies between 22.1° and 24.5°; Currently, this angle is 23.44° and is decreasing.
Axial Precession 26,000 years As the Earth spins it wobbles like a top running down. The effect is for the seasons to take place at different points on the Earth's orbit making winters and summer warmer or cooler.
Apsidal precession 20,000 years The Earth's orbital ellipse slowly revolves around the sun this has the effect of changing the precession from 26,000 to 22,000 years. In 10,000 years mid-summer day will occur on Jan 4 in the Northern Hemisphere
Orbital inclination 100,000 years A slow change of the Earth's orbit relative to the plane of the solar system; seems to be linked to ice ages. Although the change in theory makes little difference to the sunlight received it is believed that the change of plane takes the Earth into an orbit where it passes through a dust cloud which cuts down solar radiation. Today we are in an interglacial period, which marked the beginning of the Holocene epoch. This began between 10,000 and 15,000 years ago and the northern ice sheets from the last Ice age have been melting ever since.
Volcanoes irregular Volcanic eruptions put dust into the atmosphere which cools the Earth; affects a few years only; no recent eruptions of significance. To cause a longer term event the volcano needs to put dust and sulphur dioxide into the stratosphere. Most volcanoes do not do this.
Earthquakes irregular A major earthquake can produce dust in the atmosphere causing short term cooling.
Cosmic rays irregular

A nova or supernova explosion can influence our climate but this is far from a regular occurrence, the last being two million years ago. The most likely next candidate would be the star Antares which is three times as far away as the last event.

Now - let's see what this would lead us to expect, ignoring any 'global warming' for the moment. First it seems that in the two winters following a sunspot minimum you aught to get one which is much colder than usual. The Earth's oceans act as a heat sink causing the delay. We have just passed a sunspot minimum so we could expect the 2010/2011 winter to be colder than usual. This would be especially likely if a major eruption occurs in the Philippines as expected. Conversely summers at a sunspot maximum should be hotter than usual so expect summers to gradually get hotter with 2013-15 being scorchers! Added to this the Earth should gradually be warming at least until 2040 when the temperature will start to fall.

Countering this as far as the Earth's orbital changes are concerned over the next thousand years or so we should start cooling down as cool summers are not enough to melt the previous year's ice. This will be most noticeable at the South Pole which at the moment is further away from the sun in winter.

So the changes in solar output will heat the Earth until at least 2040 and the Earth's orbit will cool the Earth over an even longer period. Overall I would expect it to get hotter for a while at least, especially true in the Northern hemisphere which receives 6.8% more heat in summer than the southern hemisphere. Of course a major volcanic eruption could change all this making the Earth cooler as dust from the eruption darkens the skies.

The obvious thing now is to see how that fits in with observed weather patterns.

First here's a graph showing average temperatures at the South Pole over the last 800,000 years. The temperatures are calculated from the relative abundances of gas isotopes trapped in the ice cores

Scalable image

As can be seen there is a fairly regular rise and fall in temperature with a gradual increase in extreme highs and lows. In the last 20,000 years the temperature has been rising and, if it follows the same pattern, can be expected to rise further before dropping gradually. The temperature now is not as high as it was 130,000 years ago. The data was obtained from the Epica ice core.  http://en.wikipedia.org/wiki/Ice_core#EPICA.2FDome_C The nature of the data is such that newer data is more accurate than older data.

Now - What about the North Pole? We have to look at Greenland ice cores which don't cover such a long period since the Greenland ice cap has completely melted several times in the past and moves more than the EPICA ice core. This data was obtained from the NGRIP cores http://www.glaciology.gfy.ku.dk/data/PC1.txt and covers the years 1245 to 1970

Scalable image

I'm sure, like me, this graph doesn't tell you much. This data is based on annual results.

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Here's the same data averaged every eleven years (sunspot cycle) Still not very informative.

Scalable image

This time I've averaged the data every 55 years. Much more informative. You should be able to pick out a relatively warm period from 1250 to 1600 where there was a period of mild winters. Around  1650 it got very cold. That was the time when the Sun was very calm and almost no sunspots appeared. In the UK the River Thames froze over and sea ice formed around the UK coastline. It was warm around 1740, cold again 1850 and now we are in a warm phase again. Over the time period shown there have been gradually increasing variations in the average temperature. I've added a trend line which shows a gradual increase of 0.1°C over the period. The data ends in 1970. As you can see it doesn't look like the much quoted 'hockey stick' graph.

Before you get wildly excited about the graph above I have to point out that averaging temperatures can give some strange results. The graph above shows dates plotted showing temperature averages for the next 55 years. Look what happens when you plot temperature averages for the last 55 years. To this graph I've added air temperatures for Southern Greenland for the years 1971 to 2000 since the ice cores don't provide this data. Of course when you are shown graphs of average temperatures most writers fail to point out that selecting different years to average can create a totally different graph. In the graph below, although you can still see that we are in a warm period, you wouldn't be able to pick out the medieval warm period; 800-1300; or the 1650, 1770, and 1850 mini-ice ages. The graph still shows a very small overall temperature increase of about 0.1°C over the period.

Scalable image

Now hang on! What about global warming? We haven't got to that bit yet but despite the conflicting 'average' graphs what these ice core results show is evidence of climate warming. About 0.1°C (0.16°F) over the last 700 years. They also show that temperature variation is becoming increasingly unstable which, if you consult the top graph, is exactly what happens before a major climate shift.

Now lets take a look at some of the 'Global Warming' issues raised

Sea levels

Effect of melting ice

Greenhouse gases

  • Water vapour (Causes 4 times the warming of an equal volume of CO2) Makes on average 1-4% of the volume of air but varies dependent on temperature and humidity.
  • Carbon dioxide (CO2) Makes up 0.0387% of the volume of dry air
  • Nitrous Oxide (Causes 298 times the warming of CO2) Makes up 0.00003% of dry air
  • Methane (Causes 25 times the warming of an equal volume of CO2) Makes up 0.000179% of dry air
  • Ozone (Causes 0.3 times the warming of an equal volume of CO2) Makes up 0.000007% of dry air
  • Fluorocarbons (Present in vanishingly small amounts)
  •           o Hydrofluorocarbons (HFCs)
  •           o Perfluorocarbons (PFCs)
  •           o Sulfur hexafluoride (SF6)

You will notice that water vapour has the greatest concentration in air and causes four times the warming effect of an equal volume of carbon dioxide. However since there is little we can do to control it it's usually ignored by global warming activists. This shouldn't be the case since the greater the temperature the more water vapour which is held by the atmosphere. Assuming an average of 1% water vapour in air then it will cause 1/0.0387 x 4 or a little over 100 times the warming of the CO2 in the atmosphere. In the same way methane causes 0.12 of the warming; nitrous oxide causes 0.23 of the warming and the other greenhouse gases are insignificant.

The fluorocarbons are all man made and will persist in the atmosphere for decades. Methane is slowly oxidised to carbon dioxide and water vapour. Half of it is oxidised within seven years. Nitrous oxide is quickly washed out of the atmosphere by rain. Fluorocarbons catalyse the destruction of ozone in the upper atmosphere changing it back to oxygen which isn't a greenhouse gas and therefore decreases the greenhouse effect. Of course that causes yet another problem - the ozone hole which leads to increased skin cancers in polar latitudes.

There's not a lot we can do about water vapour, methane and nitrous oxide have relatively little impact, ozone is desirable (at least in the upper atmosphere) and we've done as much as we are able to do about the fluorocarbons. That leaves the carbon dioxide for us to concern ourselves about so let's give it a separate section.

Carbon dioxide (CO2)

First - lets get things in perspective. Carbon dioxide is largely produced by volcanoes, by decomposition, by animals breathing and by Man burning fossil fuels in that order. About 25% of the carbon dioxide in our atmosphere is there as a direct result of Man, either by burning fossil fuels or by cutting down the rain forests which are effective at removing carbon dioxide.

In nature carbon dioxide is removed from the atmosphere by plant photosynthesis and by the gas dissolving in water. In the sea carbon dioxide is slowly converted to calcium carbonate by living organisms and this eventually forms rocks such as chalk, limestone and marble effectively removing it from the 'carbon cycle'. On land decomposition slowly returns carbon temporarily fixed by plants back to the atmosphere although small amounts fail to decompose and eventually would form new coal and oil reserves. One way in which man is affecting the carbon cycle is by preventing forest fires! When trees burn a significant amount of charcoal is produced which does not decompose and effectively removes carbon from the cycle.

There is no doubt that CO2 levels are rising as the result of Man burning fossil fuels. In the 1970s when I taught chemistry all the text books told me the concentration of CO2 in the atmosphere was 0.03% but whenever I measured it I got an answer nearer 0.04% even if I took the air sample from outside the lab.

Carbon dioxide is transparent to visible light but absorbs infra red light (heat). That's what makes it a greenhouse gas. The concern is that by putting an extra 25% of CO2 in the atmosphere we may be causing the Earth to warm up to the point which would make life difficult by changing the climate and melting the icecaps causing a sea level rise. The question is will that happen in reality or is Man's effect insignificant? Despite all the argument we still don't have a definite answer. What is known is as follows:

There's more to come but in the meantime here are a few extra bits of information I've come across.

Dust and sulphur dioxide ejected into the upper atmosphere by major volcanic eruptions cause the formation of clouds which reflect sunlight causing cooling. They act as 'reverse greenhouse gases.'

Temperature measurement

IPCC statement - '11 of the last 12 years have been the hottest since records began in 1850' - Question: Where and how were these temperatures recorded? Even without answering this question the statement is hardly surprising in view of the graph shown here

So what do I think?

Global warming Conference Timing

And my climate predictions?

Climate is what we expect, weather is what we get. - Mark Twain


December 2009

Since I made this prediction back in November 2009 winter has hit us with a vengance! -20°C predicted for tomorrow and...

Scalable image

Isn't it nice to be able to say 'I told you so!'

16th April 2010

...and now we have the eruption! A volcano in Iceland has sent a huge cloud of ash up which has already affected most of Northern Europe and has shut down all our airports since the ash is capable of causing the engines to fail. News broadcasts are talking about the disruption being for a few days but the last time this volcano erupted it took two years to settle and also triggered an even bigger eruption in a different volcano. As yet the talk is only about air travel but in a little while expect to start hearing about the cooling effect this eruption will cause. Now I wonder what would happen if that volcano in the Philippines decided to erupt this year also?

December 2 2010

Well here we are a year later and last year's record snowfall has already been beaten by the snow which started falling a full month earlier this year. Where I live, the temperature has been below freezing now for over a week and over 1 foot of snow has fallen so far. Of course it's not quite as bad as it was in 1963 - but that didn't start until February!

January 30 2012

So far the winter of 2011/2012 has been much milder - exactly as predicted. That is despite the severe cold which plagued Europe. I expect a hot summer this year with an even hotter one in 2013. It's important to remember that we are dealing with climate as a whole and that local weather in your area might seem different. It's interesting that three articles appeared on the BBC website relating to weather. In one was a report on the little ice age being caused by volcanic activity http://www.bbc.co.uk/news/science-environment-16797075 . In the other the suggestion was made that UV output from the sun might be responsible for changes in global temperature associated with solar cycles http://www.bbc.co.uk/news/science-environment-15199065. The third article? Well that's cautious about interpreting the results but in a way, says much the same as I said here back in November 2009 http://www.bbc.co.uk/news/science-environment-13792479.

April 30 2012

You might like to take a look at this article relating to the work of a Danish astronomer, Prof. Henrik Svensmark of the Technical University of Denmark, who studied how the Earth's climate has been affected by the movement of the solar system through star clusters where there is a high incidence of supernovas.

July 22 2012

Here's the latest prediction of sunspot activity. Peak activity is predicted for summer 2013. Since there is a 1-2 year delay in the weather this would indicate 2014 summer is likely to be the hottest.
Sunspot prediction

September 24 2012

Well summer is now over and here in the UK we have had a cool and very wet summer. So much for my prediction of a warm one huh? Well the picture isn't quite as clear as that. In North America they have had a scorching hot summer. The UK Met office explains why it's been wet and cool in the UK but a heatwave in the US and Canada - It's all to do with the jetstream which this year, didn't quite follow it's normal pattern. Find the explanation here.

Also in the news at the BBC is a report on sea level. It seems that they are rising at an average of 3 mm per year. Err guys. Isn't that exactly what I said back in 2009 in the section on sea level? The sea has been rising at that rate (apart from the meltwater pulse 14,000 years ago) at that rate for the last 20,000 years.

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