Global Warming and Cooling - The Reality

From http://co2sceptics.com/news.php?id=1041

Global Warming and Cooling - The Reality

Stephen Wilde
CO2 Skeptics
Thursday, May 8, 200

Stephen Wilde has been a Fellow of the Royal Meteorological Society since 1968. The first two article's from Mr Wilde were received with a great deal of interest throughout the Co2 Sceptic community.

In Stephen Wilde's third and exclusive article for CO2Sceptics.Com, he explores the mechanics and mechanism involved that are attributed to the Earth's Warming and Cooling, needless to say the presence of CO2 is not part of the process.

Global Warming and Cooling - The Reality.

It’s all very well doing what alarmists do which is to say that Co2 is rising and temperatures are rising so in the absence of any other known cause it must be man made CO2 that is warming the planet. That approach ignores both the differing scale of the possible influencing factors and the clear historical relationship between cooler climates and periods of a less active sun. The presence of the sun must be a much bigger influence on global temperatures than the greenhouse characteristics of CO2 on it’s own.

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At most the greenhouse effect can only be marginal though some have tried to talk it up by asserting that the planet would be very much colder without a greenhouse effect, which is correct, but avoids the issue of the rather small proportion of the overall greenhouse effect provided by CO2 and the even smaller proportion provided by man. It also begs the question as to whether the oceans are slowly releasing CO2 as a result of natural warming. If the oceans warm for any reason they will release CO2 into the atmosphere because water holds less CO2 at higher temperatures.

The greenhouse effect, as a whole, may smooth out rises and falls in temperature from other causes but is not itself the determining factor for global temperature. If the heat from the sun declines the global temperature will fall with or without any greenhouse effect and if the heat from the sun increases the global temperature will, of course, rise. The greenhouse effect does not create new heat. All it does is increase the residence time of heat in the atmosphere.

In the ice core record, CO2 increase has always lagged behind temperature rises and the lag involved is estimated to be 400 to 800 years. There has never been a period when a CO2 rise has preceded global warming. I have seen it argued that the past 30 years has been so exceptional that it MUST, for the first time in the history of the globe, be CO2 driving the warming trend. That is an assertion of such low probability that it should require very powerful evidence to support it. I have seen no such evidence. Indeed, on a cursory inspection the slow but steady increase in atmospheric CO2 is clearly not coming through in a slow but steady rise in global temperatures. Instead we see rises and falls in global temperatures that bear no obvious relationship to the steady rise in CO2 unless one puts the cart before the horse and announces that there is no other possible reason and the trend period adopted is carefully chosen to suit the proposition.

All it needs to cast doubt on the CO2 theory is an alternative possibility to explain a rising global temperature trend over the past 500 years and there is one. Everyone will have heard of the Little Ice Age and the global temperature would appear to have been recovering from it ever since. On a balance of probability is that not the more likely explanation of an overall warming trend ever since? Why introduce manmade CO2 at all except for politically motivated reasons? By all means exclude a recovery from the Little Ice Age as the reason if one can but the burden of proof is heavy and probably impossible to discharge with current knowledge. There was also a Mediaeval Warm Period (MWP) that preceded it. It has been asserted by some that the MWP was not as warm as the planet is now but there is evidence to the contrary such as Viking settlements in Greenland at the time. It has also been asserted that the MWP was not worldwide but some recent indications have been found in South America that it was warm there at about the same time. In any event it is unlikely that such a warm period affecting Greenland and Western Europe would not be worldwide. The heavy burden of proof is on those who would seek to deny it.

Be that as it may, there is a probability rather than a possibility that the warming trend since the lowest point of the Little Ice Age is continuing to this day and is the real cause of recent observed warming with only a minimal contribution, if any, from man made CO2 emissions.

Then there is the matter of scale. The greenhouse effect is mainly a phenomenon of the land surface and the atmosphere because more of the incoming heat is absorbed by water as compared to land and a lower proportion is reflected to participate in the greenhouse effect. However the surface of Earth is 70 % water. Water has a hugely greater heat carrying capacity than the land or the atmosphere above it. Land loses most of the heat it receives during the day via overnight radiation and the atmosphere loses heat rapidly via convection, rainfall and radiation to space despite the greenhouse effect. The true heat store that we need to consider, dwarfing by far any atmospheric greenhouse effect is all that water. I describe the implications of that below.

It seems so complex but the global heat balance only comes down to three parameters that swamp all others.

Heat from the sun.

The fact that 70% of the planet is water covered.

Heat, radiating out to a very cold Space.

Extra heat is constantly being generated within the Earth by convection and movement caused by external gravitational forces from the sun and other planets but that only seems to disrupt the basic scenario intermittently.

The heat from the sun varies over a number of interlinked and overlapping cycles but the main one is the cycle of 11 years or so. That solar cycle can last from about 9.5 years to about 13.6 years and appears to be linked to the gravitational effects of the planets of the solar system combining to affect the sun’s magnetic field which seems then to influence the amount of heat generated and incidentally affects the number of sunspots. For present purposes I will concentrate on the past 1000 years during which the 11year cycle has been the main factor linked to observed temperature changes. For pre thermometer numbers we have to rely on less reliable indicators of past temperature.

It is clear that temperatures have varied so much over the past 1000 years that there have been substantial effects on human societies so disruption caused by weather and climate is by no means unusual. Many civilisations have fallen as a result of entirely natural changes in climate. Interestingly, they often blamed themselves for offending the Gods, nature or the planet (that sounds familiar!).

It is necessary to note that those disruptive changes have occurred quite quickly. A decade or two is quite enough to see changes that result in considerable hardship.

Because 70% of the planet is covered by water most heat from the sun is accepted by water. The seas take a long time to warm up or cool in comparison to land. Heat reaching the land by day is soon radiated back out to Space at night. Water has a much greater lag both in warming and cooling which also means that as a store of total heat the oceans are hugely effective. The strongest sunlight reaching the Earth is around the Equator that is primarily oceanic. The equatorial sun puts heat into the system year in year out whereas loss of heat is primarily via the poles with each alternating as the main heat loser depending on time of year.

The Earth therefore accumulates or loses heat to and from, primarily, the oceans. The land and the atmosphere are largely an irrelevance. That heat then has to find it’s way out into Space over time. Before it can be radiated out into Space heat has to pass through the atmosphere.

The planet cannot maintain and does not maintain a constant temperature. It is not even possible to identify a specific current temperature for the whole planet and for present purposes there is no need to do so.

All I need to assert at this point is that whatever the Earth’s temperature is at any given moment it will always be in the process of warming or cooling and, of course, the rate of that warming or cooling is highly variable.

Because the Earth is always either warming or cooling the point of balance could well be very fine so to attribute ‘blame’ to any particular factor we have to ascertain the scale and degree of sensitivity of each factor we wish to consider.

The point I need to make here is that on the basis of historical evidence from weather and solar cycle records the largest single factor influencing global temperature, whatever it might be at any time, is variations in the input of heat from the sun.

It is clear from the historical record that warmer weather accompanies short solar cycles and cooler weather accompanies longer solar cycles. Although I refer to weather the fact is that weather over time constitutes climate so for present purposes they are the same. During the recent warming the cycle lengths were less than 10 years so that meant we were getting more heat from the sun whatever the alarmists say about Total Solar Irradiance (a flawed and incomplete concept).

So far, the current solar cycle (number 23) is into the 12th year in length and may go to the full 13.6 years for known astronomical reasons. The very fact that it is longer than the previous two cycles suggests we are getting less solar energy already and, surprise, surprise, it is now being accepted by alarmists that warming has stalled and the planet may be cooling for the next 10 years at least. All they can do now is bleat that the underlying man made warming signal is still there but they cannot prove that to be the case nor can they demonstrate the scale of it in relation to natural causes.

As far as I can see nobody seems to be able to say why the observed changes in weather that accompany changes in solar activity actually happen. They seem to be disproportionate to the changes in heat coming from the sun. This is where I feel the need to make a suggestion.

The ENSO (El Nino Southern Oscillation) Cycle has been heavily investigated for many years but seems to be looked at as a freestanding phenomenon that just redistributes heat around the globe, sometimes warming and sometimes cooling.

I think that is wrong. I believe that ENSO switches from warming to cooling mode depending on whether the sun is having a net warming or net cooling effect on the Earth. Thus the sun directly drives the ENSO cycle and the ENSO cycle directly drives global temperature changes. Indeed, the effect appears to be much more rapid than anyone has previously believed with a measurable response occurring within a few years of a change in solar energy input. Indeed I see some evidence for the proposition that for various reasons cooling occurs faster than warming but I will save that for another time.

It was no coincidence that during the years from 1975 to 2000 we had a strong emphasis on El Nino with warming-also known as a period of positive Pacific Decadal Oscillation (PDO), and now, with an emphasis on La Nina we have cooling or at least a stall in the warming (a period of negative PDO).

As regards the Pacific Decadal Oscillation that is simply a periodical change in the predominance either of El Nino (positive mode) or of La Nina (negative mode). El Nino events can occur in a positive PDO mode and vice versa.

I believe that both ENSO and PDO are manifestations of the same process and are directly driven by shifts in the balance of heat output from the sun as it switches to or from net warming and to or from net cooling effects on the Earth.

It was no coincidence that the change from one ENSO mode to the other was approximately contemporaneous with the extension of solar cycle 23 to a period longer than the preceding two solar cycles and at about the same time the PDO switched from positive to negative.

Although there are similar periodic oscillations in other oceans such as the Atlantic and the Arctic I believe that they follow the lead of ENSO and PDO. In effect they simply continue the distribution of the initial warming or cooling state around the globe and of course there are varying degrees of lag so that from time to time the other lesser oceanic oscillations can operate contrary to the primary Pacific oscillations until the lag is worked through.

I believe that this is a clear and simple theory of solar driven global climate change which should now be tested empirically.

Just looking at the activity levels of the past few solar cycles and the temperature and ENSO changes that occurred at about the same time would have revealed the truth if those who should have known better were not trying to implicate man generally and western nations in particular. Refer to my two earlier articles for fuller detail.

The fact is that the Earth could well be a highly sensitive water based thermometer as far as solar input is concerned. The balance between overall warming and overall cooling is probably finely linked to the energy received or not received from the sun over decadal time periods or possibly even less.

Advances have been made in predicting the likely activity levels of the sun so it should be possible to make general predictions as regards the onset of warming or cooling trends on Earth from solar observations and astronomical measurements of planetary influences on solar cycles.

Finally, one should consider whether other warming or cooling influences might have any significance to humanity and the environment.

The fact is that the solar effect is huge and overwhelming. Other influences can only ever delay or bring forward what would have happened anyway because of the time scales involved with solar changes that tend to develop and intensify over centuries. One must also remember that, the warmer the Earth gets, the faster the radiation of heat to Space because of an enhanced temperature differential so it would be false to propose an ever increasing positive differential as a result of adding any warming effect of man made CO2 to the effect of solar changes.

The length and intensity of a solar cool down would strip out the human portion of any extra CO2 quite ruthlessly because the cooler temperatures would increase the amount of CO2 absorbed by the oceans and oceanic life would flourish to lock it away in the carbon cycle again in the form of organic calcium carbonate from a multitude of tiny sea creatures (which generally prefer cooler waters) falling to the sea bed.

In effect, all life on Earth has the benefit of an oceanic and atmospheric air conditioning system that clears out excess CO2 as well as well as dust, other particulates and noxious substances created by either the planet itself or the life forms on it from time to time.

Of course a single organism can upset the balance of it’s own environment for a time but the planet always renews itself and repopulates with new life forms if necessary.
The solution is always a new balance between numbers and lifestyle for any particular organism and that includes us.

That is why, despite hugely different environmental conditions in the past, including far higher CO2 levels, there has never been a ‘tipping’ point that changed the pattern of glaciations and interglacials that have occurred with clockwork precision based on astronomical movements throughout the historical record.

Nor need we fear any man made addition to solar warming because the proportion of the warming which we would be responsible for would be insignificant against the scale of the solar induced portion.

In any event, since cooling is worse than warming for humanity and most life on the planet, our production of CO2, however large in our puny terms, would be wholly beneficial for life on Earth.

CO2 is the least of our problems so our attention and resources should be better directed to a more general concept of sustainability.