1. The long term trend of over the past 100 years is about 0.1 degrees per decade. What do you base your "factor of three" on? Climate models you yourself won't take with a grain of salt?
http://www.cosmosmagazine.com/news/4604/no-snow-more-drought-climate-report-warns

2. Humans have been modifying the planet to suit since agriculture was discovered, and adapting to the changes. Adapting to changes however they occur is part of our proven survival strategy and will (obviously) continue to happen regardless of what the climate does.

By the way it seems your heat stress paper is bunkum....

"The Sherwood and Huber paper is just a model sensitivity study, not a verifiable prediction. Moreover, not only is it scientifically flawed, but the dissemination of a press release illusrates that this is really not a science study. The funding of such a study by the National Science Foundation (whose predictions cannot be verified) illustrates another failure by the NSF to properly support climate science."

http://pielkeclimatesci.wordpress.com/2010/05/13/comments-on-the-study-researchers-find-future-temperatures-could-exceed-livable-limits/

Paul Frijters rule of thumb estimate for global warming is lower than pretty much all the projections in the IPCC's AR4 Synthesis Report (http://www.ipcc.ch/publications_and_data/ar4/syr/en/mains5-4.html#table-5-1).

But Michael we do have some error problems in the IPCC models which you were going to look into. Also with Trenberth's curved trend now showing a decline in sea surface temperatures, that decline continuing with the last 12 months having been, on average, cooler than 2003 as anyone can check on the NASA website.

It is appropriate to consider sea surface temperatures because the oceans contain close to 90% of all heat above the crust and it is the surface temperatures which have the most influence, not only above the oceans (which make up about 70% of the Earth's surface area) but also on islands and coastal areas where large portions of the population live.

But, even compared with the oceans, the amount of heat in the Earth itself is several orders of magnitude greater because the mass is far larger and the temperatures get up to about 5,400 degrees C in the liquid core. This heat below the surface has a huge stabilising effect on climate as I shall explain below.

There is a temperature drop (or gradient) as heat flows from the liquid core out through the mantle and crust to the surface and thence through the atmosphere and out to space. Above the surface there is of course far more heat contributed by the sun on a temporary basis each day, but the temperature in the first millimetre of so of the air is usually very close to that of the solid surface. So there is a continuous temperature plot from the hot core to the top of the atmosphere (which is at about -270 deg.C) with a change in gradient at the surface. (Strictly speaking there is a temporary small rise in the stratosphere, but that is not important in this discussion.) So the stable base temperature at the surface is locked in by the temperatures at each end in the core and in space at the top of the atmosphere.

Under the surface the process of heat transfer is mostly by conduction which involves collisions between electrons. Then, between the surface and the air, some heat is also transferred by collisions when air molecules hit the surface. This is a form of conduction which can also be called diffusion as explained in the second paragraph here. Once that heat is in the air it then starts to rise by convection which involves physical movement of the air molecules. In addition, some molecules (mostly so-called greenhouse gases) are also able to emit heat in the form of infra-red (IR) radiation, and the surface itself also reflects some high-energy radiation direct to space and emits some low-energy IR radiation. Some of the IR radiation is captured by greenhouse gas molecules and re-emitted in all directions. So some heat energy returns to the surface and exits again by conduction, convection and radiation. This process probably extends the warmth of the day by a few minutes but there is no evidence that there must be a long-term warming effect - as explained below.

Over the life of the Earth we thus have a natural cooling process with associated temperature gradients from the hot liquid core to the surface and then from the surface to the top of the atmosphere (TOA) where the temperature is almost down to absolute zero. Obviously humans have no control over the heat generated inside the Earth, nor the temperature in space. But it is important to note that any natural variation in the heat generated under the surface will in time have an effect on the equilibrium temperature at the surface.

Now, the Sun will of course also warm the surface during the day, and it will cool off again at night. We need to think of the underlying temperature gradient as providing a "stable base temperature" which would be about what we would expect perhaps an hour before sunrise on a calm mid-winter morning. The Sun's heat flows some short distance into the surface and then back out again. It is possible for some to be retained in local summer, especially in the oceans, but this tends to escape by winter.

Radiation does not carry any temperature information, so you don't become as hot as the Sun when you stand in its radiation. Hence the equilibrium which we observe in similar temperatures between the surface and the lowest few millimetres of the air must have been achieved by the diffusion process mentioned above. This is facilitated by the flow of heat from the Sun into and out of the surface each day. Any measurement of upwelling radiation will not distinguish between that from the surface itself and that from the air molecules. The proportion of diffused heat which is then carried up by convection thus appears to be significantly understated in the models used by the Intergovernmental Committee on Climate Change (IPCC) and others.

This in itself casts serious doubts upon the accuracy of such models which focus on radiation. The models are endeavouring to determine if there is any net "trapping" of heat which would be shown by a net inward flux of radiation at TOA. However, measurements show that the upwelling radiation usually varies only between 99.5% and 100.5% of the downwelling radiation at TOA. But the errors in the models when they calculate the above two totals are well over 1%, and so they cannot say for certain if the net figure (of the order of 0.5%) is actually positive or negative. This makes all the difference between warming and cooling.

Above all, the models do not consider the possibility of the underlying temperature trends varying by natural means. Instead, because they focus only on flows of heat energy, they dismiss the net heat flow from underground as being insignificant. Indeed the net flow is very small and only about 0.2% of that of total incoming solar radiation, but this is not the point. Firstly, it is greatly supplemented by inward and outward temporary heat from the Sun each day, this heat increasing the amount of heat carried by convection in the atmosphere, and secondly, it ignores the "supporting" effect of the temperature under the surface which has built up over the life of the Earth, albeit from this very small heat flow. It is not the rate of heat flow that matters; rather it is the temperature that has built up over at least a billion years.

The underground situation is in fact somewhat more complex. Probably only about 10% to 30% of that small heat flow originates in the liquid core, the rest in the mantle and crust. A very small amount (about 1%) is generated in the very outer crust by "tidal" friction caused by the moon's gravity. The effect of the moon's gravity is altered to a small extent by that from Jupiter, Saturn and a bit by Venus. Over the course of many revolutions of the Earth this could have a noticeable effect on that component of the surface temperature which has resulted in a build up of heat from tidal friction. This could explain long term cooling and warming, such as that seen since the 17th century. The warming effect of Jupiter has been increasing in that period, but will turn to cooling in another 50 years or so. Saturn is already starting to cause a smaller cooling effect which could last until about 2028. It would be difficult to quantify the possible effect of planetary orbits, but just as difficult to disprove the possibility of any effect.

A more detailed explanation of the temperature "support" mechanism is required because an objection is often raised that the net outward heat flow from the core is far too small to warm the atmosphere. Indeed that is the case, but over the course of even the last billion years there has been ample time for it to do so, especially with the aid of the Sun.

It may help to picture the whole distance from the liquid core to the top of the atmosphere (TOA.) We have no control over that relatively fixed distance, nor over the liquid core temperature (maybe averaging about 5,400 deg.C.) Nor can we control the TOA temperature which is known to be about -270 deg.C. There is a temperature gradient from the core to the surface and then a different gradient from the surface to the TOA. Hence there will be a natural equilibrium temperature at the surface (in the absence of solar radiation at night) as the heat passes through the surface/atmosphere interface. So we can say this temperature is "supported" by the heat flow. If we had no significant core heat and no atmosphere it would get very cold at night, probably around -230 deg.C as on the Moon.

Now, we do not have accurate measurements of core heat at various latitudes, but we do have hundreds of boreholes which provide data at depths around 300 to 500 metres. So we can "pick up the plot" at those depths, which are well beyond the influence of solar heat, and we can extrapolate the trend to the surface. The theory is possibly supported by the fact that such projections from underground do in fact correlate extremely well with temperatures observed just above the surface. Hence it seems highly probable that this does describe the mechanism which is in fact controlling Earth's climate.

It is important to understand that the rock and clay etc in the crust has low thermal conductivity which is similar to an insulating material like porcelain in an electric jug. If you boil such a jug and keep the water at boiling point, the outside of the jug will soon warm to a stable temperature somewhat less than boiling point (100 deg.C) but also quite a bit warmer than the room temperature. (The air very close to the jug will in fact start to warm up.) If the jug had been made of metal of the same thickness it would have been hotter still on the outside surface, because the conductivity of metal is higher.

Now the water in the jug may be compared with the liquid core of the Earth, and the porcelain can be considered similar to the Earth's crust. The point is that the temperature of the outside surface will reach a stable level while the water keeps boiling, and it will also cool down soon after the temperature of the water cools. The stable temperature depended upon the conductivity of the material in the jug. If we plotted a graph of the temperature at various points where the heat passed through the porcelain, then that plot would slope down with a gradient which is inversely proportional to the conductivity.

As with the jug, the heat from the Earth's core tries to get out to the surface as quickly as the conductivity will allow, and so the temperature gradient is as steep as possible while there is no opposing heat source. However, when it gets very close to the surface (perhaps 30 metres underground) it may meet up with incoming heat from the Sun. The temperature plot will then have a trough at that point and there will, in effect, be a pool of "temporary" extra heat that flows in from the Sun but then flows out again during the late afternoon and night.

Now, if we only consider borehole data at somewhat deeper levels than that trough, we find that the temperature plot is "aiming for" a temperature at the surface which turns out to be very close to what we will call the "stable base temperature" which is (approximately) the temperature we would measure just above the surface perhaps an hour or so before sunrise on a calm mid-winter night.

The fact that this happens in hundreds of boreholes at a wide variety of latitudes strongly suggests that the surface temperatures are in fact determined by the extrapolation (extension) of these underground temperature plots.

It is probably not difficult to envisage why the water near the floor of the ocean is at about the same temperature as is found in the crust just under the floor, because we are all familiar with heating water on a stove. Heat is transferred by conduction (sometimes called diffusion) from the stove (or the crust) to the water and an equilibrium state is achieved.

However, on land we get a more direct and immediate effect from the Sun, and so there is a tendency to assume that the Sun does all the warming and the surface has nothing to do with it. But, in fact, heat can also transfer from the solid surface (let's say a rock platform) to the adjacent air by the process of diffusion. But there is very little net heat coming out of the surface compared with that coming from the Sun. Notice, however, that I said "net" heat. In fact, every day (in which the Sun shines) a considerable amount of heat from the Sun flows into that rock surface, and then back out again by night. The net difference is very small, but the total amount of heat transfer each way is quite significant, so the rock can become quite warm. This total heat flow is sufficient to establish an equilibrium so that, as we do observe in calm conditions, the temperature of the first few millimetres of the air is very similar to that of the rock surface. Notice that the heat energy has come almost entirely from the sun.

Now, if cold winds from the nearest pole cool the air at night below the stable base temperature, then when the Sun rises it can more easily warm the air near the surface by temporarily warming the rock a little with heat that then flows back to some molecules in the adjacent air. But when the air temperature reaches that of the surface, some of the Sun's heat enters more deeply and stays in the surface perhaps for most of the day. This slows down the rate of warming of the air. Then, when the heat starts to flow out late that afternoon and night it will only do so until the temperature of the surface cools back down to the stable base temperature, because the temperature trend line for the trickle of heat from the core will still determine the minimum "break out" temperature at the surface. Note that it is possible for some build up of heat during summer months (especially in the ocean) but that will usually dissipate by winter.

And so, just as that same heat flow supports much higher temperatures on the way out from the core, so it will support the surface temperature.

Over the course of many years it is perfectly feasible that that core temperatures could vary a little. A portion of the heat generated comes from friction caused by "tides" in the liquid core which are "stirred up" by the Moon, just like ocean tides. There are also solid Earth tides in the outer crust. It is of course gravity from the Moon which does this, and it creates more friction near the Equator than at the Poles because of the spinning motion of the Earth and the fact that the Moon is circling the Earth. This contributes to underground temperatures (and thus surface temperatures) being lower at the Poles. Variations in solar insolation (due to different angles) of course also contribute.

What reasons can there be for variations in core heat? Marginal variations in total gravity which result from gravity coming from the planets could well provide an explanation.

The March 1998-early 2000 El Niño was the biggest on record, but there have been plenty of others. Most others have had very little effect on sea surface temperatures and a one or two year running mean is quite OK with such temperatures as they vary less than land temps. Trenberth's trend smoothes out any El Niño / La Niña effects anyway. It was still declining during the July 2009-May 2010 El Niño.

El Niño: ... 1994-1995 and 1997-1998, 2002-2003, 2004-2005 and 2006-2007. July 2009-May 2010

La Niña: ...1988-1989 1995-1996 March 1998-early 2000. Late 2000-early 2001. 2007-2008. 2008-April 2009. July 2010 - Current

The key issue is the amount of conduction (or diffusion) between the land surface and the first 1mm of air, and also between the ocean floor and deepest water, and between the sea surface and air. I suggest that this is somewhat greater than the figure for "thermals" in the models. (We can reconcile the upwelling radiation by recognising that there is more coming from the lowest levels of the atmosphere than estimated, rather than directly from the surface.)

The point about the high level of conduction/diffusion is that it is necessary to establish the equilibrium which is observed at the above interfaces, because radiation on its own would not produce such. The process is facilitated by the daily inward flow of heat (as the Sun warms the surface) followed by an outflow by night.

Now, once this conduction / diffusion process is acknowledged it follows that we have a continuous temperature trend from the liquid core (around 5,400 deg.C) to space which is close enough to -270 deg.C. The latter won't alter, but we simply cannot assume that the temperature of the liquid core has not and will not alter, at least a little, due to natural causes. (Some heat is thought to be generated by nuclear fission, for example, and there is a degree of randomness associated with such. Some heat is generated by friction in underground tides caused by the gravitational force exerted by the Moon, modified a little by that from the major nearby planets.)

If the temperature of the liquid core varies then whole temperature trend right through to space (including the surface interface) will move in the same direction, up or down.

So, in that sense, the underground temperatures will force climate.

But the temperature in space will not alter that at TOA, so there won't be temperature variations emanating from the TOA end of the trend.

Now all this in itself is enough to debunk IPCC claims, simply because their assumption of correlation of climate with CO2 levels was clearly stated to depend on a prior assumption that there could be no other cause. They specifically dismissed underground temperatures on the grounds of there being insufficient heat flow. This is pseudo-physics, because it does not require large rates of heat flow to bring about a change in the gradient. That trend is "supported" by a build up of heat over many years, and of course there has been quite a lot of heat flow in total since the Little Ice Age.

So, firstly we have the basic assumption being incorrect. Secondly, we see far too much error in the accuracy of both the models and the measurements of radiation. For example, if there were just 2% error in the models and 2% in the measurements, then we have doubt over a range of nearly 4% of total downwelling radiation. Now, when the difference in real life is rarely more than 0.5% (plus or minus) we simply do not have sufficient accuracy to state categorically that the models confirm that the net is positive or negative, that is, whether there should be warming or cooling. Now of course there must have been a net positive mean purely because temperatures did in fact rise since the Little Ice Age.

But if those temperatures rose because the core temperature rose, then there is absolutely no proof that CO2 played any part in it. And a rise in core temperature is a distinct possibility. Such variations in core temperatures would also explain ice ages.

You can see the arguments that are going on about radiation here: http://www.pas.rochester.edu/~douglass/papers/KD_InPress_final.pdf

It really is time for the world to sit back and question the whole matter, especially since the (curved) trend in sea surface temperature data has been declining since about 2006, according to the Trenberth and Fasullo plot kindly posted on Skeptical Science a few weeks back.

Michael, further to my as yet unanswered question about errors in radiation measurements and IPCC models, please see my post above in reply to Derek. I believe I have explained my hypothesis cogently and concluded with more detail about the errors.

Andrew. You seem keen to work with radiation figures so I'm hoping you might be the first in the world to explain a little dilemma for me ... refer first to ... http://www.agu.org/pubs/crossref/2004.../2003JD004457.shtml

The above reference talks about improvement by way of error reduction which is now down to 5-10 W/m2 at TOA and 10-15 W/m2 at surface.

It would appear then that, in calculating the difference between downwelling and upwelling radiation the models would have a total error of 15 to 25 W/m2 approximately, anyway.

Now the fact that empirical measurements may well be more accurate in measuring your 3.2 W/m2 (or whatever the mean has been since 1750) does not mean that the models are confirmed if they come up with a similar figure. They still have intrinsic error within.

We know it did in fact warm from the 17th century until about 2006 (based on Trenberth's curved trend of sea surface temperatures now past its maximum) so we would expect net downwelling radiation over that period. But we cannot prove that it was not due to some other cause than CO2, such as small natural variations in the 5,400 deg.C temperature in the liquid core or variations in cloud cover related to variable cosmic rays intensities coming from a (variable) Sun. After all, sunspot activity did also increase and appears to lead temperatures by 20 years or so.

In order to prove that all warming was due to CO2 and other GHG, the models must stand up on their own (if you follow my logic) and show that, given the concentrations of GH gases, the result was indeed expected to be 3.2 w/m2 with a high degree of accuracy. If the error bars were more than 3.2 then that small positive figure could have been negative. And indeed the error bars are up to 25 W/m2, so all the models can show us is that we should have expected between about +28 (meaning warming) to about -22 W/m2 meaning cooling. Do you find that convincing?

Anyone else got an explanation?