Climate Conversation Group

On 8 March, 2010, David Archibald wrote a guest post on WUWT entitled “The Logarithmic Effect of Carbon Dioxide”. This was brought to my attention recently as an article worthy of attention, so here it is.

The greenhouse gases keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere, so instead of the average surface temperature being -15° C, it is 15° C. Carbon dioxide contributes 10% of the effect so that is 3° C. The pre-industrial level of carbon dioxide in the atmosphere was 280 ppm. So roughly, if the heating effect was a linear relationship, each 100 ppm contributes 1° C. With the atmospheric concentration rising by 2 ppm annually, it would go up by 100 ppm every 50 years and we would all fry as per the IPCC predictions.

But the relationship isn’t linear, it is logarithmic. In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic heating effect of carbon dioxide relative to atmospheric concentration:

The logarithmic relationship between atmospheric CO₂ concentration and temperature forcing. In other words, Willis Eschenbach shows that later increments of carbon dioxide added to the atmosphere have lesser effects on atmospheric temperature.

And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
Read more… »

The last post being sounded at a ceremony honouring the fallen. Is it time to bid farewell to the great global warming gambit?

The last post?

Here is the tireless, incomparable Willis Eschenbach posing a simple question and answering it simply and irrefutably. After reading this, all the alarmist nonsense in the world will make no difference to our thinking. In just a few words with plain facts he removes the belief — or even the need to believe — that the humble carbon dioxide has the power to command the climate. The more people know this, the faster we’ll all regain the will to live; spread it widely.

I found it on WUWT under the heading:

Congenital Climate Abnormalities

13 Feb 2010, by Willis Eschenbach

Science is what we use to explain anomalies, to elucidate mysteries, to shed light on unexplained occurrences. For example, there is no great need for a scientific explanation of the sun rising in the morning. If one day the sun were to rise in the afternoon, however, that is an anomaly which would definitely require a scientific explanation. But there is no need to explain the normal everyday occurrences. We don’t need a new understanding if there is nothing new to understand.

Hundreds of thousands of hours of work, and billions of dollars, have been expended trying to explain the recent variations in the climate, particularly the global temperature. But in the rush to find an explanation, a very important question has been left unasked:

Just exactly what unusual, unexpected temperature anomaly are we trying to explain? Read more… »

Brian Rudman, in White roofs are good for society, in the Herald last Wednesday, dredges up Professor Steven Chu’s wacky idea from last May to paint our roofs white, reflect more sunlight and thus temper the severe global warming presently afflicting us.

Professor Chu, US Energy Secretary and Nobel-prize-winning physicist, said lightening roofs and roads in urban environments would offset the global warming effects of all the cars in the world for 11 years.

He doesn’t tell us how long everything must remain painted white to earn those 11 years, or how much we’d need to pay for all the paint.

We can tell him, however, that it wouldn’t make any difference to global warming, although it might reduce the urban heat island (UHI) effect.

How does the UHI work? Well, roads and buildings absorb heat from the sun more than trees or grasslands do. So, as a village becomes a town and the town grows into a city, adding more and more roads and buildings, average temperatures climb, especially at night. This happens in both hot places and cold places, it makes no difference; if you build a city, you raise the temperature.

But if more surfaces were light-coloured instead of dark, more sunlight would be reflected and downtown wouldn’t get so hot.

The trouble is, it’s just not enough to combat global warming. With only about 0.1% of the sun’s energy being reflected away even if every road and building in the whole world was painted white (which would be a miraculous feat of co-operation), we wouldn’t see any change in the global average temperature, which might go down by about 0.1°C.

So we’d pay trillions to keep our parts of the world painted and we wouldn’t see any result for it.

The irony of this proposal is that the US-managed global surface temperature record is contaminated by the UHI effects from urban weather stations all over the world, since so many of them are in towns and cities. Anthony Watts, at Watts Up With That, has gathered evidence of this and for years has been lobbying to have adjustments made to the dataset to remove the spurious UHI warming and see whether we really do have global warming.

There is strong evidence that if this was done most of the surface “warming” recorded over the last part of the 20th century would simply disappear.

How ironic that Rudman picks up on a solution incapable of solving a problem that doesn’t exist, but whose effect could be to remove evidence of the problem.

Uh, so it will solve global warming! White paint, anyone?

By the way, it’s important to remember that this solution only makes sense in low latitudes (closer to the equator), where cooling your building is sensible. In higher latitudes (closer to the poles), where it’s already colder, you must heat the building and you really want darker colours to warm it a bit and save that heating money. So you can’t really paint all the buildings white, only those in the warmer places. And you don’t want to paint the colder roads white, since they ice up more readily.

What a pity. It was such a good idea.

There was a recent post by Steve McIntyre at Climate Audit that was difficult for some of us to understand. Fortunately, there’s an exposition of it at Climate Skeptic called “How to manufacture the trend you want” that makes it all clear. It’s regrettable, but please have a look.

It has to do with rates of calcification in Great Barrier Reef coral growth over the past 400 years. On January 2, 2009, in Science, De’ath et al reported an ‘unprecedented’ decline. But it seems aimed more to alarm than inform us. They showed a graph to support their claims. Steve revealed a graph of a longer time series that tells quite a different story.

Then we got to see the actual data followed by the deficiencies in the data; well, what a trend! It turned out that ‘unprecedented’ referred only to the last 153 years.

Richard Treadgold

This is a stunning piece of work. Have a look. I hope to say more later.

Who knew that the sun has increased its output by 30% since the far geological past, and yet the earth did not heat up as it did so? It’s called the Faint Early Sun Paradox and it was always a bit tricky to explain, until now…

The stability of the earth’s temperature over time has been a long-standing climatological puzzle. The globe has maintained a temperature of ± ~ 3% (including ice ages) for at least the last half a billion years during which we can estimate the temperature. During the Holocene, temperatures have not varied by ±1%. And during the ice ages, the temperature was generally similarly stable as well.

Willis Eschenbach has proposed a thermostat for the control of global temperature. His clear exposition of it has just appeared on Watts Up With That. Will it survive scrutiny? Read it through, have a think, let us know.

Richard Treadgold

Clouds are the issue in more than one facet of global warming. Apart from causing rain, clouds have two important effects: cooling and warming. Dr Roy Spencer, one of few scientists studying clouds, has said that a sustained change in cloud cover of just 1%, up or down, can cause a Medieval Warm Period or a Little Ice Age.

Cooling is achieved by reflecting back the heat from the sun; warming is done by keeping that heat in, like a blanket. I’m not an expert on clouds, but from my reading I’ve got the impression that low-level clouds usually cause cooling and high-level clouds usually keep the warmth in. I also think they might do both, at different times of the day.

For example, low clouds at night keep things warm — a clear sky means a cold night — while low clouds during the day reduce temperatures. We’ve all experienced the sudden cooling as a cloud moves across the sun on a hot day.

It’s a current and vexed question to discover just how these conflicting effects are influenced by increasing humidity, whether that acts to raise or to lower air temperatures and what the balance of the effects is around the world. As the global temperature rises (though I’m not suggesting that it is right now) more water evaporates. Where does the resulting water vapour go? What does it do? Are more clouds created, or fewer clouds? Do they warm or cool?

This post on Watts Up With That introduces and enhances a recent post on Climate Audit describing strong negative cloud feedbacks found by the Climate Process Team on Low-Latitude Cloud Feedbacks on Climate Sensitivity.

I especially like, as does Anthony Watts, the remarks of the first of Steve’s commenters, Willis Eschenbach:

Cloud positive feedback is one of the most foolish and anti-common sense claims of the models.

This is particularly true of cumulus and cumulonimbus, which increase with the temperature during the day, move huge amounts of energy from the surface aloft, reflect huge amounts of energy to space, and fade away and disappear at night.

I love the stunning picture of cumulonimbus on WUWT and the clarifying diagrams he gives to help us understand. Who can fail to notice that a cloud is not simply a cloud, but an ever-changing expression of shifting forces?

Richard Treadgold

A controversial new tax on CO₂ emissions has just been set by the Air Quality Management board. Companies are to measure and report their own emissions. Businesses say out-of-area firms get an instant advantage over them. Once again, California leads the charge into radical action. Read the original story and see local comment on the new tax at Watts Up With That.

A review of the major world temperature datasets: RSS, UAH, HadCRUT and GISS. The world still cools but there is some disparity between the datasets and GISS gets axed from the graphs — can it be trusted? Read the full story at Watts Up With That.

It’s a simple question: “What is the temperature of the earth?” But for those who live here it has no simple answer, nor ever will have—only approximations. For it not only depends on where you put the thermometer, but also, apparently, on who interprets it. For if you own the dataset, you can reduce older temperatures and increase recent ones, just as NASA has been doing, and give the impression of greater warming. Naughty, naughty. more…

In the 12 months to the end of January, the temperature dropped -0.629°C, rivalled in the last 10 years only after the 1998 El Nino peak. more…