All possible influences are considered, and at different times, different influences can dominate. But they all work by affecting two basics: the rate of heat energy coming in from the sun and the rate of heat energy escaping. If an asteroid hits the Earth and dust turns day to night for a few years, we don't need to worry too much about other influences for some time.

But CO2 is far from insignificant. At current concentrations, IR photons of the right frequency have a mean free path of around 25 metres before they get captured by a CO2 molecule and randomly re-radiated, so it's quite a struggle for the radiation to escape.  The net result is that CO2 is currently retaining 2.0 Watts/metre2 more than in 1750, and satellite measurement shows this to be increasing, and the rate of increase to be increasing:



Year  W/m2
1980 1.058
1990 1.253
2000 1.513
2010 1.791


Wikipedia - Radiative Forcing
That may not look much compared to the Sun's input of about 340 W/m2, but the rate of change is much, much faster than the Sun ever manages.  To get us out of the Little Ice Age, solar input increased by between 0.01 and 0.02 W/m2 per decade, only 3 to 7% of the current CO2 rate of increase.
Buzzard's Roost, 20 August, 2017
‘That's why the name has been changed to climate change’

I'm tired of hearing this nonsense. The seminal paper, the one which first set the bells ringing, was Plass 1956, entitled "The Carbon Dioxide Theory of Climatic Change", and the CC in IPCC (1988) surely does not stand for Global Warming.

Climate Change, 21/Sept/2015

‘0.01 degree F higher than the last "warmest year on record"’

No it wasn't.  It was 0.12°C higher than the last warmest year 2015, and 0.35°C warmer than the "year warming stopped  wink" 1998.

For those of you stuck in the 19th century, that's 0.22°F and 0.63°F - sixty-three times higher than your claim and well outside the margin of error.

NASA/GISS Global Temperature data.

Buzzard's Roost February 6th, 2017.

Funny Times February 2010

‘I really believe that if all the months when averaged over a decade had shown a warming trend then we would have been told.’

That's an interesting thought; it hadn't occurred to me to check. I'll run NASA/GISS's data through my software and see what if comes up with. There is such a lot of month to month variability that it would be a bit unlikely for ALL 12 months to show the warming trend over all 5 decades of warming.

Anyway, here are the monthly averages in °C per decade:

Decade   Jan   Feb   Mar   Apr   May   Jun   Jul   Aug   Sep   Oct   Nov   Dec
1966-75 -0.05 -0.05 +0.05 +0.01 +0.03 -0.01 -0.01 -0.02 -0.01 +0.01 -0.02 -0.02
1966-75 -0.06 -0.05 +0.06 +0.01 +0.04 -0.01 -0.02 -0.02 -0.01 +0.02 -0.02 -0.03
1976-85 +0.23 +0.17 +0.21 +0.17 +0.18 +0.11 +0.13 +0.13 +0.15 +0.09 +0.17 +0.20
1986-95 +0.38 +0.42 +0.40 +0.37 +0.32 +0.33 +0.34 +0.29 +0.27 +0.32 +0.24 +0.31
1996-05 +0.51 +0.61 +0.58 +0.53 +0.51 +0.50 +0.49 +0.51 +0.53 +0.53 +0.56 +0.52
2006-15 +0.63 +0.60 +0.71 +0.66 +0.66 +0.62 +0.63 +0.67 +0.70 +0.74 +0.74 +0.66

As it happens, of the 60 averages, 59 DO show the warming trend. Only the last decade's February is different, falling one hundredth of a °C from the 2nd last.  Every other month shows warming over every decade.

So, now you have been told.  Here it is graphically, each decade very clearly warmer than the previous one:

NASA/GISS Global Temperature Anomaly data
Link: DiverseCity, 28 July, 2016

It's early days yet, but I thought you might be interested in how Die Kalte Sonne's projection from 2011 was working out:

NASA/GISS Global Temperature Anomaly data

Die Kalte Sonne

It is only a short time since publication of Die Kalte Sonne, but it is quite remarkable how their prediction could have gone so wrong so quickly.

Link: Climate Change 10th September 2015

In fact, as I said to iemnutz elsewhere (unanswered), the numbers don't add up to a new Little Ice Age.

From 1600, to 1650 when the LIA bottomed out, solar heating fell by 0.325 Watts/metre2. That's 0.065 Watts/metre2 per decade. Currently, heating due to rising CO2 levels is rising at 0.2 Watts/metre2 per decade (, which would swamp any solar decrease like the one causing the LIA.

‘Carbon dioxide is ALWAYS a lagging indicator of warming because during EVERY LAST WARMING PERIOD’

That is correct.  It is not news and does not affect the theory and measured fact of CO2's greenhouse effect.

Some people hold on to the belief that, because warming will cause increased CO2, increased CO2 cannot cause warming.  That is logically incorrect and factually false.

Warming increases CO2 level, not because of increased life, but because it makes it less soluble in water and so drives it out of the oceans into the atmosphere.  The CO2 then amplifies the warming that drove it out in the first place - positive feedback.

Although CO2 increase lags temperature at the start of the warming period, the period ends with temperature lagging CO2 level.

Link: Sassy's Place 3rd September 2015

‘... any quantitative data’

Here's a bit more based on the Berkeley Lab experiment, which measured the rise in heat energy returned by CO2 over 10 years as 0.2±0.06 watts per square metre.

0.2 watts/metre2 in a decade adds up to 0.2×24×365×10/1000 = 17.52 kwh more per metre2 than 10 years previously.  But only 3% goes into the atmosphere, ie 0.53 kwh.

1 kwh will raise the temperature of 860 kg of air by 1°C.

The troposphere weighs about 7000 kg per metre2, but heating tails off towards the top, so we could assume it effectively to weigh half, ie 3500 kg. So 0.53 kwh/metre2 would warm the troposphere from the bottom up by 0.53×860/3500 = 0.13°C

0.13°C is the amount we would expect the temperature to be driven higher by the decade's CO2 increase.  The reality?

Temperature data source: NASA/GISS

1.66°C per century or 0.166°C per decade over the 50 years of global warming.  We are in the right ball park.

Link: Sassy's Place 7th September 2015

You have in the past suggested that the Dansgaard-Oetsger cycle might well have played a part in the warming that the Earth has recently experienced.

Strictly speaking, D-O events only occur during glacial periods, but Bond events are an equivalent phenomenon during interglacial periods, so I thought it would be interesting to perform a Fourier analysis of Loehle 2008, the temperature reconstruction which most emphasises the Medieval Warm Period and the Little Ice Age.

The analysis highlighted three potential cycles, 1540, 418, and 239 year periods:

T = 0.365cos(2Π(year-844.7)/1540) + 0.117cos(2Π(year-139.3)/418) + 0.101cos(2Π(year-113.3)/239)

Skeptical Science (Loehle)

NASA/GISS Global Temperature Anomaly data
WikiPedia (Fourier analysis)

The pink curve is a good fit, seldom straying outside the ±0.16°C uncertainty limit given for the Loehle original. At least it doesn't UNTIL we get to the 20th century. At that point the actual temperature zooms up and away from the curve, ending 0.7°C above, well outside the uncertainty margin.

So let's try again, this time allowing for the CO2 greenhouse effect:

T = 1.517log(CO2)/log(2) + 0.368cos(2Π(year-850.85)/1540) + 0.104cos(2Π(year-138.38)/418) + 0.101cos(2Π(year-107.8)/239) - 12.31

Skeptical Science (Loehle)

NASA/GISS Global Temperature Anomaly data
WikiPedia (Fourier analysis)

Link: Climate Change, October 25th, 2015.

‘It is not Co2, but cloud cover which controls temperatures’

You seem to be on a quest to find a non-existent Holy Grail - a single factor that controls all temperature.

Many things influence global temperature change. In the last half century the dominant factor has been increasing atmospheric carbon dioxide. That has now been clearly demonstrated; all else is illusion.

Someone yesterday suggested that it was the 60-year Altlantic Multidecadal Oscillation which was the main driver, so I did a bit of curve fitting on that and it seemed to contribute 20-25% of the warming, with CO2 contributing the rest.  But you could just skip to the last of the three exercises to see what happens when we rule out CO2:

Temperature data source: NASA/GISS

- and although the 60-year cycle is plain to see, it only has an amplitude of ±0.074°C, ie 0.15°C top to bottom, out of a warming 1975-2014 of 0.7°C, ie 21%.

Much of the remaining noise is down to El Niño/La Niña, a few volcanic eruptions, and some solar variation. A curve (red) incorporating these fits the data (blue) quite well:

Temperature data source: NASA/GISS

However, if we include everything except CO2, then the result is quite lamentable:

Temperature data source: NASA/GISS

Link: The Big Picture, November 4th, 2015.

Here's a bit more based on the Berkeley Lab experiment, which measured the rise in heat energy returned by CO2 over 10 years as 0.2±0.06 watts per square metre.

0.2 watts/metre2 in a decade adds up to 0.2x24x365x10/1000 = 17.52 kwh more per metre2 than 10 years previously.  But only 3% goes into the atmosphere, ie 0.53 kwh.

1 kwh will raise the temperature of 860 kg of air by 1°C.

The troposphere weighs about 7000 kg per metre2, but heating tails off towards the top, so we could assume it effectively to weigh half, ie 3500 kg. So 0.53 kwh/metre2 would warm the troposphere from the bottom up by 0.53x860/3500 = 0.13°C

0.13°C is the amount we would expect the temperature to be driven higher by the decade's CO2 increase.  The reality?

Temperature data source: NASA/GISS

1.66°C per century or 0.166°C per decade over the 50 years of global warming.  We are in the right ball park.
‘... claim that global warming between 1975 and 1998 was unprecedented.’

It was unprecedented in the last 2000 years according to ALL reconstructions. Global temperature rose with unprecedented speed to an unprecedented level, and it did so during the final 50 years while solar irradiance was declining.
You could posit a 1500 year cycle operating throughout the above period. If there were one then it would seem to have a peak at 900AD and troughs at 1650AD and 150AD. The next peak would come around 900+1500 = 2400AD, so you cannot use the 1500 year cycle as an explanation for modern warming.  The year 2000 would be halfway twixt peak and trough.  The plot would look something like:

Like so many promising alternative hypotheses, this one looks fine fitted to past data but goes all to hell as soon as it reaches the 20th century.

Link: Sassy's Place Sept 7th, 2015
There is no question but the climate is warming.

The adjustments made to pre-WWII temperatures, particularly in the USA, did cause official land temperatures rises to increase. But adjustments to above-ocean temperatures caused the opposite effect: reducing the apparent warming rate. The net result of ALL homogenisation adjustment globally was to REDUCE the apparent warming:



NOAA have been making more corrections recently which only really impact the years just prior to 1940, as you can see in the upper graph below.  See for details. 

The lower graph shows the effect of ALL corrections, confirming that the net effect is to decrease the apparent warming.  Not what you would expect if they were trying to fake global warming.

Generalised Climate Model Equation.

Generalised Climate Model Equation

model = c1(Log(CO2+1)/Log(2)) + c2E + c3A + c4Cos(2Π(T+c5)/c6) + c7Cos(2Π(T+c8)/c9) + c10Cos(2Π(T+c11)/c12) + c13R + c14S + c15V + c16

Since I am now addressing the nit-picker par excellence, I suppose I should clarify my use of 'know' as meaning 'believe to a high degree of certitude'.

An element of all belief comes from what others have told us, but in my case I have put quite a lot of work into the subject, analysed the data from all angles I could think of, and that analysis work is the main basis for my certitude.

In particular, I have tried very hard to model the last 130 years global temperature with and, just as importantly, without considering CO2.  A good way to test a model is to use about ¾ of the data to create the model, then use it to forecast the remaining ¼.  So I built a model for 1881-1980 using solar radiation, oceanic oscillations, sulphur aerosol, and volcanic data, and used it to predict what would happen in the tears 1991 to 2010.  The result:

Temperature data source: NASA/GISS

Not very good as a prediction for the 30 years following the analysis, is it? But if we include CO2 in the analysis, we get:

Temperature data source: NASA/GISS

Work is in progress on improving the prediction of short-term oceanic movements like AMO and ENSO, which drive most of the short-term variations.  It can be done reasonably well for 30 years, but there remains a bug which smooths forecasts too much too quickly. 

Yes there were, and it's worth having a look at the temperature graph again to see why. After WWII the temperature did indeed seem to be in decline, causing some scientists to conjecture that that we might be in danger of another ice age. But even by 1970, after 30 years of decline, for every scientific paper published about a coming ice age there were SIX predicting warming due to increased carbon dioxide. By 1980, with temperature still in the doldrums after 40 years, virtually ALL papers were predicting a CO2 forced rise.

Now that was a genuine climate forecast, made in the face of 40 years of temperature decline, predicting that it would start to rise soon.

There is no denying the accuracy of that forecast. These people knew what they were talking about then, and they do now still.

(Click for link)

I cannot agree that the ups and downs in the last 15 years yet indicate that warming has stopped, nor that there has been cooling since 1998. 1998 was one of the peaks but it looks like 2010 might surpass it as did 2005. The decade 2000 to 2009 contained 4 of the 5 hottest years since temperature readings began. 1998 was the only one outside that decade. Since the 70s, the average for each decade has exceeded that of the previous one. We shall have to wait and see what the average for 2010 to 2019 will be. Meanwhile, here's the very latest graph from NASA GISS:


It is a myth. The popular press seized on a scientific paper by Rasool and Schneider (1971), which said that IF industrial sulphate aerosols increased fourfold then the cooling effect would overwhelm the warming effect of the CO2. In fact aerosols decreased because of the clean air acts enacted in most countries at the time and warming was not overwhelmed.  By 1976 Stephen Scneider was in the forefront of scientists predicting global warming.

During the period 1965-1979 for every scientist predicting global cooling, six were predicting the global warming that actually happened.

But if you were a popular press editor trying to sell papers, what headline would do the trick: "Ice age coming!" or "Earth to warm a few degrees"?

(Click for

We are discussing the global warming that has occurred since the 1970s, and what I said was quite correct: there has been NO INCREASE in solar radiation during that period. Certainly it is at a high level, but since the 70s there has been no increase to correspond to the rise in temperature.

Here is a very accurate graph from NASA showing solar radiation during most of the period. As you can see, it wobbles up and down by about 0.1%,  showing the well-known 11 year cycle, but there is no systematic rise.

Scientists know that a prolonged change of 0.5% would profoundly affect the climate. But it is worth noting that the present high value is only 0.2% higher than during the Little Ice Age.

(Click for NASA Earth Observatory)

Sorry Scott; I missed that request. I am surprised that you can't find any solar radiance charts. There is nothing wrong with the wattsupwiththat version if that's what you prefer:

As you can see, there is no explanation there for the temperature rise since the 1970s, though it might have contributed to the pre-1940 rise.

(Click for Watts Up With That?)

Astronomy and Physics

Current greenhouse gas levels are far higher than for the previous 650,000 years The current atmospheric concentrations of carbon dioxide is 35% greater than pre-industrial levels. Methane concentrations have increased by 250%. These dramatic increases in greenhouse gases are human-caused.

(Click for

So far as the warming period 1970s onward is concerned, it is overlooked for good reason: there has been no change corresponding to the temperature rise. Correlation may not prove causation, but complete lack of it rather puts the damper on things.

There is good reason to believe that cosmic ray variations do cause variations in low cloud cover and so affect climate, but the flux in the short term depends almost completely on the solar radiation, and it slavishly follows the 11 year solar cycle, so it is not useful as an independent predictor in the short term; it's simpler just to use solar irradiance.

Cosmic Rays (red) and Cloud Cover (blue). Click for

However, cosmic ray flux coming into the Solar System does vary significantly and independently on a very long time-scale as the Solar System orbits the rest of our galaxy, and there is a persuasive evidence that it is a highly significant driver of long term climate cycles measured over hundreds of millions of years.

Click for

The figure right shows the results of two sets of computer simulations of the global average surface temperature of the 20th century using a particular climate model. In the first set, denoted by blue, only natural, time-varying forcings are applied; these consist of variable solar output and “dimming” owing to aerosols produced by known volcanic eruptions. The second set (in red) adds in the man-made influences on sulfate aerosols and greenhouse gases.

The two sets of simulations diverge during the 1970s and have no overlap at all today, and that the observed global temperature also starts to fall outside the envelope of the all-natural simulations in the 1970s.

Click for article

I wonder why you picked 2007?  Did you honestly think that 2007 represented a halt to the decline of ice? Everybody knows that it goes up and down but that there is an overall trend as well.

Here is the most recent graph:

Back in 1986 you could have seen the ice increase a bit and say "look - the ice is increasing FACT!" And you could have said it again in 1992, 1995 and 2000. And you would have been just as wrong as you are now.

Arctic Sea Ice News

Words come here ...
Click for Climate Progress

For the MOC to be causing 40 years of warming the oceans would have to be releasing heat energy to the atmosphere throughout that period and so the oceans would have to be cooling. But the oceans are warming too, indeed it is estimated that 90% of the extra heat energy that the Earth has absorbed has gone into warming the oceans.

The Oceans do have a dramatic effect - eg El Niño - but this typically reverses itself within an erratic 2-8 year cycle. A 100 year cycle would be needed to explain 40 years of warming. The record year 1998 coincided with a record El Niño event.