Deviation Actions
The models
The climate models have failed to get global warming right. As the IPCC has confirmed, for the period since 1998,
“111 of the 114 available climate-model simulations show a surface warming trend larger than the observations”. [IPCC Synthesis report 2014, p 43]
That is to say there is a consensus that the models are exaggerating the rate of global warming.
The warming has so far resulted in no significant or consistent change in the frequency or intensity of storms, tornadoes, floods, droughts or winter snow cover.
As two climate scientists, Richard McNider and John Christy, have put it,
“We might forgive these modelers if their forecasts had not been so consistently and spectacularly wrong. From the beginning of climate modeling in the 1980s, these forecasts have, on average, always overstated the degree to which the Earth is warming compared with what we see in the real climate.”
In 1990, the first IPCC assessment included this statement, forecasting a temperature increase of 0.3 Cº per decade (with an uncertainty range of 0.2 Cº to 0.5 Cº).
In fact in the two and half decades since, even though emissions have risen faster than in the business-as-usual scenario, the temperature has risen at an average rate of about 0.15 C per decade based on surface measurements, or 0.12C per decade based on satellite data; that is, less than half as fast as expected and below the bottom of the uncertainty range!
What about 2015 and 2016 both being record hot years? Well, because of the massive El Nino, the HADCRUT4 surface temperature line just about inched up briefly in early 2016 into respectable territory in among the lower half of the model runs for a few months before dropping back out again [Clive Best chart]. That’s all.
Notice also that the warming has been twice as fast in the Northern hemisphere as the southern, that it has been concentrated in colder areas, colder seasons and at night. The difference between the red and blue lines on this chart is 20 years of global warming.
Notice too that the warming has definitely not taken us into uncharted territory. We are in the cooling part of the current interglacial, as shown by Greenland’s ice cores, and tree lines in the Urals are still lower than they were in the middle ages.
[S]
By the way, I trust the satellites more than the surface temperature data sets.
The latter are hopelessly contaminated by failures to correct properly for urbanization around measuring stations and a habit among those who control these data sets of “adjusting” old temperatures downwards without giving good reason. The global temperature in 1910 has been mysteriously falling over the last eight years. The global temperature in 2000 has been mysteriously rising.
But – and here is the amazing thing – even if you take the surface data sets, the rate of global warming is far slower than predicted by the models.
The Intergovernmental Panel on Climate Change says it is 95% sure that more than half of the warming since 1950 is man made. If you use the surface temperature sets that still implies less than half a degree of man-made warming in more than half a century.
This is still nothing like a dangerous change. At this rate dangerous warming is at least a century away. And the slower it happens the less dangerous it is, and the easier to adapt to.
Sensitivity
So why is the atmosphere not doing what it is told?
Actually it is. These results are precisely in line with the physics of the greenhouse effect.
We think recent warming was mainly caused by a change in the composition of the atmosphere, an increase from 0.03% to 0.04% carbon dioxide.
We know that the next 0.01% increment, expected soon after mid century, will have a lesser effect than the last 0.01% – that’s basic physics, the diminishing returns or logarithmic nature of the curve, as shown by Guy Callender in 1938.
[S]
A doubling of CO2 in the atmosphere cannot on its own produce dangerous warming.
The sensitivity of the atmosphere to CO2 is about 1.2C per doubling. That is the consensus, spelled out clearly (if obscurely) by the IPCC several times over the years. And that’s what we are on course for at the moment.
So what is the problem? Well, the theory of dangerous climate change depends on a whole extra step in the argument, one that very few politicians and journalists seem even to know about – the supposed threefold amplification of carbon dioxide’s warming potential, principally by extra water vapour released into the atmosphere by a warming ocean, and accumulating at high altitudes.
This is Warren Meyer’s diagram to show the difference.
This is where the evidence is much more shaky. Some studies find an increase in water vapour high in the atmosphere, others do not. One complication is that water vapour condenses into clouds and we cannot either measure or model clouds anything like adequately yet.
We know that clouds keep the surface warm at night, while low clouds in particular cool it during the day by reflecting sunlight back into space. But whereas the models generally claim that there is a positive correlation between the net cloud radiative effect and temperature, boosting the water vapour amplification, NASA’s CERES data show that there is a strong and significant, negative correlation: that higher temperatures lead to more cloud cooling. That’s a glaring discrepancy between models and data.
Consistent with these discrepancies, recent attempts to measure the sensitivity of the climate system to carbon dioxide using real data nearly all find that it is much lower than the models assume, as Nic Lewis, Marcel Crok, Judith Curry and Pat Michaels have shown in recent years.
Of particular note, the cooling effect of sulphate aerosols is smaller than thought, so cannot be an excuse for the slowness of recent warming.
So, if it’s consensus that floats your boat, there is an emerging consensus from observational estimates that climate sensitivity is low.
The models are assuming too rich a feedback.
What’s more, all the high estimates of warming are based on an economic and demographic scenario called RCP 8.5, which is a very, very unrealistic one.
It assumes that population growth stops decelerating and speeds up again.
It assumes that trade and innovation largely cease.
It assumes that the ability of the oceans to absorb CO2 fails.
It assumes that despite all this the income of the average person trebles.
And most absurd of all, it assumes that we go back to using coal for almost everything, including to make motor fuel, so that by 2100 we are using ten times as much coal as we are today.
In short, it is a barking mad scenario, yet whenever you hear a scientist or a politician say something like we are committed to warming of “up to” four degrees, that – and implausibly high sensitivity – is what they are assuming, often without knowing it.
www.thegwpf.com/matt-ridley-gl…
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The only people who can look at this information and STILL insist that it is somehow right... are those who don't really make the effort TO LOOK AT THIS INFORMATION.
Or use rational thought and common sense.
Instead all you will hear is shrieks about 'CO2!' Or links to sites designed to smear and demonize anyone who dares point out the FRIGGING OBVIOUS! comments.deviantart.com/1/6664…
