JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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Settled! Global Warming and the pause, caused by changes in cloud cover, not CO2

That’s it: It was 4% cloudier in 1985, then roughly the same after 2000 — that’s the Pause and the Cause

A new paper in Russian, by OM Pokrovsky, shows that global cloud cover decreased markedly from 1986 to 2000. This is a very large decline in terms of the planetary atmosphere. Pokrovsky uses ISCCP satellite data (the “International Satellite Cloud Climatology Project” — a US program). It’s the best cloud data there is. The effects of clouds are so strong that most of the differences between IPCC-favoured-models comes from the assumptions the models make about clouds. Cloud feedbacks are the “largest source of uncertainty”. [IPCC, 2007]

Clouds cover two-thirds of the Earths surface, reflecting around 30% of the total energy from the Sun back to space. A small change in cloud cover can easily warm or cool the planet, like a giant pop-up shade-sail.

This, on its own, explains all the warming that occurred from 1986 – 2000. It explains the pause. We don’t know why clouds decreased, but we know it wasn’t due to CO2, which kept rising relentlessly year after year, and even faster after the turn of the century.

Something else is driving cloud formation, or density or [...]

Chiefio: minor changes in clouds swamp the effect of CO2 — see it every day

I was taken by the way Chiefio slices away the clutter to leave bare the most pertinent point. From day to day, the sun, the latitude, our orbit, and the CO2 levels are the same as the day before, yet the temperature can swing wildly. Over a whole month, most variables are constant, yet one obviously dominates the monthly average, a factor we don’t even have good data one in the long run.

Is The Average Variation Of Clouds CO2?

Now the one big thing I can add to the graph itself is simple. I watched the sky during that time, closely. The cool days were cloudy to overcast. The hot days were clear blue sky. Temperature directly matched to degree of clouds. Cloudy days are cool. Clear days are hot.

During these three weeks of data, there is nearly zero change of any of the Milankovitch parameters. Insolation is a functional constant to a large number of decimal places. Our latitude and longitude and distance to water do not change. All manner of variables in this complex soup are held constant by the nature of their 1000s of year rate of change. On the scale of [...]

Cloud forming bacteria?

File this under: “How little we know.”

The upper troposphere is apparently teeming with particles of bacteria and fungi, surprising researchers.* Proving that life is tenacious and that microbes can survive just about anywhere, a team at Georgia Institute of Technology have discovered that quite a bit of what we assumed was dust and sea-salt may be bacteria aloft. Some of the little critters made it as high as the upper troposphere which is 10km up (where commercial flights cruise). No one is quite sure if the microbes “live” up there, or were just visiting.

The study showed that viable bacterial cells represented, on average, around 20 percent of the total particles detected in the size range of 0.25 to 1 microns in diameter. By at least one order of magnitude, bacteria outnumbered fungi in the samples, and the researchers detected 17 different bacteria taxa – including some that are capable of metabolizing the carbon compounds that are ubiquitous in the atmosphere – such as oxalic acid.

The bacteria were probably tossed up there by wind and waves:

When the air masses studied originated over the ocean, the sampling found mostly marine bacteria. Air masses that originated over land had [...]

Models get cloud feedback wrong, but *only* by 70W/m2 (that’s 19 times larger than the CO2 effect)

Yet another paper shows that the climate models have flaws, described as “gross” “severe” and “disturbing”. The direct effect of doubling CO2 is theoretically 3.7W per square meter. The feedbacks supposedly are 2 -3 times as strong (according to the IPCC). But some scientists are trying to figure out those feedbacks with models which have flaws in the order of 70W per square meter. (How do we find that signal in noise that’s up to 19 times larger?)

Remember climate science is settled:  like gravity and a round earth. (Really?)

Miller et al 2012 [abstract] [PDF] find that some models predict clouds to have a net shortwave radiative effect near zero, but observations show it is 70W per square meter. Presumably, cloud shortwave radiative effect means the sunlight bounced upwards off the surface of the clouds and out into space.

What’s especially interesting about this paper is the level of detail. They test shortwave and longwave radiation, precipitation flux, integrated water vapor, liquid water path, cloud fraction, and they have observations from the top of the atmosphere and the surface. With so much information they can test models against short wave and long wave radiation, to see [...]

The incredible power of clouds (and Roy Spencer’s work)

Joint Post by Tony Cox and Jo Nova Clouds cool the planet as it warms

Clouds cover an enormous 65% of the planet and are responsible for about half of the sunlight that is reflected back out to space.[i]  The effects of clouds are so strong that most of the differences between IPCC-favoured-models comes from the assumptions the models make about clouds. Cloud feedbacks are the “largest source of uncertainty”.[ii] Numerous studies show models project wildly different results for clouds, and yet few could correctly simulate clouds as recorded by satellites.[iii] One researcher described our understanding of cloud parameters as being “still in a fairly primitive state.” [iv]

Sunlight that travels 150 million kilometers can be blocked a mere 1km away from the Earth’s surface and reflected back to space.  The situation is complicated though, because clouds also slow the outgoing radiation — which has a warming effect. In general lower clouds are thicker and have a large cooling effect, while higher clouds are thinner and tend to trap more heat than they reflect (i.e. net warming).  Observations show the cooling effect of clouds dominates the warming effect. (Allen 2011[v]) which means that, in general, more clouds means more cooling.

[...]

Clouds dominate everything

Al Gore describes how carbon dioxide beats up Mr Sunbeam and stops him leaving the atmosphere. But he “forgot” to mention that clouds reflect around a quarter of all the sunlight that hits the earth. Those beams of light travel all the way from the sun to get bounced off into space when they are just a few kilometers from the ground.

Any change in cloud cover makes a major difference. The IPCC assumes clouds respond to warming, but clouds could easily drive the warming.

[...]