Negative feedback: clouds lowering in response to warming

Cloud height anomaly

All the feedbacks in the alarmists’ climate models are positive. The CO2-induced warming of about 1 degree is amplified several times as a result of these feedbacks to produce the catastrophic warming projections of the IPCC. The possibility that negative feedbacks may be at work to reduce or eliminate such amplification is discounted without a second thought.

Here, however, is empirical evidence that a natural mechanism is providing precisely that:

Clouds around the world may be falling in response to rising global temperatures and having a cooling effect on global warming, according to analysis of satellite data by Auckland University scientists.

The first 10 years of data from the NASA Terra satellite, which uses nine cameras at different angles to produce a stereo image of the world’s clouds, shows their average height has lowered by about 1 per cent, or 30 to 40 metres.

Most of the reduction was due to fewer clouds occurring at very high altitudes, says the study, published in the journal Geophysical Research Letters.

“This is the first time we have been able to accurately measure changes in global cloud height and, while the record is too short to be definitive, it provides just a hint that something quite important might be going on,” said lead researcher, Professor Roger Davies.

In a “negative feedback mechanism”, lower cloud height would allow the Earth to cool to space more efficiently, reducing the surface temperature of the planet and potentially slowing the effects of global warming.

“We don’t know exactly what causes the cloud heights to lower but it must be due to a change in the circulation patterns that give rise to cloud formation at high altitude,” Prof Davies said.

The Terra satellite is scheduled to continue gathering data through the remainder of this decade.

“If cloud heights come back up in the next 10 years we would conclude that they are not slowing climate change,” Prof Davies said.

“But if they keep coming down it will be very significant.” (AAP)

A longer explanatory piece is here.

The paper is entitled:

Davies, R. and M. Molloy (2012), Global cloud height fluctuations measured by MISR on Terra from 2000 to 2010, Geophys. Res. Lett., 39, L03701, doi:10.1029/2011GL050506.

and the abstract is here.


  1. Daniel J. Anderson II via Facebook says:

    That means a Tornado is about to form and will visit you shortly.

  2. More evidence that the science is unsettled, however a seemingly worthwhile venture into broadening our understanding of the climate system.

    It’s a shame that so much is wasted on modelling and mitigation where there is little certainty involved, when it could be spent on observing.

  3. Clouds are getting lower – The sky is falling! I’m off to buy a crash helmet…

  4. “If cloud heights come back up in the next 10 years … “

    10 years! So much for Joolya’s, With the science so clear we shouldn’t waste time on shock jocks … we need to act now. Not in a couple of generations’ time, or even a couple of years’ time, but now.”

    Somebody better tell those Auckland University scientists to hurry up … we don’t have 10 years to wait!

  5. it is interesting the use of the word amplify. where does the extra energy come from to cause that amplification? feedbacks? dont make me laugh…

  6. I’m confused. I thought thered been no warming for 15 years — making their hypothesis false from the outset.

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