Tuesday, 22 March 2011


Vincent Gray. IPCC Lead Author
MARCH 21st 2011


The real Greenhouse effect is the cooling of the earth's surface by the atmosphere in the same way as in a greenhouse. The atmosphere is held in place by gravity, so that the top of the troposphere performs the same function as the glass ceiling of a greenhouse. It  removes heat  by contact with the earth that has been heated by absorbed radiation from the sun and has risen to be replaced by cooler air. This process is called convection.

In a greenhouse,  the heated air  cannot  mix with the entire atmosphere, and is therefore warmer. .

The extent of real greenhouse cooling is reviewed in "Earth's Annual Global Mean Energy Budget" Kiehl, J. T. and Trenberth, K. E., 1997 Bull. Amer. Meteor. Soc., 78, 197-208. and Trenberth, K. E., J. T. Fasullo and J. Kiehl (2009). Earth's Global Energy Budget. Bull. Amer. Meteor. Soc., 90: 311-323

TK97 covers the ERBE (Earth Radiation Budget Experiment) period from February 1985 to April 1989.

TFK09 covers the  CERES (Clouds and the Earth's Radiant Energy System) period from March 2000 to May 2004

The details of both results are given in TFK09 and the graphs from both papers are attached

There are two items representing heat loss from the earth.

Latent Heat is the easiest to calculate, from the total annual precipitation. TK97 chose 78 W/msq which is less than any of the other calculations listed (80.2. 82.3 and 85.1 W/msq)

TFK09 chose 80.0 W/msq, which is again less than the other values listed (83.1 and 90.2 W/msq)

The other item , called  :Sensible Heat" in their tables and "Thermals" in the graphs, is the heat loss from the real greenhouse effect.

TK97  chose 24 W/msq for this quantity although the other authorities have much smaller values (15.3, 15.3 ans 18.8 W/msq). There is a suspicion that they needed the extra in order to "balance" the budget.

TFK09 chose  17 W/msq for "Sensible Heat, where other authorities had found 15.6. 19.4 and 17 W/msq They had evidently abandoned all hope of "balancing" their budget, and they came out  with a surplus of 0.9 W/msq which so horrified Trenberth that he famously called it a "travesty" in his Climategate email.

Both papers give separate estimates are  for "Land" and "Ocean"

TK97 has figures from other authorities of  27.1, 25.8 and 27.5 W/msq for :"Land": and 11.0, 11.5, 15.8, 9.5 and 14.0 W/msq for "Ocean" but no figure was chosen by the authors

TFK09 chose a figure of 27 W/msq for "Land" with other authorities gining 36.3 and 27,4 W/msq. They chose 12 W/msq for "Ocean"  where the other authorities gave 11.7, 16.6, 14.6 and 10.8 W/msq.

There is evidently much greater heat loss to the atmosphere over land than ocean. This is because of the greater turbulence caused by the irregular surface profile.

The difference is slightly greater because of the lower albedo over land which gives a lower solar absorption.

TK97 quoted Global albedo values  between 28.1- 33.8% "Land" between 30.8 and 35.8% and Ocean is 27.1-33.3% but did not make a choice itself

TFK90 quoted figures for Global albedo of 27.9-34.2% and chose 29.8%, "Land" 30.6-35.2% and chose 34.4%, "Ocean:", 27.0-33.9% and chose 28,3%

They therefore now consider that there is a difference of 6.1% between the albedo of "Land" and "Ocean"

It should be noted that the claimed global warming from the fake greenhouse effect (the absorption of infra red radiation by trace gases) is claimed to be a mere 1.6 W/msq since 1700. Changes in the real greenhouse effect could easily amount to more than this but the uncertainties involved in calculating its actual amount make it difficult to estimate..

Changes in the real greenhouse effect could include a number of natural  climate changes in the earth's orbit,  sun, ocean circulation and volcanic eruptions

The amount of heat lost by the real greenhouse effect would also be reduced by  anthropogenic efforts to reduce convection, so these effort should be considered as contributions to "global warming":if any such warming is detected

A greenhouse, by preventing natural convection, reduces its extent. .There are many other ways that humans try to stop the natural convection process. All buildings act in the same fashion as a greenhouse. Shelter belts and wind barriers reduce heat loss. .Changes in albedo which reduce the surface from darker to lighter also are  warming devices. Forests have a higher albedo than farmland, concrete roads and airport runways.

Devices that capture part of the natural heat loss such as windmills or solar panels do not reduce natural greenhouse cooling but merely capture it before it leaves.

It is surprising that the real greenhouse effect has never been examined as a possible reason for changes in the earth's surface temperature. Some of its effects may be summarized as urbanisation and land use change and they undoubtedly provide an upwards bias to temperature readings by weather stations; a bias that the compilers of the Mean Global Surface Temperature Anomaly Record resolutely refuse to take into account when they are claiming global temperature rises from the fake greenhouse effect

I have pointed out in my "Greenhouse Delusion" that the average  0.02 W/msq of heat which is generated by humans is very unevenly distributed and there are some industrial areas where the amount generated exceeds that attributed to the fake greenhouse effect by almost 100 times The attached graph (from Tom Quirk) shows how this heat is predominantly emitted between 30-60 degrees N


Vincent Gray
Energy Balance
Tom Quirk