Posts Tagged ‘climate feedbacks’

Earth’s Thermal Sensitivity to a Doubling of Atmospheric CO2

Wednesday, June 27th, 2012

Source: CCR

Lindzen, R.S. and Choi, Y.-S. 2009. On the determination of climate feedbacks from ERBE data. Geophysical Research Letters 36: 10.1029/2009GL039628.

What change in the mean surface air temperature of the planet would be caused by a doubling of the air’s CO2 content? In the IPCC’s Fourth Assessment Report, the most likely range for this thermal sensitivity parameter, as determined by numerous climate models, is something in the range of 2 to 4.5°C; yet even this significant degree of warming has been suggested by many of the world’s climate alarmists to be too small. And as a result, a great hue and cry has been raised by folks such as Al Gore, who is hard at work attempting to convince everyone that they have a moral responsibility to “save the planet” by demanding legislative actions designed to drastically reduce anthropogenic CO2emissions. (more…)

New Paper “Climate Physics, Feedbacks, And Reductionism (And When Does Reductionism go Too Far?)”

Friday, June 22nd, 2012

Source: Climate Science

Dr. Richard Lindzen, MIT

I was alerted to an important, informative new paper by Dick Lindzen (h/t to Anthony Watts) on the issue of climate. The paper is

R.S. Lindzen, 2102: Climate physics, feedbacks, and reductionism (and when does reductionism go too far?). Eur. Phys. J. Plus (2012) 127: 52 DOI 10.1140/epjp/i2012-12052-8.

The introduction reads (there is no abstract) [highlight added]

The public perception of the climate problem is somewhat schizophrenic. On the one hand, the problem is perceived to be so complex that it cannot be approached without massive computer programs. On the other hand, the physics is claimed to be so basic that the dire conclusions commonly presented are considered to be self-evident. Consistent with this situation, climate has become a field where there is a distinct separation of theory and modeling. Commonly, in traditional areas like fluid mechanics, theory provides useful constraints and tests when applied to modeling results. This has been notably absent in current work on climate. In principle, climate modeling should be closely associated with basic physical theory. In practice, it has come to consist in the almost blind use of obviously inadequate models.

In this paper, I would like to sketch some examples of potentially useful interaction with specific reference to the issue of climate sensitivity. It should be noted that the above situation is not strictly the fault of modelers. Theory, itself, has been increasingly idealized and esoteric with little attempt at real interaction. Also, theory in atmospheric and oceanic dynamics consists in conceptual frameworks that are generally not mathematically rigorous. Perhaps, we should refer to it as physical or conceptual reasoning instead. As we shall see, when reductionism goes beyond the constraints imposed by these frameworks, it is probably going too far though reductionism remains an essential tool of analysis.

The concluding remarks read (more…)

Weak Warming of the Oceans 1955-2010 Implies Low Climate Sensitivity

Thursday, May 19th, 2011

Source:  Global Warming

by Roy W. Spencer, Ph. D.

Since the issue of deep ocean warming (below 700 m depth) has been raised in the comments section, I have re-run the forcing-feedback model for the following two observations: 1) a net 50 year warming of 0.06 deg. C for the 0-2000 meter layer, and (2) a surface warming of 0.6 deg. C over the same period. The results suggest a net feedback parameter of 3 W m-2 K-1, which corresponds to a climate sensitivity of 1.3 deg. C from 2XCO2, which is below the 1.5 deg. C lower limit the IPCC has placed on future warming.

Weak Warming of the Oceans 1955-2010 Implies Low Climate Sensitivity

Assuming that the Levitus record of global oceanic heat content increase is anywhere near accurate, what might it tell us about climate sensitivity; e.g., how much global warming we might expect from increasing atmospheric carbon dioxide concentrations? As we will see, the oceans have not warmed nearly as much as would be expected if the climate system really is as sensitive as the IPCC claims. (more…)