Gavin Schmidt can retire Part I - The EPA sticks it to Steckis

Caerbanog brings word that Richard Steckis has been channeling Steve Goddard at the Sr. Pielke's vanity site WUWT, about Venus at Real Climate and Gavin is NOT amused. However, as Cthulhu has pointed out, the EPA has already answered the off earth questions. Sometimes, you just have to look it up

Comment (3-49):
A commenter (2210.1) states that Venus is not an example of the greenhouse effect but is merely warmer because it is closer to the sun. Another commenter (2210.5) attributes Venus' warmth to higher atmospheric pressure because compression causes temperature increases (for example, this occurs when inflating a bicycle tire, due to the proportional relationship between pressure and temperature represented in the ideal gas law, pV=nRT, i.e., pressure times volume equals amount of gas times temperature times a constant), and that a 95% CO2 atmosphere is actually cooler than a 100% biatomic atmosphere would be.

Response (3-49):
Venus is warmer than the Earth both because of the greenhouse effect and because of its distance to the sun; in contrast, Mercury is cooler than Venus despite being even closer to the sun. Were Venus’ atmosphere to be transparent to radiation, then the surface temperature of Venus would be determined only by the blackbody radiation of the surface, and the pressure of the atmosphere would not change this equilibrium temperature. There is a large body of literature on Venus’ climate; one example is Bullock and Grinspoon (2001)—all of which show that CO2 is a significant contributor to the planet’s warmth.

Because volume is not held constant, it is not appropriate to use the ideal gas law to determine the temperature on the surface of Venus based only on knowledge about its pressure. Therefore, the scientific literature shows clearly that the temperature of Venus is an example of a greenhouse effect, in contrast to the assertion by the commenters.

Comment (3-51):
One commenter (3013) mentions Mars and states that even given the lower atmospheric pressure, his calculation shows that it has twice as much CO2 as Earth, and further claims that the National Aeronautics and Space Administration (NASA) found that the even with this high CO2 concentration, the atmosphere of Mars does not retain heat.

Response (3-51):
The commenter did not provide any evidence for his claim that NASA has found that the atmosphere of Mars does not retain heat. Mars does have an atmosphere that is mainly carbon dioxide, but because of the low atmospheric pressure, it is only 16 times the quantity of carbon dioxide on Earth. At the same time, it receives less than 45% as much sunlight, so the increased radiative forcing from the CO2 is not sufficient to make up for the decrease in solar insolation. Thus, the commenter’s claim that the atmosphere of Mars does not retain heat is not consistent with the scientific literature.

Comment (3-39):
A few commenters (0717, 4003) noted that there is warming on other planets, mentioning Mars, Jupiter, and Pluto, and stated that this was evidence for the solar cause of global warming.

Response (3-39):
The commenters did not provide any peer-reviewed literature to support their argument. One indication that Mars is warming was a retreat of the South Polar Cap, but Colaprete et al. (2005) discuss the fact that the South Polar Cap is unstable, and that it is therefore difficult to extrapolate short-term changes in the cap to a long-term global trend. Martian climate is also influenced by non-solar mechanisms such as positive feedbacks between albedo changes and changes in dust storms (Fenton et al., 2007).

Therefore, it is neither clear that Mars is warming nor that the warming is solar induced. The climate on Jupiter is dominated by the dynamics of the massive standing vortices on the planet (Marcus, 2004), and solar energy is a less significant contribution to the temperature of Jupiter than it is for Earth. It is also unclear whether the warming of Jupiter is global or regional.

The changes in Pluto’s atmosphere have been detailed in Elliot et al. (2007). The basic atmospheric expansion is well modeled by the frost migrations models of Hansen and Paige (1996), without requiring any solar effects beyond Pluto's seasonally changing sub-solar latitude. Because Pluto takes about 248 years to orbit the sun, Pluto’s seasons can be measured in decades. Finally, Triton is the last commonly referenced “warming” planet. The last good measurements of Triton were in 1998 (Elliot et al., 1998), and the changes in Triton's pressure have been explained by the change in Triton's subsolar latitude uncovering polar icecaps to the sun as a result of Triton's obliquity.

Therefore, there is no indication that solar variability is the cause of recent warming on any solar system body. Additionally, the lack of recent observed trends in solar insolation (discussed in responses in this section of the Response to Comments document) makes it implausible that there would be such solar induced warming trends on solar system bodies.

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