How would you improve this critique of Roy Spencer's recently published study?

This is an argument from an online debate I'm currently participating in. I plan on posting it tomorrow, so I would appreciate any quick suggestions or recommendations that you may have.

"Dr. Roy Spencer argues that previous studies have overestimated the Earth’s climate sensitivity. He presents two main pieces of evidence to support this argument:

1) Lag regression analysis of satellite data shows that net radiative gain precedes, and radiative loss follows temperature maxima. A simple forcing-feedback model appears to show that this is the behavior expected from radiatively forced temperature changes. However, only in the case of non-radiative forcing can an accurate diagnosis of the feedback parameter be made.

2) “There is a rather large discrepancy in the time-lagged regression coefficients between the radiative signatures displayed by the real climate system in satellite data versus the climate models.”

I will demonstrate that both of these arguments are likely incorrect, and Spencer’s resulting conclusions are physically unrealistic.

Regarding Spencer’s first argument:

I agree that Spencer’s lag regression analysis “supports the interpretation that net radiative gain precedes, and radiative loss follows temperature maxima”. However, this does not necessarily imply that the temperature variations during the relative time period were radiatively forced.

The simple forcing-feedback model Spencer used to draw this conclusion was much too simple. For instance, his model did not have the ability to simulate ENSO or the hydrologic cycle.

In addition, the model was likely tuned to give the result it gave. Spencer used an ocean mixed-layer depth of only 25 meters. However, it appears that mixed-layer depths of 100–200 meters are more appropriate for simple climate models. Spencer also used a lambda value of 3, much greater than the consensus value of about 1.4.

Notably, Spencer made no attempt to find out how sensitive his model fits were to these different parameter values. In fact, he never presented any error bars or uncertainties in his study.

As Dr. Andrew Dessler stated, “The argument made in these papers...is extremely weak. What they do is show some data, then they show a very simple model with some free parameters that they tweak until they fit the data. They then conclude that their model is right. However, if the underlying model is wrong, then the agreement between the model and data proves nothing.”

Regarding Spencer’s second argument:

Spencer claims to have demonstrated that, “There is a rather large discrepancy in the time-lagged regression coefficients between the radiative signatures displayed by the real climate system in satellite data versus the climate models.”

However, this argument does not withstand the slightest amount of scrutiny. As other scientists have pointed out, Spencer failed to account for decadal variability in the model simulations.

Clearly, climate model simulations for one decade will never precisely match model simulations for another decade. This is simply due to factors such as random fluctuations in ocean circulation within the climate models.

When scientists account for this decadal variability, they find that the satellite observations fall well within the range of simulations for most models. Thus, there is no fundamental discrepancy between the IPCC climate models and the satellite data.

The implications of Spencer’s paper are physically unrealistic:

As Spencer stated himself, “Since much of the temperature variability during 2000–2010 was due to ENSO, we conclude that ENSO-related temperature variations are partly radiatively forced. We hypothesize that changes in the coupled ocean-atmosphere circulation during the El Niño and La Niña phases of ENSO cause differing changes in cloud cover.”

However, energy budgets of the surface show that ENSO related temperature variations are not radiatively forced. Therefore, Spencer’s conclusions cannot be correct.

Moreover, Spencer’s conclusions imply that climate sensitivity is considerably lower than estimates from current climate models. However, numerous paleoclimate reconstructions do not support this. Therefore, past climate changes couldn’t have occurred if climate sensitivity were as low as Dr. Roy Spencer alleges."