Watt about the UKMO Report – Part 1?

Watts Up With That (WUWT) has a new post by Bob Tisdale called Part 1 – Comments on the UKMO Report about “The Recent Pause in Global Warming”. This post is a comment on one of the new reports released by the UK Met Office. The reports can are described here and the first one is titled Observing changes in the climate system.

Now, I haven’t read the reports in detail, but what I have read seems good – I would say that though, wouldn’t I? Bob’s post is also rather long, so wasn’t going to comment on much. There were two things that caught my eye though. He includes the figure below, which is from the IPCC’s 4th Assessment Report. The top figure is a comparison between the observed global surface temperature anomaly and an ensemble of model means that include anthropogenic and natural forcings. The lower figure is one in which the models only include natural forcings.
Bob then goes on to say

The IPCC wanted the people of the world—and, more importantly, lawmakers—to believe that only manmade greenhouse gases could have explained the warming since the mid-1970s.

This isn’t really a fair representation of what the IPCC concluded on the basis of this figure. What they conclude is that including anthropogenic and natural forcings provide(s) a consistent explanation of the observed temperature record. Models with only natural forcings do not simulate the warming observed over the last three decades. This doesn’t say it has to be anthropogenic, simply that including anthropogenic forcings produces results that are consistent with observations. Leaving out the anthropogenic forcings produces results that – in the last 3 decades – are not. So, it could be something else, but what is it? Also, as I tried to explain in an earlier post today, trying to explain what we’re currently experiencing through natural variability alone is difficult.

The other thing I noticed was that Bob is repeating his normal it’s all because of ENSO events idea. He includes the following figure which shows the global surface temperature anomaly since 1950 and also indicates the time of some kind of climate shift and the times of major El Nino events.
Bob’s interpretation is that the global surface temperature is simply responding to El Nino heating events. I’m sure it does, but as I try to explain in this post, El Nino events cannot really change the equilibrium surface temperature. Consequently any energy released by El Nino events should be lost in a reasonably short time period. The temperature cannot remain enhanced if the equilibrium temperature is unchanged and ENSO events can’t change the equilibrium surface temperature.

Furthermore, what I try to explain in this post is that it’s not unreasonable that the oceans absorb a large fraction of the excess energy. The amount of energy that a particular patch of the surface absorbs will be determined (approximately) by the difference between the incoming flux (from the Sun) and the outgoing flux (based on the surface temperature). On average, I believe, the oceans are likely to have a larger difference than the land and hence typically absorb a bigger fraction of the excess than the land. If so, it seems reasonable, that there might be periods where the surface warming is slow (most of the energy going into the oceans) followed by a sudden jump at a large El Nino event where energy in the oceans is brought to the surface to heat the land and atmosphere. The ENSO events are, therefore, simply providing a mechanism for transferring some of the excess energy through the climate system to eventually heat the atmosphere and land. They, alone, can’t explain the long-term warming trend that is clearly evident in the figure above.

Anyway, that’s my “brief” comment on Bob Tisdale’s review of the first of the Met Office’s recent reports. Sadly, more of the same from Bob and, unless someone can convince me otherwise, another indication that he doesn’t really understand the basics of global warming and the concept of energy conservation.

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9 Responses to Watt about the UKMO Report – Part 1?

  1. t_p_hamilton says:

    Shorter Bob Tisdale: Shift happens.

  2. The problem with the El Nino argument of Bob is that he never explains where this heat is coming from. During an El Nino event the ocean releases stored heat, and that has to come from somewhere. Especially when the oceans themselves are still warming.

    Without accounting for how that happens he just has a interesting idea with nothing backing it.

  3. Exactly. Hence my comment at the end that he doesn’t appear to understand energy conservation 🙂

  4. Very good, I may have to use that at some stage 🙂

  5. Tom Curtis says:

    My biggest problem with Tisdale’s nonsense is that he does not use it to retrodict past temperature changes. He purports that the current temperature increases are due to ENSO, and are natural. Given that, similar ENSO drive events should have occurred in the past. We now have reconstructed ENSO records going back at least a thousand years so Tisdale should be able to retrodict past temperatures back to the MWP. Of course, as his process is a one way ratchet, that would mean retrodicting a rapidly increasing warming ever since the MWP. His refusal to put his theory to any serious test shows that he is simply playing games, not doing science, whatever he claims to the contrary.

  6. Exactly, I had wondered something similar. If it’s a one-way ratchet why have we not had an ever increasing surface temperature, which seems to be roughly what his model would predict. He could argue that there is some tipping point when it reverses (for some unknown reason) but since global surface temperatures appear to be higher today than they’ve been for at least 1000 years, that doesn’t really make sense either.

  7. Excellent post! What continues to amaze me is the lengths to which these people try to muddy the issue by confusing natural variability with an actual forcing. The IPCC data clearly show a forcing outside of natural variability is evident. And a massive consensus of scientists agree that this forcing comes from human greenhouse gas emissions. The data, the models all validate this view. NASA, NOAA, and the major scientific bodies around the world all agree.

    Without an outside forcing, the natural variability line between El Niño and La Niña would, over time run as flat to ever so slightly declining (as it has over the last 2000 years). But because there is a forcing involved we see a flattening of temperatures when natural variability would push for cooling and large temperature step increases when natural variability pushes toward warming. IPCC shows exactly this as do global temperature records.

    Deniers celebrate a pause or slow down in warming miss the obvious fact that we should have seen a drop. And, in the long view, they are always proven wrong in their assertions that temperatures will return to normal. Further their missing the total Earth system warming by ignoring and denying entirely pertinent ocean temperature data confirming the raging heat uptake throughout this system is yet one more visible evidence of willful ignorance.

    I honestly don’t understand how a thinking person can be pursuaded by such tom foolery and what amounts to little more than verbal slight of hand. And yet the worm tonguing continues.

  8. Thanks. It is posts like this that got me starting on my blogging about this whole subject. Without being an expert on climate science (but at least understanding the fundamentals), there is clearly so much that is fundamentally wrong that you’d hope people would realise that it is largely nonsense. Sadly, not the case though.

  9. Skeptikal says:

    Consequently any energy released by El Nino events should be lost in a reasonably short time period.

    That’s exactly what happens… all that heat is lost.

    Bob hasn’t shown how a short duration heat burst can affect the long term heat retention of the atmosphere, so I cannot support his theory.

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