Levitus was 2012, not 2008. You're pointing to a Nature news feature, rather than dealing with the substance of 700-2000m ocean heat content measurements either the IPCC AR5 or the measurements referenced in Levitus et al. But I guess they are an inconvenient truth for you! I could equally point to
Foster and Rahmstorf 2011 or
Kosaka and Xie 2013 (discussed in the Nature News article), showing that what appears to be a 'hiatus' is dominated by the expected natural variations of ENSO, and not a change in the long-term climate forcing.
That is also supported by the positive trend in El Nino years and La Nina years that extends through to the present day - 2010 was the hottest El Nino, and 2012 was the hottest La Nina. All La Nina events since 1998 are warmer than all El Ninos before 1997, I wonder why?
It's funny how Otto et al deals with transient climate response, not equilibrium sensitivity,
and the author states that their work agrees with IPCC ECS estimates of 2-4.5C [and by extension the review of dozens of studies by Knutti and Hegerl 2008]. But I'm sure you knew that when you tried to convince me that there were soooo many papers that point to low climate sensitivity!
Ring et al, who are one of few studies on the low side for an ECS estimate, state that "
Although we believe, given our relatively low values for equilibrium climate sensitivity, that the 2˚C goal is attainable, we emphasize that steep emissions cuts must begin now in order to reach this goal".
I'm sure as you've referenced this paper, you'll heartily agree!
Nic Lewis' paper suffers from the problem that their estimate of climate sensitivity completely changes when you add just six years worth of data! This is pretty damning for a paper proposing to estimate a robust value.
I'll leave the discussion of Aldrin et al to the approving voice of a top class climate modeller
Gavin Schmidt at RealClimate:
Quote:
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And then there are the recent papers examining the transient constraint. The most thorough is Aldrin et al (2012). The transient constraint has been looked at before of course, but efforts have been severely hampered by the uncertainty associated with historical forcings – particularly aerosols, though other terms are also important (see here for an older discussion of this). Aldrin et al produce a number of (explicitly Bayesian) estimates, their ‘main’ one with a range of 1.2ºC to 3.5ºC (mean 2.0ºC) which assumes exactly zero indirect aerosol effects, and possibly a more realistic sensitivity test including a small Aerosol Indirect Effect of 1.2-4.8ºC (mean 2.5ºC). They also demonstrate that there are important dependencies on the ocean heat uptake estimates as well as to the aerosol forcings. One nice thing that added was an application of their methodology to three CMIP3 GCM results, showing that their estimates 3.1, 3.6 and 3.3ºC were reasonably close to the true model sensitivities of 2.7, 3.4 and 4.1ºC.
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I'll conclude with a note that nothing's personal. If I'm ever at the same star party, you're welcome to come say hi, look through the scope or whatever. Though you're desperately wrong about climate, it's your information that is desperately wrong (goes with trusting a British right-wing lobby group I guess), and nothing more than that.
Genuinely, clear skies!