New study: Cooling cloud cycle caused global warming hiatus

Posted: March 10, 2018 by oldbrew in climate, Clouds, Natural Variation, Ocean dynamics, pause, research
Tags: ,

Is this how it works? [image credit:]

An obvious problem with studies like this is that as soon as natural climate variation is invoked – to explain the lack of expected warming from so-called greenhouse gases – the argument that such gases could be a dominant factor in climate processes is then severely weakened to say the least. It is in effect an admission that such variations could cause warming as well as cooling. How long can a ‘hiatus’ last before it becomes the status quo?

Reinforcement of Climate Hiatus by Decadal Modulation of Daily Cloud Cycle
– By Jun Yin and Amilcare Porporato, Princeton University

Based on observations and climate model results, it has been suggested that the recent slowdown of global warming trends (climate hiatus), which took place in the early 2000s, might be due to enhanced ocean heat uptake.

Here we suggest an alternative hypothesis which, at least in part, would relate such slowdown to unaccounted energy reflected or re-emitted by clouds.

We show that the daily cloud cycle is strongly linked to pacific decadal oscillation (PDO) and that its decadal variations during the climate hiatus have an overall cooling effect. Such an effect may have partially, and temporarily, counteracted the greenhouse warming trends.

The slowdown of global warming in the early 21th century, referred to as the climate hiatus, raises growing political and public concerns. Observations and climate modelling results suggest that such a phenomenon is caused by the compounding effects of inter-annual and decadal variations of ocean circulation, aerosols, volcanic eruptions, and variation of solar irradiance.

While enhanced ocean heat uptake is regarded as one of its primary causes of the recent climate hiatus, there are still debates over which parts and depths of the ocean may be responsible for absorbing the imbalanced energy.

Such uncertainties stem in part from the temporal interpolation method used for satellite calibration and the sparse spatial/temporal sampling of the ocean heat content measurement.

It is thus logical to wonder whether the estimation of Earth’s energy balance might have missed some energy component linked to the finer temporal resolutions (e.g. sub-daily timescale).

Continued here.
– – –
Full paper here.

  1. Phoenix44 says:

    It then becomes chicken and egg – did this cause cooling or did the lack of this cause warming?

    My own wholly unscientific guess is that global average temperature is a wholly unstable thing, and will naturally move up and down and sideways over all sorts of timescales. The idea it “should” be stable seems wholly unlikely as well as wholly unproven.

  2. A C Osborn says:

    That was also my first thought on reading the summary, Cloud Cover caused the hiatus, but Lack of cloud cover didn’t cause the warming, according to them that could only be caused by CO2.
    The Tropical Cloud Cover was a mirror image of Temperatures, unfortunately I have not see any data for later years.

  3. oldbrew says:

    From the paper:
    Clarifying these climate processes at finer temporal resolutions could shed light into the difficult problem of disentangling the impacts of anthropogenic activity and nature variability on climate change. [bold added]

    Doesn’t sit very well with assertions that ‘the science is settled’ – in terms of predictions at least.

    The paper offers a natural explanation for temperature variability and then tries to shoehorn in the idea that there should be ‘man-made’ factor(s) as well.

  4. Ron Clutz says:

    From the global dimming project at ETH Zurich:

    Changes in surface solar radiation observed in regions with good station coverage during three periods.(left column) The 1950s–1980s show predominant declines (“dimming”), (middle column) the 1980s–2000 indicate partial recoveries (“brightening”) at many locations, except India, and (right column) recent developments after 2000 show mixed tendencies. Numbers denote typical literature estimates for the specified region and period in W m–2 per decade. Based on various sources as referenced in Wild (2009).

  5. oldbrew says:

    How the Climate Alarmists Managed to Get Everything Wrong
    Alan Carlin | March 9, 2018

  6. ivan says:

    This looks to be climatologists clutching at straws to try and keep the grant money flowing.

    The more they try the more the whole IPCC fiasco falls apart, but that was always going to happen because it was designed to take tax money from the people and use it to enrich the rich – it was never about ‘saving the planet’, the planet can look after itself without problems.

  7. John MacDonald says:

    “It is thus logical to wonder whether the estimation of Earth’s energy balance might have missed some energy component linked to the finer temporal resolutions (e.g. sub-daily timescale.”

    This sure sounds like Willis’ thunderstorms.

  8. oldbrew says:

    variation of solar irradiance

    It’s not just ‘standard’ irradiance – there’s also EUV, solar flares etc.

    Auroras point to magnetic variation.

    Variations in the solar wind cause short term variations in the magnetic field on timescales of seconds to days. These variations are usually quite small compared to the strength of the internally generated magnetic field; large variations can amount to 1-3% of the strength of the field at the Earth’s surface.

    Latest Kp index [‘used to characterize the magnitude of geomagnetic storms. Kp is an excellent indicator of disturbances in the Earth’s magnetic field’ – NOAA].

  9. oldbrew says:

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