New data imply slower global warming

Posted: April 24, 2018 by oldbrew in climate, Emissions, research
Tags: , ,

Leaving aside whether ‘climate sensitivity’ (to carbon dioxide) is a valid concept in the first place, it’s been obvious for a while that climate modellers have seriously overestimated the actual level of any warming that has occurred in recent years. If that doesn’t suggest to them that something is wrong, what would?

London, 24 April — A paper just published by the Journal of Climate concludes that high estimates of future global warming from most computer climate simulations are inconsistent with observed warming since 1850. The implication is that future warming will be 30 to 45% lower than suggested by the simulations.

The study estimates climate sensitivity — how much the world will warm when carbon dioxide levels increase* — from changes in observed temperatures and estimates of the warming effect of greenhouse gases and other drivers of climate change, from the mid/late 19th century until 2016.

The paper also addresses previous criticisms of the methodology used, finding that these are unfounded.

Nicholas Lewis explains:
“Our results imply that, for any future emissions scenario, future warming is likely to be substantially lower than the central computer model-simulated level projected by the IPCC, and highly unlikely to exceed that level.”

Nicholas Lewis adds:
“Our new sensitivity estimates are slightly lower than those obtained in a predecessor study published several years ago, despite the inclusion of the strong 2015–16 El Niño warming. Importantly, the upper uncertainty bounds of the new estimates are much lower.”

Highlights here.

ECS assumption:
*Two standard metrics summarize the sensitivity of global surface temperature to an externally imposed radiative forcing. Equilibrium climate sensitivity (ECS) represents the change in temperature to a doubling of atmospheric CO2 concentration once the deep ocean has reached equilibrium. The transient climate response (TCR), a shorter-term measure over 70 years, represents warming at the time CO2 concentration has doubled when it is increased by 1% a year.

  1. chaamjamal says:

    Sounds interesting. I will read the paper.

  2. oldbrew says:

    Sooner or later another El Niño will come along to give obsessive warmists a short break.

  3. sailboarder says:

    Until the models have their feedback formula’s corrected, no published paper using models should be taken seriously.

  4. ivan says:

    As it stands until their climate models can be validated against real world conditions papers using those models in any form should not be accepted for publication

  5. oldbrew says:

    Date: 25/04/18 Ronald Bailey, Reason Online

    A new study in the Journal of Climate compares global temperature data trends since 1850 with model outputs.

    Climate researchers have spent decades trying to pin down the planet’s equilibrium climate sensitivity. Also known by the initials ECS, that figure represents how much it would ultimately increase global average temperatures if the amount of carbon dioxide in the atmosphere doubles above the pre-industrial level.

    Figuring out the ECS has huge implications for policy.
    – – –
    But it all rests on the belief that there’s a direct relationship between the trace gas CO2 (0.04% of the atmosphere) and global temperatures.

    The fact that ‘Climate researchers have spent decades trying to pin down the planet’s equilibrium climate sensitivity’ and have failed, is just another indication that their theories are not correct.

    Meanwhile policy is based on flimsy unproven claims, marketed as ‘settled science’.

  6. oldbrew says:

    Delingpole: Earth in ‘Greatest Two-Year Cooling Event in a Century’ Shock

    To put this temperature drop in context, consider that this is enough to offset by more than half the entirety of the global warming the planet has experienced since the end of the 19th century.
    . . .
    So is this sudden cooling an even-worse thing? Not necessarily. As Brown goes on to explain in his piece, you can’t extrapolate trends from such a short time scale. Well, not unless you’re a climate alarmist… As we know from long experience, if it had been the other way round – if the planet had warmed by 0.56 degrees C rather than cooled, the media would have been all over it.

    My point is that statistical cooling outliers garner no media attention.
    – – –

  7. nickreality65 says:

    Well, I’m mystified.

    Radiative greenhouse effect theory requires the GHG up/down/”back” radiation energy loop to “trap” energy and “warm” the earth/atmosphere.

    The up/down/”back” radiation loop requires the surface to emit as an ideal Black Body to wit: 289 K, 1.0 emissivity, 396 W/m^2. (K-T diagram)

    My modest experiment clearly demonstrates that the non-radiative heat transfer processes of a contiguous participating media, i.e. atmospheric molecules, prevents ideal BB radiation from the surface. In fact, radiation might move less than half the heat from the surface: 63/160 = 39.7%. (K-T diagram)

    This is a wooden stake straight into the heart of greenhouse theory, gorebal warming and CO2/man-caused climate change.

    Where’s the defense? Fingers in ears hoping I’ll just go away?