Worst-case global warming scenarios not credible: study

Posted: January 18, 2018 by oldbrew in alarmism, climate, predictions, radiative theory, research, Temperature
Tags: , ,

Earth and climate – an ongoing controversy

But the researchers are still hooked on the unlikely idea that trace gases alone can ‘determine’ variations in global temperatures, despite lack of correlation in the data and poor results from climate model ‘projections’.

Earth’s surface will almost certainly not warm up four or five degrees Celsius by 2100, according to a study released Wednesday which, if correct, voids worst-case UN climate change predictions, reports Phys.org.

A revised calculation of how greenhouse gases drive up the planet’s temperature reduces the range of possible end-of-century outcomes by more than half, researchers said in the report, published in the journal Nature.

“Our study all but rules out very low and very high climate sensitivities,” said lead author Peter Cox, a professor at the University of Exeter.

How effectively the world slashes CO2 and methane emissions, improves energy efficiency, and develops technologies to remove CO2 from the air will determine whether climate change remains manageable or unleashes a maelstrom of human misery.

But uncertainty about how hot things will get also stems from the inability of scientists to nail down a very simple question: By how much will Earth’s average surface temperature go up if the amount of CO2 in the atmosphere is doubled?

That “known unknown” is called equilibrium climate sensitivity (ECS), and for the last 25 years the UN’s Intergovernmental Panel on Climate Change (IPCC)—the ultimate authority on climate science—has settled on a range of 1.5 C to 4.5 C (2.7 to 8.1 degrees Fahrenheit).

Cox and colleagues, using a new methodology, have come up with a far narrower range: 2.2 C to 3.4 C, with a best estimate of 2.8 C (5 F).

If accurate, it precludes the most destructive doomsday scenarios.

“These scientists have produced a more accurate estimate of how the planet will respond to increasing CO2 levels,” said Piers Forster, director of the Priestley International Centre for Climate at the University of Leeds.

Gabi Hegerl, a climate scientist at the University of Edinburgh who, like Forster, did not take part in the research, added: “Having lower probability for very high sensitivity is reassuring.

“Very high sensitivity would have made it extremely hard to limit climate change according to the Paris targets.”

Continued here.
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  1. Bitter@twisted says:

    Still too high.
    Observational data suggest around 1.5c/doubling.
    The climate fraudsters/nutters are starting to backpedal, slowly but surely, just so they can keep the gravy-train moving, yet not appear criminal, when the whole corrupt edifice collapses.

  2. tallbloke says:

    Heh, bring the ludicrous upper limit down but shove the lower limit up to an equally ludicrous 2.2C.
    It’s junk science.

  3. ivan says:

    tallbloke, they have to do that to keep the scam alive a little longer. It is also done in the hope that all the people that question the old higher figure will let this slip by.

    The other thing it does is give a position where they can reduce the sensitivity using ‘new improved models’ based on this work.

  4. TA says:

    “Observational data suggest around 1.5c/doubling.”

    What observational data?

  5. Agree with Roger. The effect of CO2 on surface temperature is so small to be unmeasurable. It should be clear from looking at the Chapters on heat transfer in Marks Mechanical engineering handbook or in Perry’s Chemical Engineering Handbook. Further, the supposed effect of methane is just a straight out lie.

  6. ren says:

    The magnetic activity of the Sun since 2015 was quite high for this solar cycle. It particularly increased in September 2017. This allowed La Nińa to develop and activate hurricanes. In December 2017, a large drop is already visible.
    This activity was mainly associated with coronal holes. Coronal holes in front of Earth send fast streams of solar wind.

  7. Paul Vaughan says:

    “Worst-case global warming scenarios not credible: study”

    … BEST-case scenarios ALSO NOT credible !

  8. Jaime Jessop says:

    I can’t profess to understanding this ‘new method’ of estimating climate sensitivity based on natural departures from the long term trend, which somehow magically renders cloud feedbacks irrelevant in the calculations. It will be interesting to see the response from Nic Lewis, if he has one.

  9. Gamecock says:

    ‘”These scientists have produced a more accurate estimate of how the planet will respond to increasing CO2 levels,” said Piers Forster, director of the Priestley International Centre for Climate at the University of Leeds.’

    More accurate? Estimate? How the planet will respond?

    Quantification of predictions of the future! An absolutely foolish endeavor.

  10. Gamecock says:

    ‘Cox and colleagues, using a new methodology, have come up with a far narrower range: 2.2 C to 3.4 C, with a best estimate of 2.8 C.’

    Their use of a decimal point shows they have a sense of humor.

  11. dennisambler says:

    According to NOAA’s 1997 state of the climate report:-

    “The global average temperature of 62.45 degrees Fahrenheit for 1997 was the warmest year on record, surpassing the previous record set in 1995 by 0.15 degrees Fahrenheit.”


    62.45 F = 16.92 C

    According to NOAA’s 2014 state of the climate report:-

    “The year 2014 was the warmest year across global land and ocean surfaces since records began in 1880. The annually-averaged temperature was 0.69°C (1.24°F) above the 20th century average of 13.9°C (57.0°F), easily breaking the previous records of 2005 and 2010 by 0.04°C (0.07°F).”


    This says quite clearly, that 2014 global temperature was 13.9 C plus 0.69 C. I make that 14.59C, or 2.33 C colder than 1997, job done!

  12. oldbrew says:

    Jaime J says: ‘magically renders cloud feedbacks irrelevant in the calculations’

    Maybe clouds work opposite ways day and night 😎

  13. tom0mason says:

    I note here an interesting study on CO2 levels and planetary movement https://principia-scientific.org/shock-study-atmospheric-co2-levels-change-with-planetary-movements/

    If this study has legs surely the IPCC basic meme of global warming being caused by the rise in human originated CO2 levels is to be questioned.

  14. oldbrew says:

    tom – IMO it boils down to the carbon cycle. Warmer/warming waters outgas CO2 while cooler/cooling waters absorb it. This has been known for a long time but often seems to get ignored.

    Relating the process to ENSO and planetary/solar frequencies is a good line of research.

  15. oldbrew says:

    Another fake climate scare bites the dust…

    Date: 20/01/18 Michael Bastasch, Daily Caller

    The Pentagon released a National Defense Strategy that for the first time in more than a decade does not mention manmade global warming as a security threat.


  16. oldbrew says:

    Date: 20/01/18 Ron Clutz, Science Matters

    All parts of the world’s oceans are clearly cooler than at any time in the past 3 years.


  17. nickreality65 says:

    For the greenhouse theory to operate as advertised requires a GHG up/down/”back” LWIR energy loop to “trap” energy and “warm” the earth and atmosphere.

    For the GHG up/down/”back” radiation energy loop to operate as advertised requires ideal black body, 1.0 emissivity, LWIR of 396 W/m^2 from the surface. (K-T diagram)

    The surface cannot do that because of a contiguous participating media, i.e. atmospheric molecules, moving over 50% ((17+80)/160) of the surface heat through non-radiative processes, i.e. conduction, convection, latent evaporation/condensation. (K-T diagram)

    No GHG energy loop & no greenhouse effect means no CO2/man caused climate change and no Gorebal warming.


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