Renowned, Award-Winning Climate Scientists Earlier Predictions Today Looking More Like Rants From Lunacy Land

Predictions of the climate’s development in response to elevated atmospheric CO2 levels started in earnest over 25 years ago. James Hansen led the way beginning in 1988. In Germany the director of the prestigious Max-Planck-Institute for Meteorology Hartmut Grassl was vocal.


Around 1990 former Max Planck Institute of Meteorology director Hartmut Grassl (left) and former NASA GISS director James Hansen predicted global temperatures would rise 1.5°C by 2020.

Both men played instrumental roles in getting governments to take action against the emissions of greenhouse gases, especially CO2. Since 1990 global CO2 emissions have actually even surpassed the worst case scenarios of the climate science community, meaning temperatures indeed should have increased even more then what the two scientists projected.

Both Hansen (1988) and Grassl (1990) predicted that global temperatures would rise about 1.5° by 2020, under business-as-usual CO2 emissions. Today plotted observed temperature data show that their predictions completely overshot and even resemble the ravings of an end-of-world lunatic, see the following chart, bold red line. This is nothing short of embarrassing,


Chart above depicts Hansen’s and Grassl’s predictions from 1988 and 1990 respectively. Other model predictions also overshot actual observed temperatures, which are given by the HADCRUT4 surface and UAH lower troposphere curves. Original chart:

 In 2012, Die kalte Sonne site here researched Grassl’s earlier predictions and found this quote from 1990:

Already in the next 30 years the earth will warm up with high probability by one to two degrees Celsius.”

The plot above is the average of that, i.e. 1.5°C, which corresponds to Hansen’s 1988 bleak outlook. Moreover Grassl in 1994 already declared the debate over:

On the scientific side, the process of indications when it comes to the subject of the greenhouse effect is over, the guilty verdict is in. It is no longer about getting more evidence, rather it is about reducing the sentence a bit. The global mean temperatures will rise between 1 and 2°C in the next decades.”

Hansen at the time was pretty much saying the same thing.

Both men have gone on to receive many medals and awards for their work, and still continue today being taken seriously by policymakers and media outlets. How much longer that can be sustained is a question climate science critics are watching very closely.

Photo Credits:
Hartmut Grassl: own work, Creative Commons Attribution-Share Alike 3.0 Unported license.
James Hansen: Ben Powless, Creative Commons Attribution 2.0 Generic license.


21 responses to “Renowned, Award-Winning Climate Scientists Earlier Predictions Today Looking More Like Rants From Lunacy Land”

  1. Dave Spencer

    Hansen and Grassl? Sounds like the title of a fairy tale to me, or is it just coincidence?

    Regards, Dave

  2. mwhite

    It’s all about the Headline in the mainstream media.

  3. ArndB

    A very interesting accumulation of Graßl’s idle talk back in 1990 is an article (~10p. co-author: R. Klingholz) published by DER SPIEGEl, 01March1990;, closing with a code of conduct suggesting in 50 items (Google translation) inter alias:
    31 Turn off the lights in rooms where no one is staying.
    32 Make use of energy saving lamps.
    33 Eat less meat.
    34 Buy more local produce. …..cont
    35 Convert your ornamental garden at least partially into a fruit and vegetable garden.
    36 Plant trees.
    37 Avoid gardening with artificial fertilizers and pesticides.
    43 Showers instead of a bath. This saves per wash cycle about four kilowatt hours of energy.
    44 Cook possible with gas.
    45 Put the lid on the pot. This saves at least six per cent of energy.
    46 Take a pressure cooker for foods that need to cook for a long time. This saves up to 43 percent energy.
    47 Do not use the hot water cycle. It is almost never required.
    50 If all citizens follow these civic duties, a good part of the climate problem would be solved in a jiffy. … cont.

  4. D.M.

    This week I saw a potential politician and an ex-politician put down someone who expressed doubts about “man-made global warming/ climate change”. They both made the statement “so you disagree with 97% of the worlds climate scientists”. That flawed survey caught the headlines at the time and it was easy to remember, because the rebuttal showing the flawed results never made the headlines. What we need now is a catchy slogan, easy to remember, which gets repeated over and over so that ordinary people remember it and will quote it without thinking too much. Here is my suggestion, but others may have something better.

    “97% of climate model predicted temperatures disagree with actual observed temperatures.”

    This should be added at the end of all climate blog articles. Repeating it over and over eventually gets the message across just like the original 97% claim. The difference is this time the slogan is factual and correct!

  5. William Connolley
    1. Alfred Alexander

      Thank you P.G.

    2. DirkH

      Wait, that lunatic you link to doesn’t understand the concept of normalizing graphs at a certain date? And that comes from one of the anomaly cultists?
      Are your brains falling apart?

    3. Jimbo

      As long as the standstill continues then William Connolley’s efforts will be in vain. They keep pointing us to RealClimate and Hansen et al but the longer the standstill continues then the greater the yawning gap. It’s that simple – sooner or later they will have to concede defeat.

  6. Joe Chang

    The Surface (green) and sat (blue) only marginally matched to 1.5C/30 year slope in 88-89, with 89-91 being a better match. What is the black dot line? that matches the slope from 87-91. There must have also been some time lag in getting the data? So this 1-2C projection was based on 2 years data for Hansen and perhaps 4 year for Grassi? talk about a leap of faith.

  7. Joe Chang

    In the 1990 AR1, IPCC shows radiative forcing growing steadily from 2W/m2 in 1980 and the model best estimate that seems to be inline with HG 1.5C in 2020. The model results shown here for 1983-2013 period are recent simulations that include one-time injections for aerosols and lowering of CO2 sensitivity so as to walk the tight line between not being completely laughable, and yet still predict dire consequences. No doubt that in several years, we will be shown new model results with more training adjustments for the then known 1983-2020 period, yet still predicting future catastrophic warming.

  8. JF

    Pierre, the curve from Spencer is distorted after 1997 because it follows a 5 year running average, which shmears the warming from earlier years into the 21st century. In the unsmoothed data, the only trend after 1997 is cooling.

    1. DirkH

      Now the use of a running average is illegal? Are you all crazy?

  9. El Sabio
    1. Mick J

      He did not rest on his laurels, here is one he made later as recounted at

      He was the man who had us rolling in the aisles with the epic “Snowfalls are now just a thing of the past “. Of course, we must not be too unkind. Everyone is entitled to one mistake. He made that claim in 2000, but fast forward six years, and it seems as if he was at it again.

      In 2006, he wrote a report that claimed

      Climate change could “dramatically” change the face of British tourism in the next 20 years, with European tourists flocking to the UK to escape unbearably hot continental summers, experts say.

      Research shows that European tourists may choose to holiday in Britain as resorts nearer to home become too hot.

      Weather changes may provide revival opportunities for northern seaside towns such as Blackpool and put new strains on roads and development in southern coastal resorts, a study in the Journal of Sustainable Tourism said.

      The likelihood is that Mediterranean summers may be too hot for tourists after 2020, as a result of too much heat and water shortages.

      1. Jimbo

        Ahhh but there’s more.

        Guardian – 14 Feb 2004
        Dr. David Viner Climatic Research Unit, University of East Anglia
        Global warming forces sale of Scottish winter sports resorts
        …“Unfortunately, it’s just getting too hot for the Scottish ski industry,” said David Viner, of the Climatic Research Unit at the University of East Anglia. “It is very vulnerable to climate change; the resorts have always been marginal in terms of snow and, as the rate of climate change increases, it is hard to see a long-term future.” …

        It was reported 2 days ago that Scotland has more snow than the winter olympics resort and huge snowfalls to boot.

        1. Jimbo

          In fact it was EXACTLY 10 years to the day when Viner talked of the Scottish ski industry’s demise. How fitting.

          1. Jimbo

            I mean 10 years to the day of the Daily Mail report on huge Scottish snows.

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