Wednesday, April 14, 2021

GISS March global up by 0.22°C from February.

The GISS V4 land/ocean temperature anomaly was 0.88°C in March 2021, up from 0.66°C in February. This increase is similar to the 0.252°C increase reported for TempLS. Jim Hansen's report is here.

As usual here, I will compare the GISS and earlier TempLS plots below the jump.

Here is GISS V4


And here is the TempLS V4 LOESS-based plot


This post is part of a series that has now run for seven years. The GISS data completes the month cycle, and is compared with the TempLS result and map. GISS lists its reports here, and I post the monthly averages here.
The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.

The reporting cycle starts with a report of the daily reanalysis index on about the 4th of the month. The next post is this, the TempLS report, usually about the 8th. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses a spherical harmonics to the TempLS mesh residuals; the residuals are displayed more directly using a triangular grid in a better resolved WebGL plot here.

A list of earlier monthly reports of each series in date order is here:

  1. NCEP/NCAR Reanalysis report
  2. TempLS report
  3. GISS report and comparison with TempLS



11 comments:

  1. OT: Monckton never met a Scenario he could not misrepresent, huh? You may or may not find this entertaining:

    "I had not recalled that IPCC had made its 1 k by 2025 prediction under Scenario A. However, Scenario A was its business-as-usual scenario, and it had incorrectly predicted a far greater rate of forcing, and hence of temperature change, than actually occurred"

    https://wattsupwiththat.com/2015/01/16/peer-reviewed-pocket-calculator-climate-model-exposes-serious-errors-in-complex-computer-models-and-reveals-that-mans-influence-on-the-climate-is-negligible/

    [January 22, 2015 5:45 am]

    Shortly after that exchange, my posts stopped appearing at WUWT. Which was a blessing.

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    1. Thanks, Phil, it is interesting. Here is a direct link to your comment. And here is Monckton's latest on Hansen's predictions.

      Here is my main comment on the misuse of scenario A. And here is my refutatiion of another furphy that Monckton propagates, claiming that Arrhenius recanted his estimate of climate sensitivity.

      ps WUWT has gone downhill in many ways. But they no longer seem so keen to ban people.

      Delete
    2. It is quite correct that scenario A was assumed to result in a greater forcing than hav actually happened, but hansens scenarios was (according to skeptical science) NOT defined by the predicted forcings, rather than emission levels.
      From skeptical science
      "In 1988, James Hansen projected future warming trends. He used 3 different scenarios, identified as A, B, and C. Each represented different levels of greenhouse gas emissions. Scenario A assumed greenhouse gas emissions would continue to accelerate. Scenario B assumed a slowing and eventually constant rate of growth. Scenario C assumed a rapid decline in greenhouse gas emissions around the year 2000. " https://skepticalscience.com/Hansen-1988-prediction.htm
      Hence, since emissions continued to accelerate at least until 2005, and kept growing until now/2018, it can be argued that the actual emissions devolpment was somewhere between Scenario A and B. However, Hansen probably underestimated the uptake of Co2 from the greening of the planet and perhaps from oceans, so that the resulting forcings have increased less than he predicted given the increase in emissions that have occurred.

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    3. As suppl. to my earler commen above;
      Here is the actual papaer from Hansen 1988, https://www.sealevel.info/1988_Hansen_Senate_Testimony.html#scenariosABC

      and here is a graph showing global emissions https://www.epa.gov/sites/production/files/styles/large/public/2017-04/fossil_fuels_1.png

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    4. "However, Hansen probably underestimated the uptake of Co2 from the greening of the planet and perhaps from oceans, so that the resulting forcings have increased less than he predicted given the increase in emissions that have occurred."

      That is actually wrong, and from a pervasive misunderstanding. Hansen made no use of what we understand as emissions, in Gtons CO2. Data on that in 1988 was sparse. Instead he quantified everything by change in observed ppm CO2. That bypasses any worry about airborne fraction, greening etc. And when SkS speaks of accelerating emissions, I'm pretty sure they mean tonnage. What actually happened was that tonnage emissions accelerated, airborne fraction dropped (a little), and the net effect on ppm CO2 was much as Hansen envisaged.

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    5. Notice that the 2015 thread ends with Monckton, having run out of obfustication, resorting to a bare faced lie.

      And he is still promulgating the same discredited untruths six years later, and WUWT is still publishing them.

      I admire your stamina.

      Delete
    6. OK Nick, I see your point. I was stupid enough to think that what is written on Skeptical Science would not quote Hansens paper incorrectly:
      As you can see here, the scenarios are described as follows;

      " In 1988, James Hansen projected future warming trends. He used 3 different scenarios, identified as A, B, and C. Each represented different levels of greenhouse gas emissions. Scenario A assumed greenhouse gas emissions would continue to accelerate. Scenario B assumed a slowing and eventually constant rate of growth. Scenario C assumed a rapid decline in greenhouse gas emissions around the year 2000."
      https://skepticalscience.com/Hansen-1988-prediction.htm

      Delete
    7. To be fair, the Hansen 1988 paper does always refer to emissions with regards their scenarios, not concentrations or radiative forcing, though the methods section then clarifies that Scenario A CO2 is produced simply by applying an annual 1.5% acceleration to the growth rate of the Keeling Curve (i.e. atmospheric concentrations) as of the early 1980s. My guess is they assumed airborne fraction would remain roughly constant so CO2 concentration/emission growth is interchangeable.

      The interesting part is that they went with a 1.5% acceleration despite a much higher rate over the previous few decades and there being no obvious downward trend in acceleration over that time. They don't state any reason for this choice in the paper, but it has proven to be remarkably prescient about how CO2 concentrations developed, whether through luck or judgement. There is one possible reason, which is touched upon in the relevant paragraph where it states that "Scenario A... must eventually be on the high side of reality in view of finite resource constraints and environmental concerns." So, he's referring to controls on air pollution and ozone depletion, and maybe eventually climate change policy. But also resource constraints. I think Hansen is quite sympathetic to "peaker" supply side arguments and by the early 1980s it seemed that US oil and gas production had peaked. He may have considered it unlikely that enough attainable fossil fuel resources existed to follow Scenario A CO2, which I think would now be considered incorrect.

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  2. Thanks for good commment. I do think the term "Business as usual" must be regarded as referring to what happens in society and with emissions to have any sensible meaning, 'CO2 PPM business an usual' would be an odd concept unless you meant that the increase in ppm is not determined by what happened to emissions.
    Also, as regards Scenario C, the original paper describes this in terms of emissions.( i.e. " and scenario C assumes a rapid curtailment of trace gas emissions such that the net climate forcing ceases to increase after the year 2000.").
    I think you are quite correct that the assumed limitation of available oil and gas resources were misjudged in 1988, and hence other factors har limited the actual CO2 growth.

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    1. Well, to be clear, actual CO2 growth has been remarkably close to Scenario A. CO2 growth has not (yet) been limited as Hansen thought and has instead followed his worst case/"business-as-usual" path.

      Scenario A forcing is too high not because of CO2 but the other GHGs, which were largely curtailed through environmental policies.

      Delete
  3. I update my prediction for GISS temperature anomaly using data up to Mar21. I'm using the new version that uses MEI2 values.
    GISS.v4
    MAM21 0.86+-0.08
    JJA21 0.92+-0.09
    SON21 1.06+-0.12
    J-D21 0.94+-0.06
    DJF22 0.97+-0.23
    Now it gives a 0.1% chance of breaking the 2020 record again in 2021.

    ReplyDelete