This page shows “GMST Milestones Anomalies”, using purely Copernicus ERA-5 data (see GMST Data Sets). As per Climate Reporting – Why so many different values, the Copernicus ERA-5 data tends to be midway between NOAA/GISSTemp (low end) and Berkeley Earth (high end). The Copernicus ERA-5 data shows acceleration a bit more sharply than other data sets.

The trend line is calculated using Loess smoothing, with a 30-year window.

There is a similar graph at Climate Milestones – NOAA, GISS, Copernicus, HadCRUT, Berkeley Earth showing the same information but using a mixed GMST Data Sets.

The graphic above (using Copernicus-only-data), showsthe “GMST Trend °C” passing through “GMST Anomaly milestones” slightly earlier than with the Mixed data sets.

  • 1985 – “GMST Anomaly Trend °C” passes 0.50C (just using Copernicus ERA-5 data)
  • 2000 – “GMST Anomaly Trend °C” passes 0.75C (just using Copernicus ERA-5 data)
  • 2012 – “GMST Anomaly Trend °C” passes 1.00C (just using Copernicus ERA-5 data)
  • 2021 – “GMST Anomaly Trend °C” passes 1.25C (just using Copernicus ERA-5 data)
  • 2024 – “GMST Anomaly Trend °C” can reasonably be claimed to be 1.35C in September 2024

As per comment in Climate Milestones – NOAA, GISS, Copernicus, HadCRUT, Berkeley Earth, there is some subjectivity, regarding choosing the exact year that a “GMST Milestone” has passed, but I haven’t yet found a trend-line-algorithm that (both goes through the data points… and) gives dates more than a few years either side.

Trend lines weave through the Yearly averages

Following my twitter post of the 1000 Days above 1.5C before Trend passes 1.5C? graphic, I received some excellent criticism, I made a few updates, to check the trend lines. Note. I am planning to post updates to the graphics every month or so, and I will refine the designs as I get useful feedback.

  • The graphic above shows the individual yearly averages, so you can see the trend lines weaving through the individual years. 2021 / 2022 were below trend (and part of triple dip La Nina).
  • Note that the “2024 year-so-far” point is plotted on the graph, but 2024 data wasn’t included in the processing to calculate the trend lines.
  • My trend line now uses Loess-smoothing with a 30-year-window. This is an improvement on my homemade smoothing line I used previously
  • My trend lines go above other ones I’m seeing posted by establishment figures / authorities, so it will be interested to see what trend algorithm I can find that produces those trend lines.
  • I have stopped calling it “The Climate”, and started calling it “Trend °C”.
  • Previously my graphic stated “The Climate” passed some value, and that was overreach on my part, and probably devalues / distracts-from the graphics. I have moved to loess-smoothing, and then I can just say the loess trend line reached x-C in year y.
    • There seems to be an interesting debate between:
      • “Michael Mann Analysis”:
        • 2023 / 2024 Data / Observations are in keeping with CMIP6 models
        • Acceleration has not been proven. “The truth is bad enough”
      • “Hansen Analysis”:
        • Keep an eye on the 2024 data: Acceleration is highly plausible
        • Hansen has significant concerns that the models have the GHG / Aerosol / Climate Sensitivity incorrect.
        • Hansen points to paleo-climate data and the IMO “inadvertent sulphur experiment”
        • Hansen’s expectations are more in line with my trend lines, which is interesting but of no practical importance.
      • I have no scientific qualifications, so will stick to my lane of making interesting graphics, and make it clear how I produce my them.
      • It will be super interesting to see how the trends play out over the next years.
      • I’m going to play with the different graphs produced by different entities, so I can understand more, what the differences are.

How the Graphic was Created

Same technique as outlined in Climate Milestones – NOAA, GISS, Copernicus, HadCRUT, Berkeley Earth … but just using Copernicus data.