This page shows “GMST Milestones”, 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.

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 milestones” slightly earlier than with the Mixed data sets.

• 1984 – “GMST Trend °C” passes 0.50C (just using Copernicus ERA-5 data)
• 2000 – “GMST Trend °C” passes 0.75C (just using Copernicus ERA-5 data)
• 2012 – “GMST Trend °C” passes 1.00C (just using Copernicus ERA-5 data)
• 2020 – “GMST Trend °C” passes 1.25C (just using Copernicus ERA-5 data)
• 2024 – “GMST Trend °C” can reasonably be claimed to be:
  • April 2024 – Using only the Copernicus ERA-5 data (see Climate Milestones Copernicus – ERA5)
    • … applying a 10-year linear smoother: 1.30C
    • … applying a 10-year quadratic smoother: 1.42C

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 lines are use 241-centre-averaged calculations, so the line is fixed up until the last 120 months (because the 120 months before / after the date have happened). However the last 120 months, when I recalculate when a new month/year is added, then that part of the trend line will update accordingly. Not ideal, and I am looking for “correct” or “standard” data trendline calculations. I have a suspicion that this is an intractable issue. Having access to climate models is obviously an advantage with this. It would be useful if institutions published by observed monthly data and projected monthly data.
• 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”.
• I have added a “± X” to the year that the “Trend °C” crosses a GMST milestone, to indicate more clearly that there is some subjectivity / wriggle room to the exact dates. I will do more work on this, as I have a feeling more conservative trends are way slower.
• Me saying “The Climate” passed some value was overreach on my part, and probably devalues / distracts-from the graphics. I am just applying different trend line algorithms to the data, to see what it shows.
  • 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.