Adjustment for Pre Industrial Climate 1850-1900
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pre-industrial.bsky.social
Adjustment for Pre Industrial Climate 1850-1900
@pre-industrial.bsky.social
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So many datasets and baselines: 1850-1900, 1880-1920, 1991-2020 ...

https://parisagreementtemperatureindex.com/global-warming-baseline-adjustments/

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pre-industrial.bsky.social
Adjustments for Global Warming graphs

Adjust y-axis to get the Temperature Anomaly relative to Pre-Industrial (1850-1900)

Table gives a quick adjustment, tailored to different Global Warming Datasets.

This table works for annual anomaly data. Individual month anomalies need further adjustments.
A table with data related to Global Warming. Sometimes you get a graph which gives "Global Temperature Anomaly", relative to 1991-2020" (or some other baseline). For the Paris Agreement, you need to adjust the value, to get the temperature anomaly relative to pre-industrial (1850-1900). This table gives you the "temperature anomaly adjustments" for datasets from: Copernicus, Berkeley Earth, HadCRUT, NASS GISS and NOAA. The adjustments from different baseline periods E.g. 1991-2020 ... to get from those adjustments to 1850-1900 baseline. There are more accurate tables available at https://parisagreementtemperatureindex.com/global-warming-baseline-adjustments/ ... Sometimes you need even more accurate tables, E.g. if you need to adjust individual months (baseline 1991-2020) to individual months (baseline pre-industrial). This is because the seasons have actually shifted.
November 11, 2025 at 2:52 PM
pre-industrial.bsky.social
Quick'n'Dirty Adjustments for Global Warming graphs

How to adjust y-axis to get the Temperature Anomaly relative to Pre-Industrial (1850-1900)

E.g. If the graph uses a 1991-2020 baseline, then add 0.9°C to get the Temperature Anomaly relative to Pre-Industrial

More accurate tables are available
A table with data related to Global Warming. Sometimes you get a graph which gives "Global Temperature Anomaly, relative to 1991-2020" (or some other baseline). For the Paris Agreement, you need to adjust the value, to get the temperature anomaly relative to pre-industrial (1850-1900). This table is "Quick and Dirty", because the values are rough, and don't take into account which dataset is used (copernicus ERA5, Berkeley Earth, GISS, NOAA, HadCrut). There are more accurate tables available at https://parisagreementtemperatureindex.com/global-warming-baseline-adjustments/ ... which take into account the dataset. Sometimes you need even more accurate tables, E.g. if you need to adjust individual months (baseline 1991-2020) to individual months (baseline pre-industrial). This is because the seasons have actually shifted.
November 11, 2025 at 2:33 PM