Do you have a dumb question that you're kind of embarrassed to ask in the main thread? Is there something you're just not sure about?
This is your opportunity to ask questions. No question too simple or too silly.
Culture war topics are accepted, and proposals for a better intro post are appreciated.
Posted because I didn't see Zorba post one today. Feel free to delete if that's an issue.
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Notes -
I've read several times here that the climate forecast often described by news articles as "business as usual" (RCP8.5) is based on outdated assumptions and that actual emissions are already well below that forecast.
The explanations seem reasonable, but when I've tried to look for data to confirm / quantify it I havent had any luck.
Does anyone have a good source with numbers for forecast emissions from RCP8.5 (and possibly other forecast models) directly compared against actual emissions since the forecast was made?
I've been DIYing this for some years; I don't have the links handy but the CMIP5 model results and the HADCRUT global temperatures are publically available.
There is indeed significant divergence; https://imgur.com/a/krYXyKu.
IIRC RCP4.5 was a better match -- but if you look at the modelling assumptions actual emissions have been more in line with the RCP8.5 assumptions. Which makes me think that we don't actually have a great idea of what we are modelling.
This doesn't prevent climate activists from using the RCP8.5 assumptions as a bailey ("we are on track for +4 degrees C by 2100") while still retreating to the motte ("nonono, you can't just pick the worst-case scenario just because gross carbon emissions keep going up") when presented with graphs like the above.
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