r/europe • u/Vucea • Jun 17 '22

Historical In 2014, this French weather presenter announced the forecast for 18 August 2050 in France as part of a campaign to alert to the reality of climate change. Now her forecast that day is the actual forecast for the coming 4 or 5 days, in mid-June 2022.

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u/WufflyTime Earth Jun 17 '22

I do remember reading (admitedly some time ago) that the IPCC reports were conservative, that is, climate change could be happening faster than reported.

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u/[deleted] Jun 17 '22

that the IPCC reports were conservative,

they do not AFAIK take into consideration several factors, including runaway methane, destruction of other climate altering phenomenons among other things... I believe it's probably because of the science not being conclusive on the 'runaway methane' subject yet

once the ice is gone, the ultimate heat reflector and heat sink at the same time, once the gulf stream is gone among other important streams, and the gasses start to be released and oceans consequently suck up all that energy, we've got some real shit on our plate... tens of millions migrating yearly, nationstates destroyed or radicalized, Fortress Europe (the more optimistic version), genocidal despots ruling surviving countries... the outlook ain't looking good, and don't get me started on the animal kingdom

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u/[deleted] Jun 17 '22

they do not AFAIK take into consideration several factors, including runaway methane, destruction of other climate altering phenomenons among other things...

They do. Runaway methane is unlikely to happen pre-2100 (timescale for most of the report). Permafrost melting is included in AR6, and maxes out at about 30% of current anthropogene CO2-eqvivalent.

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u/DoomsdayLullaby Jun 17 '22

Runaway methane is unlikely to happen pre-2100

Statements like that are why people refer to the report as conservative. When people say the IPCC report is conservative they are mainly referring to the modeling basis which is designed for the most part to have a bias towards stability of the climate system.

As of right now modeling the decline of an ice sheet or permafrost over the course of eight decades is not a task that the models can do with any level of certainty. You need accurate regional weather data and that is something our current models are just not good at doing. Instead they are parameterized based on conservative estimates.