This is a very important point (which Zeke and Glen do make, but it seems to get overlooked) Any particular emissions scenario can give rise to many different future concentration pathways, some rising faster and some slower, depending on the strength of carbon cycle feedbacks
-
-
Prikaži ovu nit
-
Most climate modelling studies that use RCP8.5 are using the scenario in the form defined in terms of concentrations (the amount of CO2 & other GHGs bulding up in the atmosphere), not the form defined in terms of emissions (the amount humans are releasing). This is a key point.
Prikaži ovu nit -
RCP stands for Representative Concentration Pathway. These scenarios were originally defined in terms of concentrations, for use as input to climate models. Some standard emissions scenarios were developed to go along with them for studies which required this instead / as well
Prikaži ovu nit -
The original RCP8.5 concentration pathway has CO2 reaching 939 ppm by 2100 Variants of the HadCM3C model can project a CO2 rise above that when driven by the lower emissions scenario SRES A1B https://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-16-0178.1 … (box: 25%-75% interquartile range, whiskers: full range)pic.twitter.com/QZrt9KTDIx
Prikaži ovu nit -
That paper (Booth et al 2017) used a perturbed-parameter ensemble of HadCM3C, exploring the effects on climate-carbon cycle feedbacks of varying the values of key uncertain parameters in the model This still suggests RCP8.5 concentrations are less likely, but can't be ruled out
Prikaži ovu nit -
This highlights how problems with communicating scenarios go beyond incorrectly calling RCP8.5 "business-as-usual" Unfortunately many papers discussing RCP-driven climate projections say they're using an "emissions scenario" when in fact they're using a *concentrations scenario*
Prikaži ovu nit
Kraj razgovora
Novi razgovor -
-
-
haha , very good
..... but NO!
This is the whole point - I'm not saying that at all
There is a huge difference between emissions and concentrations
This is at the heart of the confusion here - Još 10 drugih odgovora
Novi razgovor -
-
shouldn't one add that even a given concentration pathway can lead to many different outcomes, depending on sensitivity & tipping processes e.g. in ice cover?
-
Yes, absolutely!
Kraj razgovora
Novi razgovor -
Čini se da učitavanje traje već neko vrijeme.
Twitter je možda preopterećen ili ima kratkotrajnih poteškoća u radu. Pokušajte ponovno ili potražite dodatne informacije u odjeljku Status Twittera.