Talk:Representative Concentration Pathway

New criticism of RCP

An article came out calling into question the validity of RCP since projections are based on estimates of coal growth in China prior to the economic crash of 2008. Estimates may not be accurate with new measurements. Scientific American

Orphan tag

I have removed the "orphan" tag on the grounds that this article is not yet ready to have any other article link to it. When (if?) there is some actual substance to point to then links can be added. ~ J. Johnson (JJ) (talk) 21:31, 25 January 2012 (UTC)

Should be singular?

Why is the article's name plural? Each pathway in the list of four is singular. Vaughan Pratt (talk) 19:02, 19 June 2015 (UTC)

I do agree as a lemma should use the singular form. --Gunnar (talk) 06:39, 11 October 2018 (UTC)

Incorrect graph key

Graph key should have RCP 2.6 not RCP 2.5 Galerita (talk) 05:33, 1 August 2019 (UTC)

1750 baseline?

I think it would be helpful to readers if some expert here could add information about the 1750 baseline. In other words, a change of 8.5Wm-2 is more meaningful if compared to a starting power density. (I _think_ the baseline might be zero forcing balance i.e. the solar constant multiplied by albedo (~0.7) and divided by four (pi r^2/(4 pi r^2)) for the area ratio so 238Wm^-2 but I'm not sure and I'm not WP:bold enough to guess.) Readers could then see that 8.5 Wm-2 is (say) a 3.5% deviation (8.5/238) from the neutral point. Thanks! ^{Talk to} SageGreenRider 13:38, 20 December 2019 (UTC)

historical tracking

I don't get the idea behind the sentence from the RCP8.5 paragraph: "RCP8.5 remains useful for its aptness in both tracking historical total cumulative CO2 emissions". Scenarios are possible sequences of events, which are used to analyse in a what-if-style future decision making. For tracking historical data you don't need scenarios but a good statistician. Does this claim make sense in this context? --Gunnar (talk) 07:06, 10 October 2021 (UTC)

I don't think so. I removed it William M. Connolley (talk) 07:32, 10 October 2021 (UTC)

RCP 8.5

I propose to add some corrections to this section to improve its rigor and neutrality.

The second sentence states that "Since AR5 this has been thought to be very unlikely, but still possible as feedbacks are not well understood.[21][22]".

1. The first part of this sentence contradicts the next reference ([23]), in which the authors state that "CP8.5 is also the best match out to midcentury under current and stated policies with still highly plausible levels of CO2 emissions in 2100." Besides, the reference [21] is a 'comment' in the journal Nature. Commentary pieces in Nature are not peer-reviewed and reflect the personnal point of view of their authors, often in a provocative way, and not necessarily the most consensual point of view among scientists . There have been debates in the scientific community about the likelihood of RCP8.5, with diverging views ^e.g. , but "highly unlekily" is not a common position. Therefore, I suggest to temper the idea conveyed in this sentence.
2. The references only refer to the first part of this sentence, and not to the second. I suggest to add a reference about the uncertaineties of feedbacks:

I would propose to reformulate this section in this way:

In RCP 8.5 emissions continue to rise throughout the 21st century.^[13] RCP8.5 is generally taken as the basis for worst-case climate change scenarios. Since AR5 the likelihood of this RCP has been debated, due to overestimation of projected coal outputs^[21][22]. On another side, many uncertainties remain on carbon cycle feedbacks, which could lead to warmer temperatures than projected in RCP . RCP 8.5 is still used for predicting mid-century (and earlier) emissions based on current and stated policies.^[23]

Alexandre Coche (talk) 15:55, 16 June 2022 (UTC)

Hi User:Alexandre Coche, I've made your proposed change now. Sorry that it took two years for someone to react. EMsmile (talk) 07:22, 15 August 2024 (UTC)

Hi @EMsmile, no problem, thank you for notifying me. Best, Alexandre Coche (talk) 22:14, 9 October 2024 (UTC)

References

problem with source

"A 2021 paper suggests that the most plausible projections of cumulative CO2 emissions (having a 0.1% or 0.3% tolerance with historical accuracy) tend to suggest that RCP 3.4 (3.4 W/m^2, 2.0–2.4 degrees Celsius warming by 2100 according to study) is the most plausible pathway.[15]"

This claim is linked to a pre-print. That is, a study that has yet to be peer-reviewed and mroeover, the lead author is a known impact sceptic. Not that being a sceptic should disquality you form being cited it is just this is the only source for this claim and it seems problematic for two reasons. Vincent Choya (talk) 05:18, 8 October 2024 (UTC)