DOI 10.5281/zenodo.4584562
Ins uc ions o he Tool:
Global Pa hs Based on RM Scena io Types
www.sa e- he-clima e.in o
[email p o ec ed] (mail o)
The la es e sion o he ool can be downloaded a : h ps://doi.o g/10.5281/zenodo.4584562
Web applica ion linea global emission pa hways: h p://global-pa hs.clima e-calcula o .in o
O e iew o ou web apps and Excel ools: h p://clima e-calcula o .in o
Ve sion ins uc ions: 22/11/2025
Con en s
1 Basic idea behind he ool “Global Pa hs” ................................................................................ 2
2 B ie in oduc ion o he ool ..................................................................................................... 2
3 En ies in he shee ‘base da a’ .................................................................................................. 2
4 De e mina ion o emission pa hs ............................................................................................... 2
4.1 En ies in he shee ‘goal seek’ ............................................................................................ 2
4.2 Whe e and how he pa hs a e de e mined ............................................................................ 2
4.3 Phases de e mining pa hs ..................................................................................................... 3
4.4 Mac o in he shee ‘goal seek’ ............................................................................................. 3
4.5 Mac o secu i y ..................................................................................................................... 3
5 RM Scena io Types 1 – 6 .......................................................................................................... 4
6 Resul s ....................................................................................................................................... 4
7 IPCC illus a i e pa hs P1 – P4 ................................................................................................. 4
Re e ences .................................................................................................................................... 5
Ins uc ions o he ool “Global Pa hs Based on RM Scena io Types” page 2 o 5
1 Basic idea behind he ool “Global Pa hs”
The ool o e s he Regensbu g Model Scena io Types RM 1 - 6 o de i e plausible global pa hs o
2100 ha adhe e o a global budge 2020 - 2100 (Wol s eine & Wi mann, 2023). This scena io
ypes co e he ange o plausible possibili ies well.
2 B ie in oduc ion o he ool
In he shee 'base da a' you can se he basic condi ions such as he budge , which is o be me , and
he minimum alue o global annual emissions (po en ial o ne nega i e emissions).
Fo de i ing global pa hs, he ool o e s he scena io ypes RM 1 - 6. The e di e in pa icula in
e ms o di e en assump ions on he ajec o y o annual educ ion a es esp. educ ion amoun .
When modi ying inpu da a (which he cells shaded in yellow a e designa ed o ), you mus always
execu e he mac o in he shee ‘goal seek’ o adjus he ee pa ame e in he scena ios such as o
mee he global budge 2020 - 2100 which is se ou in shee 'base da a'.
3 En ies in he shee ‘base da a’
A. In a i s s ep, a global budge 2020 - 2100 is se ha can be based on he emaining budge s
acco ding o he IPCC (c . Wol s eine , 2025).
C. Global minimum emissions:
He e you can speci y which minimum he global pa hs can achie e in 2100 (E_min). I you
speci y a nega i e alue, his means ne nega i e emissions. See shee "IPCC SR15 esul s"
on he po en ial o ne nega i e emissions acco ding o he IPCC epo om 2018 (IPCC,
2018a).
4 De e mina ion o emission pa hs
4.1 En ies in he shee ‘goal seek’
• RM 2 – 5: a es o change o he s a yea (RRSY)
En e he s a ing change a e o he i s yea . This is he i s yea o which no ac ual
emissions a e known. The co esponding yea is speci ied. Values om he pas a e gi en
o o ien a ion.
• RM 1; 2 – 5: h eshold alues (TV)
In he scena ios RM 1 - 5, a cons an educ ion amoun is applied om his h eshold alues
o he ansi ion o ne nega i e emissions. F om he TV onwa ds, he e is he e o e a linea
emission pa h.
The po en ial o ne nega i e emissions speci ied in he ‘base da a’ shee is gene ally used
as TV (as a posi i e alue). This means ha he highe he po en ial o ne nega i e emis-
sions, he ea lie a swi ch o a linea emissions pa h occu s. You can inc ease his alue by
a supplemen . Plausible alues a e p e-se o his, bu hese can be changed. Minimum al-
ues mus s ill be speci ied o TV. 3.5% o RM 2 - 5 and 4.5% o RM-1 ha e p o en o be
sui able.
4.2 Whe e and how he pa hs a e de e mined
The pa hs a e calcula ed in he shee ‘scena ios’.
The emission pa hs a e be de e mined using he Regensbu g Model Scena io Types RM 1 – 6 (see
Chap e 5). The pa hs a e essen ially de e mined by speci ying he annual a e o change (RM 1 -
Ins uc ions o he ool “Global Pa hs Based on RM Scena io Types” page 3 o 5
5) o he annual cons an educ ion amoun (RM-6). F om he speci ied h eshold alue (TV), a
cons an educ ion amoun is used un il he emissions each he p ede ined minimum alue (E_min).
In he shee 'goal seek' he ee pa ame e o he espec i e scena io is de e mined o each sce-
na io ype using an i e a i e solu ion me hod so ha he budge is adhe ed o. The 'goal seek'
mac o in his shee uses he a ge alue sea ch in eg a ed in Excel o his pu pose (see Chap e
4.4).
The ac ual emissions a e he base yea 2019 will be aken in o accoun as soon as hey ha e been
published by he Global Ca bon P ojec (GCP, 2025). You can see he yea s al eady a ailable in
he 'base da a' shee unde poin B.
4.3 Phases de e mining pa hs
This usually leads o he ollowing h ee phases o de e mining he pa hs:
1. Applica ion o he annual educ ion a es (RM 1 - 5) o he annual educ ion amoun (RM-6).
2. Annual emissions less han o equal o TV: The las annual absolu e educ ion is con inued in
RM 1 - 5.
3. Minimum o he annual emissions (E_min) speci ied in he shee 'base da a'.
These h ee phases can be ound in he o mula o he annual emissions in he indi idual scena io
ypes in he shee 'scena ios'.
4.4 Mac o in he shee ‘goal seek’
The mac o 'goal seek' ies o de e mine he ee pa ame e in he scena io ( ow 12 o 13) so ha
he global budge ( ow 16) is adhe ed o (► ow 15 = ow 16). The mac o also ensu es ha he
cons ain s o he ee pa ame e s a e me .
I his does no succeed a i s go, he mac o ies o ind a solu ion wi h a di e en a e o change
o 2020 in he scena io ypes RM 2 - 5. The ini ial alue you speci y is changed by a maximum o
2.5 pe cen age poin s in bo h di ec ions in 0.01 s eps. The s a alue you speci ied will he e o e
be changed. I a solu ion canno be ound ei he , he mac o will in o m you and ad ise you o change
he s a alue mo e signi ican ly.
In he RM-1 scena io, he mac o inc eases he h eshold alue (TV) i necessa y o ind a solu ion.
The mac o also ies in scena io RM-1 ha he minimum alue (Emin) speci ied in he shee 'base
da a' is eached (► ow 18 = ow 19). I his does no succeed s aigh away, he mac o inc eases
he h eshold alue (TV) in he RM-1. I E_min can s ill no be eached, he o iginal TV will be ese .
4.5 Mac o secu i y
Please use Mic oso 's ins uc ions o allow mac os i hey ha e been blocked.
In mos cases, you can unblock mac os by changing he p ope ies o he ile as ollows:
• Open Windows File Explo e and go o he olde whe e you sa ed he ile.
• Righ -click on he ile and selec P ope ies om he con ex menu.
• A he bo om o he Gene al ab, selec he Unlock check box and hen OK.
I you do no wan o use he buil -in mac os, you can sa e he ile as an xlsx ile. This will emo e
all mac os.
Ins uc ions o he ool “Global Pa hs Based on RM Scena io Types” page 4 o 5
We ha e published he code o he key mac o 'goal seek' he e:
h ps://doi.o g/10.5281/zenodo.7494168
This gi es you he op ion o in eg a ing he mac o in o you Excel ile you sel . Please use a ian 2
he e.
5 RM Scena io Types 1 – 6
Fo a comp ehensi e ma hema ical desc ip ion, we e e o ou pape ‘Ma hema ical Desc ip ion o
he Regensbu g Model Scena io Types RM 1 – 6’ (Wol s eine & Wi mann, 2023) published on
zenodo. He e is a u he b ie desc ip ion o he RM Scena io Types.
6 Resul s
In he shee ‘g aphs’ you can see he g aphical esul s.
7 IPCC illus a i e pa hs P1 – P4
In he shee 'IPCC SR15 g aphs we show o compa ison he illus a i e model pa hways ha he
IPCC published in i s 2018 special epo (IPCC, 2018a).
In he shee 'IPCC SR15 esul s', esul s a e shown ha may be use ul in he Regensbu g Model o
he Ex ended Smoo h Pa hway Model, which can be used o de e mine Pa is-compa ible na ional
emission pa hways (in o ma ion on hese models a www.sa e- he-clima e.in o).
The esul s o use in ou models a e summa ised he e: h p://luc.clima e-calcula o .in o
(Wol s eine & Wi mann, 2025).
Ins uc ions o he ool “Global Pa hs Based on RM Scena io Types” page 5 o 5
Re e ences
GCP, 2025. [Online]
A ailable a : h ps://globalca bonbudge .o g
[Accessed 13 11 2025].
IPCC, 2018a. Special Repo 1.5°C. Chap e 2: Mi iga ion pa hways compa ible wi h 1.5°C in he
con ex o sus ainable de elopmen . [Online]
A ailable a : h ps://www.ipcc.ch/s 15/
[Accessed 15 12 2018].
Wol s eine , A., 2025. Wha does he IPCC say abou he emaining CO2 budge s?. [Online]
A ailable a : h p://ipcc-co2-budge s.clima e-calcula o .in o
Wol s eine , A. & Wi mann, G., 2023. Ma hema ical Desc ip ion o he Regensbu g Model
Scena io Types RM 1 – 6. [Online]
A ailable a : h ps://doi.o g/10.5281/zenodo.4540475
Wol s eine , A. & Wi mann, G., 2025. T ea men o he opics LUC and ne nega i e emissions in
he RM and ESPM ools. [Online]
A ailable a : h p://luc.clima e-calcula o .in o
