Graphic
Emissions survey
In November 2025, we conducted an informal survey of experts in our Researcher Database and others in the solar geoengineering community. Respondents shared their estimates for the most likely trajectory of net annual carbon dioxide emissions and how sunlight reflection methods (SRM) would affect progress on emissions cuts.
SRM360 survey: likely CO2 emissions trajectory
billion tonnes
60
50
40
Average
30
20
10
0
–10
’20
’30
’40
’50
’60
’70
’80
’90
2100
How much would solar geoengineering delay progress on emissions cuts?
One survey response
-30%
-20
-10
0
10
20
30
40%
Emissions milestones would be delayed by x%
Emissions milestones would be reached x% sooner
Note: There were 29 respondents to the survey.
Source: SRM360.org
SRM360 survey: likely CO2 emissions trajectory
billion tonnes
60
50
40
Average
30
20
10
0
–10
2020
’25
’30
’35
’40
2050
2060
2070
2080
2090
2100
How much would solar geoengineering delay progress on emissions cuts?
One survey response
-30%
-20
-10
0
10
20
30
40%
Emissions milestones would be reached x% sooner
Emissions milestones would be delayed by x%
Note: There were 29 respondents to the survey.
Source: SRM360.org
SRM360 survey: likely CO2 emissions trajectory
billion tonnes
60
50
40
Average
30
20
10
0
–10
2020
’25
2050
2060
2070
2080
2090
2100
2030
2040
How much would solar geoengineering delay progress on emissions cuts?
One survey response
-30%
-20
-10
0
10
20
30
40%
Emissions milestones would be reached x% sooner
Emissions milestones would be delayed by x%
Note: There were 29 respondents to the survey.
Source: SRM360.org
