Table 1.

Intervention names, descriptions, and relevant statistics.

Intervention	Description	Relevant Statistics
Dynamic Social Norms28	Informs participants of how norms are changing and “more and more people are becoming concerned about climate change”, suggesting that people should take action.	Median duration (SD): 49.50 (126.28) Raw N: 6820 Cleaned N (%): 5172 (75.84)
Work Together Norm29	Combines referencing a social norm (i.e., “a majority of people are taking steps to reduce their carbon footprint”) with an invitation to “join in” and work together with fellow citizens toward this common goal.	Duration: 162.97 (253.76) Raw N: 6835 Cleaned N: 5160 (75.49)
Effective Collective Action30,31	Features examples of successful collective action that have had meaningful effects on climate policies (e.g., protests) or have solved past global issues (e.g., the restoration of the ozone layer).	Duration: 154.34 (321.56) Raw N: 6818 Cleaned N: 5169 (75.81)
Psychological Distance32	Frames climate change as a proximal risk by using examples of recent natural disasters caused by climate change in each participants’ nation and prompts them to write about the climate impacts on their community.	Duration: 289.55 (337.26) Raw N: 6717 Cleaned N: 4737 (70.52)
System Justification33	Frames climate change as threatening to the way of life to each participant’s nation, and makes an appeal to climate action, as the patriotic response.	Duration: 80.17 (152.10) Raw N: 6854 Cleaned N: 5179 (75.56)
Future-Self Continuity34	Emphasizes identification with future selves by asking each participant to project themselves into the future and write a letter addressed to themselves in the present, describing the actions they would have wanted to take regarding climate change.	Duration: 258.02 (523.07) 6491 Cleaned N: 4226 (65.11)
Negative Emotions35,36	Exposes participants to ecologically valid scientific facts regarding the impacts of climate change framed in a ‘doom and gloom’ style of messaging that were drawn from different real-world news and media sources.	Duration: 213.10 (295.31) Raw N: 6778 Cleaned N: 5167 (76.23)
Pluralistic Ignorance37	Presents real public opinion data collected by the United Nations that shows what percentage of people in each participant’s country agree that climate change is a global emergency.	Duration: 36.89 (1055.17) Raw N: 6876 Cleaned N: 5172 (75.22)
Letter to Future Generation38,39	Emphasizes how one’s current actions impact future generations by asking participants to write a letter to a socially close child who will read it in 25 years when they are an adult, describing current actions towards ensuring a habitable planet.	Duration: 346.20 (490.72) Raw N: 6404 Cleaned N: 4044 (63.15)
Binding Moral Foundations40	Invokes authority (e.g., “From scientists to experts in the military, there is near universal agreement”), purity (e.g., keep our air, water, and land pure), and ingroup-loyalty (e.g., “it is the American solution”) moral foundations.	Duration: 13.48 (58.64) Raw N: 6877 Cleaned N: 5092 (74.04)
Scientific Consensus22	Informs participants that “99% of expert climate scientists agree that the Earth is warming, and climate change is happening, mainly because of human activity”.	Duration: 11.76 (272.47) Raw N: 6892 Cleaned N: 5296 (76.84)
Control Condition	Participants read a brief paragraph that was unrelated to climate change (i.e., a short paragraph from the novel “Great Expectations” by Charles Dickens).	Duration: 70.92 (247.49) Raw N: 6847 Cleaned N: 5094 (74.40)