The case for longtermism: concern for the far future as a catalyst for pro-climate action

The study investigates whether endorsing longtermism—the ethical view that present and future generations warrant equal moral consideration and that today’s actions can shape a vast future population—predicts stronger climate-related beliefs, policy support, and behaviors. Against the backdrop of record global heat and IPCC projections, the authors ask who feels responsible to address climate threats and whether longtermist principles can identify and motivate individuals ready for climate action. Prior work shows people often discount future welfare, yet about a quarter of Americans endorse longtermist beliefs as measured by the Longtermism Beliefs Scale (LBS). The authors hypothesize that longtermists will demonstrate heightened concern about climate change, support for climate justice for both future generations and present-day minoritized groups, and greater individual and collective pro-environmental engagement. They further predict that a sense of responsibility to future generations underlies these relationships and test whether interventions that make intergenerational impacts salient can increase responsibility and pro-environmental behavior (e.g., donations).

Emerging research indicates that longtermists transcend psychological distance—reduced temporal and social discounting—and show broader moral concern and prosociality relative to controls. While bridging psychological distance has been proposed to increase climate action, recent analyses suggest its effects may be overstated. More consistently, feeling responsible for future generations predicts pro-environmental intentions, support for climate policies, and conservation behaviors. Longtermism alignment correlates with this intergenerational responsibility, suggesting a plausible pathway from longtermist beliefs to climate engagement. Related literatures on effective altruism, mental contrasting, perspective-taking, and legacy motivations provide additional frameworks for interventions to foster intergenerational concern and climate action.

Design and preregistration: Four preregistered studies recruited online samples via Prolific. Analyses were conducted in SAS. Continuous outcomes were analyzed with independent-samples t-tests; binary outcomes with chi-square. Mediation models used the PROCESS Macro (Model 4; 10,000 bootstraps). Covariates (gender, age, subjective SES, political orientation) were included in supplementary models. IRB approval was obtained; participants consented online. Study 1 (N = 790): Participants completed the Longtermism Beliefs Scale (LBS; 7 items each shown for 4 future timeframes: 1,000; 10,000; 100,000; 1,000,000 years; sliders 0–100; α = 0.97). Longtermists were identified by scoring >75 at 1,000 years and equal or higher scores at more distant timeframes. Climate attitudes were measured using the Yale Program on Climate Change Communication (YPCCC) items: beliefs about global warming (existence, anthropogenic cause, scientific consensus), perceived weather impacts, worry, perceived risks to multiple entities, timing of harm, personal experience, policy support (nine policies), perceptions of whether enough is being done, priority for addressing warming, discussion frequency, and media exposure. Ordering of item blocks and items within blocks was randomized. Primary tests compared longtermists vs non-longtermists using t-tests and chi-square; covariate-adjusted models were reported in SOM. Study 2 (N = 768): Measures included the LBS (α = 0.96), a 5-item responsibility to future generations scale (α = 0.93), a 21-item recurring pro-environmental behavior scale (α = 0.82), and a 13-item pro-climate collective action scale (α = 0.82). Measures were randomized. Group comparisons used t-tests; mediation (longtermism → responsibility → behaviors/collective action) was tested with PROCESS Model 4 (10,000 bootstraps). Study 3 (N = 769): Participants completed the LBS (α = 0.96), the responsibility to future generations scale (α = 0.93), and climate justice measures adapted from recent YPCCC reports. These included beliefs about disproportionate impacts on minoritized groups (6 items; α = 0.87), awareness of climate justice, general support for climate justice, belief that climate justice should be a national priority, policy support (7 items; α = 0.90), engagement in climate justice campaigns, and likelihood of voting for a candidate supporting climate justice. Parallel items were framed with future generations as the recipient group (reliability for subscales: α ≈ 0.74–0.83). Analyses included t-tests and mediation via PROCESS; covariate-adjusted models were reported in SOM. Study 4 (N = 2143 retained after exclusions): Participants were randomly assigned to one of five conditions: (1) future generation harm reduction thought exercise (N = 467) emphasizing preventing harm to future people; (2) letter to the past (from year 2500) (N = 399); (3) future challenges + solutions mental contrasting (N = 435); (4) future generations committee role-play (N = 365); (5) control (N = 477). All four interventions emphasized the present generation’s ability to positively influence distant future generations, using distinct persuasive framings (imagination, perspective-taking, mental contrasting, role-based impartiality). Outcomes: responsibility to protect distant future generations (4 items; 0–100 sliders; α = 0.96) and a donation task allocating part of a potential $10 bonus to Trees for the Future (forest protection for future generations). Analyses used t-tests, linear regression, and mediation (PROCESS Model 4) to test whether intervention effects on donations were mediated by responsibility.

Study 1: Relative to non-longtermists (N = 570), longtermists (N = 220) were 2.25× more likely to believe global warming is mostly human-caused, 2.99× more likely to believe there is scientific consensus, and 4.39× more likely to believe global warming is happening now. Longtermists reported greater worry, believed harms would arrive in the U.S. about 10 years sooner, perceived greater impacts on themselves, Americans, developing countries, animals/nature, and future generations, and more often experienced impacts. They felt society is not doing enough, prioritized addressing global warming more, supported policies more, and discussed global warming more often. Effect sizes ranged d = 0.34–0.73 and were robust to demographic covariates; media exposure did not differ between groups. Study 2: Longtermists (N = 178) reported higher moral responsibility to protect future generations than non-longtermists (N = 590): F(440.35) = 11.96, p < 0.001, d = 0.91. They reported greater engagement in pro-environmental behaviors, t(766) = 3.99, p < 0.001, d = 0.34, and greater pro-climate collective action participation, t(765) = 2.05, p = 0.041, d = 0.17. Mediation: responsibility fully mediated effects on behaviors (indirect b = 0.20, SE = 0.02, 95% CI [0.16, 0.24]) and collective action (indirect b = 0.46, SE = 0.05, 95% CI [0.35, 0.56]). Study 3: Longtermists (N = 186) vs non-longtermists (N = 583) more strongly endorsed climate justice beliefs, had greater awareness, supported climate justice policies, reported higher intentions to vote for climate-justice-oriented candidates, and higher intentions to participate in climate justice campaigns. Effects held for climate justice concerning minoritized people (ds ≈ 0.20–0.60; most remained significant after covariates except minoritized people beliefs) and future generations (ds ≈ 0.48–0.62). Mediation: responsibility to protect future generations explained pro-climate justice attitudes and policy opinions for minoritized people (indirect b = 0.34, SE = 0.03, 95% CI [0.27, 0.40]) and for future people (indirect b = 0.36, SE = 0.04, 95% CI [0.29, 0.44]). Study 4: All four interventions significantly increased responsibility to protect distant future generations versus control: harm reduction d = 0.63 (F(n942) = 9.67, p < 0.001); letter to past d = 0.39 (F(n874) = 5.71, p < 0.001); future challenges d = 0.30 (F(n910) = 4.57, p < 0.001); future generations committee d = 0.45 (F(n840) = 6.55, p < 0.001). Donation outcomes: only the harm reduction condition increased donations to Trees for the Future (F(942) = 2.20, p = 0.028, d = 0.14). Responsibility predicted higher donations (b = 0.02, 95% CI [0.01, 0.02], β = 0.18, p < 0.001; covariate-adjusted b = 0.01, 95% CI [0.01, 0.02], β = 0.15, p < 0.001). Mediation: the harm reduction condition’s effect on donations was fully mediated by increased responsibility (indirect b = 0.33, SE = 0.08, 95% CI [0.19, 0.49]); similar indirects appeared for other conditions without direct effects on donations.

Across studies, approximately a quarter of participants identified as longtermists displayed a consistent, robust pattern of heightened environmental concern, stronger support for both individual and collective climate action, and greater endorsement of climate justice for future generations and present-day minoritized groups. Central to these effects is an elevated sense of moral responsibility toward future generations, which mediated relationships between longtermist beliefs and pro-environmental behaviors, collective action, and climate justice attitudes and policy support. The findings align with evidence that cognitive and neural mechanisms underpinning social and temporal discounting overlap, suggesting that concern for distant future others can generalize to concern for socially distant present-day groups. Importantly, responsibility to future generations proved malleable: brief, scalable interventions, especially a vivid harm-reduction thought exercise, increased intergenerational responsibility and, in one case, actual donations to an environmental charity via increased responsibility. These results indicate that leveraging ethical reasoning, imagination, and perspective-taking can cultivate intergenerational duty and translate into tangible climate-supportive actions.

The research demonstrates that endorsing longtermist principles is associated with a comprehensive pro-environmental profile, including concern about global warming, support for pro-climate policies, engagement in individual and collective actions, and climate justice advocacy for future and minoritized populations. A sense of responsibility to future generations largely explains these relationships. Critically, this responsibility can be increased through brief, low-cost, scalable interventions, one of which also boosted environmental donations. Future work should test the durability of intervention effects over time, evaluate cross-cultural generalizability and the role of cultural values (e.g., long-term orientation, collectivism), examine whether effects are moderated by baseline longtermism or intergenerational concern, and compare framing approaches (e.g., preventing harm vs positively shaping the future) to optimize pro-environmental behavior change.

Samples were online and U.S.-based, limiting generalizability; cross-cultural replications are needed, especially considering cultural values like interdependence, collectivism, and long-term orientation. In Study 4, the mediator (responsibility) was measured without concurrently re-measuring longtermism beliefs, so changes in longtermism per se were inferred from its strong correlation with responsibility rather than directly observed. The studies cannot determine whether interventions are differentially effective based on individuals’ pre-existing intergenerational concern or longtermism alignment. Longitudinal designs are needed to assess the stability of responsibility and longtermist beliefs (state vs trait) and the persistence of behavioral impacts.