Public perceptions and support of climate intervention technologies across the Global North and Global South

The study investigates how publics across the world perceive climate intervention technologies—carbon dioxide removal (CDR) and solar radiation modification (SRM)—and how support differs between Global North and Global South contexts. It addresses the urgency and growing consideration of these technologies amid insufficient emissions reductions and increasing climate impacts, which disproportionately affect the Global South. The research aims to establish a global baseline of public perceptions, focusing on familiarity, perceived risks and benefits, support for research/field trials/deployment, and policy preferences. It responds to gaps in the literature: limited cross-country comparisons, few studies evaluating multiple technologies per respondent, and inadequate engagement with the Global South, despite its heightened vulnerability and likely divergent perspectives.

Prior work shows persistent low familiarity with climate intervention technologies and indicates framing effects (e.g., naturalness) on public acceptance. Most existing studies are quantitative, concentrated in the Global North (especially USA, UK, Germany), with few cross-country designs and minimal focus on the Global South. Literature often shows a preference for CDR over SRM and greater favorability toward approaches perceived as natural (e.g., afforestation, soil carbon sequestration). Concerns about moral hazard (mitigation deterrence) and unequal distribution of risks have been highlighted, alongside mixed evidence regarding how information provision affects support. The current study extends this literature by offering broad cross-country coverage (including multiple regions and Global South countries), simultaneous appraisal of multiple technologies by respondents, and systematic comparisons of risk/benefit and policy preferences across technology categories.

Design and ethics: Online surveys administered by Norstat on behalf of Aarhus University across 30 countries in 19 languages (August–December 2022), with ethical approval from Aarhus University (#2021-13). Informed consent obtained; data anonymized; participants compensated. Sampling: Nationally representative samples (age 18–74, gender, region; broad quotas for education and income), minimum N≈1000 per country, total N=30,284. Countries classified per UN Finance Center for South-South Cooperation: Global South (Brazil, Chile, India, Nigeria, Indonesia, South Africa, Kenya, Saudi Arabia, Dominican Republic, China, Singapore); Global North (USA, Canada, Australia, Japan, Austria, Germany, UK, France, Sweden, Poland, Switzerland, Greece, Italy, Netherlands, Norway, Spain, Denmark, Estonia, Turkey). Minor deviations from full representativeness in specified subgroups/regions. Procedure and information: All participants received background information on climate change, mitigation, adaptation, CDR, and SRM, with graphics; minimum time on information screens enforced to reduce careless responding; comprehension checks included. Participants were randomly assigned to one of three technology clusters: SRM (stratospheric aerosol injection, marine cloud brightening, space-based geoengineering); ecosystem-based CDR (afforestation/reforestation, soil carbon sequestration, marine biomass/blue carbon); engineered CDR (enhanced weathering, biochar, DACCS, BECCS). Each technology had standardized descriptive text and graphics outlining operation, potential benefits, and risks. Measures: Familiarity (post-info; 1–5 scale). Perceived risks/benefits: eight items (four benefits: controlled safety, cost-efficiency vs cutting fossil fuels, environmental friendliness, long-term reliability; four risks: unintended side effects, unequal risk distribution rich vs poor, threat to humans/nature, decreased motivation to reduce CO2), 1–7 Likert (no “Don’t know”). Weighing risks vs benefits (5-point summary item; high correlation with support; not central to main analyses). Support: three items for each technology—research, small-scale field trials, broad deployment (1–5 scale plus “Don’t know”); items highly correlated (lowest Spearman’s rho 0.956); composite support measure computed (mean of three; PCA one-factor; Cronbach’s α > 0.90 for all technologies). Policy preferences: for each category (SRM, engineered CDR, ecosystem-based CDR), participants selected any number of options deemed necessary before use: domestic restrictions; national support/funding for R&D; information/engagement campaigns; international ban/moratorium; international oversight organization; special report (e.g., IPCC). For CDR, also global carbon market; for SRM, international scientific agency for research/testing. Climate beliefs and experience: concern about climate change (1–5), perceived personal harm (1–4), personal experience with major natural disaster in past three years (Yes/No), belief that science/technology will solve climate change (1–5). Analysis: SPSS v28. Nonparametric tests due to non-normality. Between-cohort tests (Global North vs South) via Mann–Whitney U; between-category differences via Kruskal–Wallis; within-respondent comparisons for activity support via Friedman’s two-way ANOVA by ranks and Wilcoxon signed-rank tests; Bonferroni corrections applied. Hierarchical linear regression at country level examined explanatory power of mean age and climate beliefs for support differences across cohorts; effect sizes reported (Cohen’s f²).

Overall familiarity is low, except for afforestation/reforestation; ecosystem-based CDR is relatively more familiar than SRM and enhanced weathering. Global South respondents report significantly higher familiarity in 9/10 technologies (all p<0.05), with afforestation/reforestation not significantly different (p=0.052). Perceived benefits vs risks by category: • Benefits are rated highest for ecosystem-based CDR, then engineered CDR, and lowest for SRM. Global South perceives greater benefits across all categories (all p<0.05), with the largest Global North–South gap for SRM. • Risk perceptions are mixed. For SRM, Global North expresses more concern about unintended side effects and threats to humans/nature, while Global South is more concerned about unequal risk distribution and mitigation deterrence. For engineered CDR, cohorts are aligned on most risks except Global South’s higher concern about mitigation deterrence. Ecosystem-based CDR is generally viewed as less risky, though Global South rates threats to humans/nature slightly higher than Global North. Support across activities: Small-scale field trials receive the highest support, followed by research and broad deployment (global Friedman’s χ²(2)=347.215, p<0.001). Broad deployment is least supported (global mean 3.699) but still above neutral (3). Global North supports research over deployment (Wilcoxon W=3761.00, Z=−6.927, p<0.001), whereas Global South rates them equally (p=0.857). Support by technology (composite of research, field trials, deployment; 1–5): Global North vs Global South means and significance (Mann–Whitney) • Stratospheric aerosol injection: 3.11 vs 3.70 (p<0.001) • Marine cloud brightening: 3.27 vs 3.89 (p<0.001) • Space-based geoengineering: 3.17 vs 3.80 (p<0.001) • Afforestation/reforestation: 4.42 vs 4.47 (ns) • Soil carbon sequestration: 4.10 vs 4.30 (p=0.003) • Marine biomass/blue carbon: 4.07 vs 4.24 (p=0.004) • DACCS: 3.55 vs 4.04 (p<0.001) • BECCS: 3.58 vs 3.99 (p<0.001) • Enhanced weathering: 3.31 vs 3.76 (p<0.001) • Biochar: 3.73 vs 4.06 (p<0.001) Patterns: Ecosystem-based CDR is most supported overall, with afforestation/reforestation highest. SRM and enhanced weathering sit at the bottom of support rankings. Enhanced weathering is notably less supported than other CDR options, potentially reflecting concerns about mining and ocean interventions. Determinants of support: Global South participants are younger (mean age 36.97 vs 45.07 years), more worried about climate change (3.999–4.069 vs 3.644), perceive greater personal harm (3.253 vs 2.772 on 1–4), report more disaster experience in past 3 years (53.35% vs 33.28%), and have stronger belief in science/technology as a solution (3.810 vs 3.337); all differences p<0.001. Hierarchical regression shows country mean age explains much of the North–South support difference: once mean age is included, “Global North vs South” is no longer significant. Age has strong explanatory power for SRM support (F(1,87)=40.423, p<0.001, f=0.466) and smaller for engineered CDR (F(1,117)=15.026, p<0.001, f=0.128); age does not explain support for ecosystem-based CDR (p=0.259). Policy preferences: Global South shows consistently higher support (often by ≥10 percentage points) for most policies, especially national R&D funding and international oversight/reporting. Least supported options globally are domestic restrictions and international bans/moratoria. Global carbon markets receive limited support (<~36% Global South; ~24–26% Global North). “None of the above” is selected far more in the Global North (≈9–12%) than the Global South (≈3–4%).

The study provides the first global baseline of public perceptions for CDR and SRM across 30 countries, revealing both shared preferences and critical Global North–South divergences. Publics broadly prefer ecosystem-based CDR, consistent with naturalness framing and lower perceived risks. SRM is viewed most skeptically, particularly in the Global North, where concerns center on unintended side effects and threats to humans and nature. In contrast, Global South publics show greater openness to SRM and engineered CDR, while emphasizing distributive justice and moral hazard risks, reflecting higher perceived climate harm and experiential vulnerability. Support gradients across activity types (field trials > research ≈ deployment) suggest publics seek real-world feasibility testing but remain cautious about large-scale deployment. Regression analyses indicate that demographic structure—especially younger population age—accounts for much of the observed North–South support differences, particularly for SRM and engineered CDR. Policy preferences are coherent across categories, favoring supportive national measures and international oversight/information, with little appetite for bans/moratoria or global carbon markets. These findings underscore the importance of inclusively engaging Global South publics in research and governance debates and caution against assuming Global North perspectives are universally representative.

This study establishes a comprehensive, cross-country baseline of public perceptions of climate intervention technologies, showing: (1) strong and consistent preference for ecosystem-based CDR; (2) greater support in the Global South for nearly all technologies (except afforestation/reforestation, where support is similarly high); (3) distinct risk salience—environmental/safety (Global North) versus distributive justice and moral hazard (Global South); and (4) policy preferences favoring supportive national R&D and international oversight/information. The work advances understanding by integrating multiple technologies per respondent, spanning both CDR and SRM, and heavily representing the Global South. Future research should: • Examine moral hazard perceptions and justice concerns in Global South contexts in depth. • Disaggregate field trial types/scales and explore how intent affects support. • Track longitudinal changes as familiarity and real-world demonstrations evolve. • Investigate within-country heterogeneity and the roles of media, cultural response styles, and local contexts. • Develop governance scenarios aligned with public preferences for supportive and informational policies, while addressing concerns about equity and mitigation deterrence.

Findings should be interpreted cautiously due to low baseline familiarity (risk of pseudo-opinions) and potential malleability to new information. Online survey design may introduce response-style and cultural biases; despite standardized texts/graphics, unavoidable complexity differences may remain. The study does not differentiate detailed scales/intents of field trials, which could influence support. While samples are broadly nationally representative, minor deviations exist in selected subgroups/regions. Grouping technologies into three clusters may shape comparative judgments. Cross-sectional design precludes causal inference beyond reported associations, and some constructs rely on self-report measures without “Don’t know” options for risk/benefit items.