Widening Polarization in Americans' Perception of the Health Harms of Climate Change

What the evidence shows

This is a ten-year check-in on the exact question the library’s earlier Maibach et al. (2015) entry raised: do Americans understand that climate change harms health? Rather than a one-off snapshot, this study tracks the same core questions across three survey waves (2014, 2018, 2024) to see whether the original knowledge gap has closed, and — new to this study — whether recognition of climate-health harms has become politically polarized the way most other climate beliefs have.

The team also extended the original inquiry into new territory: energy-source misperceptions (do people correctly understand which energy sources harm health?) and trusted-messenger dynamics broken out by political party, not just overall. The explicit motivation, per the authors, is to inform how health professionals and communicators should now approach this topic — not from a baseline of general public ignorance (the 2015 framing), but from a baseline of rising but sharply divided public understanding.

Key Findings

• Overall recognition of specific climate-health harms (heat stroke, respiratory conditions, pollen allergies, mental health impacts, and others) has increased since 2014 — a genuine improvement on the original study’s “illusion of knowledge” baseline.

• That improvement is heavily concentrated among Democrats: by 2024, an average of 57% of Democrats said each health harm asked about would become more common in their community (up 39 points since 2014), compared to just 19% of Republicans (up only 11 points) — a rapidly widening partisan gap.

• Trust in first responders and one’s own primary care doctor remains high and comparatively bipartisan; trust in institutional sources (CDC, WHO, EPA) has become substantially more polarized along party lines.

• Misperceptions about clean energy have grown: increasing shares of both Democrats and Republicans now incorrectly believe that wind and solar power harm human health.

• Between 2018 and 2024, Democrats grew more likely to recognize the health harms of coal and gas, while Republicans became less likely to recognize the health harms of coal specifically — a divergence rather than a shared shift.

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Stand-out data points

• 57% vs. 19% (2024), a gap that grew from 2014: Democrats’ belief that climate-related health harms will become more common in their community rose 39 points since 2014, while Republicans’ rose only 11 points — the study’s central “widening polarization” finding.

• 65% vs. 38%: the share of Americans who believe coal (65%) vs. natural gas (38%) is harmful to health in 2024 — a useful benchmark for how unevenly the public understands relative energy-source health risks.

• First responders and primary care doctors remain the most trusted messengers across both parties — the one finding from the original 2015 study (physician trust) that not only held up but proved to be the most bipartisan-resilient result in the entire ten-year comparison.

Examples of how Understories uses this research

• Actionability The coal/gas recognition data (65% vs. 38%) is useful for scoring whether a message accurately calibrates which energy sources it’s asking audiences to act against.

• Clarity Reinforces the earlier finding that vague “climate change harms health” framing underperforms specific, named harms — and adds that which specific harms resonate now differs sharply by the audience’s political identity.

• Emotional resonance Supports segmenting messaging: health-harm framing may already resonate emotionally with Democratic-leaning audiences, but for Republican-leaning audiences the same framing may need a different messenger or entry point rather than more emotional intensity.

• Solution focus The rising misperception that wind and solar harm health is directly relevant here — Understories should flag messages that assume audiences already understand clean energy as health-neutral or health-positive, since a growing share of the public (both parties) now incorrectly believes otherwise.

• Explainability Findings are specific enough (exact percentages, comparison waves) to support scored, cited recommendations — e.g., “Indian audiences show near-universal (90%) worry; don’t lead with threat, lead with actionable solutions since 94% already support one.”

• Beneficence Helps advocates avoid a one-size-fits-all health message and instead points toward messengers (health professionals, first responders) shown to work across the political spectrum, which serves broad public benefit rather than just reinforcing existing in-group beliefs.

• Justice:  An improvement on the original 2015 study in one respect — this analysis explicitly breaks results out by political affiliation rather than treating “Americans” as a monolith, which is itself a more equity-aware analytical choice. It still doesn’t disaggregate by race, income, or geography, which remains a gap.non-exhaustive

Key quote

The authors’ central conclusion: “these perceptions are strongly politically polarized, and this polarization has increased since 2014.”

© Environmental Research: Health (IOP Publishing), Yale/GMU, CC BY 4.0.

Library entry updated: 7 October 2026