Fact check: Is climate change caused by burning fossil fuels?

1. Sharp Claim: Fossil Fuels as the Primary Driver—Numbers and Warnings

The materials present a sharp, numerical claim that fossil fuels are the largest contributor to global greenhouse gas emissions and nearly 90% of CO2 emissions, placing fossil fuel combustion at the center of observed warming ^[1]. The U.S. EPA analysis reinforces that human activities—particularly burning fossil fuels—are the dominant cause of warming since the 1950s, explicitly citing CO2 and other greenhouse gases (p1_s2, dated 2025-08-25). Separately, a group of leading scientists framed fossil fuels and the fossil fuel industry as drivers of intersecting crises—public health, biodiversity loss, and environmental injustice—calling for a phase-out of extraction and use (p1_s3, dated 2025-03-31). These claims collectively present a consistent, forceful attribution to fossil fuel combustion.

2. Mitigation and the Implicit Admission: Renewables as the Remedy

Several sources focus on renewable energy and transitions as mitigation, which implicitly links fossil fuel use to climate change by proposing replacements for combustion-based energy systems ^{[4] [5] [6]}. The IPCC-aligned review discusses renewable deployment for mitigation without restating attribution directly, but its emphasis on transitioning the energy system signals that cutting fossil fuel emissions is central to any chance of limiting warming (p3_s1, 2025-04-11). Research on feasibility of 100% renewables and IRENA’s 1.5°C pathway present concrete routes to net-zero CO2 by mid-century, framing renewables not as an ideological choice but as a necessary technical response to emissions associated with fossil fuel burning ^{[5] [6]}.

3. Agreement Across Agencies and Scientists: Convergence of Evidence

The analyses show broad convergence between governmental agencies, scientific bodies, and research organizations: the EPA’s explicit attribution ^[2] aligns with academic and advocacy voices asserting fossil fuels’ centrality ^{[1] [3]}. The temporal spread—studies and statements from late 2024 through mid-2025—indicates consistent messaging across time, from feasibility studies on renewables (p3_s2, 2024-11-01) to urgent scientist warnings in March 2025 ^[3] and EPA guidance in August 2025 ^[2]. This cross-cutting agreement strengthens the causal inference that burning fossil fuels is a primary driver of recent climate change and that reducing those emissions is essential for mitigation.

4. Nuance and Omitted Forcing Factors: What the Materials Do and Don’t Emphasize

While these sources stress fossil fuels, they also acknowledge other forcings and context—natural variability, solar changes, and volcanic activity are noted as influencing climate but are not presented as the main drivers of recent warming ^[2]. The IPCC-related mitigation focus ^[4] and IRENA pathway ^[6] concentrate on policy and technology, thereby de-emphasizing non-anthropogenic factors in favour of actionable solutions. The provided materials omit detailed quantitative attributions of non-fossil anthropogenic drivers (e.g., agriculture, land-use change) and lack comprehensive discussion of uncertainties or regional differences in attribution, leaving gaps in the fuller causal mosaic.

5. Messaging and Possible Agendas: Scientists, Agencies, and Policy Advocates

The scientist statement ^[3] carries advocacy framing—calling for a phase-out of extraction and linking fossil fuels to justice and health harms—which indicates an agenda to accelerate policy change. The EPA’s presentation ^[2] is regulatory and public-health oriented, framing attribution to inform policy. Renewable-transition analyses and IRENA’s pathway reports ^{[5] [6]} are solution-focused and may emphasize feasibility and pathways that align with institutional goals to promote renewables. Each source’s emphasis—urgent phase-out, regulatory attribution, or pathway design—reflects different organizational priorities even while they converge on fossil fuels’ leading role.

6. Timing Matters: Recent Publications Strengthen the Consensus Portrait

The timeline across sources—feasibility and pathway reports in late 2024 ^{[5] [6]}, an IPCC-aligned mitigation piece in April 2025 ^[4], a scientist warning in March 2025 ^[3], and an EPA statement in August 2025 ^[2]—shows updates and reinforcement of the same conclusion over successive months. This temporal clustering indicates not a fleeting claim but ongoing, cross-institutional reinforcement of fossil fuel combustion as the main recent driver and a push toward renewable-based mitigation. The sequence suggests mounting urgency in both scientific warnings and policy-oriented guidance during 2024–2025.

7. Bottom Line: What Can Be Concluded from These Sources

Taken together, the provided analyses constitute a consistent, multi-source assertion that burning fossil fuels is the principal human cause of recent climate change, supported by numerical attribution, policy statements, and mitigation pathways ^{[1] [2] [3] [4] [5] [6]}. Important omissions remain: granular attribution to non-fossil anthropogenic sources, explicit uncertainty ranges in the summaries, and regional detail. Readers should note each source’s possible agenda—scientific, regulatory, or advocacy—while recognizing their agreement on the central role of fossil fuel combustion and the need for rapid energy-system transformation to mitigate further warming.