Fact check: Is climate change mostly caused by human activity?

1. Summary of the results

The analyses overwhelmingly confirm that climate change is predominantly caused by human activity. Multiple authoritative sources provide strong evidence for this conclusion:

NASA states that human activities have increased atmospheric carbon dioxide concentrations and that the current warming trend since the mid-20th century is attributed to human expansion of the greenhouse effect ^[1]. The EPA reinforces this position, noting that human activities, particularly burning fossil fuels, have released large amounts of greenhouse gases into the atmosphere, leading to increased global temperatures ^[2]. The EPA further states it is extremely likely (>95%) that human activities have been the primary driver of observed warming since the 1950s ^[2].

The scientific consensus is remarkably strong: more than 99.9% of peer-reviewed scientific papers agree that climate change is mainly caused by humans, based on a comprehensive survey of 88,125 climate-related studies ^[3]. Additionally, 97% or more of climate scientists agree that human-caused climate change is real and ongoing ^[4].

The NRDC confirms that scientists agree human activity is the primary driver of current climate change through greenhouse gas emissions ^[5]. Key human activities identified include:

• Burning fossil fuels
• Deforestation
• Industrial processes that release carbon dioxide, methane, and nitrous oxide

2. Missing context/alternative viewpoints

While the question focuses on causation, the analyses reveal important natural climate factors that provide broader context. The British Geological Survey notes that natural factors such as changes in Earth's orbit and volcanic eruptions do contribute to climate variations ^[6]. However, this same source emphasizes that current climate change is occurring more rapidly than shown in geological records, which distinguishes human-caused warming from natural climate variations.

One analysis points out that the current warming trend cannot be explained by changes in Earth's orbit or solar activity ^[4], which helps differentiate between natural and anthropogenic causes.

The analyses also reveal that climate change has significant health impacts through natural disasters and socioeconomic pathways ^[7], providing important context about why this scientific question matters for human welfare.

3. Potential misinformation/bias in the original statement

The original question "Is climate change mostly caused by human activity?" appears to be a straightforward scientific inquiry without apparent bias or misinformation. However, the phrasing using "mostly" could potentially understate the scientific consensus, as the evidence shows human activities are not just the majority cause but the dominant and primary driver of current climate change.

The question appropriately focuses on causation rather than existence of climate change, which aligns with the current scientific discourse. No misleading framing or loaded language is present in the original statement.