Are humans responsible for climate change?

Yes, humans are the primary cause of recent climate change (global warming since the Industrial Revolution, particularly the rapid warming of the past several decades). This is the overwhelming scientific consensus, described as "unequivocal" by the Intergovernmental Panel on Climate Change (IPCC) and supported by multiple independent lines of evidence from observations, physics, paleoclimate records, and climate models.[1]

Scientific Consensus

Key Evidence

Human activities—primarily burning fossil fuels (coal, oil, gas), deforestation/land-use change, and agriculture—have sharply increased atmospheric concentrations of greenhouse gases (GHGs) like CO₂, methane (CH₄), and nitrous oxide (N₂O). CO₂ levels are about 50% higher than in 1750 and higher than at any time in at least the last 800,000 years (from ice cores). The isotopic “fingerprint” of the added carbon matches fossil fuels, not natural sources.[5]

Natural climate variability (e.g., El Niño, orbital cycles, volcanoes, solar variations) exists and has driven past changes, but it does not account for the magnitude, speed, or specific patterns of recent warming. Human influence has overwhelmed these factors in the modern era.[9]

In short, the evidence is robust, multi-decadal, and multi-method. While details of future projections, regional impacts, and exact sensitivities involve ongoing research and some uncertainty ranges, the core conclusion—that humans are responsible for the bulk of recent climate change—is settled science at the highest level of confidence.