Yes, humans are the primary cause of recent climate change.
The overwhelming scientific consensus, based on extensive evidence from multiple independent lines of research, is that human activities—primarily the burning of fossil fuels (coal, oil, and gas), deforestation, and industrial processes—are responsible for the observed global warming since the mid-20th century.
Key Evidence
•Greenhouse gas emissions: Human activities have dramatically increased atmospheric concentrations of CO₂, methane, and other greenhouse gases. CO₂ levels have risen from about 280 ppm in pre-industrial times to over 420 ppm today, primarily from fossil fuel combustion. This traps more heat in the atmosphere (the greenhouse effect).
•Temperature records: Global average surface temperatures have risen by approximately 1.1–1.2°C (about 2°F) since the late 19th century, with the majority of warming occurring since 1950. The rate of warming is unprecedented in at least the last 2,000 years.
•Fingerprinting and attribution studies: Climate models that include only natural factors (solar variability, volcanic activity) cannot explain the observed warming. Models that include human-caused greenhouse gases match the observations closely. The warming pattern (troposphere warming + stratosphere cooling, greater warming over land and at night, etc.) matches the expected human fingerprint.
•Other indicators: Ocean heat content increase, sea level rise (from thermal expansion and melting ice), shrinking glaciers and ice sheets, declining Arctic sea ice, and shifts in precipitation and extreme weather patterns are all consistent with human-driven warming.
Scientific Consensus
Major scientific organizations worldwide affirm this, including:
•Intergovernmental Panel on Climate Change (IPCC): "It is unequivocal that human influence has warmed the atmosphere, ocean and land." (AR6, 2021). Human activities are responsible for essentially all of the observed warming.
•NASA, NOAA, Royal Society, National Academies of Sciences (US and others), American Meteorological Society, and virtually every major scientific body.
•Surveys of climate scientists show 97–99%+ agreement that humans are the main cause.
Natural factors (solar output, orbital cycles, volcanoes) play roles on longer timescales or shorter ones, but they do not account for the rapid warming of the past 50–70 years. In fact, solar irradiance has been relatively stable or slightly declining recently while temperatures rose.
Nuance
•Climate has always changed naturally over Earth's history (ice ages, etc.), driven by orbital variations, solar changes, tectonics, and feedbacks.
•The current rapid change is overwhelmingly anthropogenic.
•Uncertainty remains on exact future projections, regional impacts, climate sensitivity, and some feedbacks, but not on the basic attribution of recent warming to humans.
•"Climate change" broadly includes both warming and associated changes; "global warming" specifically refers to the temperature rise.
This conclusion is based on physics (radiative transfer of GHGs has been understood since the 19th century), direct measurements, paleoclimate data, and sophisticated modeling—not models alone. Denial often relies on cherry-picking short-term weather, outdated data, or misrepresenting uncertainty.
For primary sources, see IPCC AR6 reports, NASA's climate site, or NOAA.