Are humans responsible for climate change?

Yes, the overwhelming scientific consensus is that human activities are the primary driver of climate change observed since the mid-20th century. Here's the core evidence and reasoning behind this conclusion:

Key Evidence

Greenhouse gas emissions: Burning fossil fuels (coal, oil, natural gas), deforestation, and industrial processes have significantly increased atmospheric concentrations of carbon dioxide, methane, and other greenhouse gases. CO2 levels have risen from about 280 parts per million in pre-industrial times to over 420 ppm today—levels not seen in at least 800,000 years based on ice core data.

Temperature correlation: Global average temperatures have risen roughly 1.1-1.2°C since the late 1800s, with the most rapid warming occurring since the 1970s—correlating closely with the acceleration of industrial activity and emissions.

Scientific consensus: Major scientific bodies, including the Intergovernmental Panel on Climate Change (IPCC), NASA, NOAA, and national academies of science worldwide, agree that human influence is the dominant cause of observed warming. Multiple independent studies have found that 97% or more of actively publishing climate scientists agree on this.

Isotopic and physical evidence: Scientists can trace the carbon in the atmosphere using isotopic signatures, confirming that the increase comes from fossil fuel burning rather than natural sources like volcanic activity or solar variation.

Ruling out natural causes: Climate models that account for only natural factors (solar activity, volcanic eruptions, natural climate cycles) cannot reproduce the warming trend seen since the mid-20th century. Models that include human-caused greenhouse gas emissions match observed temperature records much more closely.

What This Means

While natural factors do influence climate (and always have), the current rate and pattern of warming is best explained by human activity. This is reflected in the IPCC's Sixth Assessment Report (2021), which stated unequivocally that human influence has warmed the atmosphere, ocean, and land.

If you'd like, I can search for the latest data or specific reports (like recent IPCC findings or current CO2 levels) to give you more current figures.