I'll gather the scientific evidence on humanity's role in climate change.
Yes, humans are responsible for modern climate change, according to the overwhelming scientific consensus.
> There is unequivocal evidence that Earth is warming at an unprecedented rate. Human activity is the principal cause.
Evidence and consensus:
•The United Nations Intergovernmental Panel on Climate Change (IPCC), the UN body for evaluating climate science, concluded it is "unequivocal" that human activity is driving climate change, and that humans are 'unequivocally' responsible for this rapid global warming.
•The IPCC stated there is 95 percent certainty that humans have caused most of the warming of the planet's surface that has occurred since the 1950s. The report confirms that it is extremely likely (95-100% probability) that most of the warming since 1950 has been due to human influence.
•In its summary formulation, the IPCC stated it is “extremely likely that more than half of the observed increase in global average surface temperature” from 1951 to 2010 was caused by human activity, where extremely likely meant between a 95% and 100% probability.
•Using the scientific method, scientists have shown that humans are extremely likely the dominant cause of today’s climate change. NASA summarizes that Scientific evidence continues to show that human activities (primarily the human burning of fossil fuels) have warmed Earth’s surface and its ocean basins.
•NASA states "Scientists have known for some time, from multiple lines of evidence, that humans are changing Earth’s climate, primarily through greenhouse gas emissions."
•Direct observational evidence confirms this. A NASA study confirmed predictions with direct observations for the first time: radiative forcings are increasing due to human actions, affecting the planet’s energy balance and ultimately causing climate change. Researchers said "It’s direct evidence that human activities are causing changes to Earth’s energy budget".
Mechanism - greenhouse gases from human activity:
•The dominant cause is emissions of greenhouse gases, especially carbon dioxide from burning fossil fuels - coal, natural gas and petroleum. In the United States, most (about 74%) human-caused (anthropogenic) greenhouse gas (GHG) emissions come from burning fossil fuels.
Natural factors such as solar variations and volcanic activity have played a role in past climate changes, but the evidence shows the current warming cannot be explained by the Sun and requires human greenhouse gas increases.
•Multiple independent analyses of the peer-reviewed literature and surveys put agreement that humans are causing recent warming at roughly 97% or higher, with some large-scale literature reviews reporting consensus estimates above 99%.
In summary, climate change has natural drivers over geological time, but the rapid warming observed since the mid-20th century is unequivocally dominated by human activities.