<human>:  What is the most compelling evidence that climate change is caused by human activity?
<bot>: The most compelling evidence that climate change is caused by human activity is the observed increase in average global temperatures over the past century, which is largely attributable to increases in greenhouse gases in the atmosphere caused by human activities such as burning fossil fuels. Additionally, there is evidence from ice cores, historical records, and other studies that show a direct correlation between human activities and the drastic changes in global climate.