Global warming is a serious threat to human existence. The relatively higher level of global warming in recent times poses higher health risks to humans, both directly and indirectly. The aim of the study was to investigate public knowledge of global warming and its effects on human health. A nationally representative survey of Ghanaian adults ( = 1130) was conducted from November 1, 2018 to February 28, 2019. Results show that 84.4% of the respondents understood the meaning of global warming. Respondents' perceived causes of global warming include natural processes, deforestation, act of the gods, burning of fossil fuel, and carbon dioxide (CO emission from vehicles and industries. The majority of the respondents (83.4%) indicated that global warming has an impact on human health, while 8.5% indicated that it does not. Majority (78.6%) of the respondents are willing to support efforts to reduce the intensity of global warming. Television (19.1%) and social media (18.6%) were the leading preferred methods for receipt of global warming information. These findings provide useful insights for policy directions. The Government of Ghana and other stakeholders in health should develop a communication strategy to increase and sustain publicity and education of the citizenry on global warming.