Final answer:
Carbon dioxide and water vapor have been known as greenhouse gases for more than 100 years.
Step-by-step explanation:
The concept of greenhouse gases and their effect on the Earth's climate has been known for more than 100 years. In 1896, Swedish physicist Arrhenius proposed the idea of the greenhouse effect and the role of gases like carbon dioxide in trapping heat. Since then, scientific research and data have provided evidence supporting the relationship between greenhouse gases like carbon dioxide and water vapor and the warming of the Earth's atmosphere. Today, we know that carbon dioxide and water vapor are major greenhouse gases, contributing to the Earth's climate change.