What gas contributes most to global warming?

Answer 1

Carbon dioxide (CO2) is mostly responsible for global warming.

CO2 and other gases (water vapor, methane and others) contribute to the natural greenhouse effect, which has been keeping the planet comfortably warm for millions of years.

However, since the Industrial Revolution 200 years ago, we have been burning more and more fossil fuels, releasing carbon that has been hidden for millions of years. It is this extracarbon, in the form of the greenhouse gas, carbon dioxide, that climate scientists believe is causing the warming of the planet.

Answer 2

• Water vapour and Carbon dioxide (CO2) are responsible for the natural greenhouse effect.
• Carbon dioxide and methane are responsible for the enhanced greenhouse effect which is causing global warming and climate change.

Answer 3

The gas contributing the most to global warming is carbon dioxide (CO2). Without the increases in carbon dioxide levels since the Industrial Revolution, 200 years ago, the greenhouse effect, supported largely by water vapour, would be keeping the Earth comfortably warm enough for life, as it has for millions of years.