What is the greenhouse effect?

The greenhouse effect is actually a naturally occuring phenomenon.Energy that is released or reflected by the earth's surface is trapped and reflected back by greenhouse gases in the atmosphere (e.g. carbon dioxide, methane, water vapour), leading to the warming of the earth. This is actually very necesaary; without this process the earth would be a lot colder and less inhabitable. However, it becomes problematic when it is enhanced by humans, for example through carbon dioxide emissions. By increasing greenhouse gases in the atmosphere, more energy is reflected back to the earth's surface, causing global warming.