Everywhere can be read that carbon-dioxide increases greenhouse effect. But there are other gases having worse effect than carbon-dioxide, e.g. methane. Is carbon-dioxide emission the real threat, or can we fight more effectively against global warming by reducing the emission of other gases?

Everywhere can be read that carbon dioxide increases greenhouse effect. But there are other gases having worse effect than carbon dioxide, e.g. methane. Is carbon dioxide emission the real threat, or can we fight more effectively against global warming by reducing the emission of other gases?