If you suppose methane is "irrelevant" to climate change, like the adviser suggests, that surely implies made-made CO2 contributions are about as relevant. In

If you suppose methane is "irrelevant" to climate change, like the adviser suggests, that surely implies made-made CO2 contributions are about as relevant. In this case not very, or irrelevant. Definitely doesn't sound as humorous when written like that, though I'll clarify as it seems you are asking earnestly