The various politicos and ecotard lobbies have unilaterally stated that the cause is specifically due to human activity.
Why?.. Well, because Mother Gaia can't pay taxes, fees, etc, therefore, the low info mouth breathers can't blame Gaia now, can they?.. Interesting how groups like the UN that are on the verge of bankruptcy propose a save-the-planet-tax (only payable by 'have' nations) that the UN will graciously collect and administer?
This is the reason that the aforementioned NEVER refer to the multiple episodes of continental glaciation (and consequent receeding of said glaciers) that occurred before... (wait for it)... humans ever walked the Earth
You can obfuscate the conversation with all kinds of goobledegook about forcings - OR - you can use easily digestible words like 'natural cycles'... Even the mouth breathers will understand that
Okay....
Why is it warming?