I think the assumption that there ever was a long term climate equillibrium is false. Climate has always been changing. The radiative input from the sun is always changing. The composition of the atmosphere is always changing. The albedo of the earth is always changing.
I believe humans may be contributing significantly to current change by increasing greenhouse gases.
It is unknown whether this is a significant problem or a problem humans can or should solve.
The assumption has been that climate does change over time. The problem with the current climate change is the rate of change is much higher that most changes not driven by human actions. Most plants/animals (and civilizations) will struggle to adapt to this rate of change.
Maybe. But again I think it would be a bumpy road regardless. Humans have undergone an inflection point in the past couple hundred years. We are probably vastly surpassing the long term carrying capacity of the Earth. This may be an unpopular opinion but I think the best thing that could happen to the human species in the long run would be to drop the population perhaps below 500 million in coming decades as the Georgia Guide Stones recommend.
I believe humans may be contributing significantly to current change by increasing greenhouse gases.
It is unknown whether this is a significant problem or a problem humans can or should solve.