There are fast positive and negative feedbacks all through the system.
Warm Arctic winters, for example, are degrading the ozone over the Arctic, which leads to greater heat loss. The open sea, obviously, absorbs more solar energy than the ice. Positive feedback. The glacier ice exposed by early-season melting is darker and absorbs more solar energy. Positive. There are both positive and negative cloud feedbacks.
In total there are hundreds if not thousands of feedbacks, and if you think you can eyeball one hypothesized negative feedback and proclaim victory over “Al Gore, Monbiot, Revkin, Romm, et. al” and their “dim imaginings” you are deluding yourself.