What is a negative feedback in the context of global warming?

The con or downside of global warming. For example:

Length of the growing season of trees - positive or negative feedbacks to an increase in atmospheric temperature?

This is negative feedback

Increase in temperature - > Longer growing season of trees due to more access to warmer temperature - > More uptake of atmospheric CO2 by tree growth - > Less atm CO2 - > Decrease in temperature