"...the largest of all the positive or temperature-amplifying feedbacks in  the un’s arsenal is the water-vapor feedback.
"...the largest of all the positive or temperature-amplifying feedbacks in  the un’s arsenal is the water-vapor feedback.
runaway greenhouse effect:19
an increase in temperature from greenhouse gases leading to increased water vapor (which is itself a greenhouse gas) causing further warming is a positive feedback, but not a runaway effect, on earth.