What are some of the problems with davis's geomorphic cycle theory?

The davis's geomorphic cyclic theory raised some of the problems that the davis's concept of the upliftment creates problem so that is why it is unacceptable as it basically described the rapid change in the rate of the upliftment in the very short duration.

And the concept of the correlation in the upliftment and erosion are erroneous as, according to the concept no erosion occurred unless the upliftment process are completed.

d.) greenhouse gases

this is a good question! i'll do some research and come back when i have the answer!