Below are 2 films on reversing desertification a major contributor to global warming. The first film is on the work of Dr John Liu which is quite a story. John Liu founded Ecosystem Restoration Camps, a worldwide movement that aims to restore damaged ecosystems on a large scale. The film is on his work in China.
The second is a Ted Talk by Allan Savory a Zimbabwean ecologist, livestock farmer who originated holistic cattle management a systems thinking approach that advocates using bunched and moving livestock to what he claims mimics nature, as a means to heal the environment, stating only livestock can reverse desertification. He is strongly opposed to industrial cattle raising.
Both films are well worth the watch.
Dr. John Liu about restoring degraded lands in China youtube 28 mins
Allan Savory TedTalk https://youtu.be/vpTHi7O66pI 22 mins
If Liu’s or Savory’s work intrigues you then explore further. I highly recommend Wikipedia’s description of Savory’s work. He has some opposition; however, there are a number of notable advocates who support his work including Hunter Lovins and noted farmer Joel Salatin who wrote, "History will vindicate Allan Savory as one of the greatest ecologists of all time." Savory is also a recipient of a Buckminster Fuller award.