This is an old and debunked talking point. Potential mitigation of a greening earth is easily offset by increasing emissions, and a host of other counterfactuals. Including that it stopped getting greener 20 years ago.

To this specific point you make here about how greening means more easily feeding our growing population: even if it was greening, not all land plants are created equally, and enormous swaths of "greening" regions would feature thawing permafrost, a dubious place to grow food.

I urge your readers to look at any one of the following, on balance:

https://phys.org/news/2020-12-greening-earth-approaching-limit.html

https://www.nytimes.com/2018/07/30/science/climate-change-plants-global-greening.html

https://www.scientificamerican.com/article/earth-stopped-getting-greener-20-years-ago/

https://yaleclimateconnections.org/2020/09/video-origin-of-the-myth-that-global-warming-good-for-agriculture/