Dear Shukra,

Given the fact that plants growing in green roofs have a very limited space to develop their root system, I think that their potential for carbon sequestration remains minimal. However, when we consider the other ecological services provided by a green roof (e.g.: cooling of the building, avoidance of rain water run off, contribution to improving air quality in the city, extra habitat/nectar source for pollinators), then the cumulative environmental benefits of a green roof become substantial to legitimize its design and construction.

Dear Dr.Bruno,

Yes, I agree with your opinion. Moreover, in City area, if Government will make it mandatory --atleast 20 or 30% roof top open space to be made green, it may be helpful to sequester carbon besides other additional benefits.

Regards,

Dear Dr. Shukra,

I think Yes. Please have a look at these useful links and PDF attachment.

https://pdfs.semanticscholar.org/9bc8/10429a605df92109f4c23c03f5c1659b9eb8.pdf

Article Carbon Sequestering and Green Roof Technology: A Benefit Cost Analysis

Article Green roofs and roof gardens

Article Quantifying carbon sequestration of various green roof and o...

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1058&context=rurals

https://www.arcjournals.org/pdfs/ijrsb/v3-i5/17.pdf

Good luck!

Dear Dr. Arvind,

Thank your very much for your kind cooperation and suggestion!

Best!