At 50 tonnes of carbon per hectare per year, to capture the 40B tonnes of CO2 emitted every year you'd need 800M hectares of bamboo (or 8M km²). So you'd have t

At 50 tonnes of carbon per hectare per year, to capture the 40B tonnes of CO2 emitted every year you'd need 800M hectares of bamboo (or 8M km²). So you'd have to plant almost the entirety of the Sahara desert (9.2M km²) with bamboo to get this. Also, you're saying 50 tonnes per year, but bamboo doesn't live for a very long time, and after it dies, it will relatively quickly decompose and release everything it captured back. So, in reality, you'd have to plant the whole of the Sahara with bamboo and then harvest it every year (or, to be fair, maybe every couple of years), storing all of the bamboo somewhere where it can't decompose, forever. So no, bamboo (nor any other plant) is not even close to a solution, not at the current rate of emissions.