Is bamboo really environmentally sustainable?

I was gifted a bamboo t-shirt recently. It's very soft and light and really quite comfortable once I took the scratchy label off.

Bamboo is having a bit of a moment, popping up in clothing, toilet paper, food, cutlery, packaging, furniture, construction, and crucially as a more environmental alternative to plastic. It purports to be a sustainable resource, and a step towards saving the world. But is it really that sustainable? I consulted several resources, one of the best of which was this one. As with most of these things, the answer is complicated.

Bamboo has a lot going for it. It is a fast-growing, naturally-renewable tree-like grass. It is naturally very strong, yet lightweight, although it can also be adapted to many other products where tensile strength is not the most important factor. There are many different varieties of bamboo, and it is highly adaptable, growing mainly in sub-tropical latitudes, but also in more temperate zones further north.

It grows insanely fast (up to 90cm a day!), reaching full maturity in just 1-5 years, much faster than the fastest-growing trees. Once harvested, it regrows from its own root system, thus maintaining soil structure and health and aiding water absorption. It doesn't require much in the way of added fertilizer (although that's not to say that fertilizer is never used). It is also very effective at carbon sequestration, absorbing more carbon dioxide than an equivalent mass of trees and pumping out 35% more oxygen.

Sounds great, eh? Now the bad news. Because bamboo has become such a in-demand product, it is usually grown as a monoculture, negatively impacting ecosystems, and whole forests may be razed to make way for it. Most bamboo production is still in China, from where it is shipped around the world, which has its own environmental and ethical challenges. 

Producing cloth (and toilet paper, packaging materials, etc) from bamboo requires an extensive chemical-heavy and energy-intensive industrial process, much like cotton and paper does, and it is notable that the Global Organic Textile Standards organization does not certify bamboo products, even if they are grown organically. There is as yet no fairtrade or certified sustainable designation for bamboo like there is for cotton.

The bottom line is that bamboo may be more environmentally sustainable than plastic and even many wood products, and it may be at least as sustainable as other natural fibres. But it has it's environmental challenges too (not least the fact that Chinese production is so poorly monitored). On balance, though, I think I can safely say that I can wear my t-shirt without any undue environmental angst.