Another factor is if the piece uses a sustainable resource.

I believe that developing batteries that are from renewable and sustainable resources is the biggest challenge in my field.

Hay, which comes from grass, is an economically viable, renewable and sustainable resource.

With good management they are also a sustainable resource - for future generations.

In these areas, the goal is not biodegradability, but to create items from sustainable resources.

There's also been rumors that this where we first learned how to use honey for a sustainable resource.

I firmly believe that the quality of the Scottish countryside is our greatest sustainable resource but it must be looked after.

High quality waste materials are a useful sustainable resource.

A business needs a healthy, educated workforce, sustainable resources and adept government to compete effectively.

They are offering people an opportunity to invest in the future, to help cultivate knowledge, the country's most important and sustainable resource.