generate questions: The Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Dominant uses were for furniture and building construction.
How many cubic meters of growing stock forest are there on the planet? {sep_token} What percentage of the Earth's stock forest is commercial? {sep_token} In addition to buildings, what is wood often used to make? {sep_token} About how many cubic kilometers of the vast stock forest's wood were harvested in 1991? {sep_token} In addition to being carbon neutral, what other adjective describes wood that makes it compelling as a renewable energy source? {sep_token}