Sustainable Rates

Conservatives are fond of pointing out the hypocrisy of protesting oil drilling in plastic (made from oil) kayaks or protesting logging while living in wooden houses.   For purposes of argument, I'll ignore the nonsensical disconnect and pretend that it's a credible point.

Wood is potentially a sustainable resource.  If you harvest it at a rate lower than can restore itself, there is no direct risk from logging.  For much of the 20th century, this was indeed what was practiced, but by the 1960s, demand had exceeded capacity.  Especially in the 1980s under the Reagan/Watt regime, a high fraction of the old growth lumber in America was harvested and sold off, a huge part of it to the far east.

Total worldwide consumption of wood today is about 4B cubic meters.   There are about 4B hectares of forest in the world (down from 5.9B before industrialization.  We've been losing about 13M hectares/yr).    Canadian forests contain about 432 cubic meters per hectare.   Extrapolating that to the whole world, if we were to harvest 1 cubic meter per year per hectare, the forests would thus have 432 years to recover.   My forester friend tells me that if we harvest 10% or less every 15 or 20 years, that can be carried on indefinitely without harming the forest ecosystem--that's more than double that 1 m^3 per hectare rate.  But that's not what we're doing.  We mostly clear cut, in patches of a few hectares at a time, and during the '80s, we basically clear cut alternate quads, leaving a patchwork of tiny forests. This will recover eventually, but it'll take hundreds of years, and in the meantime, we've wrecked the local ecosystem, which will make it take longer to recover than necessary.  Worse yet, we're permanently clearing areas for agriculture, industrial and residential use.

Lots of privately owned forests are harvested sustainably.  We know it can be done.  We need for the government to protect our public forests this same way.



Total proven oil reserves are about 1.3T bbl.  Consumption has roughly tripled in the last 50 years, from about 11B bbl/yr in 1965 to about 33B bbl/yr today.  This suggests that the total amount of oil that was theoretically available at the start of the 20th century was about 2T bbl.    That oil took about 200M years for the earth to make.  2T/200M = 10,000.    So a sustainable rate for oil is about 10,000 bbl/year.    We are consuming it at 3 million times that rate.  


World coal production is about 8B tonnes.  The best guesses I can find say we can keep this up for about another 100 years, which suggests that there are just about 1T tonnes left and there were probably about 1.5T to start with.   Like oil, hard coal takes around 200-300M years for the earth to create.   That means we can sustainably harvest about 5000 Tonnes per year.  But there's a difference.  Soft coals such as lignite can form much more quickly, in the order of 5M years.  That might give us a sustainable rate for those coals of 250,000 Tonnes per year.  We use between 32,000 and 1.3M times too much to be sustainable.