Lost in the current debate over how best to control greenhouse gas emissions from combustion of fossil fuels is the simple fact that it won’t be enough. Already, concentrations of CO2 in the atmosphere exceed 390 parts per million (ppm), some 40 ppm above what many climate scientists consider safe levels.
By 2050, without aggressive action, we can expect to see concentrations approaching 500 ppm, unleashing what Dr. James Hansen of NASA’s Goddard Institute has called “ . . . a devil’s cauldron of melted icecaps, bubbling permafrost, and combustible forests from which there will be no turning back.”
Hyperbole aside, it turns out that even under very aggressive fossil fuel emission reduction scenarios, the best we can do by way of limiting CO2 concentrations is something in the 425 ppm range, still far too high to safely avoid catastrophic consequences.
A recent report from the United Nations Environment Program estimates there is almost three times the amount of carbon stored on the land than is now present in the atmosphere. That’s the good news. The bad news is that this vast store of carbon is rapidly diminishing as humans clear natural areas for settlements and economic activities. Approximately 15 percent of annual global CO2 emissions are attributable to such land clearing. This continuing imbalance in the carbon cycle is a double whammy – it exacerbates our atmospheric greenhouse gas problem, and it affects rates of carbon capture and storage on the land, usually for the worse.
So how are we going to bring atmospheric CO2 concentrations down to safe levels? Four things need to happen.
First, existing biocarbon stores must be protected and their current high rate of loss reduced dramatically. This will require a halt in the loss of natural vegetative cover for human settlement and agriculture.
Second, historically depleted stores must be replenished through an aggressive policy of ecosystem restoration and improved management practices on all lands, especially working agricultural and forestry lands.
Third, where appropriate, opportunities to enhance carbon storage in suitable areas must be pursued, such as the planting of fast growing trees on otherwise tired and unproductive former agricultural lands.
Fourth, to make real progress we must not allow all of our biocarbon storage gains to be offset, or nullified, by new sources of CO2 pollution. That just won’t get us where we need to be.
Whatever the techniques applied, the goal must be nothing short of a course reversal when it comes to biocarbon. We need to create a political and economic context within which far more CO2 is stored annually in biological systems than is released from them. The Pacific Northwest is a biocarbon powerhouse with its green cities, extensive forests, and abundant agricultural lands. I can think of no better place to start.
