NASA climate scientist James Hansen’s recent book Storms of my Grandchildren makes accessible the evidence behind the judgement of many climate scientists that we need to get atmospheric carbon dioxide back to 350 ppm (or perhaps 300-325 to be really safe) to avoid dangerous climate tipping points. But he also makes it clear that merely redesigning the global energy infrastructure isn’t enough, other important climate forcings like methane, nitrous oxide and black carbon must also be reduced.
What do we need to do?
Here’s Hansen’s todo list. Stick it on the fridge.
- Phase out all coal fired power stations by 2030. Of course, you can still use coal if you sequester all the emissions, … good luck with that.
- Undo 200 years of deforestation. We need to start this now, but it will take over 100 years and contribute a reduction of about 50ppm by 2150.
- Reduce non-carbon dioxide forcings. Hansen is a little vague here, but the argument implies that pre-industrial levels are required.
Now, if the next sentence doesn’t hit like a shattering ice-shelf, then reread until it does. All three items are mandatory. This isn’t a smorgasbord where you pick what you want and ignore the rest. With countries around the world still building new coal power plants, the first todo is looking shaky. Fortunately the second and third are technically easier. We don’t need any new science or technologies but the politics are diabolical.
You can’t tackle reforestation without a global food system rethink. People who’ve read my previous posts on BNC understand this, but be patient while I race through a little background for new readers.
As with reforestation, steep reductions of methane, black carbon and nitrous oxide forcings also require a rethink of the global food system. This is because 96 megatonnes of the 350 mega tonnes of anthropogenic methane emitted annually are due to livestock. It’s also livestock production which is responsible for the bulk of the annual global conflagrations responsible for preventing plenty of natural reforestation while also contributing rather a lot of black carbon. This is covered in Boverty I. The good news is that 38 megatonnes of methane emissions will go when we stop mining coal and another 73 megatonnes are tied up with oil and gas production and can be relatively easily dealt with when there is a will to do so.
The livestock reforestation impediment
Currently, a major sticking point on reforestation is the attitude to animal product consumption of the UN FAO which is summed up in the just released report on the greenhouse gases associated with the dairy sector: Without concerted action, emissions [from livestock] are unlikely to fall. On the contrary, they are rising, as global demand for meat, milk and eggs continues to grow rapidly. Projected population growth and rising incomes are expected to drive total consumption higher–with meat and milk consumption doubling by 2050 compared to 2000 (FAO, 2006b).