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- cross-posted to:
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- [email protected]
Air New Zealand has abandoned a 2030 goal to cut its carbon emissions, blaming difficulties securing more efficient planes and sustainable jet fuel.
The move makes it the first major carrier to back away from such a climate target.
The airline added it is working on a new short-term target and it remains committed to an industry-wide goal of achieving net zero emissions by 2050.
The aviation industry is estimated to produce around 2% of global carbon dioxide emissions, which airlines have been trying to reduce with measures including replacing older aircraft and using fuel from renewable sources.
How much better is biofuel than fossil CO2-wise, if you need to cut down forests for arable land?
A very good question.
It is a very common misconception that trees and plants just always absorb CO2. The Carbon © in CO2 does not just disappear when plants produce Oxygen (O2). Plants use it as material to grow themselves and their fruits. Once they are fully grown, they don’t really absorb any more. So if you burn a tree in a fireplace and grow a new tree in its place, the new tree will eventually re-capture all the CO2 burning the wood released as it grows. This works even better with fast growing plants used for biofuel. The CO2 released by burning biofuel is re-captured when you grow more plants to make more biofuel.
So chopping down a forest to create fields is bad in the short term since it releases and does not recapture the CO2 from the trees, but is sustainable in the long term since you “recycle” the same Carbon.
Some quick searching gave me around 100 tons of carbon for 1 ha of forest and around 5 m^3 of biofuel per year for the same area of arable land. I.e. one liter of biofuel initially releases 20 kg of carbon or around 60 kg of CO2. So biofuel starts to be better for the CO2 levels after about 20 years?
Almost, yes. It should be close enough as an estimate.
If you want to be precise, one thing you want to be careful about is that not every fuel releases the same amount of energy per kg of CO2. So you should be comparing to the CO2 released by whatever is being replaced by the biofuel (most likely fossil fuel), not the biofuel itself.
Another consideration is how much CO2 is released by the production of the biofuel compared to what it is replacing. Since farming equipment, transportation etc. all could produce CO2.