That study is making the exact same error I already mentioned: They are counting the embodied energy of the flammable plastic as GWP, while not discounting the energy saved by burning the plastic instead of some other fuel.
They literally cite that as the benefit it provides over landfill. All of the studies, that this is a meta review of, do that. It's just a fact that it releases CO2.
> Similar discretion is needed while comparing the results obtained for the WTE [waste to energy] option
by the four studies. It is known that the incineration process emits greenhouse gases,
but it also generates thermal energy and electricity which can be used as an alternative
to fossil fuel consumption. However, the results indicate that overall, the WTE option
contributes adversely towards the global warming problem, with all high positive impact
values between 50% and 100%. However, all four studies indicated a negative impact value
for AP, indicating that the incineration process is advantageous in reducing the impact of
acidification, making it the second most environmentally friendly method of disposal, and
suitable for disposal of the residues discarded by the MRF process.
The key point being, if you can get your heat or electricity from a non-fossil source, then it's preferable to do so. Because releasing CO2 into the atmosphere is bad for climate change.
But luckily for WTE, the are other aspects that make landfill even worse. Still not as good as recycling, just like all those environmentalists have been saying, correctly, for years. How boringly non-contrarian of them.
That paragraph you quoted is logically inconsistent. I mean think about it - if you are substituting other oil for this plastic, how in the world can your plastic have "100%" GWP?
That would imply they somehow manage to emit double the CO2 that the plastic actually contains. Or they burn it and don't capture any energy at all, so there is no substitution taking place.
And the negative GWP for recycling? That's impossible. Recycling something does not remove CO2 from the air - rather it costs CO2 to do the recycling. I suspect they are subtracting the embodied energy of the plastic to get that figure, which is dishonest.
Sorry, but this "study" is worthless. But it's an excellent example of the sorry state of environmentalism.
29 published Life Cycle Analysis papers from different authors in different reputable journals in different countries all got confused about this, then the meta review that talks in detail about the different assumptions they all made also missed this?
That seems unlikely.
I've never even seen this specific meta review before, I just knew that's what they all said and grabbed the first link I found to a recent one. Feel free to check others, they will all broadly agree because this is fairly boring stuff.
Welcome to the club. Yah, that is the current state of environmental research. It's just junk.
This is why I started this thread with "Because environmentalists have a truly terrible track record.". And this is also why so many people are so distrustful of what "experts" say about this topic.
Environmental research is so dependent on assumptions it's basically impossible to do it honestly. Usually an author will have a goal in mind, then write a paper to reach that goal, and he'll have no trouble doing so - just change an assumption here or there, and you'll be successful.
If you want a way to cut through the nonsense just follow the money: Resources cost money, the method that is cheapest, to a rough approximation, is the one that uses the fewest resources.
