People dramatically over weight how bad plastic is for the environment. The impact of a 10 min car ride = 10,000+ plastic bags of emissions. And in first world countries almost no household plastic ends up in the environment.
Can't imagine this survives napkin scrutiny. A ten mile drive isn't using nearly as much hydrocarbon mass as 10k plastic bags. While most of the plastic hopefully winds up in a landfill, most of the gasoline is water and carbon dioxide by the end. It's tires versus bags. While tires shed, the mass lost in 10min is definitely quite a bit lower than 10k bags or the fraction that escapes the waste pipeline.
30mpg, 10 miles, means two pounds of gasoline, 910grams, knock off or add 100g for ethanol per your preference, a google says about 5grams per bag, so nearly 200 bags.
Nowhere close to 10k, but nontrivial. And, this gets reduced and sometimes outright negated if you reuse the bag. Doesn't mean we shouldn't evaluate if plastic shopping bags are the beat choice though.
I don't think replacing them with store bought doggy poo and cat litter bags is better. It's not a reduction and theres no reuse. If you find yourself discarding them outright, then find an alternative I guess.
Don’t forget that a lot of carbon went in to making the road, the parking (deforestation or other land destruction for those should be considered too), the car itself, emissions from tyre wear, brake dust, some plastic for the single use medical devices necessitated by treatment of people struck by drivers, etc etc.
Though what is often forgotten is the insane amounts of plastic used in farming. Occlusion fabric for weeds, polytunnel skins, silage wrap, etc
I think the units there are off, a Camry hybrid is about 100g direct CO2 per km. One widely repeated calculation has total direct + indirect emissions for a grocery bag at 200g. So 1km driven vs 1 bag is a similar magnitude of emissions.
Please be careful of such "metrics/statistics." Their very nature means they're politically and financially incentivized lean towards a higher or lower number than "the other guy." And, of course, a big number is scarier in a vacuum. What if a paper bag is 250g of emissions?
The poster child for me for this is low-GWP refrigerants. Sounds good, right? Well, think about how CO2 captured filtered and compressed compares. I'll leave everybody to argue with their-self on this. Does co2 vs r-whatever use more energy? Less? Does it somehow justify the emissions and pollution of manufacture?
We have enough data to estimate the reasonable range of possibilities and exclude the upthread assertion that a ten minute car ride is similar emissions to 10k plastic bags. A degree of uncertainty need not make us helpless in the face of loud ignorance, that's how we end up giving equal weight in the media to common consensus of professionals in whatever field and political operatives with fringe beliefs but no evidence.
As for a kilo of gas per 10 miles- see https://en.m.wikipedia.org/wiki/Gasoline - says 0.71-0.77g/mL, standard conversion table says 3.785L per gallon. (https://www.engineeringtoolbox.com/volume-units-converter-d_...), and finally- since we're comparing burning gas for a car vs using it in plastic: the figure of merit is petroleum usage, not greenhouse gas emission. Technically, plastic and gasoline aren't going to be 1:1. But that's not napkin math anymore unless you're a petroleum engineer/chemist.
Where did I say that? I was only responding to the assertion "in first world countries almost no household plastic ends up in the environment" pointing out that I see it everywhere.
>People dramatically over weight how bad plastic is for the environment.
I can only give a: what in the fuck are you talking about?? Modern medicine is literally finding microplastics in men's testes. "People" are dramatically underestimating how completely and utterly screwed the next dozen generations of humanity are with the plastic waste we've blanketed the earth in. Assuming humans survive that long.
Sure plastic aren't great for the environment when we're just dumping it out there without much care. Obviously reducing waste and reusing is what we should strive for on all fronts. Demonizing one thing results in overcompensation on the flip side and we know for a fact that that's not where we want to end up either. Remember when we tried to reduce paper use as much as possible because of deforestation? Or saturated fats?
At least microplastics don't make you angry and violent that we can tell.
On the other hand, it's going to be around (relative to pre-emission levels) for a lot longer than the lead (paint gets chipped off and disposed of, we stopped using it in end-consumer products, etc)