• oleorun@lemmy.fan
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      1 year ago

      Density reduces emissions

      I reply to your infographic with a scientific paper that shows higher densities lead to higher CO2 emissions: https://www.mdpi.com/2073-4433/12/9/1193#:~:text=Regarding CO2 emissions%2C the,density%2C the higher the emissions.

      This study was done in Spain.

      Another study, in Nature, also shows that lower density is better for reducing carbon emissions and climate change. https://www.nature.com/articles/s42949-021-00034-w

      Sorry, but you and your infographic/sources are not supported by science.

      • baseless_discourse@mander.xyz
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        1 year ago

        Literally the frist sentence in the abstract:

        More than 50% of the world’s population lives in cities. Its buildings consume more than a third of the energy and generate 40% of the emissions.

        “higher densities lead to higher CO2 emissions” you say…

      • Nouveau_Burnswick@lemmy.world
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        1 year ago

        The low density/low height example in the nature article is still 5k people per Km^2. While definitions vary wildly, I usually see 1000-400 people per km^2 for suburb definitions.

        Does example D look like suburbs to you? As something undefined it could be considered suburbs, but probably “streetcar suburb” in the Canadian/American context.

        Critically the article also mentions a requirement for best practice greenery management to maximize carbon sequestration. I’m no botanist, but I’m guessing caretaken parks do better then monoculture lawns (assumption).

        Edit: missed that the first link was a different study. That like on spanish cities has its lowest density group defined as <100 pop/hectare, if my math is right, that means <10,000 pop/km^2. Significantly denser than any suburb. This is also a region when thermal energy is spent of cooling, not heating. And while it adjusts for climate effect, it doesn’t seem to adjust for the modernity/thermal effectiveness of the buildings. Such to say, a building with an air-conditioner will spend more thermal energy than one without.

        Basically your two links are showing that cities can be too dense, and there is a point when they lose GHg efficiency. There is no mention of anything lower than what, as a Canadian, I would still call high density (just not super high density).

        • Fried_out_Kombi@lemmy.worldOPM
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          1 year ago

          It’d probably depend on the park and how it’s designed/managed, but I’d be shocked if monocultured lawns sequestered any carbon. I know in agriculture it’s a huge problem that industrially-grown monocultures – where they till the soil and crop-dust fertilizers and pesticides and herbicides and fungicides – emit huge amounts of previously-sequestered soil carbon. A result is that doing the reverse – i.e., growing food regeneratively in polycultures and without tillage and artificial fertilizers and without all the -icides – is considered a good way to sequester carbon.

          Considering we grow grass lawns similarly to how we grow corn monocultures, I’d bet grass lawns are similarly awful for the soil and thus the climate as well.

          • Nouveau_Burnswick@lemmy.world
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            1 year ago

            I’m obviously biased by the parks I live near and see/use every day, but when I think of a park, I think of tree’d sitting areas, tree’d play areas, tree’d walking paths, and some monoculture sports fields, with trees for the stands.

            There are lost of community gardens around, but as a black thumb I don’t use them and bias them out.

            Basically my city has a hard on for trees in parks, and I’m all for it. I also think I’ve developed a bias that roads have no trees, and streets have trees.

      • Fried_out_Kombi@lemmy.worldOPM
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        1 year ago

        https://coolclimate.org/maps

        Feel free to zoom in on essentially every city in America. You can even download the raw data yourself.

        Further, your Nature study you link, actually read the paper and you find this nugget:

        These limiting assumptions were necessary based upon the urban scale scope of this study. Providing additional levels of detail at the building scale would greatly improve the accuracy of the analysis and can be refined in future works. Employing a cradle-to-cradle approach to consider resource reuse, the impact of retrofitting existing building stock over rebuilding; the inclusion of transportation impacts; adding a dynamic time component to investigate material inflows and outflows; and including a detailed time-related analysis of carbon sequestration potential offered by urban greeneries in the simulated environments—are all valuable and important avenues for future work to build on this study and expand its relevance while reducing its limitations. This study therefore acts as a stepping-stone to provide a strong foundation from which extensive future work can be born.

        It literally doesn’t even model transportation emissions. Considering this whole conversation is about sprawl causing more cars, this is kinda a glaring omission.

      • ForgetPrimacy@lemmygrad.ml
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        1 year ago

        I’d like to come back and read over this later. The point OP is making seems pretty obvious but it is quite directly contradicted by the sources you just provided. I want to read those later

        • Fried_out_Kombi@lemmy.worldOPM
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          1 year ago

          From a quick read of the Nature article they posted:

          These limiting assumptions were necessary based upon the urban scale scope of this study. Providing additional levels of detail at the building scale would greatly improve the accuracy of the analysis and can be refined in future works. Employing a cradle-to-cradle approach to consider resource reuse, the impact of retrofitting existing building stock over rebuilding; the inclusion of transportation impacts; adding a dynamic time component to investigate material inflows and outflows; and including a detailed time-related analysis of carbon sequestration potential offered by urban greeneries in the simulated environments—are all valuable and important avenues for future work to build on this study and expand its relevance while reducing its limitations. This study therefore acts as a stepping-stone to provide a strong foundation from which extensive future work can be born.

          It doesn’t even model transportation emissions, which kinda makes it worthless in the context of this discussion.

          As for Spain, does Spain even have much “suburbia” as we understand it in a North American context? Data for cities in Spain may have nothing to say about the emissions of suburban sprawl vs denser communities, which is what the OP is mainly about.