4 ms·

Yes, but..... It emits a lot less greenhouse gas right? Even if we only have 100-150 years, that is a long time horizon for us to figure out nuclear fission whi

Yes, but..... It emits a lot less greenhouse gas right? Even if we only have 100-150 years, that is a long time horizon for us to figure out nuclear fission which doesn't use uranium. Our current problem is that we need energy, and we currently have several ways of producing it several of which produce much more green house gas than others. Nuclear looks like a less than ideal solution, but one that we know how to do today, and one that can replace coal/gas in the interim buying time while we get other tech ready to go.

hinkley 5y ago
The embodied energy problem with nuclear plants is nothing to laugh at. The barrier for getting new plants up is going to increase as we tackle the carbon footprint of concrete. At least until someone certifies these new concretes for building nuclear plants.
- foxyv 5y ago
  Nuclear energy offers an excellent source of energy for the production of concrete. I can imagine that a new plant would not take very long for it to offset enough CO2 to make up for the CO2 used in its production. Similar to electric cars and solar panels.
  - hinkley 5y ago
    My understanding was that the processes for replacing fossil fuels in the redox reactions for making cement are still being worked on. Last I heard, one or two companies have rolled one or two of these processes into production, and everyone else is playing wait and see or doing R&D. Some cement plants are reducing their emissions by including fly ash into their mix, and as coal plants wind down across the world, I don't know what other waste streams there are to backfill that, or if in the near term removing coal from our energy mix actually amplifies the percentage of our overall carbon footprint represented by concrete.
    - foxyv 5y ago
      Only about 50% of the CO2 emissions from standard concrete production are an unavoidable byproduct, the rest are from energy generation and transportation. Currently only 8% of CO2 generation is from Concrete. Replacing coke and natural gas as heat sources would reduce that to about 4%. Electricity and heat make up 30%. Transportation is another 15%. I think the target is a 60% reduction. If we can replace electric generation, half of concrete, and transportation that would account for about 49%. The rest is agriculture and methane which are their own headaches. Concrete is probably one of the last things on our CO2 emission hit-list. Kind of an extra credit compared to power generation and transportation. https://www.c2es.org/content/international-emissions/#:~:text=CO2%20accounts%20for%20about%2076%20percent%20of%20total%20greenhouse%20gas%20emissions https://www.c2es.org/content/international-emissions/#:~:tex....
      - hinkley 5y ago
        > Currently only 8% of CO2 generation is from Concrete. So I have this conversation with coworkers all the time. Thinking in fractions of the status quo is a logic trap, and most of us fall into it. As Gretzky famously said, "skate to where the puck is going to be." We need to halve our CO2 emissions. That means concrete is 16% of the target. That is way too large of a fraction to ignore. We will not get where we are going if we don't look at this, and hard. 1/6th of our target is practically a call to action. 8% is more likely to invite foot dragging. If you lose your job and have to change careers, it doesn't matter if your fancy car is 12,15,18% of your current monthly expenses. What matters is that it's now 40% of what you have available to spend, and you simply cannot be spending that much on a car. Getting rid of the car is more important that weening yourself off of a daily Starbucks run, steaks, or starting to use coupons. We cannot be spending 1/6th of all carbon output on concrete. Especially if we're going to make suggestions that involve huge increases on concrete usage. I wish as a species we could all wrap our heads around this. It gets really old explaining to people that they need to look at the thing that is taking 5% of run time because it's "only 5%" when rationally it should be using .25% of resources and thus it's taking 20x as long as it has any right to be. They won't look at it until overall runtime is down 25% and now we are creeping up on double digits. It's a delaying tactic, and we can't wait for other people to do their part before we start on ours. These are not ordered lists.

hinkley 5y ago

The embodied energy problem with nuclear plants is nothing to laugh at. The barrier for getting new plants up is going to increase as we tackle the carbon footprint of concrete. At least until someone certifies these new concretes for building nuclear plants.

foxyv 5y ago
Nuclear energy offers an excellent source of energy for the production of concrete. I can imagine that a new plant would not take very long for it to offset enough CO2 to make up for the CO2 used in its production. Similar to electric cars and solar panels.
- hinkley 5y ago
  My understanding was that the processes for replacing fossil fuels in the redox reactions for making cement are still being worked on. Last I heard, one or two companies have rolled one or two of these processes into production, and everyone else is playing wait and see or doing R&D. Some cement plants are reducing their emissions by including fly ash into their mix, and as coal plants wind down across the world, I don't know what other waste streams there are to backfill that, or if in the near term removing coal from our energy mix actually amplifies the percentage of our overall carbon footprint represented by concrete.
  - foxyv 5y ago
    Only about 50% of the CO2 emissions from standard concrete production are an unavoidable byproduct, the rest are from energy generation and transportation. Currently only 8% of CO2 generation is from Concrete. Replacing coke and natural gas as heat sources would reduce that to about 4%. Electricity and heat make up 30%. Transportation is another 15%. I think the target is a 60% reduction. If we can replace electric generation, half of concrete, and transportation that would account for about 49%. The rest is agriculture and methane which are their own headaches. Concrete is probably one of the last things on our CO2 emission hit-list. Kind of an extra credit compared to power generation and transportation. https://www.c2es.org/content/international-emissions/#:~:text=CO2%20accounts%20for%20about%2076%20percent%20of%20total%20greenhouse%20gas%20emissions https://www.c2es.org/content/international-emissions/#:~:tex....
    - hinkley 5y ago
      > Currently only 8% of CO2 generation is from Concrete. So I have this conversation with coworkers all the time. Thinking in fractions of the status quo is a logic trap, and most of us fall into it. As Gretzky famously said, "skate to where the puck is going to be." We need to halve our CO2 emissions. That means concrete is 16% of the target. That is way too large of a fraction to ignore. We will not get where we are going if we don't look at this, and hard. 1/6th of our target is practically a call to action. 8% is more likely to invite foot dragging. If you lose your job and have to change careers, it doesn't matter if your fancy car is 12,15,18% of your current monthly expenses. What matters is that it's now 40% of what you have available to spend, and you simply cannot be spending that much on a car. Getting rid of the car is more important that weening yourself off of a daily Starbucks run, steaks, or starting to use coupons. We cannot be spending 1/6th of all carbon output on concrete. Especially if we're going to make suggestions that involve huge increases on concrete usage. I wish as a species we could all wrap our heads around this. It gets really old explaining to people that they need to look at the thing that is taking 5% of run time because it's "only 5%" when rationally it should be using .25% of resources and thus it's taking 20x as long as it has any right to be. They won't look at it until overall runtime is down 25% and now we are creeping up on double digits. It's a delaying tactic, and we can't wait for other people to do their part before we start on ours. These are not ordered lists.