|
>a lot of insight. so nuclear has the potential but isnt there
>yet? with more research we expect we could get there but how
>soon would that be? i might have misunderstood you on this.
>
>i know on reddit a lot of people were saying the candidates
>need to embrace nuclear if theyre serious. is nuclear
>something that could work for us now if we went with it?
Well, nuclear can mean two things. Nuclear fission (the kind that's done with Uranium in giant cooling towers) has existed since the fifties and could go a major fraction of the way toward solving the problem, but at a cost.
The main cost is waste --- what to do with all the highly radioactive depleted uranium that's left over. There isn't a perfect solution to this. But some are better than others. The standard solution is to build a massive repository deep underground. It's actually relatively straightforward to calculate how thick the walls of such a facility would have to be to store any given amount safely.
But there an understandable NIMBY problem here ("not in my back yard"). Nobody wants to be the state with the massive nuclear waste dump. Specifically, plans have been in place for decades to build a facility under Yucca Mountain in Nevada. Then Harry Reid (whom I generally admire as much as any politician) became Senate Majority Leader and put an end to that. Even now that he's out of politics and a different party is in power, the status of Yucca Mountain is still very much in limbo.
As a result, fission facilities are storing their waste on-site, which is vastly more ecologically hazardous (though again, they are regulated to shield it very heavily).
Then there's the other NIMBY issue of transporting nuclear waste to Yucca Mountain, even if it did become a reality. That's a more reasonable concern, as far as I'm aware. We don't want truck accidents to turn into the equivalent of a "dirty bomb." It would be relatively straightforward to ensure safety in this process under today's conditions, but then there's the other problem...
We burn A LOT of fossil fuels. I saw an expert give a talk at a physics conference a few years ago about the feasibility of replacing our fossil fuel budget entirely with nuclear. The takeaway was that it *IS* possible. HOWEVER, in order to do it in time to reduce all current fossil fuel use by standard target dates, we'd have to build a new fission power plant, somewhere in the country, something like once per MONTH. (I could be getting that number wrong. My memory is hazy. But I remember it was a frequent enough rate that there were gasps in the audience, especially since this was a very good physics talk and he backed up all his arguments with very clear numbers.)
Whereas, if you look at the list of plants in the US, it takes a very sharp eye to find a plant that entered operation since 1990. (I count one.)
https://en.wikipedia.org/wiki/Nuclear_power_in_the_United_States#Nuclear_power_plants
This isn't entirely surprising. Not only are people afraid of fission plants (and they shouldn't be, really --- there have been more deaths and injuries per kilowatt-hour in both the coal and fossil fuel industries), but they're also really fucking expensive to build. And they need to be -- those expenses go into satisfying very strict regulatory requirements that most definitely serve a purpose.
The OTHER nuclear that gets talked about is nuclear fusion. Roughly speaking, this means superheating hydrogen atoms to get them to merge and form helium atoms. The process, if it could work, is fucking magical. The fuel is literally water (preferably OCEAN water, in fact, though the quantities needed are small enough that we wouldn't even notice it), and the "waste" is inert helium gas. The full story could be more complicated (in particular, some elements of the material that houses the reaction could become radioactive due to the extreme temperatures), but the energy that comes from it is so abundant it's almost like we're getting energy for free. Moreover, it's an inherently safe process because it's not based on a self-sustaining chain reaction like fission is. If there were an accident, yeah there might be a big ugly explosion, but the energy would dissipate like in any other explosion and the material that's leaked would not be radioactive (at least not significantly so).
The problem is, we've understood the basic science of this for 70 years, and we've had very promising progress on the engineering for about 60 years. For all that time, people have thought fusion power was about 10 years off, but there's always been another challenge around every corner. Perhaps we get lucky and it all falls into place THIS decade instead of all the others. But it would be wishful thinking to expect that.
>considering both your responses i think its pretty obvious we
>need to find ways to be more efficient about the energy we
>use. i dont know if thats easier/quicker than transitioning
>fully to carbon free energy but it would definitely help
>right? if we use less energy than it gets less complicated.
Definitely. But that WILL be painful. And even those of us who understand the problem on a logical level are still unwilling to give up things like world travel (myself included), local travel (even electric cars, when all is accounted for, aren't really much more CO_2 efficient than gasoline cars), or eating meat.
There's also the problem that we don't have a clear accounting of what costs what, energy-wise. Case in point: we've all gotten in the habit of using reusable grocery bags. It's very easy to think that using a single-use plastic bag and throwing it away when you get home is worse "for the environment" than a reusable bag. And in some ways it is (the health of the oceans, mainly). But as far as climate is concerned, the energy that goes into making a reusable grocery bag is so much higher than the energy to make a single-use bag that you'd have to reuse the bag thousands of times to even break even; often more times than the reusable bags are strong enough to survive anyway. And besides, if we need to do all this in the next 10 to 20 years, do you really go to the store enough that you'd reach the break-even point by the target date when we're we're trying to "address" the climate crisis? For most people, single-use plastic bags are actually BETTER for the climate than the reusable bags that we THINK mean we're "doing our part."
Similar story with some aspects of recycling. We were told years ago that it was good for the environment to recycle. And again, in some ways it is. But we were lured into this modern world with two cans and two pickups by a purely ECONOMIC force that really didn't care much about climate or even the environment. Chinese companies wanted to save money on source materials (especially plastic), so they started building plants to recycle it. And for a good 20 years or so every city in the US had a recycling program that would just take mixed materials, sort them, and send them off to be dealt with, usually at these Chinese facilities.
But here's where it gets tricky. The energy needed to CLEAN plastic to prepare it for recycling, plus the recycling itself, is actually in most cases GREATER than the energy to produce new plastic. And in the end this means the CO_2 cost of recycling plastic is GREATER than the CO_2 cost of creating new plastic. And if we want to say, "Well I'll be especially good and make sure I wash out my recyclables COMPLETELY before I put them in the bin," turns out that doesn't work. The energy that YOU use, at your own sink, rinsing out your jars with warm water is actually even greater than the energy that would have been used at one of these Chinese recycling plants.
Now, to add further insult to injury, I say "would have been used" for a reason. Those Chinese plants that sprang up in the 90s to handle the American plastic goods? Well now the economics have changed. The many of those plants have shut down over the years, and lately the Chinese government has changed the rules in such a way that it's impossible to import most of those recyclables to their plants for recycling anyway.
The result of this: nearly all of the plastic that we carefully separate out and put in the recycling bin, goes to some nearby recycling center that in the past would have prepared it for shipment. But they can't do that anymore, so they send it to the local landfill.
And that private company (Republic Services or whoever) only stays in business if somebody pays them. These Chinese facilities aren't paying for the plastic anymore. So either they squeak by on the handling of other recyclables (metals are still very recyclable; paper is about even-money as far as I'm aware), or the city government subsidizes them to stay in business just so that the citizens can have a "recycling" program. They want it so that they can *think* they're "doing their part."
Only it happens to be a recycling program that spends a great deal of its effort carrying plastic to the landfill in a separate truck but still on the city's dime.
And as ridiculous as it sounds (and it's just as ridiculous as it sounds), this actually REDUCES greenhouse gas emissions, because again, recycling plastic has higher carbon cost than dumping it and making it new.
>in case its not clear im asking most of my questions on this
>from ignorance. the more i read about this the more i see i
>dont know much.
Hey, me too. I'm supposedly an expert on a lot of things tangentially related to all this, but I'm still learning it too. I didn't know all this shit about plastic until a year or two ago. Part of the problem is that A LOT of it is very counterintuitive.
One thing that I think will inevitably need to be added to the public discussion is geoengineering. This means interfering in the climate AGAIN to try to fix the problems we triggered with all our CO_2. For example, we could release aerosols into the upper atmosphere that would basically "dim the sun," reducing the total amount of incoming solar radiation to counterbalance the stuff that's stuck here due to the greenhouse effect. It would be like artificial volcanoes (or in a less pleasing analogy, intentional nuclear winter, though it wouldn't be nuclear). It probably goes without saying that this would be FUCKING dangerous, because it's easy to overshoot and make matters much much worse. On the other hand, if we know what we're doing, this would be a way to fix the problem AFTER it happens, when the whole of society has the benefit of hindsight. For many years the scientific community intentionally avoided even mentioning that such a thing might be feasible, in part because it would discourage much safer (but more difficult) climate action. But now might be the time to at least ramp up research on the topic. If it comes to that point, we need to know what the fuck we're doing.
|
Printer-friendly copy 
Email this topic to a friend
General Discussion
