| General > General Technical Chat |
| heartbroken that John Clauser seems to have joined climate change denial. |
| << < (20/67) > >> |
| vad:
--- Quote from: tom66 on August 02, 2023, 03:11:41 pm --- --- Quote from: vad on August 02, 2023, 02:38:23 pm ---The climate has always been changing. That is a well-known fact. --- End quote --- Nobody is arguing otherwise, but climate skeptics love their strawmen with this statement. The question is not whether the climate is warming or cooling, but whether it is warming or cooling too much, and it appears that it is, and that humans are the direct cause of the vast majority of that warming. --- End quote --- Claiming that there is 'too much' warming is an unscientific statement. Climate alarmists usually support such statements by comparing the current temperatures to cherry-picked points in time when the annual average atmospheric temperature was at its minimum in the history of observations or by referencing cherry-picked minimum estimates of historical temperatures before systematic instrumental readings began. Additionally, when presenting estimated historical data, the alarmists conveniently omit showing error ranges on hockey stick charts, which can impact the overall perspective of the data. As a physicist by education, I find it concerning when someone who claims to be a scientist presents their measurements or model predictions without including error bars on their charts. --- Quote from: tom66 on August 02, 2023, 03:11:41 pm --- --- Quote from: vad on August 02, 2023, 02:38:23 pm ---I do not see how burning hydrocarbons to mine, refine and transport elements for EV battery production helps in reducing CO2 emissions. --- End quote --- Surely you can see the simple relation of fixed cost + ongoing cost, it is not just a fixed cost. Call it K1+nK2, and K3+nK4 is cost of fossil car, both sum of manufacturing and running emissions over 'n' years, if K1+nK2 is less than K3+nK4 then extra CO2 emissions to produce EV batteries can be a net winner. In Europe the figure 'n' is about 2-3 years for EV batteries. In China it is closer to 3-4 years due to higher levels of coal on Chinese powergrid. Still, a car lasts ~15 years, so generally a winner. --- End quote --- Indeed, the question of the million (or billion) tons of CO2 is closely tied to the K1...K4 factors. However, we must approach the estimates provided by BEV manufacturers' lobby with caution as they may not be entirely reliable. Independent sources suggest that accurate estimations are challenging, often leading to wide ranges for the carbon footprint of BEV batteries. Some estimates place the carbon footprint at around 100-200 kg of CO2 per kWh of battery. Taking the average value of 150 kg/kWh, we can calculate that a typical small sedan BEV, like the Tesla Model 3 with an 82 kWh battery, emits approximately 12 metric tons of CO2 during the production of its battery. To put this in perspective, burning one gallon of petrol produces about 9 kg of CO2. Thus, the production of the Model 3's battery is equivalent to burning about 1,300 gallons of petrol. Comparing this to a modern ICE vehicle, like the VW Jetta with a mileage of 35 mpg, it would drive about 45,000 miles (approximately 75,000 km) on 1,300 gallons of petrol. Considering that the average annual mileage driven in the EU is 11,300 km, a brand new Tesla Model 3 causes as much CO2 pollution as the average similar-sized car in the EU over a span of 6.5 years. In China, the time frame is also 6.5 years, while in the US, it's 3.5 years. However, it's important to remember that we have only addressed the impact of K1 and K3 variances here. K2 and K4 remain unexplored factors. In countries like China, Russia, and India, where fossil fuels dominate electric generation, Tesla is unlikely to catch up with comparable ICE vehicles before the battery needs replacement or the vehicle is scrapped. Furthermore, we must not ignore the additional resources required for BEV infrastructure, such as new generation plants, charging stations, grid enhancements, transformer upgrades, etc. This leads to doubts about whether the BEV revolution will significantly reduce the carbon footprint of car transportation at all. If you, unlike me, are concerned about CO2 emissions and believe that moderate climate warming is harmful to the planet, it's worth considering the implications before investing in a BEV. Choosing to keep your current ICE vehicle may at least spread the release of CO2 over many years. |
| Siwastaja:
--- Quote from: nctnico on August 02, 2023, 06:46:39 pm ---It is not pseudo science, it is a snapshot. A long time ago people thought the earth was flat (snapshot 1), then they realised that based on scientific evidence the earth is a sphere (snapshot 2). After another while due to improvement measurement techniques it turns out the earth is not a perfect sphere, but sphere shaped (snapshot 3). How close to a perfect sphere? Last time I checked nobody seems to know. --- End quote --- Now here's the thing: during snapshot 1, if you wrote a paper which disagreed with "scientific consensus" of earth being flat, you were "cancelled". During snapshots 2 and 3, this was not the case anymore; the driving reason why we were able to create a better model and understand the Earth was a sphere was the change in attitudes, allowing differing viewpoints no matter how ridiculous and against the consensus they could have been. Now during our current snapshot, we are getting back in the middle ages. That's my point, this "strong consensus" through political / social means is both old and new thing, but IMHO doesn't belong to science, and actually hinders the process of creating a better model of the truth. Yes! Ignoring what I personally think is the truth and just looking at the discussion dynamics and scientific process, I'm really saying sphere-earthists of the middle ages were the climate change denials of today: both were/are being silenced because the "scientific community" is so damn sure about their own right-being, because otherwise is a disgrace. But we can choose to disagree. |
| Siwastaja:
--- Quote from: PlainName on August 02, 2023, 08:09:22 pm ---Plastic is generally made from a finite resource, isn't it? So 'recycling into energy' would be a net loss and we'd have to make more of it. --- End quote --- The point is: we are burning massive amounts of fossil fuels anyway. Any even remotely realistic model is only about reducing this amount, maybe even significantly, maybe even by 90%. And you don't have to go to zero fossil fuels to solve the CO2 issue, that's just ridiculous. When we accept this premise, then recycling plastic as energy directly offsets the need of burning similar amount of raw fossil fuel, bringing net loss of the material itself to zero. What remains is the environmental cost (mostly energy) of turning oil into a finished plastic product, but I think it's probably even less than turning wood into a paper straw (I think the chemical process of making plastics is not that energy intensive; it's only the material itself which contains a lot of energy; I could be wrong). --- Quote ---In contrast, paper is pretty much zero sum in that the waste can be used to grow more --- End quote --- This paper waste recycles poorly in practice. It ends up mixed with biowaste, plastic, metal and whatever, gets wet and smushy, and just decays somewhere, releasing the CO2 into the atmosphere (this is even the advertised point, biodegradability). Which then surely can be used to grow more trees, but then again the same people who call for paper straws also call stopping using the forests for paper production, because, and I can very well understand their point, it is easy to just cut more forest than you plant. Recycling newspapers etc. seems to work quite well at least here, but paper straws are not even allowed in the same process and even if they were no one would collect them separately, they go in mixed waste. --- Quote ---Whatever, the massive garbage patch in the middle of the Pacific doesn't seem to have much paper since it's biodegradable, but there is lots of plastic. --- End quote --- Yet, plastic as used by me never ever goes there. This is exactly like saying knives must be banned because some people commit crimes with them. The problem is, even if we reduce plastic use, those who put their plastic into the Pacific won't do that. --- Quote ---If the root problem is that we're not turning plastic into energy then we surely need to start doing that. --- End quote --- It's not the root problem; this is a tiny distraction, it's a tertiary thing to optimize; yet I again made the mistake of going on with this discussion. In reality we should really concentrate on HVAC and transport primarily, and industrial and agricultural processes secondarily. Everything else is too small to matter. Amdahl's law applies here, too! People think that combining many small action makes a total large impact, but this depends on how small those actions are and how many of them. These tertiary-class actions of "plastic straw replacement" size are simply too small, even if they were as effective as imagined. --- Quote ---2,000,000,000Kg --- End quote --- You have one zero too much. Still a lot of course, just a nitpick. |
| Siwastaja:
--- Quote from: vad on August 03, 2023, 04:42:08 am ---Comparing this to a modern ICE vehicle, like the VW Jetta with a mileage of 35 mpg, it would drive about 45,000 miles (approximately 75,000 km) on 1,300 gallons of petrol. Considering that the average annual mileage driven in the EU is 11,300 km, a brand new Tesla Model 3 causes as much CO2 pollution as the average similar-sized car in the EU over a span of 6.5 years. In China, the time frame is also 6.5 years, while in the US, it's 3.5 years. --- End quote --- This calculation seems roughly correct, there seems to be some sort of scientific consensus ( ;D ) of replacing ICE cars with equivalent EVs offers some 30-50% reduction in total lifecycle CO2, depending on source (ignoring biased sourced like oil or EV industry, which of course give numbers outside of this range). It's something, but it's not that much. It's especially problematic if and when small ICE cars are replaced with larger luxury EVs, as the difference goes to basically zero. Personally, I'm driving a 1996 state of art in low fuel consumption vehicle which in my use gets 5.5l/100km = 43mpg, and all EVs I have been looking at have significantly more weight and frontal area so keeping the old one alive by welding rusty spots to pass inspections every year while waiting for EVs to get even better than they already are seems environmentally a sane choice. |
| tszaboo:
--- Quote from: EEVblog on August 03, 2023, 03:56:17 am ---Also, when it comes to "global warming", has anyone stopped to consider the ultimate technical question, can we actually measure and track the temperature of the the globe accurately? How do we know we are doing it accurately? How accurately exactly? NOTE: I am NOT syaing that the globe is not warming, I'm just asking the technical question, how do we measure this, and with what degree of precision and reliability. Because, AFAIK, everything hinges on that. And maybe, is it excessive technical hubris to think we can even do that at all? --- End quote --- We have, that's the big satellite debacle. The temperature measurement satellites had a slight upward temperature drift in their measurement of temperature. The engineers calibrated the new sat correctly, sent it up, and there was a downward jump in temperature. So the climate scientists said, we cannot have that, corrected it so the data is continuous. And then the new sat started drifting. We are not talking about large drifts here, its in the order of 0.05K/decade, but it's enough to completely mess up any climate model. It's likely in the local two point calibration system, but they actually don't know what's causing it. You are engineers, so here is a challenge: Show me a circuit that would be able to do local measurements with 0.05K/decade noncertainty. Measure a PT1000 and guarantee that drift for 10 years. |
| Navigation |
| Message Index |
| Next page |
| Previous page |