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Air Travel Emissions Vastly Outpace Predictions

nytimes.com

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Re: Air Travel Emissions Vastly Outpace Predictions

#221

Post by coryrc »

flavor8 wrote: post #132
ddxxdd wrote: post #107

Earlier quoted context omitted.

I have repeatedly heard scientists say that planting 1 trillion trees will singlehandedly set climate change back 10 years. I've done the math on that myself and found that such a plan is about 5000 times more cost-effective than driving Tesla vehicles: https://news.ycombinator.com/item?id=19714034 Anytime anybody says anything about the social cost of carbon being greater than $0.50 per ton, I just tune them out.

On what timescale? I.e. trees take time to grow and accumulate carbon. As I understand it, the climate clock is ticking - there's a threshold beyond which some runaway effects kick in.

Growing is the only time they collect carbon. We could plant enough trees to zero out carbon usage (for now).

Re: Air Travel Emissions Vastly Outpace Predictions

#222

Post by snowwrestler »

loeg wrote: post #150
blunte wrote: post #136

If you need to travel long distances, there's little substitute for an airplane. If air travel accounts for less emissions than passenger cars, and if the top 15 polluting large container ships produce as much (noxious oxides of nitrogen and sulphur) pollution as all cars, then we need to fix shipping first. And if you look at a lot of the crap that is being shipped, it's stuff we just don't need. A lot of things are…

(And little substitute for burning hydrocarbons as airplane propellant. Energy density and stuff like fire safety really really matters in aviation.) Totally agree that air travel is one of the last places to look for carbon savings. That said, carbon offset taxes should be applied where they are not already. The market can price this cost in and judge whether the value is there, if the incentives are structured corr…

An area of research that I don't hear much about is creating hydrocarbon fuels for applications that really need them, like airplanes. Essentially, using hydrocarbons as a chemical battery instead of an out-of-the-ground energy source.

As with any contributor to climate change, the issue is not burning the fuel, the issue is that the fuel is bringing new carbon out of the ground into today's carbon cycle. Hydrocarbons generated in real time from carbon currently in the environment, using carbon-free energy[1], would not contribute to global warming.

The chemistry is complicated and presumably it would take a tremendous amount of energy to do so. I think I read that the Navy was exploring it for aircraft carriers--which have plenty of energy thanks to redundant nuclear power plants onboard, and obviously would benefit from being able to generate more jet fuel whenever they need it.

[1] I know there is not really such a thing yet; nuclear, wind, even solar panels take fossil fuel to make today. But in theory man-made jet fuel would decouple the end use from the generation, allowing planes to keep flying the same way they always have, while cleaner fuel generation could incrementally supplant new oil in the supply chain.

Re: Air Travel Emissions Vastly Outpace Predictions

#223

Post by js8 »

TulliusCicero wrote: post #191
mehrdadn wrote: post #143

Earlier quoted context omitted.

> If you need to travel long distances, there's little substitute for an airplane. The emphasis here isn't on substitute, it's on "need". Not many people need to travel long distances on a regular basis; they're just made to believe they need do.

People traveling, the tourism that is so often bemoaned, is a huge part of the connections between countries, a huge part of diversity and understanding. A world with greatly reduced air travel is a more insular and less understanding world.

> A world with greatly reduced air travel is a more insular and less understanding world.

I don't think there is an evidence for that. It is more likely that immigration increases cultural understanding rather than travel.

In any case, emissions of travel can be greatly reduced by using other modes of transport and by making the stay in the target country longer. Such a cultural shift could actually even improve the understanding between nations.

Re: Air Travel Emissions Vastly Outpace Predictions

#224

Post by sokoloff »

mehrdadn wrote: post #211
sokoloff wrote: post #190

Earlier quoted context omitted.

Vastly more business travel is done for sales or sales-support purposes than attending conference purposes. Humans are tribal animals; we respond to communications in person better than over video conference and we tend to trust people with whom we've shared meals and drinks. Arguing that that just shouldn't be isn't likely to change anything about business behavior. I get on airplanes across oceans because it's effe…

Well, to be blunt, so what? That sucks for sales stuff, it's not like I said conferences are the only things that need to change. Maybe the practices there need to change there just like for conferences and other stuff. Nobody said it's easy or nice or effective or whatever for humans to do long distance. Just that you need to start sacrificing somewhere and I sure as heck find it more reasonable and humane to start…

"So what?" Incentives. If subgroup A doesn't travel for sales, subgroup B who travels will likely outcompete them by more than the cost of the travel, or subgroup C who is large enough to have many local offices will outcompete A, making it harder for new entrants to a market to compete and concentrating business activities in select cities (which is great if you're rich enough to live in those prosperous cities).

I'm not making moral value judgments here; I'm making economic value judgments as that drives much more behavior I think.

Re: Air Travel Emissions Vastly Outpace Predictions

#225

Post by m4rtink »

asdfadsfgfdda wrote: post #176
misiti3780 wrote: post #2

"Over all, air travel accounts for about 2.5 percent of global carbon dioxide emissions — a far smaller share than emissions from passenger cars or power plants." 2.5% means we should focus on reducing somewhere else in the near term.

And imagine all of the benefits we get from only 2.5%. More migration - the smartest researchers in photovoltaics can move to a city where they can make a bigger impact, and still visit their families. Even without migrating, researchers can collaborate across continents. Increases economic productivity - when production stops at a nuclear plant, you can fly in parts/personnel quickly. Economic development - if you c…

Not to mention people learning more about other countries, people and cultures from personal experience.

This can make them more rational and less prone to manipulation & hysteria than if they never left the town or country they were born in.

Re: Air Travel Emissions Vastly Outpace Predictions

#226

Post by TheGallopedHigh »

phkahler wrote: post #68
misiti3780 wrote: post #2

"Over all, air travel accounts for about 2.5 percent of global carbon dioxide emissions — a far smaller share than emissions from passenger cars or power plants." 2.5% means we should focus on reducing somewhere else in the near term.

Air travel is more important because of the water vapor far more than the carbon. The week following 9/11 was dramatically different. NASA recorded the change in daily temperature range. Less significantly, we had crystal clear skys where I live - for a week! Water vapor can also seed cloud formation. Air travel causes a daily cycle in this, which might just keep more heat in at night. You can look at data and see th…

Note also that cloud cover increases albedo, namely how much light is reflected back to outer space. Does that mean contrails are good for the environment? Probably not, but this a very complicated system that one can’t make simple statements without sitting down and doing the math.

Re: Air Travel Emissions Vastly Outpace Predictions

#227

Post by andrepd »

martamoreno2 wrote: post #8

2.5% eh? We should all immediately stop flying... This is outrageous. Just imagine, 2.5%!! But on a more serious note, this article is again wrong, like so many others about climate change. Being a combination of clickbait and false assumptions, it fails to miss the point entirely that first, 2.5% are irrelevant, but also that it makes no sense whatsoever to tackle this now. The technology is just not there yet. What…

What about fusion power? It's the dream energy source: the fuel is seawater, the waste is slightly lighter seawater. It seems the perfect target for a Manhattan project/moonshot sort of effort. Giving several teams with competing designs $100B each to develop and test their reactor, in parallel. The potential benefit of near-free clean energy is so absolutely world-changing that it seems worth it to spend on the order of hundreds of billions of dollars to develop it.

Re: Air Travel Emissions Vastly Outpace Predictions

#228

Post by phkahler »

andreasley wrote: post #105
wmf wrote: post #95

Earlier quoted context omitted.

https://web.archive.org/web/20160411094048/http://www.atmos.... https://www.nature.com/news/2008/081231/full/news.2008.1335....

The second link actually states the opposite: "A new analysis now claims that altered US temperature patterns during the three flight-free days can be explained by natural variations in cloud cover, rather than the absence of planes."

But that's not conclusive either. There is this:

The research by Hong and his colleagues, published in Geophysical Research Letters, follows other studies arguing that the September 2001 temperature variations can be explained by the clear, dry weather on the crucial days4, and that climate-modelling results do not support the contrail effects claimed by Travis's group5.

I contend the clear dry weather was a consequence of the lack of planes. It sounds the one of the original authors does too.

All I know is the weather here was beautiful. And very uncharacteristically so. Unfortunately nobody is going to repeat the experiment by grounding the entire fleet for 3 days just to test it.

Re: Air Travel Emissions Vastly Outpace Predictions

#229

Post by wongarsu »

js8 wrote: post #219
blunte wrote: post #136

If you need to travel long distances, there's little substitute for an airplane. If air travel accounts for less emissions than passenger cars, and if the top 15 polluting large container ships produce as much (noxious oxides of nitrogen and sulphur) pollution as all cars, then we need to fix shipping first. And if you look at a lot of the crap that is being shipped, it's stuff we just don't need. A lot of things are…

Actually, there are substitutes. People who need to travel (and most of them don't) can just use trains or ships, and make the overall stay longer (decreasing overall number of trips). It was already possible more than 100 years ago, and it would be much less of a problem in today's digital economy.

Trains are an option, but ships seem equally bad or worse than planes for transporting people

Re: Air Travel Emissions Vastly Outpace Predictions

#230

Post by m4rtink »

elihu wrote: post #149
WhompingWindows wrote: post #103

Earlier quoted context omitted.

Near term, we should be slamming money into batteries and energy density of said batteries, if we want to decarbonize air-travel. Electric planes have numerous advantages, but jet fuel is just so much more energy dense than a battery at the current juncture. Hopefully by 2050, we will be able to scale up from smaller electric airplanes in the 2020-2030 timeframe, such that jet liners will be decarbonized too.

It seems to me that synthetic or plant-based carbon-neutral fuels are more feasible in the near-term, though I don't know what the current state of the art is. In the long term, electric planes would be ideal if we can figure out energy storage (or perhaps wireless energy transmission).

This is ideal - if you use a C02 neutral power source & use atmospheric CO2 (either directly or via plants) you are effectively making planes flow battery powered.

With the flow battery using synthetic fuel you produce & atmospheric oxygen to produce energy & CO2. Which will then get captured again by your synthetic fuel factory.

Win win. :)

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