I was wondering how airlines were going to cut emissions. Turns out they're not.

To be clear, the 15-year agreement would not force airlines to cut their pollution. Instead, companies would compensate for any emissions growth after the accord begins in 2020 by buying credits that back renewable energy development, forest preservation or other environmental endeavors.

What a great barrier to competition. If a smaller airline grows, they'll have to buy "credits".

Cap and Trade is political bullshit. If you want to tax carbon emissions, tax the fuel coming out of the ground and let the drillers and diggers pass that on to whomever uses the fuel. It's the only way to be fair about it. Otherwise just accept that this is nothing more than a political game.

Why wouldn't the tax on fuel be a barrier to competition too, under your reasoning? To grow, the smaller airline would need more fuel, and so would be paying more.

Emissions are approximately proportional to fuel use, so I don't see how a tax on fuel (which would be proportional to fuel use) would have any lesser or greater effect than a credit system on emissions (assuming credits needed are proportional to emissions).

If I understand the accord correctly, the difference is existing emissions are grandfathered in/exempt. The offsets are only required on emissions growth (new emissions above current levels). So a new entrant would have to pay the "tax" on all new flights while the legacy carriers only pay on the difference from present flights.

>> Why wouldn't the tax on fuel be a barrier to competition too, under your reasoning? To grow, the smaller airline would need more fuel, and so would be paying more.

Under the proposal, nobody pays anything if they maintain their current emissions. But if a small airline grows and takes market share from a big one, the small one will have to buy credits and the big one will be able to sell credits. The little guy in effect pays the big guy for taking his market share.

If you tax the fuel directly, everyone gets a cost increase right away which they should pass on to their customers. But it doesn't have adverse effects on the free market like the credit system does. You fly more planes, you'll pay more taxes but in proportion to your new revenue so it doesn't really matter.

I think the difference is that under a tax, air travel can still expand without bound as people are willing to pay more for the air travel, but if you cap emissions, then air travel can't expand, regardless of whether people are willing to pay more than the cost of the environmental damage.

(And yes, folks, the environmental damage from any one use is bounded; it can't possibly cost more than the cost to undo that damage. If your model of the environmental damage implies it is infinity, it's just wrong, and it's driving bad policy.)

But it seems like credits needed aren't proportional to emissions, but emissions growth.

Why would you bother making the system more complicated. If it's determined that use of fuel creates emission problems, then just tax it at the start and don't try to worry about every industry to come.

> If you want to tax carbon emissions, tax the fuel coming out of the ground and let the drillers and diggers pass that on to whomever uses the fuel.

Isn't that what cap and trade is? What's the distinction here?

Cap and trade limits emissions, but then allows you to buy off that limit by paying what amounts to a fine, but a fine that is directed at certain uses (sustainable energy, etc.). One could argue it's not really a market based solution to the problem, since unless the "trade" is high enough, there's no real reason to address the actual problem -- emissions. Making fuel more expensive would force companies to adjust to an immediate operating cost, rather than being able to lobby for higher "caps" or lower "trades". You are essentially creating a new market (with its own rules and inefficiencies), instead of trying to manage an existing one.

The problem with taxing the oil coming out of the ground is the incredibly complex nature of an unstable global market that is managed largely by a small number of players artificially controlling the price and a whole futures market trying to hedge against that roller coaster. It's also a market that wars are literally fought over. Finally, it's political suicide since it will impact consumers directly in the amount it costs them to fill their cars instead of indirectly, which they are less likely to blame on oil taxes.

>> The problem with taxing the oil coming out of the ground is the incredibly complex nature of an unstable global market...

Just put a fixed tax per barrel, or per carbon atom, or whatever. The tax shouldn't depend on the price paid for the oil. Just put $1 for every barrel pumped in the US, and every barrel imported and presto - $19M per day of tax revenue ($7B per year) without a major impact to the consumer, and without creating that new market for credits and the associated politics. Do the equivalent for coal and gas too - you know all the carbon sources. People act like passing on a price increase is going to hurt their business, but when everyone has to do it that's not true.

Well, other than the fact that you are oversimplifying a complex issue, I don't necessarily think you are wrong. But just to address some of the possible externalities that would have to be considered:

1. Not all oil that comes into the US is in the form of barrels of crude oil. It may come in refined (a small amount, I assume, considering the oversupply of refineries in the US). But more likely it comes in as part of an imported product.

2. Which leads to the problem we already have: if oil is expensive in the US, that further incentivizes moving to where it is not expensive. Instead of buying your expensive fertilizers to grow food in the US, why not grow more crops in Mexico or Canada and import them?

3. Or perhaps oil is a part of the manufacturing process (i.e. plastics). Now it's all of a sudden even cheaper to manufacture outside of the US. Of course, you also have the complicated problem of recycled materials as well.

4. Or it's part of the shipping process. I'm not sure how you even tax this.

All these problems need to be managed. We would need to address figuring out how much oil goes into any one thing we consume. We need to address free trade agreements (can we charge duty on a product depending on how much oil was used to make it, ship it or grow it?). We would need to provide incentives to recycling, manufacturing, organic agriculture, etc. etc.

It's not that these aren't problems we should try to solve, it's just that "presto, 7B of income a year" is not what will happen.

Since this is an international agreement, you'd have to tax ALL carbon producers around the world. How you divide that tax revenue between the different countries would then be a political game but much simpler than creating a whole new market for carbon credits. Again, tax the carbon at the source and it won't matter weather it's refined, burned directly, or turned into plastic products, carbon out of the ground will all be taxed at the same rate to discourage it's unearthing. You say I'm oversimplifying a complex issue, but I'd argue that others are making it a complex issue when in fact it's conceptually very simple.

> Again, tax the carbon at the source and it won't matter weather it's refined, burned directly, or turned into plastic products, carbon out of the ground will all be taxed at the same rate to discourage it's unearthing.

Doesn't that create the wrong incentives? Digging up carbon and using it to make stuff that is kept around indefinitely / recycled into more stuff / buried when life-expired should be fine - it's putting it into the atmosphere that we want to discourage.

(Also there should be a positive incentive for taking carbon out of the atmosphere permanently).

cap and trade is pure political theater where politicians can decide who providing credits, so favorite sons type stuff. If we just tax the stuff coming out of the ground at the source the politicians cannot play favorites in the credit game.

its one way that countries try to avoid fair trade as it gets harder to follow the money. it also lets politicians unfairly subsidize some businesses over others because of whom runs them, not what benefit they provide.

so tax it once and get it done with

The finance industry loves cap and trade schemes as it creates a new market to trade and create financial products for.

The generally accepted solution is a carbon tax that increases over time. The tax can even be revenue neutral with everyone getting an equal share of a year end rebate.

Airlines are paying for any additional growth after 2020, not for current pollution.

There can be zero quota cap and trade, where everyone starts from zero and all the emissions rights are auctioned. (I'm not an economist or lawyer so might misuse the exact terms, but I hope you get the point.)

Offsets/credits are a fine idea, assuming they work. And forest preservation by Brazil would hopefully be domestic, and not chopping down the Amazon has additional non-carbon environmental bonuses.

Since emissions will cost more, they'll have more incentive to upgrade their fleets to more efficient planes.

Sure, but the incentives are mostly already there. And they're not buying the new super-efficient large jets because they have a hard time selling enough tickets to fill them. So I don't think they're going to be physically able to reduce emissions too much further, certainly not enough to hold overall emissions steady as flights rack up 3x as many miles over the next few decades.

To put it a different way, most of the advances here will not be in more efficient ways to fly, but in more effective ways to sell carbon credits to the airlines.

Cost them $24B? Hahaha. No. Come on now, you know airlines aren't going to embrace anything that costs them money.

If every airline has to pay the fees, carriers will be free to raise prices to cover the additional cost. Fewer people will fly, so ticket prices will go up more, eventually reaching an equilibrium where the carriers make about what they make today moving fewer people from place to place.

Air travel is already pretty efficient and clean? Certainly when calculating emissions per passenger-mile. Compare them to shipping, which is at the other end of the emissions spectrum. Lets hear something about cleaning up the oil-burners sometime.

Well of course per passenger-mile shipping is less efficient than air travel, because shipping is primarily transportation for goods, not for people. A big container ship has what, 20 people? Nonetheless, you're right that shipping should receive more attention. I think that it's less visible, less profitable, and more economically critical than air travel, which is often seen as a luxury. This would make taxing it more of a tax on economic activity.

Air travel produces a factor of ~100 more C02 per unit mass transported than maritime transport [1].

It seems that shipping is a little understudied, but apparently a leaked UN IPCC report (from 2008, so pre-crash, peak globalization) states that shipping produced 1.1 billion tonnes† [2] of CO2 annually. This number is ~4x higher than other studies so maybe it's more accurate, maybe it's not.

Air travel on the other hand produces 780 million tonnes of CO2 per year [3]. The major issue is that, as stated in TFA, it's supposed to triple in coming decades. I am not sure that global shipping is.

†I am quoting 'tonnes' in both which I think refers to metric tons, not imperial measurements, so I believe the units are comparable.

Shipping may be much easier to improve technologically than air travel, though. I'm sure many of the ships burn low-quality diesel. However, they're of the scale where very small nuclear reactors are available, and I have heard talk of ships being powered by natural gas. Ships can also deal with heavy batteries, so maybe in some instances offshore wind or solar farms could provide electricity? I have also heard of ships actually being powered directly by wind, but maybe this is a rumor, some far off Silicon Valley pipe dream.

[1]: http://www.davidsuzuki.org/issues/climate-change/science/cli...

[2]: https://www.theguardian.com/environment/2008/feb/13/climatec...

[3]: http://www.atag.org/facts-and-figures.html

Shipping burns tar and sludge. The worst smokey emissions possible. Its appalling.

I believe there are exactly two direct-wind-powered cargo ships in the world. http://www.skysails.info/

You have that reversed, shipping is vastly more energy efficient than air travel. ~30% of most airlines budget is for fuel.

Not the first time this confusion has come up on HN. https://news.ycombinator.com/item?id=10716102 CO2 emissions are low (which is what this article is about), but particulate and other emissions can be pretty extreme.

Agreed, it should be noted that most shipping related pollution has a short half life in the atmosphere and are released far from people limiting it's impact. However, the impact near ports can be rather significant and it will travel over a large area.

Because only people need clean air? This is the armchair ecologist viewpoint I hear all the time. If it doesn't bother me, its not a problem for the environment right?

Scale is important.

Not a lot of stuff lives over the middle of the ocean or even under it past the continental shelf's. Further, the ocean really does dilute this stuff to a rather extreme degree. Granted, it's still an issue, but it's simply a smaller one than CO2.

Almost all life in the ocean is in the top two meters. That's the part that would be most affected by air pollution. Its the part doing the 'diluting'.

Again, this is a case of "its not bothering me so its ok" ecology.

> Its the part doing the 'diluting'.

This is really far from true.

Acid rain is one of the primary issues with SOx pollution. It concentrates in rivers for example because the volume of rain water to overall water is very high. In the ocean new rain water never makes up a significant fraction of the top two meters of water.

PS: There is no need for gut reactions here, it's not hard to test for sulfur compounds.

what about ocean acidification that i keep hearing about?

This is mostly caused by CO2.

PS: First line "When carbon dioxide (CO2) is absorbed by seawater, chemical reactions occur that reduce seawater pH, carbonate ion concentration, and saturation states of biologically important calcium carbonate minerals." http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidificati...

Compare jet travel to other forms of hauling humans around, and they start to look pretty good. Of course we're not going to be stacking people into ship cargo holds; that comparison is pointless.

Joe, you're the one who brought up shipping.

The article says air travel already accounts for 2% of global CO2 emissions, and the absolute amount is set to triple between now and 2050. Hopefully other sources of emissions decrease over that time, so air travel will be >6% of global CO2 emissions. It needs to be addressed quickly and globally, even if it is relatively clean.

And as air travel increases, does other forms of surface travel decrease? Surface travel is terrible in comparison. This trend could be the best news, emissions-wise.

Of course as it becomes a major mode of travel, its worth addressing. But for now, air travel is actually the preferable mode.

Surface travel can be great, depending on what you're comparing against.

Against single-occupant cars, airliners win big. Airliners typically see 80-100 passenger-miles per gallon, versus about 36MPG for the average American car.

But if you get a more efficient car and add more people to it, airliners don't win anymore. Put four people in a new Prius and you're looking at about 200 passenger-miles per gallon. Long-distance busses and trains do really well too. And of course you can power surface transportation with alternative energy sources much more easily. Electric trains are common and electric cars can make long trips now, while nobody really even knows how to build a useful electric airliner.

I don't understand the emphasis put on air travel when it comes to emissions, and it's definitely better than typical car habits, but surface travel in general can be a lot better than air travel.

> And as air travel increases, does other forms of surface travel decrease?

No.

Air travel is generally a separate category of travel that's mostly independent from other forms of travel. It directly competes with long range high speed rail, but it's far worse than rail travel. http://www.seat61.com/CO2flights.htm

Air travel sit's between single passenger cars and buses in terms of pollution. The break-even is generally ~3 people in a car depending on MPG and how out of the way the airport is.

6000 ships produce what, 25% of all the air pollution in the world? How can that possibly be true?

You are thinking of a very specific type of pollution such as sulphur oxide. Ships have zero emission standards and burn very low grade fuel. Cars/jets etc have the sulphur removed from their fuel. However, this stuff tends to go away fairly quickly, in terms of long term pollution such as CO2 they are very low.

Don't forget Jet fuel takes a lot of processing and produces a lot of pollution before it's added to the aircraft.

Or more likely, the original source for that claim was thinking of a very specific type of pollution, but it then got badly reported and mangled so that a surprising number of people now think that a small number of ships produce a major chunk of all emissions.

As I recall, the article which really made a splash on this topic was clearly written about sulphur dioxide, but the headline just said "pollution" and everybody ran with it.