Can we get to 350 ppm? Yes we can | Hacker News Reader

Can we get to 350 ppm? Yes we can

crookedtimber.org

36 pointsjseliger26 comments

Until recently I would wring my hands and feel sad for a situation I couldn't change.

Several months ago, though, I joined the Citizen's Climate Lobby, which is building political will for a carbon tax and dividend (the only truly market-based approach to limiting green house gas emissions). I know that warming has happened and will happen due to past emissions. But at this point I feel I'm working to avoid the most disastrous scenarios by limiting future emissions.

I have been inspired by my involvement with this organization, and I encourage other concerned Hacker Newsers to consider joining.

citizensclimatelobby.org

> carbon tax and dividend (the only truly market-based approach to limiting green house gas emissions)

I always heard cap-and-trade described as a market-based approach (by people who talk about the actual policy instead of just trying to vacuously demonize it). Can you briefly explain (or link to a good argument) how it fails to live up to that description?

Ideally it is, but it is more complex to implement, and complexity can create loopholes that undermine it. There's more opportunity for graft in how the credits are distributed.

This is right, but I'd also add that the benefit to cap and trade is that it's politically easier to do (since it's not called a "tax").

It's beyond any human organization right now to know what the appropriate price for or cap on carbon is, which ti me, is the largest reduction that does not cause serious problems. But if the carbon price (tax) is too high, people will lose money, but life goes on -- capitalism is naturally equipped to deal with shortages by raising prices, so working in reverse, we can push the economy towards a shortage by increasing costs. By contrast, if the carbon cap is too low, production has to stop; you get larger shortfalls. So the legislature is free to act more boldly in setting prices. The comparison with sulfur markets for acid rain is often brought up, but the difference is that a shortage of sulfur credits would only affect a few industries and there are many substitute goods. In practice, carbon markets which have existed until today have had caps too high to effectively lower emissions, and I think this is because the legislators' legitimate fears of creating a carbon credit shortage and hurting the economy caused them to be more susceptible to corporate influence. By contrast, if the carbon price were too high, the negative effects would be milder, giving legislatures time to reverse them. This allows them to raise it in the first place more fearlessly.

Also, do note how many energy companies love C&T. Do you really think it's out of the kindness of their hearts?

CCL is a great organization. I joined after the election because I was really upset and could either mope or get involved with something important to me. I like the fact that CCL has a non-partisan or bi-partisan proposal and that it sincerely works both sides of the aisle. Our country has societal problems and it's got political problems. CCL is trying to address them both.

There is really no cause for optimism. The fact is that all the CO2 emitted into the atmosphere stays there for at least ten thousand years, and we are increasing our output of CO2. So actually, the problem is getting much worse and is likely to remain bad for many thousands of years.

It is entirely possible to destroy the fragile earth, and humans are doing exactly that. There is no reason that it has to have a happy ending.

But no, we won't.

This is a nice notion, but ignores the feedback cycles which have already been set in motion - at this point, reducing our emissions to zero may provide little benefit, as as the Arctic and Antarctic thaw, relict methane is being emitted at an alarming rate, wildfires are becoming far more frequent globally, and oceans are no longer functioning terribly well as carbon sinks, further pushing emissions.

I'm not saying we shouldn't try, but I fear we're already past the point of no return for catastrophic climate change.

What do you think about the Larsen C ice shelf rifting off into a huge iceberg?

The Larsen C shelf collapse has nothing to do with climate change. Even climate scientists have been adamant about this fact.

As Antarctic glaciers flow out toward the ocean, they form shelves over the water. At ape point, the shelf becomes too large to sustain itself and collapses. This is what happened recently, and it's an event that would have happened no matter what.

The language that scientists have used is significantly less confident than yours (from http://www.projectmidas.org/blog/calving/):

> Dr Martin O’Leary: “Although this is a natural event, and we’re not aware of any link to human-induced climate change, this puts the ice shelf in a very vulnerable position. This is the furthest back that the ice front has been in recorded history."

I interpret those comments as saying it's currently an open research question. Lots of popular press I've read though does leap to there being some link. I think it pays to be open minded here and consider that ocean and polar warming could have an impact on ice shelf stability.

"This is the furthest back that the ice front has been in recorded history."

I'm curious; in the context of the ice front, when does recorded history begin?

Are we talking, 10s, 100s, or 1000s of years?

An obvious minimum link is that the area which has melted and broke off, also coincidently happens to have elevated temps recorded and indicated by modelling.

https://www.nasa.gov/topics/earth/features/warming_antarctic...

There is still the whole "correlation isnt causation / aint necessarily so" caveat, but the correlation with AWG is obvious.

While newsworthy and attention-getting, the consensus from scientists seems to be that this isn't really a sign of catastrophic climate change. While climate change likely played some role, it's mostly part of a natural process.

Indeed.

Another factor is climate lag, also called climate inertia. There is a delay of a couple of decades between emissions and temperature change. The thing is we have emitted more in the past decades than the previous 150 years before that.

So even if a miracle happened and we got to zero emissions there are still self sustaining feedbacks and a monstrous wave of warming coming at us.

Our only hope really are extreme negative emissions, but I feel we won't even be able to make it to zero emissions.

well... shit

just because a guy on the internet thinks it doesn't matter doesn't mean it doesn't matter.

He didn's say it doesn't matter, he said zero emissions won't solve the problem, that much of the damage is done.

It will still prevent exacerbating the problem.

He is right though. Couple that with the dwindling supply of food in developing countries, and there is a huge problem coming our way.

Realistically, extreme negative emissions are a practical impossibility. Zero emissions are as well.

We still have an opportunity to reduce the extent of the damage. Major climate change is likely inevitable at this point as, realistically, the modest measures taken to date are insufficiently binding to be effective.

I don't think we've past the point of no return, yet, but we will certainly do so at some point given the real cost of taking action appears to grow faster than the political will to take action.

I believe the higher levels of CO2 are a concern and we should do what we can to reduce them. Yet, the points you make are not obvious to me. Do you have reference to literature that I could read.

This article [1] in the journal Limnology and Oceanography (and others) indicates to me that we don't understand the effect of climate change on methane emissions from the Arctic and Antarctic seabed. Are emissions going up or down?

Wildfires in the western US are increasing, but we've changed the way we manage forests and forest fires in the west. The resulting accumulation of brush in forests (for one reason because we aggressively put out even small fires to protect encroaching development) makes big fires more likely. Furthermore on the scale of centuries, as long as the forests stand they will simply recycle CO2 by absorbing it as trees grow and by releasing it when they die (either through rotting and decay or by burning).

As far as the oceans not acting as CO2, the recent literature that I've read says that they are acting as CO2 sinks. The first two sentences of the abstract from a Feb. 2017 paper in Nature[2] are:

"The ocean is the largest sink for anthropogenic carbon dioxide (CO2), having absorbed roughly 40 per cent of CO2 emissions since the beginning of the industrial era. Recent data show that oceanic CO2 uptake rates have been growing over the past decade reversing a trend of stagnant or declining carbon uptake during the 1990s"

[1] Limnology and Oceanography. Effects of climate change on methane emissions from seafloor sediments in the Arctic Ocean: A review, http://onlinelibrary.wiley.com/doi/10.1002/lno.10307/full

[2] Nature. Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning. https://www.nature.com/nature/journal/v542/n7640/abs/nature2...

How about a cycle of cutting down a lot of trees, burying the wood and then replanting to sequester carbon ?

It is not clear that old trees are less efficient at sequestering carbon than young ones. It used to be thought that old-growth forests are not good carbon sinks but this may not actually be the case.

As you say, no such thing as feedback in nature. Nope. Not at all.

http://www.bbc.co.uk/news/science-environment-40686984

http://advances.sciencemag.org/content/3/6/e1700584

Not sure why you're being down-voted -- feedback is an incredibly important process that surprisingly few software engineers seem to be exposed to.

In particular, there are multiple attractor states where the planet's temperature can maintain an approximate equilibrium for long periods of time -- one of these is just below our current mean temperature, and the next one up is thought to be about 10 degrees Celsius warmer, closer to the temperature experienced during the Paleocene-Eocene thermal maximum. Then of course there are ice ages, which, if aided by low CO2 levels, can result in the extreme low temperature of a "Snowball Earth."

We are likely out of the equilibrium of our interglacial and in the beginning stages of a positive feedback loop that will continue increasing the planet's temperature until most of Earth's ice is melted and deserts expand in the low-mid latitudes, at which point blackbody radiation will offset the decreased albedo from lower ice levels.

There are more complex, unpredictable dynamics at play as well that may serve as negative feedback. For example, less Arctic sea ice is predicted to result in more snow in the far north due to increased evaporation, which may serve to build up glaciers on land.

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