Half of Glaciers Vanish with 1.5 Degrees of Warming | Hacker News Reader

Half of Glaciers Vanish with 1.5 Degrees of Warming

nasa.gov

70 pointsgeox52 comments

So the glaciers are melting because extra energy (heat) is being added to the system (well, not being radiated into space). Once the glaciers are gone, that extra heat will be absorbed by... what exactly?

I'm a bit frighted by what I think the answer is.

Glaciers are obviously important to people and wildlife in the region, but I don't think it's important as global heat reservoir. Glaciers are only 1.74% of total water on earth: https://en.wikipedia.org/wiki/Water_distribution_on_Earth

Of course the ocean itself is warming up, so I guess we're screwed either way. ¯\_(ツ)_/¯

Don't they play a role in term of light reflection?

Glaciers and ice in general reflect a lot of light/heat back into space. As they disappear you end up with a positive feedback loop so that extra heat is mostly absorbed instead of reflected.

It's yet another safety that is going to disappear.

The concern is albedo (absorption of incoming solar radiation), not heat reservoir.

Lighter surfaces (snow, ice, clouds) typically reflect more light and heat. Darker surfaces (water, ground, asphalt) absorb light and emit thermal radiation, which is then trapped within the atmosphere by greenhouse gasses.

The atmosphere is differentially transparent to visible-light frequencies (high transparency) and infra-red radiation (low-transparency). That's the essence of what causes greenhouse warming, and we're adding more of the gasses (CO2, methane, and others) which are more effective at trapping heat.

Changes to surface characteristics (such as glacial melting) and atmospheric conditions (cloud formation, with dependencies on whether these are high-altitude or low), as a result of greenhouse-gas induced warming, provide feedback cycles which amplify or dampen effects. Many of the known feedbacks accelerate warming.

That's in addition to other feedbacks such as warming arctic-region permafrost, releasing both trapped CO2 and methane and triggering decomposition which generates more of these, or the "clathrate gun hypothesis", in which frozen and dissolved methane hydrates, themselves exceedingly powerful greenhouse gasses, are released at a rapid and accelerating rate. Among potential scenarios is a runaway greenhouse gas effect where global climates warm far beyond human or biological tolerance, either regionally or globally.

<https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis>

  > 1.74% of total water on earth

That is still a lot of water, and the phase change is a terrific heat reservoir. It takes a comparable amount of energy to melt water from -1 to 1 degrees, as it does to bring the water from 1 degrees up to 99 degrees.

Got some proccesing units/key chains with stories they cant tell anymore.

The glaciers are not the only parts of the system affected by the warming. And with a complex system you get a lot of positive feedback loops that with more warming they push add more warming on their own (either more emissions like the one caused by permafrost thawing or more heat absorption because less ice reflecting light).

Glacier melting is just another milestone in a road that will be pretty hard to stop walking till the end.

It's a tipping point (with regional impact).

https://en.wikipedia.org/wiki/Tipping_points_in_the_climate_...

As glaciers (69% of fresh water) melt, oceans absorb more heat. This leads to rising sea levels and altered currents (e.g. AMOC). The warming air influences weather patterns and increases atmospheric moisture. As the permafrost thaws, it releases additional greenhouse gases. Elevated water vapor amplifies the greenhouse effect, and changing cloud formations further influence global temperatures. These shifts in ecosystems affect both Earth's reflectivity (albedo) and global biodiversity.

Some of these impacts can serve as feedback mechanisms, potentially further accelerating the rate of change.

Unless I'm mistaken, it has a lot to do with the albedo that in this case when the surface material's properties turns from reflection (glacier) to absorption (rock material).

Wikipedia: https://en.wikipedia.org/wiki/Albedo

So, fresh snow might have an albedo of up to at around 0.8 or more, where as darker surfaces like asphalt are at around 0.04 to 0.12, so, the less albedo, the more it'll absorb instead of reflect (esp. back out into space).

The thing is that darker type rock materials also work as sort of heat capacitors in the sunlight, so basically, instead of reflecting that heat energy back into space, it'll stay around and warm up things.

Not sure if this constitutes as an example of a climate feedback loop (or an accelerant to one), but at least the albedo loss is one of the main concerns among climate scientist when they talk about i.e. (northern) polar ice cap melt -- instead of reflecting the heat back into space via snow and ice sheets, the heat energy gets absorbed by the sea, and that causes all sort of additional wacky stuff.

Arctic News often talks about it and even have this illustration on what happens if i.e. ocean ice is gone: https://3.bp.blogspot.com/-AHyeWIcSSVw/U70d6UBytbI/AAAAAAAAN... (although 0.9 albedo in that one is like at the higher end of expectancy for a fresh snow pack/ice sheet covered with white snow, the albedo drops rapidly with subsequent surface melt etc.)

I wonder what effect white pavement would have.

Probably even hotter days, though cooler nights.

I think ironically this causes the Jetstream and polar vortex to breakdown, the polar vortex is what keeps arctic air from dipping further south, if the vortex fails we could be ushered into an ice age where the feedback loop is reversed. more ice, more reflection, more ice. at least that's what I learned on a YouTube video recently (some meteorologist channel).

it's amazing how many runaway feedback loops can take us to extreme heat or cold near the extinction line either way. I think we could weather an ice age, but I think billions wouldn't make it. We'd create underground homes with lights to grow food or something in a space station or on the moon.

We're pretty resourceful, I think it'd take more than that to take us out. An asteroid is much more certain extinction, unless we do have an actual colony in space or on the moon.

  > We're pretty resourceful, I think it'd take more than that to take us out.

I'm less concerned with the survival of the species as a whole, as I am with the survival of my family and culture. Note that my culture goes back three millennia, so I'm not really interested in preserving the exact modern way of life.

Do they come back with 1.5 degrees of cooling? Just curious.

Do you mean back to pre-industrial levels or 1.5 degrees below pre industrial levels?

I don't know about other regions, but the Rocky Mountain glaciers weren't in steady state at pre industrial temperatures, they were slowly retreating. They are remnants of the ice age.

The glaciers in the Cascades of the PNW were advancing in the early 1900s (a new one in the crater where most of Mt St Helens used to be is still advancing!) so at pre-industrial temps those would absolutely come back.

To advance a glacier needs both moisture and cold. The PNW receives a lot more moisture than Alberta.

For sure. I was merely commenting on one of the "other regions" you referred to.

No, you'd need to go back to ice-age temperatures again

I'm convinced that global warming is a threat. But I'd rather watch the world burn than listen to people who fly around in private jets or own mega mansions tell a regular person like me what steps I need to take to cut my carbon emissions. It may be irrational, but I just don't care.

Individual actions of sacrifice never solve these things anyway.

We'll stop burning fossil fuels when it's good for us personally. Whether by cheap clean new tech or taxes/regulations.

Worse is hearing rich first world people imply that we can’t let the billions of poor in Asia or Africa have what we have. “Yeah we know we colonized you and all, but can you stay poor to save the world?”

Of course this won’t happen. Their answer will be “fuck you.”

There is only one conceivable way to stop this: we must have sources of energy that don’t emit carbon that are objectively cheaper and more practical than those that do. Then we must make them abundant and frictionless to adopt. They have to be the easy path, not burning fossil fuels.

If we can’t do that we need to prepare for the effects of 800ppm or more CO2 concentrations. India and Africa are about to do what China did and if it’s powered by coal that’s where we are going.

Those are the two options. Anything else is a fantasy.

I don't know if Kathryn Cawdrey has a private jet or not, but even if she does I'd still welcome any work she does that helps the world.

Well since my kids will die with that attitude, I have to say you are a horrible person.

I promise that my carbon footprint is less than the virtue signalers in the media talking about climate action. I walk to work. I don’t air condition my home. I paid to have my home made energy efficient. But because I’m honest about my attitudes, I’m “a horrible person.”

They and everyone else will die no matter what we do. The whole personal responsibility thing is complete horseshit. Even if everyone made a real effort to "do the right thing", cutting down on meat and getting rid of cars if possible etc, we'd still be completely fucked.

And just to be clear, this is a fictional scenario, it will not happen. The only thing that might make a real difference is if everyone on the planet gets together and collectively make huge changes to modern society. Obviously this also won't happen but I'd stand behind it if it did.

Go right ahead and outlaw beef, I love it but I can live without it if I have to. Go ahead and tax the biggest emitters, we'll have to pay more for things but I can live with that. Go ahead and do anything that can help improve our situation on a national or international scale and I'll support it.

But as long as we can buy beef in the store with no limits, buy cars with unnecessarily large combustion engines, fly around the world at our whim - people will. And it's not just these few popularized things we need to change. Everything needs to change. Where we produce things, how we produce them, the materials we produce them from. It's an enormous problem that I honestly don't expect us to be able to solve.

How very snowflakey of you.

Oh, that sounds like a coded critique of Al Gore, amiright?

You know, the guy that was warning us all and was mocked by people like you as being crazy. Now that there's irrefutable evidence he was right it's down to ad hominem attacks, because that's all you've got.

I'm sure this is very important and so on and so forth. But we really need to find some way of communicating this stuff more "bite sized". Every few days over the summer scienticians predict that all life in the universe will be violently exterminated if we don't tax meat - and it's probably true, but it's just too loud, and too boring.

Alternatively: people care more about this stuff than ever before. So who’s to say that your preferred communication style is actually what will move the needle?

Unfortunately, there is no “bite sized” way that is acceptable to communicate to the public to eat less meat because it’s terrible for the environment, or, even more bluntly, any way to tell people it’s just consume less without a large part of the population getting defensive and antagonistic.

I imagine if a core aspect of your lifestyle, work, culture, and traditions were being attacked for "destroying the planet", you may feel defensive and antagonistic as well.

My grandfather was a cattle rancher. His father was a cattle rancher, etc. When my extended family gets together we eat roast beef because that is our tradition. We eat beef hamburgers and hot dogs at 4th of July cookouts because that is our culture.

Most of the folks telling people like us to stop would never dream of telling another culture how to exist but since we are poor and white we don't really exist since we've been swept under the rug of white privilege.

Culture thrives on traditions, but if ours impacts others negatively, it's time for reflection and adaptation. Heritage grows when it embraces change.

I imagine you likely travel by air. I haven’t in more than a decade. So please stop. Your customs are hurting me.

I don't. I lowered my consumption habits significantly. And switched to veganism. It isn't that hard.

https://www.theguardian.com/environment/2018/may/31/avoiding...

Animal agriculture has 8+ times more emissions than air travel.

https://www.researchgate.net/publication/352100490_Emissions...

https://ourworldindata.org/emissions-by-sector

And that's just emissions ... we're not talking about biodiversity loss, eutrophication, deforestation, soil erosion, water usage, ...

The Lottery: https://en.m.wikipedia.org/wiki/The_Lottery

Tradition is a pretty terrible defense when the tradition in question has measurable, known harms.

Luckily, most rational people would probably agree that there is a middle ground between "change nothing" and "eliminate the tradition". For example, cutting beef consumption to once a week or once a month would considerably lower your environmental impact without eliminating a valued tradition.

> Most of the folks telling people like us to stop would never dream of telling another culture how to exist but since we are poor and white we don't really exist

Aww yeah that sweet nectar of victimhood. There are westerners telling Africans to stop female genital mutilation, should that also be allowed to continue, because, "culture"?

Unfortunately people are already being displaced and/or dying from climate related causes. That does not fit into any soft messaging and requires drastic intervention.

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