I was also under the impression that melting ice would push the level of the oceans by multiple meters. If 75-80% of ice has already melted, wouldn't we have seen significant elevation already?
Just some facts that I found surprising, coming from someone who doesn't know much on the topic. I'm well on board with global warming, but the facts presented here don't mesh with what I understood about it.
The Greenland ice sheet, and Antarctic ice are a completely different story. Their melting will raise sea levels directly.
> Another is the pending collapse of the Greenland ice sheet, which Anderson said will raise sea level by 7 meters (about 23 feet).
The Greenland ice sheet is on land.
Most of the ice that has melted so far was probably already in the water.
The ice that is already floating in the water does not change the sea level when it melts.
> as long as objects are floating (i.e. they don't rest on the bottom) they displace enough water to support their mass [...] The water level remains the same when the ice cube melts.
This link talks about cubes of ice in a glass of water but I think it should apply to ice floating in the sea as well.
All I could find on short notice was related to Antarctic Ice cover, this article from NASA does a good job of explaining why the two are not directly correlated in the immediate term - it seems that "One of the main things we learned was that as grounded ice retreats inland, the bedrock under it lifts up elastically,"
The author goes on to say "Although this sounds like good news, the scientists say it's important to keep it in perspective. "It's like a truck traveling downhill that encounters speed bumps in the road," said Larour. "The truck will slow down a bit but will ultimately continue down the hill" - just as the ice sheet will continue to melt and sea level will continue to rise."
For actual numbers: https://sealevel.nasa.gov/
The Arctic icecap is floating, so its melting (which is happening rapidly) will have no impact on sea level rise. The Antarctic icecap is mostly on land, and if that melts, it will raise the sea level by 60 meters. That will flood most major population centers.
I don't think we can save the Arctic anymore, but I really hope we can still save the Antarctic. (The good news is that it's not melting yet.)
Technically net ice mass /could/ increase in that state
depending on precipitation vs melt rate and even an increase may not be a good thing (fresh artic snow could cause ecological issues even).
That tangent aside it opens the door to potential eventual total melt by definition - if the area is still permafrost that means it never melts year round.
Which while a worrying sign doesn't equate to total immediate melt in four years.
I understand their desire to sensationalize, but people like AOC make the same predictions, and she is not seen as smart by a large portion of the public.
I think if we just stick with the experimental science research, the general public will find more confidence in the sciences.
Can you explain why people like you who come here to post "the world won't end in 4 years" consistently do not read the article, and consistently set the bar at "literally the oblate sphereoid we are on explodes" as opposed to "the climate is so radically different it threatens every aspect of human society and triggers even more mass extinctions?"
I don't understand your mentality at all. It seems an awful lot like you're meticulously moving the goalpost of a bad outcome. But surely you have got your own internal reasoning.
You mention mass extinctions, but you don't mention that previous mass extinction events were due primarily to asteroid impacts and volcanic eruptions.
It is indeed a chart, but no one here is ignoring it. Is the argument, "Don't worry we could just trigger another ice age and after a few tens of thousands of years the fallen bodies of our families and plants will re-sequester an appropriate amount of carbon?"
That seems to be small comfort, and it further reinforces the idea that the only threat to the biosphere you're willing to consider is a movie-style asteroid impact or something else that would shatter or at least significantly deform the planet's shape, as opposed to a change in climate dramatic enough to cause massive problems for human society all over the world.
> You mention mass extinctions, but you don't mention that previous mass extinction events were due primarily to asteroid impacts and volcanic eruptions.
No, I didn't mention it because it wasn't in scope. You dodged my question and instead tried to introduce a bunch of chaff questions to raise the notion that maybe, just maybe the science hasn't come to a broad consensus about the bad outcomes we're facing.
But the consensus is obviously there. Hell, your own diagram is from an article about said consensus, debating the finer details within the parameters if said consensus.
Why? You obviously aren't stupid. Why do you cling to ideas that are so obviously and verifiably false? It's like talking to someone who believes the earth is flat, only instead of being able to be calm and detached about someone's curious religion I have to be terrified because they're advocating for practices that cause climate destruction.
And it's not just about mass extinction; humanity itself is already a mass extinction event. But it will also be harder to feed people if the climate becomes unpredictable. Inhabited places can become less habitable. And the big one: if the eastern Antarctic ice cap starts melting, we're eventually going to have to evacuate most major population centers.
That is indeed not something we'll be able to handle. And we have frankly no idea when the exact deadline is that we may be able to prevent that from happening, or whether we may already have passed it, but we do know that many other ice caps are already melting, which is bad enough in itself, but also a warning for what might still come.
Please don't misrepresent claims that "we have X years to stop global warming before it becomes irreversible" as "the earth will be uninhabitable in X years."
Maybe we should just accept that change is coming, and brace for it.
“We need to stop all industry tomorrow or ice will melt!”
“Ice will melt. We need to close a few of the worst-impacting plants so it melts a bit slower and gives us time to figure out where we might need dams. Everybody else, as you were.”
The first proposition has no chance whatsoever to be taken seriously. I understand Overton but I admit a certain tiredness on this particular falling-sky topic.
Figuring out where we might need dams may be enough for the next couple decades, but if ice caps continue to melt, dams are never going to be able to stop 60 m of sea level rise. Melting slower is not enough. And at the moment, it's only going to melt faster because we're still producing way too much CO2.
Well, we've already accepted that it's the only realistic option, because 4 years is not enough to do anything else.
If you really think that, then you should just buy a canoe today.
And even getting it to melt slower than it's currently doing requires more effort than we're currently putting into this. We can and should do way more than is currently happening.
I am utterly disgusted by this literal "apres moi le deluge" attitude.
(Albeit a calamity followed.)
This time, the scale and stakes are much bigger, potentially extinction level.
We really need to aim at zero CO2 production. We will fall short of that goal, but everything will help slow things down, and eventually bring temperatures back to what they were, after natural plant growth has gotten the time needed to remove CO2 from the air again. Once that happens, the melting will stop and climates will stabilize.
If we can get global temperatures back to normal in a century, that means we'll have about 1-2 meter of sea level rise to cope with. That means the end of the Maldives and serious investments in some coastal areas, but many coastal cities will survive.
If we can get temperatures back to normal earlier than that, that will mean less sea level rise, and significantly less other problems. Not all damage can be undone, but some will, and there will be a limit to it.
But the longer it takes, the worse the effects will be, and the longer it will take to recover.
Of course we can also help nature a bit and plant more trees and look for other ways to get more CO2 out of the air. It maybe be drops in a bucket, but we're going to need a lot of drops, so we better get started. At the moment, we're still barely doing anything.
We're also burning oil in cars of course. Fortunately, electric cars have become incredibly popular thanks to Tesla. Once electricity generation is clean, electric cars are perfect for taking advantage of that.
Planes and ships are going to be hard. On top of that, many ships burn incredibly dirty oil, and the fuel for planes and ships is untaxed, which, in a world where all other forms of energy are taxed, make them effectively subsidised. International treaties are necessary to make ship fuel cleaner, and extra efficiency may be encourages by taxing fuel. For short distances, planes may be replaced by high speed trains, but for long distances, I don't think we'll be able to get rid of them.
Fortunately, there are other things we can do: trap CO2 from the atmosphere by planing trees, encouraging other plant growth, and possibly even stimulating algae growth in the oceans because that's where the real large scale capacity for this is. There might be other ways too.
At least in part, this can be accomplished simply through better policies by governments, maybe international agreements. But to encourage businesses and people to burn less carbon, I think a growing tax on the emission of CO2. I don't see the cap-and-trade working very well, and even if it does, it merely limits it; it doesn't bring it back to zero. A carbon tax can do that. I think the carbon tax should start low, because you don't want to kill the economy with crippling taxes, you just want to make it attractive to switch to cleaner energy. The tax should then be used to either invest in cleaner technology, or to directly remove CO2 for the atmosphere. You could even pay companies to do that for you, creating a new industry that cleans up the pollution from those businesses that are unable to make the switch for whatever reason. At first, the tax won't be enough to clean up all CO2, but eventually it definitely should be. And once you're there, it doesn't really matter if some people or companies still pollute, as long as they're also paying to undo that damage again.
Our climate is like that: it takes ages to respond. We've been building up excess CO2 in the atmoisphere for over a century now, and we're finally starting to notice the effects. Even if we were to completely stop producing CO2 now, there's still enough CO2 in the atmosphere to continue to increase heat absorption. Even if we could remove all excess CO2 from the atmosphere somehow (we can't), it would still take time for the excess heat to disappear. (The quickest way to lose the excess heat is if we could somehow block the sun, which we can't and would be harmful in a dozen other ways.)
The problem is that this concept is really hard for most people to wrap their heads around, so people tend to simplify it in ways that emphasize the urgency but exaggerate the timeline of the effect, or at least sound like they do, because that's how most people tend to interpret that urgency.
So no, the Earth is not going to end in 4 years, but it will be 4 more years of accumulated damage that will have repercussions for centuries.
This alarmism does nothing but alienate. We should be sticking to the science, not dramatizing.
A population bomb leading to famine has never been the result of prolonged scientific discussion, just one guy's theories (published in book form, which is subject to editorial review but not peer review), and saying "this is a prediction that someone made that was false" is true but unhelpful. Anyone can make a prediction, and a lot of dumb stuff gets published. Never made it meaningful or true.
My father, before he succumbed to dementia, had this belief that if it's been published, it must be true. He'd read the weirdest stuff and ultimately decided that nothing is true; when really, it's because he was overly credulous at first, and in rejecting truth as a concept, he went too far the other way.
I feel like that's a lot more common than we realize; the error is not in believing in a consensus reality, it's in believing in something that wasn't very good to begin with (a book about worldwide famine, the handful of "global cooling" articles in the 70s -- not even a book! just a handful of magazine articles!! why would ANYONE put stock in that??), and deciding that, because that was wrong, nothing is knowable.
Because this is what it is going to take. Not even going underground en masse will work and that is essentially the most extreme social change I can see. (Even more extreme than space travel, cars, internet.)
Do you have a count of how many have gone extinct in the past decade?
> What makes you think humans are special?
Our brains. And yes, technology and science. Humans are extremely adaptable. Our ancestors survived an ice age with stone aged tech and spread around the world to live in all sorts of environments.
> Not even going underground en masse will work
LOL, what? Who is saying that the Earth will become so hot that we won't be able to survive on the surface? You think 3-4°C is going to have that effect?
It's also a case where the disease seems easier to live with than the cure.
ocean temperatures are rising and that's leading to widespread climate instability. These were predictions, and they are now coming true. They've been verified via a variety of methodologies.
You're insulated from the worst of the effects for now. That's because you are not at the very bottom of the human economic strata. but the hardships introduced by climate change will continue to climb up the chain of economic prosperity until only people who live like Pharaohs and ignore them.
Most critically, if we act now we can avoid the worst outcomes. Given that it's a rather good time to consider over turning all of our infrastructure in the developed world, Why wouldn't that be enough motivation for you?
there's so many problems that exist because we're all living collectively on infrastructure designed over the last 300 years. Legacy structural decisions have profound effects on our lives, not the least of which is a demand for centralized governance. By using climate changes an excuse to decentralize infrastructure, we can use it as an opportunity to decrease everyone's dependence on centralized control. It's rare that humanity has such a powerful motivating factor for both social and infrastructural change.
The economic knock on effects of this are not to be underestimated either. We can create environment electricity costs 100ths of what it does today. We can make things more reliable, and we can let local communities have more control over what they want to do and how they want to live.
Please think about this. It's a dangerous time, but it's also a time full of opportunity.
Seems like there is a lot of that going around.