Here is the paper that has just been peer-reviewed and published in Atmospheric Chemistry and Physics:
Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous.
>"The net forcing driving climate change in our simulations (Fig. S16 in the Supplement) is almost 2Wm^-2 at present and increases to 5–6Wm^-2 at the end of this century"
Thanks, from the paper it looks like they just hardcoded the warming into their model, ie it is not due to simulation of a physical process. Is that correct?
I was at a climate science workshop in Stockholm a few weeks ago and a well known researcher from Bremen University, who has a well known simulation for expected increases in global temperatures, showed that recent changes in their assumptions due to new measurements increased their expected temperature increase from 4.5 degrees by 2100 to 7 degrees. And nobody was that shocked. Shocking!
You can think of an ice sheet like a cathedral. Once you melt away the side buttress, a large portion of the whole thing falls into the sea. Many large glaciers have surprisingly small "gatekeepers". It's a dynamic process [x]. We have never seen a massive ice sheet collapse so don't know for certain if it takes two decades or two centuries. The potential to raise the sea level is large, many meters.
This now adds the ocean dynamics there, but I wonder if I got this right: The melt water has no salt, is thus less dense and hence stays on top and just keeps on warming and warming and will then melt the ice a lot quicker.
x: by dynamic I mean that one can't just get a linear relationship between temperature and melt rate. Think more of a collapsing building.
"He gained fame in 1988 when he warned Congress that global warming had already begun. He was ahead of the scientific consensus at the time, but it became clear in retrospect that Earth had been in the midst of a period of rapid global warming at the time he testified."
Does anyone who understands the methods they use for prediction care to chime in? I'm curious to know how people model such a complex system with any hope of accuracy. Do they simply rely on some sort of time series data? Or is it something more interesting?
There are a couple of ideas for engineering that would make the albedo (reflectivity) of the North Pole area controllable. One involves a space shield, the other is floating panels (one side black, one side white). The larger issue is a) predicting the result and b) the 'it could be good for Ontario' problem that all types of climate change bring benefits as well as costs. f.ex. a return to glacial conditions would suck for the Northern Hemisphere, but be good news for India, Africa etc.
I believe, but obviously cannot prove, that we've already passed the tipping point. Thawing tundra, ocean acidification, and burning forests are all now in positive feedback loops. Meaning we could stop all human activity tomorrow and atmospheric CO2 would continue to increase.
But the great unknown that scares me is the thawing methane clathrate. Hard to imagine mitigating this one.
Let's launch a solar shade! Plus - we get to decide what parts of earth to shade. I propose arid areas and also those who withholds from paying a voluntary shade tax.
My wife, my parents and most of my friends tell me when I try to bring up the climate topic.
"Either do something about it or let's talk about something else, it's depressing"...
And I often wonder - what is the root cause of this climate thing? We need to fix the root cause and then things will fall into place... Right ?
See, I don't think it's the fossil fuels. I don't think it's the pollution and the destruction of forests and the mining and the toxic rivers and the plastic in the oceans.
All these mechanistic manifestations of human activity are consequences of our dominant philosophy of life.
What's important to us, what matters more, about choices we make every day.
Forests or nice furniture ? Clean air or 6.3 liter V12 (yeah!) ? Clean rivers in China or iPhone 6s ?
Beef or Lentils ? Me or my competitors ?
Ultimately it's the answers that we have to some very simple questions - about who we are and why we are here...
These are spiritual questions.
So my conclusion was that: The state of the Planet is mirroring humanity's spiritual health.
So if this is the root cause, is there a way to cure it ? Well :)
Can you envision a way to make 7 billion people of various races and religions agree on one and true "spiritual" code ?
I find it very hard.
But maybe not spiritual - maybe we can use Science and invent new things... Well, isn't it "science" that got us here in the first place ?
Isn't it like "throwing good money after bad" ?
I don't know. As a scientist I sure hope we can figure something out.
There are a couple of ideas we could use... But there are other issues..
How can we renounce our way of life, our growth, our social order, the economy, the stock market....
Because that's what it would take to fix things.. "Going green" is too little too late.
We need to stop consuming, we need to stop growing, we need to stop competing.
And that's political and economic blasphemy right there.
Edit: Changed my mind. Although I think our chances of fixing this mess are slim, I still think there's hope.
There are things we can do about it. We are technologists. We have a lot more power than we care to admit.
Imagine Facebook "spamming" all users about climate change, about recycling, about respecting nature.
Imagine Google showing up "red spots" of pollution on the maps.
Instead of ads, why not climate propaganda from time to time ?
What if every iPhone's or Android's alarm went off at the same time warning users that the Planet is in danger ? Go plant a tree now!
Simple, cheap, yet could have dramatic effects..
Eventually it would cause political changes and hopefully we'll at least extend the problem further into the future.
The problem is Moloch. Tragedy of the Commons. No individual has an incentive to care. And even if they do, even if you do consume less, nothing stops someone else from burning up the resources you would have used.
The only solution is political. Not just a tax on using fossil fuels, but a tax on mining them out of the ground in the first place. If they aren't kept in the ground, they will keep pumping them out until its not ecomical to do so.
I agree, for everyone who stays in a more-material-stuff-is-better mentality.
By contrast, I've found reducing how much I pollute has improved my life. My experiment to buy no food for a week where I'd have to throw away packaging -- http://joshuaspodek.com/avoiding-food-packaging -- went incredibly well. After avoiding packaging for a 2.5 weeks, I don't completely avoid it not, but I've switched to almost only fresh fruits, vegetables, and dried legumes I get in bulk with bags I bring.
Similar experiments in other areas have improved my life in many ways I wouldn't have expected before.
People found ways to be happy before oil, many probably more happy than most are today.
>Well, isn't it "science" that got us here in the first place ?
No, not even a little bit. Science attempts to explain why things are the way they are and predict outcomes to given actions. It doesn't come close to telling us which actions we should take.
Science allows the development of technology and technology is responsible for most fossil fuel emissions and pollution.
I agree that theoretical science in itself is neutral - the same science can be used to build technology which is climate neutral or even useful in cleaning up the mess.
Besides, there is more than a subtle difference between the concept of "pure science" and what form science takes in reality - interweaved with politics, economics, personal egos, etc.
A headline can not contain enough information to convey scientific findings. For some more broad context, see this quote from the article:
>“Some of the claims in this paper are indeed extraordinary,” said Michael E. Mann, a climate scientist at Pennsylvania State University. “They conflict with the mainstream understanding of climate change to the point where the standard of proof is quite high.”
Indeed, my comment wasn't about the quality of the science. I read the abstract, and concluded it's beyond my ability to analyze critically (at least without devoting a ton of time to it and learning new things) so I'll leave it to the other scientists. But the public messaging sounds the same as it's been for a long time, so it's a curious headline especially as "news". (Authors often not choosing their own headlines is irrelevant here.) The article itself even notes the movie-version of a perilous shift is over a decade old. Perhaps a better headline would be "Scientists argue compromised global warming limit not good enough" (edit: especially since talking about linear vs exponential is way too complex).
It's OK if you don't want to take the time to dissect the paper's findings, or to keep up with the major highlights of climate change research, generally.
But perhaps you shouldn't attack their findings as some kind of "party line", then (and implicitly, the researchers as being party shills, basically, for toeing it).
Is the hatred of nuclear really so irrational? It's an expensive way of generating electricity which has frequent safety issues and gives the state the means to build nuclear weapons.
I'm pretty sure the current party line is something like, 2C warming is acceptable, beyond that is bad, but the big negative effects are a century or two in the future, albeit some major problems show up on a scale of decades.
That might be what cautious scientists have been saying, but that's way too complex for a party line. To rephrase my original question, since when haven't (according to news organizations) scientists been warning about perilous climate change within the span of decades?
I guess the point of the question is really a flippant "why is this on Hacker News?" You can call it defining away if you want, I don't think it's charitable to assume "party line" means "what the peer reviewed scientific papers say in their shortest summaries." A quick google search found http://www.ucar.edu/news/releases/2004/climate.shtml where "it is impossible for an ice age to strike within days, as happens in the movie. They warn, however, that climate change may have significant consequences for society in coming decades." Emphasis mine, since it's pretty much the same warning as the title. It was interesting to watch the first comment's vote tally fluctuate, anyway.
The HN moderators now support some duplicates. Sometimes things fall too quickly off the first page, or are at the wrong time of day and not really noticed, where it might be noticed a couple of hours later.
When there is a duplicate, at least in a case like this where the "past" link shows no previous postings, I tend to also include a link to the previous posts. For example: "Third time this has been posted: https://hn.algolia.com/?query=global-warming-sea-level-carbo... " works because the slug text is the same. Turns out the title of this submission uses "in" instead of "within", which is why it's not trivial to find previous submissions.
FWIW, of the previous two postings, only one had a comment; drallison posted a link to resources that cryptoz also points out in this the comments to this post.
The title of this submission is "Scientists warn of perilous climate shift in decades, not centuries". The previous two links used "Scientists Warn of Perilous Climate Shift Within Decades, Not Centuries".
Note the difference between "in" and "within".
The actual NYT article uses "within", so this submission title is incorrect.
(Edit: originally I thought it was due to the different URLs used, then I thought it was the difference in case. On the third try I noticed that one differing word.)
Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous.
http://www.atmos-chem-phys.net/16/3761/2016/
And the 15-minute video by the author to accompany the paper: https://www.youtube.com/watch?v=JP-cRqCQRc8&feature=youtu.be