Climate change: Soot's role underestimated, says study -- Black carbon, or soot, is making a much larger contribution to global warming than previously recognised, according to research. (bbc.co.uk)

science

234 ups - 72 downs = 162 votes

113 comments submitted at 12:38:32 on Jan 16, 2013 by davidreiss666

  • [-]
  • BreadstickNinja
  • 150 Points
  • 18:49:41, 16 January

You don't seem to understand the magnitude of the system. Small changes in global average temperature correspond to enormous changes in global weather patterns; global average temperatures were only about 7° lower than they are now during the last glaciation. A temperature increase of nearly a degree is a significant change in the energy content of the Earth's atmosphere; distributed across the entirety of the tropospheric mass, it's on the scale of 10^21 joules, an order of magnitude larger than world annual energy consumption.

Furthermore, warming is only one of the dangers of climate change. Even the fiercest deniers who refuse to confront the reality about rising temperatures can't argue against ocean acidification. More CO2 in the atmosphere means more dissolved CO2 in the oceans, which mean more carbonic acid, which means depleting the saturation of available calcium for calcifying organisms. In water much more acidic than the oceans are now, calcifying organisms are unable to maintain their shell due to basic chemistry, and die. The coral reefs and ecosystems they sustain help to feed more than 1 billion people globally, and that food supply is threatened.

I would strongly urge you to do more research on the issue of climate change. It's the most pressing issue of our time, and yet among laymen there are droves of misinformation. However, to anyone sufficiently motivated to review the research that supports the scientific consensus on anthropogenic global warming and climate change, the reality is entirely clear.

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  • [deleted]
  • 1 Points
  • 23:16:52, 17 January

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  • 5 Points
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  • 3 Points
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  • 02:16:24, 18 January

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  • 02:28:48, 18 January

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  • 02:40:58, 18 January

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More Comments - Not Stored
  • [-]
  • Oathbroken
  • -3 Points
  • 21:11:30, 17 January

http://en.wikipedia.org/wiki/File:65MyrClimate_Change.png

  • [-]
  • BreadstickNinja
  • 12 Points
  • 22:06:44, 17 January

Yes, the Earth is a whole lot hotter when there's more carbon dioxide in the atmosphere, and rapid release of greenhouse gases into the atmosphere causes rapid warming, such as during the PETM illustrated in your chart.

That's why we're having a discussion about it. What's your point?

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  • [deleted]
  • -3 Points
  • 20:25:53, 16 January

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  • [-]
  • BreadstickNinja
  • 125 Points
  • 21:09:25, 16 January

The first part is an oversimplification, and the second part is flat-out wrong. I understand what we can and can't know about the system; I understand the uncertainties involved, and where we can and cannot discern a causal link. The climate is not an entirely chaotic system; while certainly many aspects of meteorology cannot be known in the specific, we are entirely capable of discerning large-scale trends.

As for your latter statement, you seem to be tremendously ill-versed on the fundamental science behind carbon dioxide's infrared activity, which underlies the role it plays in the atmosphere. Let me state this as clearly as possible: It is a fundamental physical fact that carbon dioxide traps heat. This was quantified by John Tyndall in the 1850s, who performed the original laboratory testing of the properties of atmospheric gases after inventing the thermopile. You can replicate this experiment in any basically-equipped high school laboratory: Take two vessels, and increase the carbon dioxide content of one by any means you like. Expose both to a source of infrared radiation (as simple as leaving them out in the sun) and monitor their temperature. The vessel with higher carbon dioxide concentration will be warmer than the other.

Why? Because carbon dioxide, like all triatomic and larger molecules, is active in the infrared band. The fundamental vibrations of the molecule are such that it absorbs infrared radiation, then reemits it in a (very nearly) random direction. The effect that this has in the atmosphere is that, as infrared radiation is emitted by the warm surface, some of it is absorbed by carbon dioxide molecules in the air, and essentially reflected downwards when it is reemitted.

Now, I really hope you don't consider your argument that "It's a trace gas, therefore it doesn't control climate" to have any scientific validity, or this country is really in trouble. First of all, get your nomenclature in order. In the field of climatology, we talk about climate forcing mechanisms and climate response mechanisms, myriad effects which comprise the climate system. There's no one effect that "controls" the climate. Instead, we identify primary forcing mechanisms, that is, those mechanisms which play a primary role in climatic change, and contrasted to secondary forcing and feedback mechanisms.

The role of carbon dioxide in atmospheric warming is well-established; there are countless observations which confirm that increased tropospheric heat retention, and specifically that cause by increased carbon dioxide concentrations, is responsible for the trend of tropospheric warming. For instance, while the troposphere is warming, the stratosphere is actually cooling. Why? Precisely because of the increased retention of heat in the lowest layers of atmosphere. This observation alone discredits any of the variations on "It's the sun" that I so often hear from deniers, as it precludes a solar and necessitates a terrestrial explanation relating to the behavior of infrared radiation in the atmosphere. The exact same behavior leads to certain other predictions, for example that winters will warm faster than summers, and nights faster than days. Both of these predictions proved accurate.

Your own position seems to be a variation on "The climate has changed before, so this time it can't be us," another perennial favorite of deniers, which essentially posits that human activity can't result in a primary forcing mechanism. This position is incorrect; while it's true that natural changes follow relatively predictable, cyclical patterns as shown in the Milankovitch cycles, they occur due to understood changes in precession and the eccentricity of Earth's orbit which occur with 100,000 and 400,000 year periodicity, and do not explain the current warming trend. As for lesser periods of natural variation, such as the Medieval Warm Period and the Little Ice Age, these natural effects produced warming and cooling of ~0.5° C, over about 800 and 700 years respectively. By contrast, the current warming trend is ~0.76° C over 130 years, occurring roughly ten times as fast.

So:

  1. We understand that climate is a system comprised of myriad forcing and response mechanisms, including primary forcing mechanisms which assume primary responsibility for change in climate.
  2. Repeatedly, over geologic timescales, carbon dioxide shows remarkable correlation with global temperatures.
  3. Carbon dioxide is infrared active due to its basic physical properties; it is an undisputed scientific fact that, in the absence of feedback mechanisms, a doubling of carbon dioxide concentration produces about a 1° C increase in temperature, and you can prove this in a basic high school lab.
  4. Human activities are by far the primary contributor to increased atmospheric carbon dioxide concentrations. This is confirmed through bottom-up accounting, the Mauna Loa data, direct calculations of fossil fuel consumption, and so forth.
  5. Observation data unequivocally preclude a solar causal mechanism; neither do temperature trends correlate with variations in solar output, nor do divergent temperature trends between layers of the atmosphere allow such an explanation.

This is why there's 98% consensus among climatologists that anthropogenic influences are causing the current warming; there's simply no other known mechanism that explains it, and among known mechanisms, the effects of increased greenhouse gas concentrations are a stunningly good fit. Year after year, the evidence in favor of this theory piles up, while no credible evidence to the contrary has been found despite millions of dollars of research funded by the energy companies. It's absolutely ludicrous to stand before such a staggering mountain of evidence and claim it doesn't exist.

TL;DR: I didn't spend ten years at university to lose an argument about climate to an armchair expert who clearly has no background in basic science, let alone climatology. But you can feel free to try.

  • [-]
  • randomguy186
  • 2 Points
  • 21:21:38, 17 January

> The climate is not an entirely chaotic system; while certainly many aspects of meteorology cannot be known in the specific, we are entirely capable of discerning large-scale trends

Just a nitpick; I think this is the hallmark of a chaotic system. Over short periods of time, I can approximately predict the location of a particle; in the long term, I can't even approximate the location of a particle, but I know it will lie within a certain attractor. This was Lorenz's insight / discovery.

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  • BreadstickNinja
  • 9 Points
  • 22:04:50, 17 January

Your characterization is probably better, though my comment makes less sense without context.

The now-removed comment said something along the lines of "I don't know, and neither do you. No one can make predictions about a chaotic system." My point was that I may not be able to predict the temperature in Phoenix on April 3rd, but that doesn't stop me from noticing the discrepancy in Earth's energy balance that leads to heating overall.

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  • I_DEMAND_KARMA
  • 1 Points
  • 00:35:08, 18 January

Keyword: Entirely.

If it's entirely chaotic...

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  • dpsprink
  • 11 Points
  • 04:49:43, 17 January

Wish I could upvote you more than once...

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  • sisyphan_sophistry
  • -1 Points
  • 06:43:25, 18 January

On it.

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  • dpsprink
  • 2 Points
  • 05:36:22, 19 January

Got it. Good one.

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  • [deleted]
  • -4 Points
  • 21:21:09, 16 January

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  • BreadstickNinja
  • 54 Points
  • 21:29:41, 16 January

Strawman argument. The idea that the Earth was the center of the universe was based in religion and superstition, not scientific observation or mathematical calculation. One of the very first conclusions following the application of the scientific method to astronomy was that of heliocentrism. Your argument is illogical, irrelevant, and addresses exactly none of the content of my post, or any of the scientific evidence for anthropogenic global warming.

Don't even try arguing the subject if you don't know the first thing about it. Why are you even subscribed to this subreddit anyway?

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  • [deleted]
  • -2 Points
  • 14:34:57, 17 January

[deleted]

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  • BreadstickNinja
  • 61 Points
  • 14:53:50, 17 January

First of all, thanks for every point in my post you didn't address. I'll just assume that you're unprepared to discuss the actual science, and you concede every one.

Now to your post. Ten years at university, and you'd better believe I know enough about the state of the science not to fall for such an inane comment. Climate sensitivity is always presented as a range, dictated by confidence intervals, depending on the statistical certainty of each of the assumptions. You do understand how statistical certainty works, don't you?

Let's move to a history lesson. The first estimates of climate sensitivity were made by Svante Arrhenius in 1896, and the estimates have been continually refined over the 117 years since, as scientists have developed more confidence in the component factors. Much of the remaining uncertainty lies in mechanisms like cloud formation and cover, which are difficult to model precisely. However, that doesn't mean they can't be represented in a statistically accurate fashion, reflecting the range of possibilities.

Through refining those estimates, the IPCC published a likely range of sensitivity from 2° C to 4.5° C in 2007. In the years since, scientists at Oxford University have run a distributed computer project to analyze more than 152 million model years of climate simulations, comparing historical data against modeling results to determine what sensitivity factors produce the most accurate results. Fasullo and Trenberth performed a similar analysis to attempt to narrow the range. And the result? The values near the bottom of the sensitivity range were worse at replicating historical climate data than those higher in the range.

I don't know if you're grossly misrepresenting the state of the science because you're a troll, or because you don't know anything about it. But it doesn't really matter, because either way, you're wrong. And don't worry-- I'm making a note to bookmark your user page, so every time you start thinking you know more than a team of Oxford PhDs, I can stop by to give you the slapping around you so desperately need.

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  • thevoiceless
  • 19 Points
  • 19:15:21, 17 January

Assuming you've been responding to the same person every time, that's at least 2 new assholes you've torn for them...

I like you.

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  • BreadstickNinja
  • 19 Points
  • 20:10:58, 17 January

Thanks, I like you back. I'm an atmospheric chemist by training, not a climatologist, but the disciplines overlap enough that I can call in an airstrike from time to time.

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  • thevoiceless
  • 14 Points
  • 20:58:41, 17 January

I'm a computer scientist, so I appreciate people like you that take the time to create well-formed arguments about things that I care about but have very little knowledge of

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  • yosemitesquint
  • 7 Points
  • 23:10:50, 17 January

Truly, BreadstickNinja, you were a voice for thevoiceless.

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  • Shanman150
  • 3 Points
  • 05:28:47, 18 January

In the future, try to recognize in advance that unscientific comments (particularly layman speculation) get removed. So quoting the parts of the comment that you're refuting helps to give additional context.

On another note, I've learned a lot today, thanks.

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  • virnovus
  • -6 Points
  • 04:53:41, 18 January

My issue is with global warming alarmists like Bill McKibben who vastly overstate the danger of climate change, or at least its danger to humanity. To these folks, it's almost more religious than scientific; mankind has sinned with his unnatural machines, and he must turn back to the ways of his ancestors, or his future is assuredly one of doom.

But that's not true.

Earth's climate is gradually changing like it always has. We're speeding up that change, but it has never been static. 7000 years ago, there were glaciers extending all the way to the Great Lakes, when there were people living there. Arctic land ice has been retreating ever since. Over the coming centuries, the Greenland ice sheet will likely melt, raising sea levels a few inches a year, topping out at about twenty feet. The Antarctica ice caps will stay frozen; it'll still be too cold there for that ice to ever thaw.

As far as ocean acidification, it'll change the makeup of plankton for sure, and have a deleterious effect on coral reefs. But even though coral reefs are beautiful, and their absence would make us sad, they don't really contribute much to people in the way of resources. Only a small fraction of the oceans biomass (but a disproportionate fraction of its species) live in and around coral reefs. And yes, there are human populations living on coral-supported islands in the South Pacific, that may need to be relocated. But not very many. And not all coral would disappear. Coral and other calcifying organisms have existed in the fossil record during periods of much higher atmospheric CO2 levels, and would continue to exist even if we tried our hardest to kill them all.

And I guess the sad part is that most people don't care. Even if people like Bill McKibben lie and prophesy doom if they don't change their ways, they still don't care, so why would they care about crumbling coral reefs on the other side of the world, or sea levels that rise more slowly than their toenails grow?

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  • DJUrsus
  • 6 Points
  • 05:35:22, 18 January

> My issue is with global warming alarmists like Bill McKibben who vastly overstate the danger of climate change, or at least its danger to humanity.

He is himself a straw man, and should be treated as such. That doesn't make other arguments less valid.

> And yes, there are human populations living on coral-supported islands in the South Pacific, that may need to be relocated.

They are part of the food supply of about a billion people. We're not relocating that many.

> they still don't care, so why would they care about crumbling coral reefs on the other side of the world, or sea levels that rise more slowly than their toenails grow?

Most people would care if they actually believed that it's a danger for their children and grandchildren.

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  • virnovus
  • -2 Points
  • 06:18:28, 18 January

> He is himself a straw man, and should be treated as such. That doesn't make other arguments less valid.

Fair enough, but it does bother me that he can be so dishonest, while wrapping himself in the mantle of science.

> They are part of the food supply of about a billion people. We're not relocating that many.

Key word being "part". Not all South Pacific islands are coral-supported, most are volcanic or part of continental plates, and those would remain. Coral islands tend to be the smallest type of islands anyway, with the largest of them only being a few square kilometers.

When I said coral-supported, I meant actual coral islands, not people economically supported by fishing coral reefs. Coral reefs are not a major source of fish for commercial fisheries anyway.

> Most people would care if they actually believed that it's a danger for their children and grandchildren.

And that's the kicker. If you look at the science objectively, it's clear that the vast majority of humanity will get along just fine, especially in the first world. Many wild plants and animals, as well as poor people living close to nature, will not be so fortunate.

  • [-]
  • DJUrsus
  • 5 Points
  • 06:59:19, 18 January

> Coral reefs are not a major source of fish for commercial fisheries anyway.

The people to be worried for are the subsistence fishers.

> the vast majority of humanity will get along just fine, especially in the first world.

The vast majority of humanity is in the third world. Also, we in the first world rely pretty heavily on seasonal farming. If we have to re-learn how farming works, a lot of us are going to die.

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  • virnovus
  • -2 Points
  • 07:25:25, 18 January

> The people to be worried for are the subsistence fishers.

Which is a population so small they'll essentially be written off. I'm not saying they should be, just that they will be. In any case, coral reefs won't disappear, so much as be significantly reduced in size and number.

> The vast majority of humanity is in the third world.

About two thirds. And there are wealthy people in third-world countries too, who will be just fine.

> Also, we in the first world rely pretty heavily on seasonal farming. If we have to re-learn how farming works, a lot of us are going to die.

The climate won't change overnight. It will change noticeably on a timescale of decades, which is gradual enough for people to make adjustments each year. And like the drought last summer, it won't cause massive starvation, even though crop yields were much smaller than usual. Rather, people will just feed less of it to animals and eat more of it in plant form, based on commodity prices. Remember the bacon shortage? That sort of event is how climate change will effect the first world.

It actually bums me out that climate change won't have more of an effect on the first world, but like most other issues, it'll hit the poorest and least-industrialized the hardest. Personally, I think peak oil is a bigger problem for the first world, but if that ever comes to be, they'll just go with coal liquefaction, which is the dirtiest, most polluting thing to do that I can imagine. Damn it, this is making me depressed...

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  • DJUrsus
  • 3 Points
  • 14:43:29, 18 January

Each of the things you mention is terrible, and I don't understand why you're not outraged.

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  • virnovus
  • 0 Points
  • 16:32:23, 19 January

I know it's terrible. My point is just that if we look at the facts honestly, this is how it's going to happen. These predictions don't make me feel good or vindicated; rather, they're quite depressing. But studying this, and looking at all the facts, this seems like the most likely outcome.

I neglected to mention that stuff like flooding will become more common, but that will just mean more events like Hurricane Sandy, which did a lot of property damage but didn't lead to any massive loss of life.

  • [-]
  • DJUrsus
  • 2 Points
  • 17:44:49, 19 January

It's currently a more likely outcome than other, better ones. But it's possible to change that. You don't have to sit and watch history take its course. You can participate, and maybe change things for the better.

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  • virnovus
  • 1 Points
  • 00:31:41, 20 January

In a parallel universe, where Al Gore became president in 2000, (and let's say he also ignored the memo "Bin Laden Determined to Attack US") I can imagine him saying "Osama Bin Laden's family became wealthy from oil money. Money we paid the middle east for their oil. Let's ensure that we don't fund the next Osama Bin Laden by making all our energy renewable." In such a universe, I imagine the United States is considerably better off.

Everyone who knows me knows my opinion: invest more resources into nuclear energy, especially fusion reactors, and reactors that can run on either thorium, LWR waste, or both. But when the US government spends more money trying to keep people from using drugs, than it does on researching and building more reliable nuclear reactors, it shows a remarkable lack of priorities.

More Comments - Not Stored
  • [-]
  • archiesteel
  • 2 Points
  • 18:29:16, 18 January

>And that's the kicker. If you look at the science objectively, it's clear that the vast majority of humanity will get along just fine

I don't know how you can affirm this. It's quite clear that anthropogenic global warming represents a threat to humanity as a whole.

When even the Pentagon - not exactly a bunch of tree-huggers - consider AGW a threat, arguing that it doesn't seems a bit misinformed, to say the least.

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  • archiesteel
  • 2 Points
  • 18:25:38, 18 January

>Earth's climate is gradually changing like it always has. We're speeding up that change, but it has never been static.

No one has ever claimed the climate is static. The problem here isn't that we're speeding up that change, but that we're actually overcoming it. Indeed, it should be (very slowly, i.e. 0.3C/Ky) cooling right now.

>7000 years ago, there were glaciers extending all the way to the Great Lakes, when there were people living there. Arctic land ice has been retreating ever since.

I think your dates are off a little. The last glacial period ended about 12,000 years ago, and the climatic optimum (i.e. the warmest pead of this interglacial) happened 8,000 years ago.

Also, there is no "Arctic land ice"...perhaps you meant to say Antarctic? In any case, as I noted above, they should be retreating right now as we're already past the Holocene Climatic Optimum.

Also, I'm not quite sure why you say that Bill McKibben is lying...what particular lie are you thinking about?

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  • virnovus
  • 1 Points
  • 14:19:54, 19 January

> No one has ever claimed the climate is static. The problem here isn't that we're speeding up that change, but that we're actually overcoming it. Indeed, it should be (very slowly, i.e. 0.3C/Ky) cooling right now.

Yes, I meant that we're speeding up the rate of change, that the Earth is normally undergoing. Also, if the Earth were cooling, that would be significantly worse for humanity than the Earth warming. Cooler periods tend to be dryer due to lower evaporation rates, with less arable land overall.

> I think your dates are off a little. The last glacial period ended about 12,000 years ago, and the climatic optimum (i.e. the warmest pead of this interglacial) happened 8,000 years ago.

See for yourself. This is from the wikipedia page on the Great Lakes:

http://en.wikipedia.org/wiki/File:Glacial_lakes.jpg

> Also, there is no "Arctic land ice"...perhaps you meant to say Antarctic? In any case, as I noted above, they should be retreating right now as we're already past the Holocene Climatic Optimum.

The Greenland ice sheet would be considered Arctic land ice. There used to be more of it though, in Canada.

> Also, I'm not quite sure why you say that Bill McKibben is lying...what particular lie are you thinking about?

That AGW represents an existential threat to humanity. It really doesn't.

  • [-]
  • archiesteel
  • 2 Points
  • 16:41:32, 19 January

> Also, if the Earth were cooling, that would be significantly worse for humanity than the Earth warming.

Sure, but with a cooling rate of 0.3C/millenia, it wasn't exactly a rapid transition...

>See for yourself. This is from the wikipedia page on the Great Lakes:

That is only for the Northeastern part of North America, though. The last glacial period ended 12,000 years ago. This is from the wikipedia page on that specific subject:

>The end of the last glacial period was about 12,500 years ago [...]

See also:

http://en.wikipedia.org/wiki/Holoceneclimaticoptimum

>The Holocene Climate Optimum (HCO) was a warm period during roughly the interval 9,000 to 5,000 years B.P. [...] Northwestern North America had peak warmth first, from 11,000 to 9,000 years ago, while the Laurentide ice sheet still chilled the continent. Northeastern North America experienced peak warming 4,000 years later.

And also:

http://en.wikipedia.org/wiki/Holocene

>The Holocene is a geological epoch which began at the end of the Pleistocene (around 12,000 to 11,500 14C years ago) and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words ὅλος (holos, whole or entire) and καινός (kainos, new), meaning "entirely recent". It has been identified with the current warm period, known as MIS 1 and based on that past evidence, can be considered an interglacial in the current ice age.

Obviously it's hard to pinpoint an exact date as the process itself took a coupl of thousand years, but the end of the last glacial period is generally set at the beginning of the Holocene, around 12,000 years ago.

>The Greenland ice sheet would be considered Arctic land ice. There used to be more of it though, in Canada.

I'm not sure that is the right name for it, though. I think "Laurentian Ice Sheet" and "Greenland Ice Sheet" are the better names (to avoid confusion).

>That AGW represents an existential threat to humanity. It really doesn't.

If one means that it could wipe out humanity completely, I tend to agree (though any warming of more than 8C could trigger oceanic anoxia, which could cause a mass extinction event).

If one means an existential threat to human civilization, then it's not so cut-and-dry. I'd be curious to read the context in which that declaration was made.

I also think that those who deny the existence of AGW, or that say we don't need to worry about it, represent a much bigger problem than those who exaggerate it. Right now, apathy is a more serious issue than alarmism.

  • [-]
  • virnovus
  • 1 Points
  • 17:21:05, 19 January

> Obviously it's hard to pinpoint an exact date as the process itself took a coupl of thousand years, but the end of the last glacial period is generally set at the beginning of the Holocene, around 12,000 years ago.

I never argued with that, my point was just to illustrate the time scales at which Earth's climate changes entirely on its own.

> If one means that it could wipe out humanity completely, I tend to agree (though any warming of more than 8C could trigger oceanic anoxia, which could cause a mass extinction event).

The ocean is so many different temperatures though, that species would still be able to find a place, even if it had to be in the polar regions.

> If one means an existential threat to human civilization, then it's not so cut-and-dry. I'd be curious to read the context in which that declaration was made.

If the world became warmer, more people would move to Canada and Siberia. If sea levels rose, people would just live at higher elevations. There's really not much of a challenge there, for people. For wildlife, maybe though.

> I also think that those who deny the existence of AGW, or that say we don't need to worry about it, represent a much bigger problem than those who exaggerate it. Right now, apathy is a more serious issue than alarmism.

I hate dishonesty in any form. Especially when someone is dishonest and claims they have science on their side. There is a lot of false-dichotomy arguments going around too, about this issue. It's not necessarily an argument between deniers and believers; but about the potential severity and implications of the problem.

  • [-]
  • archiesteel
  • 2 Points
  • 17:29:34, 19 January

>The ocean is so many different temperatures though, that species would still be able to find a place, even if it had to be in the polar regions.

Read up on oceanic anoxia. It's not just about temperature, it's also about oxygen concentration in the water.

>If sea levels rose, people would just live at higher elevations. There's really not much of a challenge there, for people.

Not much of a challenge? Most of humanity lives in coastal regions. How easy do you think it would be to relocate billions of people?

I think you're underestimating the threat a little bit, here. Maybe you ought to check this out:

http://www.skepticalscience.com/global-warming-positives-negatives-intermediate.htm

  • [-]
  • virnovus
  • 1 Points
  • 00:16:16, 20 January

> Read up on oceanic anoxia. It's not just about temperature, it's also about oxygen concentration in the water.

True, but remember that Earth's temperature has been significantly higher in the past, and life has found a way. I suppose there's a strong argument that many species could go extinct, but others would thrive. And don't think I haven't read anything on anoxia, I've studied this issue very extensively. The sort of thermal anoxia you describe wouldn't affect the entire ocean at once, which was kind of my point.

> Not much of a challenge? Most of humanity lives in coastal regions. How easy do you think it would be to relocate billions of people?

Most of the world's population can just relocate a ways uphill if sea levels rise. (Yes, there are places like the Maldives, but that's still a minority of people) The coast would just move, and people would move with it. Anyway, people tend to relocate themselves, during other disasters like earthquakes and tsunamis.

I read the link you sent, and it's not exactly wrong, per se, since all of those problems would probably increase, at least in populated areas that tend to support the most people now. But of course, it doesn't say how much. 10%? 50%? Granted, no one knows and no one can say, which is why, like I said, the debate should be over the magnitude of the effects, not over whether the effects are occurring.

  • [-]
  • archiesteel
  • 2 Points
  • 00:19:30, 20 January

>True, but remember that Earth's temperature has been significantly higher in the past, and life has found a way.

It did...but there have also been large-scale extinction events. Oceanic anoxia is thought to have triggered the Permian-Triassic extinction in which 90% of marine species died out.

>Most of the world's population can just relocate a ways uphill if sea levels rise. (Yes, there are places like the Maldives, but that's still a minority of people) The coast would just move, and people would move with it

The cost of this would be much, much greater than moving away from fossil fuels. With regards to man-made global warming, Mitigation is a much better survival strategy than adaptation.

  • [-]
  • virnovus
  • 1 Points
  • 00:40:11, 20 January

> It did...but there have also been large-scale extinction events. Oceanic anoxia is thought to have triggered the Permian-Triassic extinction in which 90% of marine species died out.

That's one theory. It also could have been a number of other things. In any case, there was likely some large-scale trigger.

> The cost of this would be much, much greater than moving away from fossil fuels. With regards to man-made global warming, Mitigation is a much better survival strategy than adaptation.

Not really. Sea levels would rise very slowly, and buildings need to be replaced every so often anyway. Plus, sea levels will probably only rise 20 feet, which is the case where the Greenland ice sheet melts. The Antarctic ice sheet will almost certainly stay where it is, because temperatures are so cold there, that they couldn't really ever increase to the point where water would melt. (And even if they did, that would increase sea levels by 200 feet. Which would be really bad, but we could deal with it.)

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