Nuclear Winter and Global Warming?

[K^2]

11 hours ago, magnemoe said:

I do not see how reflective particles in the upper atmosphere could create an warming, It reflect sunlight before it can come further down.

Something that has very different albedo in visible and IR could. But dust/ash tends to have pretty low albedo in both. Certainly, albedo of dust/ash isn't higher than that of Earth itself. I'm going to throw a bit of math at you to illustrate this a little better. Lets start with a world with perfectly translucent atmosphere. We'll further assume that temperatures equalize around the world. That's not strictly true, but it's not too far off for a simple estimate. Lets say that planet's visible light albedo is α. In other words. So for a total incoming solar energy flux of W, αW gets reflected away. That means, (1-α)W gets absorbed. At the same time, planet looses hit via IR radiation. Albedo for IR tends to be pretty close to zero, so we'll take it at that. In that case, total radiation flux leaving the planet is 4σT₀⁴, where T₀ is temperature of the surface and σ is Stefan-Boltzmann constant. Factor of 4 comes from Earth being nearly a sphere. So we have the following.

T₀⁴ = (1-α)W / (4σ)

If you plug in values for Earth, you'll get in the ball park, but estimate will be a bit low, because we have not taken greenhouse effect and a few other corrections into account.

Now, lets add a layer of ash with the same albedo to the top layer of atmosphere. We will further assume that atmosphere does not circulate vertically, allowing perfect insulation between that ash and ground. In other words, heat exchange is via IR only. (We'll augment that in a moment.) Lets call the new surface temperature T₁ and ash cloud temperature T_a. The surface still radiates 4σT₁⁴, but all of that is now absorbed by the ash cloud. The ash cloud, in turn, radiates both with the top and bottom surface, so it radiates 8σT_a⁴, of which 4σT_a⁴ goes back to the surface, and rest leaves to space. In addition, ash cloud still receives (1-α)W of solar radiation. Putting it all together, we have two equations.

8σT_a⁴ = (1-α)W + 4σT₁⁴

4σT₁⁴ = 4σT_a⁴

After solving this, we have T₁⁴ = T₀⁴. In other words, ash in atmosphere has not changed surface temperature at all. Now, if ash happened to have significantly higher albedo, it would have caused temperature to drop. But that'd be no different from having that ash simply sit on the ground. Whether it's on the surface or up in the air makes no difference whatsoever.

But we haven't talked about atmosphere dynamics yet, and that's a crucial element in climate. Imagine that we have the same situation. Perfectly opaque cloud of ash with roughly the same reflective properties as Earth's surface. But now, we also have air circulating between ground and upper atmosphere. The circulating air is at much higher pressure near the surface and at much lower pressure up above. The compression/decompression that air undergoes is roughly Adiabatic. So we have two heat sinks with a pressure gradient between them, at surface and cloud layer, and we have Adiabatic flow between them. What we really have is a giant, planet-sized refrigerator. Except, it's pointed with the hot side towards ground and cold side towards the sky. Now, if atmosphere is transparent and there are no clouds, it doesn't matter. All it does is make it cold at higher altitudes, which we do observe on this planet. But if your clouds are completely opaque, the clouds aren't going to get colder. They are at radiation equilibrium with Sun and space. The ash cloud will stay at the same T_a = T₀ as before. What will change is the surface temperature. The atmosphere will keep pumping heat from the ash cloud down to the ground, establishing a much higher temperature on the surface. How much higher? Well, the temperature difference between ground and clouds is a starting point. It won't be quite as big of a gap, because there is still some radiation exchange, but that's the ballpark. So we aren't talking half a degree. We are talking about global temperatures rising by tens of degrees if this was to happen on Earth.

For an example of this in action, take a look at Venus. Yes, it's closer by the Sun, and should be a little warmer, but it's not a little warmer. It's very, very hot. And the reason for it is the clouds. Opaque clouds at high altitude with a very high pressure differential between cloud layer and surface. The same exact atmospheric flows carry heat from clouds down to the surface heating it up. Whereas, if nuclear winter was a thing, you'd really expect Venus to be an icicle.

[Guest]

Increasing opaque material into the atmosphere makes the planet warmer? This would only make sense to me if this material was acting like a blanket that was trapping heat produced from the planet itself, not by trapping heat originating from the sun. Example : placing a blanket on my bunk does not make the mattress warmer, in fact, it makes it colder. It insulates the mattress from the heated air in the cabin. The bunk is cold until I get in it. When I get in the bunk, the blanket traps my body heat, making the bunk feel warm after a short period of time. Of course, I saw one of my math teachers prove that 2+2=5 with a long, drawn out, multiple chalk board filling proof. It would take hours to dissect the proof and find the error. So, feel free to pontificate my "blanket" example.

[micr0wave]

i'm not sure if i read that right or there's a typo, but when 4σT₁⁴ = 4σT_a⁴   and T_a = T₀ shouldn't T₀=T₁=T_a which then means all temperatures are the same ?

[Findthepin1]

8 hours ago, K^2 said:

Whereas, if nuclear winter was a thing, you'd really expect Venus to be an icicle.

90 atm of mostly CO2 is much more than enough to combat this. In Venus' case, the greenhouse effect is so much that the albedo practically doesn't matter and it'll still be hot at an even higher albedo. If Venus' atmospheric albedo was similar to Earth's or Mars', the surface would be like 7 or 800 degrees Celsius. gonna edit this l8r gotta go work

[Admac]

What you are describing in the OP is exactly what scientists call Geoengineering. It's super controversial since it's directly messing with the environment, albeit at a lesser extent that the combined industries of Earth. The cooling shade theory has two semi realistic options, increased clouds and solar umbrellas.

To increase the reflectiveness of the planet, the idea is to get thousands of autonomous drone ships in the deep ocean, using solar or tidal or ocean currents for power, and evaporating massive plumes of steam to blanket the oceans in a semi permanent cloud layer. The perk to this is it's a thing that can be reversed fairly quickly, the drawback is monumental costs, and the effects of changing the humidity on a planetary scale is still unknown. This is a lot like your nuclear winter idea, but a lot less radioactive/murder-y.

The solar umbrella is looking more likely as launch costs keep falling, but placing some big shiny Mylar mirrors at the solar Lagrange point to reflect a bunch of the suns light back. also heartstoppingly expensive, and also filled with unknowns. 

In the end it might be what gets done, but we are decades away from any sort of consensus, and even then they will need to find a trillion-ish bucks to make it a reality.

[GeneralVeers]

On 1/18/2016 at 6:15 PM, Laie said:

Key point was that the fires, though hot and fierce, did no create enough updraft to put the dreck into the upper atmosphere (where it would have a half-life on the order of a year or three). Instead it stayed pretty low and fell down / was washed out comparatively quickly. Nasty for the persians, but not a global event.

Exactly. The fires didn't push the schmutz up.

Wait.....you said "dreck".....I got it! Let's call it "schmutzdreck"! Nation, today's Word is "schmutzdreck"!

The Kuwait oil fires didn't push the schmutzdreck up. Neither will most nuclear weapons. An airburst (which will generally be used against civilian targets such as cities) will push down. A ground burst will push sideways (though the atmospheric implosion after the detonation can suck in dirt and debris and send it upwards). Only an underground detonation can push large amounts of schmutzdreck up--except that underground detonations are hardly ever going to happen during a nuclear war. Those only happen during tests.

 

On 1/17/2016 at 10:47 PM, Chewy62 said:

Who's gonna pay to have all of the world's ports raised to accommodate rising sea levels?

What will happen when all of our coral reefs die off?

Who's going to take in all the refugees from the Persian Gulf when its constantly 125 degrees in the summer?

What about possible loss of strength in the gulf stream, leading to the cooling of Europe?

Just kidding! This is of little importance when we can grow crops in Siberia!

The locals will pay for all the above, of course. It will be worth it.

San Francisco is already largely built on land that used to be ocean. Coastal towns in many countries have been dealing with erosion for centuries. When the sea erodes the shore and houses collapse, people simply build new houses on the new shoreline because it's worth that much to them. As sea levels rise, humans will rebuild. Because in the long run it will be worth it to build something that will only be temporary, instead of to build nothing at all. A hospital that only lasts ten years before getting flooded out and torn down will still save a lot of people.

On the flip side, many of the world's worst problems, for most of the world's poorest people, have to do with lack of food, so your last line is (possibly by accident.....) right on the money. More food will definitely make it worth putting up with other problems, which by comparison will turn out to be minor.

 

On 1/18/2016 at 8:37 PM, Chakat Firepaw said:

I'm looking at the charts, comparing to the mid-20th century average:

Peak temperature c.3000 years ago:  The same as mid-20th century.

Peak temperature c.2000 years ago:  ~0.2C _below_ the mid-20th century.

 

So, are you lying about seeing the charts, lying about what they say, or did you get them from a liar like Tony Watt?

Heheheh. You chose this path. Now I have a surprise for you. Deploying surprise in 5....4....3....2....1....

I got many of my charts from people like you. In all the past global warming threads on this web site (and many other chat sites, most of which were considerably more hostile than this one!) people posted charts all the time. And guess what, they all have different numbers. Frequently only different by a small amount, sometimes different by a lot. Often the same chart would get posted in many different places. Bottom line is, you can't pick out one chart that says what you want it to, because frequently it will be an outlier and therefore bogus. I've seen enough graphs and numbers and squiggly lines (red seems to be the most popular color for some reason) to know the trends, if any, are extremely dicey.

Side note: you made a point of mentioning that the "peak temperature 2000 years ago" was below mid-20th century. Yes, I know why you said that. To which I reply: why should that be a deal? There's no reason all three peaks over the last 3000 years should be the same height (actually the trend goes back ELEVEN thousand years, but as you go further back it appears less regular, probably due to increasing difficulty in measuring from geological data). Obviously some of the warm periods should be warmer than others. Why not the current one? So, why does the current one (allegedly) appear warmer? Could be a coincidence.

 

On 1/18/2016 at 8:37 PM, Chakat Firepaw said:

When the underlying basis for a forecast doesn't happen, the fact that the forecast doesn't match the outcome says nothing about the validity of the forecast.

Yes it does. It says the forecaster made a bad forecast and should have included a "well, what if this happens instead" clause.

 

On 1/18/2016 at 8:37 PM, Chakat Firepaw said:

Human habitability already reaches as far north as the land goes and the only regions to gain in the south have the little problem of being on top of collapsing glaciers.

I never said "north" or "south".

Global warming will not extend human habitability in that sense. Global warming will cause deserts and tundra that humans already live near (or in), to shrink. Meaning. among other things, more food can be grown in those regions.

 

On 1/18/2016 at 8:37 PM, Chakat Firepaw said:

Funny how the deserts of the world are doing exactly the _opposite_ of what you expect.

I already explained the reason for this: deserts are expanding because of increasing water usage and bad farming practices. Both of which stem primarly from human overpopulation. When you get right down to it, overpopulation is the cause of most other problems.

 

On 1/18/2016 at 8:37 PM, Chakat Firepaw said:

The effects of global warming are different from those of regional warming.  This is because regional warming doesn't cause the various nasty large scale effects.

Regional warming obviously contributes to global warming. In fact, it's entirely plausible that at least some of the time, changes in solar insolation should produce regional warming rather than global! Why? Because the Earth's northern hemisphere has more land in it. Its albedo is different. There's no reason a warming trend "has to" be evenly distributed worldwide.

Regional or not, the fact is that the next natural climate optimum was scheduled to occur TODAY. It is a significant factor, probably the primary one. Possibly the only one. And there's no reliable proof to the contrary. Bottom line: anthropogenic global warming is dead. It was always a bogus idea, born from some twisted human fascination with thinking human beings are the cause of everything that goes wrong.

[K^2]

17 hours ago, micr0wave said:

i'm not sure if i read that right or there's a typo, but when 4σT₁⁴ = 4σT_a⁴   and T_a = T₀ shouldn't T₀=T₁=T_a which then means all temperatures are the same ?

They are the same. Without atmospheric circulation, ground simply reaches equilibrium with the clouds. And if the clouds are opaque, they reach the same temperature that ground would without the clouds. That's the whole point.

It's only when you take air circulation into consideration that you start picking up a temperature differential between clouds and ground. And it's always towards warmer ground.

14 hours ago, Findthepin1 said:

90 atm of mostly CO2 is much more than enough to combat this. In Venus' case, the greenhouse effect is so much that the albedo practically doesn't matter and it'll still be hot at an even higher albedo. If Venus' atmospheric albedo was similar to Earth's or Mars', the surface would be like 7 or 800 degrees Celsius. gonna edit this l8r gotta go work

Sure. If all that Venus had was perfectly transparent in visible light atmosphere of CO₂. But it doesn't. It's atmosphere is pretty opaque. So light doesn't reach the ground, so you can't use conventional greenhouse effect to explain the absurdly high temperature on the ground. Try again.

20 hours ago, Otis said:

Increasing opaque material into the atmosphere makes the planet warmer? This would only make sense to me if this material was acting like a blanket that was trapping heat produced from the planet itself, not by trapping heat originating from the sun. Example : placing a blanket on my bunk does not make the mattress warmer, in fact, it makes it colder. It insulates the mattress from the heated air in the cabin. The bunk is cold until I get in it. When I get in the bunk, the blanket traps my body heat, making the bunk feel warm after a short period of time. Of course, I saw one of my math teachers prove that 2+2=5 with a long, drawn out, multiple chalk board filling proof. It would take hours to dissect the proof and find the error. So, feel free to pontificate my "blanket" example.

Demagoguery. And a false analogy to boot. Planets don't heat from heat transfer. It's not like Sun is blowing hot air at us. Planets heat from solar radiation. Now take your blanket, go outside on a warm sunny day, and stand under direct sunlight wrapped in a blanket. Then tell me how it makes you cooler.

And it's not even just that. As I have explained above, if it weren't for pressure differential and air circulation, the surface temperature would be merely the same. But we have a refrigeration cycle running. Unless you have an alternative explanation for freezing temperatures at altitude. And it's not because "space is cold". Space is a vacuum. It doesn't have a temperature in any way that's meaningful here.

The purpose of false-proof examples is to make you re-check the work. If you can't check 6th grade math in four lines of equations, that doesn't mean you can simply dismiss the argument. "I don't understand it, so you're wrong," should have stopped working in kindergarten. If you can't follow that simple math, the adult thing to do is ask questions or wait for somebody who does understand the argument to weigh in.

Edited January 19, 2016 by K^2

[nobodyhasthis2]

On 1/17/2016 at 1:38 AM, WedgeAntilles said:

Now, before anybody goes off on a bender and starts arguing about the above: remember that all of this is actual Earth history. Everything I described up there actually happened. It's basically impossible to argue.

Which backs you right into a corner. You can't argue the point then. Proves it is going to happen anyway and now we discussing how much worse we can make it by adding unnatural events. 

It is the rusty gun argument. The odds are it will not go off but I bet you don't want it pointing at your kids.

[micr0wave]

7 hours ago, WedgeAntilles said:

The Kuwait oil fires didn't push the schmutzdreck up. Neither will most nuclear weapons. An airburst (which will generally be used against civilian targets such as cities) will push down. A ground burst will push sideways (though the atmospheric implosion after the detonation can suck in dirt and debris and send it upwards). Only an underground detonation can push large amounts of schmutzdreck up--except that underground detonations are hardly ever going to happen during a nuclear war. Those only happen during tests.

You might want to review what you wrote there, approach it a bit more from the scientific than the propaganda direction (hint: underground tests have been done to prevent atmospheric contamination)

@K^2 the atmospheric model is maybe a bit too simplified, it's not a single, uniform layer. The energy coming in will only hit the ground to a small percentage.

[magnemoe]

23 minutes ago, micr0wave said:

You might want to review what you wrote there, approach it a bit more from the scientific than the propaganda direction (hint: underground tests have been done to prevent atmospheric contamination)

@K^2 the atmospheric model is maybe a bit too simplified, it's not a single, uniform layer. The energy coming in will only hit the ground to a small percentage.

Main problem with atmospheric tests are radiation, this and especially fallout hitting other countries was the reason it was banned. 
https://en.wikipedia.org/wiki/Partial_Nuclear_Test_Ban_Treaty

Regarding ash in the atmosphere, sunlight reflected high in the atmosphere has lite chance of releasing energy in the atmosphere. The heating of the ash will generate ir who only have to escape the outer part of the atmosphere to radiate out, far simpler than having to radiate all the way down to ground. 
Best analogy is an sunshade, it will reflect some sunlight and even if its heat up far less energy reach you than without it. 

[Chakat Firepaw]

8 hours ago, WedgeAntilles said:

Exactly. The fires didn't push the schmutz up.

Wait.....you said "dreck".....I got it! Let's call it "schmutzdreck"! Nation, today's Word is "schmutzdreck"!

The Kuwait oil fires didn't push the schmutzdreck up. Neither will most nuclear weapons. An airburst (which will generally be used against civilian targets such as cities) will push down. A ground burst will push sideways (though the atmospheric implosion after the detonation can suck in dirt and debris and send it upwards). Only an underground detonation can push large amounts of schmutzdreck up--except that underground detonations are hardly ever going to happen during a nuclear war. Those only happen during tests.

 Some news for you:  Airbursts push sideways and trigger firestorms.

8 hours ago, WedgeAntilles said:

The locals will pay for all the above, of course. It will be worth it.

So people who are already poor are going to be able to afford to rebuild entire cities.

8 hours ago, WedgeAntilles said:

San Francisco is already largely built on land that used to be ocean. Coastal towns in many countries have been dealing with erosion for centuries. When the sea erodes the shore and houses collapse, people simply build new houses on the new shoreline because it's worth that much to them. As sea levels rise, humans will rebuild. Because in the long run it will be worth it to build something that will only be temporary, instead of to build nothing at all. A hospital that only lasts ten years before getting flooded out and torn down will still save a lot of people.

On the flip side, many of the world's worst problems, for most of the world's poorest people, have to do with lack of food, so your last line is (possibly by accident.....) right on the money. More food will definitely make it worth putting up with other problems, which by comparison will turn out to be minor.

Too bad that a warming world means less overall food production, not more.

8 hours ago, WedgeAntilles said:

Heheheh. You chose this path. Now I have a surprise for you. Deploying surprise in 5....4....3....2....1....

I got many of my charts from people like you. In all the past global warming threads on this web site (and many other chat sites, most of which were considerably more hostile than this one!) people posted charts all the time. And guess what, they all have different numbers. Frequently only different by a small amount, sometimes different by a lot. Often the same chart would get posted in many different places. Bottom line is, you can't pick out one chart that says what you want it to, because frequently it will be an outlier and therefore bogus. I've seen enough graphs and numbers and squiggly lines (red seems to be the most popular color for some reason) to know the trends, if any, are extremely dicey.

So you mean to say that you were lying about what the charts said.

8 hours ago, WedgeAntilles said:

Side note: you made a point of mentioning that the "peak temperature 2000 years ago" was below mid-20th century. Yes, I know why you said that. To which I reply: why should that be a deal?

Because it you can't say "warmer is better" based on it having been better when it was cooler.

8 hours ago, WedgeAntilles said:

There's no reason all three peaks over the last 3000 years should be the same height (actually the trend goes back ELEVEN thousand years,

You're lying again:  11kYa was in the last glacial and there isn't any kind of even vaguely clean pattern to the peaks.

e.g. the c3000Ya peak is actually closer to 3500Ya, 3000Ya is a nadir.

8 hours ago, WedgeAntilles said:

but as you go further back it appears less regular, probably due to increasing difficulty in measuring from geological data). Obviously some of the warm periods should be warmer than others. Why not the current one? So, why does the current one (allegedly) appear warmer? Could be a coincidence.

Or it could be because the recent warming isn't simple variation.

8 hours ago, WedgeAntilles said:

Yes it does. It says the forecaster made a bad forecast and should have included a "well, what if this happens instead" clause.

So you really think that the statement "If X, then Y" is false when !X is the case?

All forecasts based on an even happening have an inherent "well, what if this happens instead" clause:  It's called "we have not made a prediction for this case."

8 hours ago, WedgeAntilles said:

I never said "north" or "south".

Global warming will not extend human habitability in that sense. Global warming will cause deserts and tundra that humans already live near (or in), to shrink. Meaning. among other things, more food can be grown in those regions.

OK, you clearly didn't get what I meant by uninhabitable:  I mean that humans DIE in fairly short order without mechanical support.  It doesn't matter what they wear or how they act, spending any length of time outside means you become a corpse.

Once the wet bulb temperature goes above 36C, it becomes impossible for the human body to lose heat and you will rapidly get heat stroke from simply sitting in the shade drinking water in a strong breeze.

8 hours ago, WedgeAntilles said:

I already explained the reason for this: deserts are expanding because of increasing water usage and bad farming practices. Both of which stem primarly from human overpopulation. When you get right down to it, overpopulation is the cause of most other problems.

I wasn't referring to the simple expansion of deserts, but how most have been seeing _higher_ temperatures and _lower_ rainfall.

8 hours ago, WedgeAntilles said:

Regional warming obviously contributes to global warming. In fact, it's entirely plausible that at least some of the time, changes in solar insolation should produce regional warming rather than global! Why? Because the Earth's northern hemisphere has more land in it. Its albedo is different. There's no reason a warming trend "has to" be evenly distributed worldwide.

Do you really not know how you would see different impacts in the scenarios "warmer in some places, cooler in others" and "warmer everywhere, some places more than others"?

8 hours ago, WedgeAntilles said:

Regional or not, the fact is that the next natural climate optimum was scheduled to occur TODAY. It is a significant factor, probably the primary one. Possibly the only one. And there's no reliable proof to the contrary. Bottom line: anthropogenic global warming is dead. It was always a bogus idea, born from some twisted human fascination with thinking human beings are the cause of everything that goes wrong.

The natural explanations have all been eliminated as possible causes for the recent warming.  In fact, the natural forcing factors are slightly cooling.

Meanwhile, we can _observe_ the fact that human actions have caused a strong warming change in the planet's energy flux.  Anthropogenic CO2 alone is causing ~1.6W/m^2 of warming.

[Vanamonde]

Second warning for the thread: discuss the topic without calling each other liars and throwing around accusations of "propaganda," or we will start handing out infractions and/or close the thread. 

[K^2]

6 hours ago, magnemoe said:

Regarding ash in the atmosphere, sunlight reflected high in the atmosphere has lite chance of releasing energy in the atmosphere. The heating of the ash will generate ir who only have to escape the outer part of the atmosphere to radiate out, far simpler than having to radiate all the way down to ground. 
Best analogy is an sunshade, it will reflect some sunlight and even if its heat up far less energy reach you than without it. 

Do you have some sort of a source that suggests that nuclear ash cloud would have an albedo that is significantly higher than Earth albedo, which averages to 0.3. In other words, Earth already reflects 30% of incoming sunlight, and I have hard time believing that ash from nuclear war would reflect more than 30% of sunlight.

Edited January 19, 2016 by K^2

[magnemoe]

2 hours ago, K^2 said:

Do you have some sort of a source that suggests that nuclear ash cloud would have an albedo that is significantly higher than Earth albedo, which averages to 0.3. In other words, Earth already reflects 30% of incoming sunlight, and I have hard time believing that ash from nuclear war would reflect more than 30% of sunlight.

Only previous information from various sources and the https://en.wikipedia.org/wiki/Nuclear_winter article.
Do you have any sources for your claim of warming or even no effect. 

Note that if the climate models can not agree if ash in the upper atmosphere will generate cooling or heating they are far below my previous estimate of far too inaccurate and down to educated guessing or worse. 

[K^2]

The problem is that I can't find any citations of albedo for the ash. Now, volcanic ash can have albedo reaching 0.7. So I can see how that can cause a significant cooling effect.

I'm going to try and track down the original articles for the publications Wikipedia cites, and see if I can find the values they've used. I can also put together a very simple model for both the heating and cooling effects and just run it for a range of albedo values to see what the break-even point would be. A simple model wouldn't be able to give me a very precise prediction on how strong the effect would be, but it should be fairly close on the break-even point, so it'd be possible to tell, at least, whether the net effect would be heating or cooling for a particular albedo.

[GeneralVeers]

On 1/19/2016 at 10:15 AM, Chakat Firepaw said:

The natural explanations have all been eliminated as possible causes for the recent warming.  In fact, the natural forcing factors are slightly cooling.

Meanwhile, we can _observe_ the fact that human actions have caused a strong warming change in the planet's energy flux.  Anthropogenic CO2 alone is causing ~1.6W/m^2 of warming.

Sigh. This is what happens when you ditch a thread for five days.

Science has not been able to eliminate natural causes of recent (alleged) warming, for these very simple reasons:

#1: There have been three previous warm periods (which were global, as I forgot to mention--the charts all showed global average temperatures going up during the Minoan, Roman, and Medieval climate optima--so the arguments that they were regional warming is dead)

#2: Science doesn't know what caused those previous three warm periods.

#3: The next warm period is scheduled to occur right now.

Conclusion: the claim that we "can" observe human actions causing warming right now is bogus. Natural causes alone account for all of what we're supposedly seeing right now.

One can think up theories about what "might" happen all day long, but when you observe things have have happened and they don't square with your theory, said theory must be discarded. Nuclear winter? Dead. Global warming? Dead.

[peadar1987]

#2 and #3 are in direct contradiction to one another. If science supposedly doesn't know what caused the previous warm periods, how could we possibly know that another one is "due"?

[K^2]

22 minutes ago, peadar1987 said:

#2 and #3 are in direct contradiction to one another. If science supposedly doesn't know what caused the previous warm periods, how could we possibly know that another one is "due"?

Maximum Entropy. Given no other information, probability distribution that maximizes entropy under known constraints is the best guess. So if something happened every X years in the past, even if we don't know why it happened, our best guess is that it will keep happening with roughly the same intervals.

To give a banal example, people knew that sun will rise the next day long before they've learned about orbital mechanics.

That's not to say that we can't be wrong about this, but that's true of all knowledge. Best we can do is put some statistical bounds on how likely it is. Given observation of 3 events that fit the pattern and no known events that do not, the odds of pattern holding are estimated at 80%.

[peadar1987]

19 minutes ago, K^2 said:

Maximum Entropy. Given no other information, probability distribution that maximizes entropy under known constraints is the best guess. So if something happened every X years in the past, even if we don't know why it happened, our best guess is that it will keep happening with roughly the same intervals.

To give a banal example, people knew that sun will rise the next day long before they've learned about orbital mechanics.

That's not to say that we can't be wrong about this, but that's true of all knowledge. Best we can do is put some statistical bounds on how likely it is. Given observation of 3 events that fit the pattern and no known events that do not, the odds of pattern holding are estimated at 80%.

But the events WedgeAntilles is talking about do not occur at regular intervals, or last the same amount of time.

The Minoan Warm Period was an extended period of elevated but fluctuating temperatures, about 7,000 years ago. The Roman Warm period lasted for about 600 years, from 2200 to 1800 years ago. The Medieval Warm Period lasted about 300 years, from 1100 to 800 years ago.

[K^2]

We are talking specifically about a spike in temperature at the end of Minoan period. The general trend of a spike about every 1k years is very persistent. Although, there are definitely a bunch of other things going on, so it's hard to insist that we're absolutely seeing another spike coming up. Nonetheless, insisting that this absolutely couldn't be the dominant cause of the temperature trend is likewise premature. I am absolutely in favor of reasonable policy change to help us reduce impact on climate to be on the safe side, but we seriously don't understand the beast yet. And a lot of alarmists are calling for drastic measures, because they insist these are dire circumstances. And all I'm asking is that we don't shoot ourselves in the foot out of sheer panic. We're not even close to catastrophic damage yet, this planet's been through far worse without our effort, and the general trends have been good already.

[m4v]

@K^2The medieval warming period is a discredited idea, it did happen, but global averages weren't anywhere higher than is today.

1 hour ago, K^2 said:

And all I'm asking is that we don't shoot ourselves in the foot out of sheer panic. We're not even close to catastrophic damage yet, this planet's been through far worse without our effort, and the general trends have been good already.

Right. We could end making a better world for nothing.

Decoupling carbon from the economy is possible, so the people advocating for drastic measures aren't shooting anybody's foot. And we aren't close to catastrophic damage yet? I'm sure Miami is going to be grateful that nobody did anything as the sea takes it away.

[K^2]

59 minutes ago, m4v said:

Right. We could end making a better world for nothing.

Do you know what we need to make a better world? A ton of resources put into research. Do you know who funds most of the research? Private companies trying to get ahead of the competition. Do you know which departments get the ax first when profits drop? R&D. Because R&D makes profits tomorrow, all other departments make profit today.

Any environmental regulations we put in place put additional burden on the industry. We definitely need them, because we've learned that industry won't regulate itself. But we also need to be reasonable.

Status quo is that we are relying on burning fossil fuels. People won't stop driving their cars just because glaciers are melting. They just won't. If you don't realize it, you must not be from this planet. The only way we are going to make things better is by getting people off gasoline cars and onto electric. And to do that, we need to make electric cars cheaper, more convenient, and more reliable. And this isn't going to happen without corps willing to dump a ton of money into research. Which is happening right now, and the progress has been amazing. I know it's been going slower in the rest of the world, but in Cali, every fifth car I see is a hybrid and electrics have stopped being an oddity. This is very different from even a decade ago.

And the situation is the same across the board. Take a look at the charts for renewables. Many states are heading towards wind and solar dominating their grid before the decade is over. That's huge. That's fantastic. And we need to be very careful about not stomping on this progress, even if it means that we don't get to enact some strict carbon regulations for a while. It's good that companies are afraid of this happening and investing into greener research, but we also want them to have the funds to invest into that research.

For that reason, I urge everyone to make very careful considerations before making any leaps. We shouldn't enact draconian regulations just because we've heard a scary talk about global warming or because we saw that picture of a polar bear on a melting iceberg. These aren't good reasons to enact policy. We need to weigh the consequences. If something is a problem in a short term, it needs to be fixed immediately. If something is a problem on the long term, we need to make sure we fully understand the dynamics, weigh all the options, and make balanced decisions. And as I've said above, the right decision isn't always going to be to limit pollution. If we expect fossil fuel use to drop naturally in the future, and we do, there is no reason to strangle the economy.

[m4v]

34 minutes ago, K^2 said:

We need to weigh the consequences. If something is a problem in a short term, it needs to be fixed immediately. If something is a problem on the long term, we need to make sure we fully understand the dynamics, weigh all the options, and make balanced decisions. And as I've said above, the right decision isn't always going to be to limit pollution. If we expect fossil fuel use to drop naturally in the future, and we do, there is no reason to strangle the economy.

Pollution is going down, renewables are rising and that all is awesome but everybody agrees that change isn't coming fast enough, you're too worried about the economic consequences that "draconian" policies will cause today but not worried at all about the economic consequences of runaway global warming.

[Kerbart]

On 1/16/2016 at 10:43 AM, Pawelk198604 said:

Recently I read that a local nuclear war between nuclear powers, could cause disturbance to the climate, as well as nuclear winter, and to reduce the global temparatury a few degrees Celsius.
Of course, I do not want nuclear war, like most normal thinking people.

But if by chance a sudden drop in global temperatures, it would not be good in the long run, after all, here's what it all organization that are fighting with "Global Warming"  

It's a short term effect and it will wear off after a few years. Climate scientists tell us that if we'd stop pumping CO₂ in the atmosphere now (all of it)—a likely side-effect of a full scale nuclear war, global temperatures would still rise for decennia to come.

So you'd have to have a full-scale nuclear war every few years to get a lasting effect. Aside from the question of such a thing would be an improvement over global warming, remember what Albert Einstein mentioned about that: “I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones” so that scenario might not work, either.

 

Edited January 25, 2016 by Kerbart

[Darnok]

11 minutes ago, Kerbart said:

“I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones”

 

He was wrong WWIII was cold war, now we will have WWIV and it won't be war on nukes, but war on biological weapon and after that war only one race will remain the one that first release virus killing all other races.