The Ice Age, Dinosaurs and Humans

[Fluffywolf]

Although the cause of ice ages are not fully understood, but it has been said to possibly do with carbon-dioxide and methane concentrations, ocean currents but ofcourse also natural accurences like tectonic shifts, volcanoes, and so on and so forth. But obviously also the removal of ice caps, the ebb and flow changes, sea levels, etc.

It seems that the trend however is that as the earth warms up, eventually it reaches a point where there will be a turn around and dive back into an ice age. Predicting exactly how and when this happens is still way ahead of us, but it is prude to say that our climate influence negatively pushes this moment back. If anything, the climate changes we attribute to, is likely to speed up the process. Maybe only by a small fraction, maybe by a large percentage, can't really say without knowing what exactly causes an ice age. But it's still less likely that it pushes it back.

Note that we are currently in a natural warming trend regardless of global warming. If we were in a cooling trend the effect might be reversed and push the end of the coming ice age further away.

Whilest we have pretty good data on atmospheric concentrations throughout the ages however, there are many factors that aren't as easy to pin down such as what the ocean currents were like throughout the ages and what changed them over time. Not to mention that a difference of a few degrees celsius in an ocean current can have major global impact. That's not easily measured based on a few archeological and geological finds.

Basicly, if we are to attempt and draw any hypothesis from what we do know, I'm just saying it sounds to me like our tribute to global warming is more likely to speed up the coming of the next ice age rather than push it back.

 

[ragashree]

I'm glad that people have pointed out that we're IN an ice age already (the current phase being technically known as an interglacial; meaning a short, relatively warmer low-ice phase between two periods of extensive cold and glaciation). We don't know a lot about the danger of human activities prematurely restarting the cycle as Fluffy suggestsm, or whether in fact they will delay the next glacial phase by a significant amount of time; due to the fact that most current research efforts are invested in making dire predictions about current warming and trying to find evidence to support the hypothesis that humans are the major cause of it. I suspect in any case that the global cooling which we can be fairly SURE is going to happen is likely to have much more drastic long-term impact on human civilisation than any relatively small increases in temperature we may or may not be able to produce in the interim.

All of modern human civilisation, as we know and can imagine it, has developed (so far as we are aware) during the relatively warm period since the begining of the Holocene Epoch around 10 thousand years ago, and seems inextricably linked to it. Before that, humans had no agriculture to sustain large populations, and only such technology as was necessary for a largely nomadic hunter-gatherer lifestyle. The only way to survive in what are now the temperate regions was essentially to hunt big cold adapted animals like mammoths with spears. (And a damn good job of it we did too, most of the pleistocene megafauna [= big animals] that had evolved in the cold climates of the last couple of million years were killed off at the begining of the current interglacial; since we know that humans were heavily reliant on them for food and their populations began expanding as cold habitat for the animals began shrinking, it's difficult not to hold humans responsible.)

Even if humans had developed domestic animals and crops at that time, they would largely have been unable to survive outside the tropical and subtropical regions. Historic evidence shows that once the climate reaches a tipping critical point, transitions between warm and cold cycles can occur extremely rapidly in geological terms. Whether humans will have the time to adapt sucessfully seems questionable, though of course since we don't know how long it will take to get to the point where we will actually need to, there are plenty more pressing concerns for us between now and then, such as whether we suceed in misusing our technological capacity to destroy our own civilisations before Nature even gets a look in.

In any case here's a nice little graph I found showing the "recent" progress of the glaciation cycle:

It's essentially dependent on orbital variations with other likely contributors such as greenhouse gasses and sun activity being significant unknowns. They're presumably vital in some way though, as the same orbital variations were occuring before we entered the current ice age, yet global temperatures were generally stable and warmer for huge periods (many millions of years at a stretch) than the warmest temperatures we see now.

I find it interesting that the graph shows a very similar pattern taking place now to the one 400 k years ago; this fits well with the fact that the complete cycle of orbital variations that causes glaciation and warming recurrs each 400 000 years too, with several intermediate peaks and troughs in between. Historical parallels make it look like we could reasonably expect to be in the current interglacial for some time (potentially quite a few thousand years more) and be undergoing a slight temperature rise around now which does not quite reach the high point of the previous few interglacials, but persists around its peak for longer, before dropping away slowly but steadily over a long period of time to herald the next period of glaciation. I don't think we've been keeping measurements long enough to be able to identify this process yet given the timescales on which it occurs, but it is going to be important to know at some point. Given that we're still around to worry about it of course.

 

[Mal12345]

Although the cause of ice ages are not fully understood, but it has been said to possibly do with carbon-dioxide and methane concentrations, ocean currents but ofcourse also natural accurences like tectonic shifts, volcanoes, and so on and so forth. But obviously also the removal of ice caps, the ebb and flow changes, sea levels, etc.

It seems that the trend however is that as the earth warms up, eventually it reaches a point where there will be a turn around and dive back into an ice age.

Perhaps you should deal with the warming up aspect first. The Earth undergoes periods of volcanic upheaval followed by periods of volcanic quiescence. The 20th century was a period of relatively intense volcanism, but those are just the ones we can see. And they don't put enough debris into the atmosphere to create climate change. Underwater volcanoes are more influential, as their presence warms the surrounding ocean waters as water currents bring those warm waters to the coastlines. The 20th century was also a period of great tectonic activity, shifting plates creates enough friction deep beneath the earth's crust to produce lava.

As this period of volcanic activity wears down, a negative feedback loop begins to occur. Warmer ocean temperatures have produced great amounts of plankton which absorb carbon dioxide through photosynthesis.

 

[Virtual ghost]

Another global warming thread ?

 

[Mal12345]

Another global warming thread ?

I'm trying to explain how global warming causes a negative feedback loop, thus global cooling (ice age).

 

[Virtual ghost]

I am sorry but I did not have the time to write my real/full replay to this thread.
It is possible that this might be shocking to some people but I am simply going to be pretty blunt about my thoughts perspective. However I will try to keep it simple and without too much detail.



If I have to place a bet I would almost certanly not place it on the next major ice age in our lifetime.


Here is what the cryosphere today is showing. (for the 2th or August).


The arctic sea ice is growing every winter and melting back every summer. However the ratios in the proces are destabilized. What has resulted in a reduced ice cover in Arctic region. But as you can see not only that the extend is pretty low and that there is penty of open water but the quality and integrity of ice is also pretty bad. (feel free to explote this site there is interesting information on it)



So when you take a look at the estimated volume the problem becomes even more obvious.

As you can see the current year is well below any average even if the recent anomal years are calculated in. Plus it is obvious that the line for current year will end only a little bit above the black bottom line that represents ice free conditions.
So it will be interesting to watch the next month and a half since the is how long the melt season should last. (because under current conditions it is defined with orbital parameters instead of weather, weather is only the outcome)
But to be honest I am trully curious if we will see liquid water on the north pole in a few weaks from now. Since that is a possibility that is on the table.

But even if that does not happen the odds are that it will happen in some of the incoming years since the trend is speading downwards.

However this pictures shows the amount of change next to the average instead of the apsolute values. (the bottom line represents ice free condition)





Actually the ice all over the globe is not doing much better. So the most of glaciers around the world are in retreat . And only a few are progressing since the local wather and terrain structure. Plus it is too early for big melts on the Antartic.



So here are some school like examples of glacier melt during the 20th century.

Also if you are interested in this topic feel free to do you your own research with google. Some of the most interesting events in last 12 months are : great fires in Russia (this and last year) , the great flooding in Australa , Melting of glacier park, Methane bomb, Ocean acidification, The drought in Amazon basin in 2010 as well as recent droughts on the northern hemisphere.



However if you live in a big city and under climate conditioners you will probably not experiance any real changes. (except maybe food prices)

So here are the drought maps that showing the droughts created by recent anomal weather patterns and temperatures.


US


World in general


And this is one of the reasons why global warming has become such a controversy. You simply cant publish information like this without spreading massive panic. So you have to provide half truths in order to start changing something. So in the end when this passes throught the modern media machine you have what you have.


But back to the topic.


So the odds are that pretty much all ice will disapear in time. However that ice is keeping the world colder. Becuse of their temperature and the fact that ice reflects alot of energy back into space like a mirror. Plus as it melts in summer time it creates rivers and makes sure that vegetation can survive drough times. In the case that is not the case the vegetation simply dries up and turns into additional green house gases.




However there is one trick when it come to predicting the outcome based on gelogical data. The truth is that the graphs about recent ice ages are very good for understanding the geological past. But this graphs and models can't be used for our current situation.

The thing is that the graphs like the one that is posted here is correct. But the fossil fuels we are using were created over the last 700 million year.
But how long in the past does the the graph goes ? Only 450 thousand years.
Which means that today humas are releasing the carbon that was sealed under ground at that point, some 450 thousand years. Even when the dinosaurs died out 65 million years ago that is only a 10% of the time it took to create all those fossil fuels. Which means that the data from all those ice cores and similar stuff cant be trusted since the situation on the field is fundamentally different.


During the geologic history there has NEVER been a mechanism that is so good as human technology in extracting the carbon that has ended traped beneath the miles of rocks. What means that the current events have noting to do with classical/gradual natural changes, since basically the carbon is being pumped into the system at fast and faster rates.


Plus there is one more side effect of this. And that is that we cant go back and return things just as they were. The reason why we cant do that is because now we have much more carbon and its compounds in the system than we had some 200 years ago. However most of this carbon will end up in the carbon and other cycles what will create dramatic changes in those cycles. Especially since we are maining out fossil fuels wherever we find them. The problem is that we can even stop with this practice completely and sacrafice food and goods for the most of the world population and we would not solve the problem.

Since to do that we would need to destroy all crops and cities in order to plant the trees that used to exist in this area , plus we would need to find a technology that is capable of turning the carbon dioxide back into the oil so we can safely burry it back into the ground. But so far it seems that this would take a huge amount of energy we simply dont have, as well as the end of all political models we know and massive global genocide which goal would be to kill about 5-6 billion people.
So I think that it is far more likely that the current practice will continue and the result of that will be that we will release most of carbon that was removed from the biosphere during the last 700 million years.


However with that much carbon (with will end up as a green house gas) is hightly unlikely that there will be any kind of a ice age in the near future. It is possible that warming can backfire but that is pretty unlikely to happen if we have a situation we have today on this planet. It is possible that some cold air can come down from the pole while there is still ice there and that it mixes with air that has more moisture , resulting in a epic snow storms. Or it can happen that the ice melt and that the cold water that was created in the proces is distributed around ocean with the help of ocean currents. But all of that is simply not enough to turn the course of battle between hot and cold.



So if we trully relaease most of carbon stored underground it will bacially be impossible for ice to exist on the surface on the planet. Which is because we have overloaded the system. However in the new world most of the current organisms can survive . Many were viped out with human expansion and now the climate shock and snaping of food chains could be enough to crash the biosphere. As I said feel free to google "ocean acidification". In the case that they have millions of years to adap and in the case that humans dont destroy everything they touch and release aditional carbon they could manage just as they did before over the Earths history.
But as it seem for now this will probably be too much for the most of living beigns on the planet.




What means that the humans that will survive will be completely dependant on technology. Which is because the world and life as will know it will not exist anymore. So in the end the only thing you basically have is society that survives complete because of technology and as a consequance they merge more and more with their technology , creating Borg like society that will spread itself over the universe in the incoming billions of years.






Just my 2 cents.

 

[wildcat]

I sometimes wonder when the next ice age will come. Does anyone else ever think about stuff like this? I wonder what will be the fate of humans when it comes, and more interestingly what the next reigning life form will be if humans don't survive (remember the ill-fated dinosaurs?). I'm fascinated by the mammals that did survive the last ice age! If some of you think that humans and dinosaurs existed together and dinosaurs perished while humans survived, feel free to speculate what you think will happen to humans during the next ice age.

Patience.
Let the current Ice Age pass.
One thing at a time.
We are already close to the end.

Later we shall talk about another Ice Age.
Not we, exactly.
Some people.
Perhaps.