Global Warming or Ice Age?

In summary, the conversation revolves around the debate between global warming and an ice age, and whether solar variability can explain climate changes. While there is evidence that the Earth goes through cycles of warming and cooling, there is also evidence of a chaotic variation with a 1,500 year cycle. The cause of this cycle is still unknown, but it may be related to the Earth's orbital shifts and internal dynamics. Ultimately, it is inevitable that the Earth will continue to go through periods of warming and cooling, and the current warming trend may be influenced by human activities.
  • #1
Enlightened
2
0
Does anyone else believe that we are not going through global warming but actually and ice age?
 
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  • #2
Enlightened said:
Does anyone else believe that we are not going through global warming but actually and ice age?

Please post some of the reports or papers that have led you to ask this question.
 
  • #3
It depends on who you listen to and what you read.
Changing Sun, Changing Climate?

This essay is partly based, by permission, on an essay by Theodore S. Feldman (PSDI, Bedford, Mass), "Solar Variability and Climate Change," rewritten and expanded by Spencer Weart. For additional material, see Feldman's site.

Since it is the Sun's energy that drives the weather system, scientists naturally wondered whether they might connect climate changes with solar variations. Yet the Sun seemed to be stable over the timescale of human lifetimes. Attempts to discover cyclic variations in weather and connect them with the 11-year sunspot cycle, or other possible solar cycles ranging up to a few centuries long, gave results that were ambiguous at best. These attempts got a well-deserved bad reputation. Jack Eddy overcame this with a 1976 study that demonstrated that irregular variations in solar surface activity, a few centuries long, were connected with major climate shifts. The mechanism remained uncertain, but plausible candidates emerged. The next crucial question was whether a rise in the Sun's activity could explain the global warming seen in the 20th century? By the 1990s, there was a tentative answer: minor solar variations could indeed have been partly responsible for some past fluctuations... but future warming from the rise in greenhouse gases would far outweigh any solar effects.

http://www.aip.org/history/climate/solar.htm

(this site has some great background on the discovery of "global warming")
Are We on the Brink of a 'New Little Ice Age?'

By Terrence Joyce, Senior Scientist, Physical Oceanography and
Lloyd Keigwin, Senior Scientist, Geology & Geophysics

When most of us think about Ice Ages, we imagine a slow transition into a colder climate on long time scales. Indeed, studies of the past million years indicate a repeatable cycle of Earth’s climate going from warm periods (“interglacial”, as we are experiencing now) to glacial conditions.

The period of these shifts are related to changes in the tilt of Earth’s rotational axis (41,000 years), changes in the orientation of Earth’s elliptical orbit around the sun, called the “precession of the equinoxes” (23,000 years), and to changes in the shape (more round or less round) of the elliptical orbit (100,000 years). The theory that orbital shifts caused the waxing and waning of ice ages was first pointed out by James Croll in the 19th Century and developed more fully by Milutin Milankovitch in 1938.

Ice age conditions generally occur when all of the above conspire to create a minimum of summer sunlight on the arctic regions of the earth, although the Ice Age cycle is global in nature and occurs in phase in both hemispheres. It profoundly affects distribution of ice over lands and ocean, atmospheric temperatures and circulation, and ocean temperatures and circulation at the surface and at great depth.

Evidence has mounted that global warming began in the last century and that humans may be in part responsible. Both the Intergovernmental Panel on Climate Change (IPCC) and the US National Academy of Sciences concur. Computer models are being used to predict climate change under different scenarios of greenhouse forcing and the Kyoto Protocol advocates active measures to reduce CO² emissions which contribute to warming.

Evidence for abrupt climate change is readily apparent in ice cores taken from Greenland and Antarctica. One sees clear indications of long-term changes discussed above, with CO² and proxy temperature changes associated with the last ice age and its transition into our present interglacial period of warmth. But, in addition, there is a strong chaotic variation of properties with a quasi-period of around 1500 years. We say chaotic because these millennial shifts look like anything but regular oscillations. Rather, they look like rapid, decade-long transitions between cold and warm climates followed by long interludes in one of the two states.

http://www.whoi.edu/page.do?pid=12455&tid=282&cid=10046

So you might say that both "global warming" and "global freezing" are inevitable. We may have made the interglacial period a little warmer this time around but, generally, there's no stopping the warming and cooling of our planet because it is stuck on the 26,000 year long carousel ride of precession.
 
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  • #4
baywax said:
So you might say that both "global warming" and "global freezing" are inevitable. We may have made the interglacial period a little warmer this time around but, generally, there's no stopping the warming and cooling of our planet because it is stuck on the 26,000 year long carousel ride of precession.
I agree with the quote of the expert above who states that the 1,470 year cycle of abrupt warming and cooling needs a full explanation before any attempt at forecasting can be made. http://209.85.229.132/search?q=cach...storf+(2003).+timing&hl=en&ct=clnk&cd=5&gl=uk (click on html version at the top and view figure 1).
The so-called ‘‘little ice age’’ of the 16th–18th century may be the most recent cold phase of this cycle. The origin of the ‘‘mystery 1,500 year cycle’’ is thus one of the
key issues in climatology that needs to be explained
 
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  • #5
It should be noted that these D-O events (tied to 1470 years quasi-periodicity) and Heinrich events have not occurred during the Holocene interglacial. They appear to be a feature of glacial periods rather than interglacials. The yet to be determined "trigger" may still occur, especially if of orbital origin.

http://www.ncdc.noaa.gov/paleo/abrupt/images/data3-gisp2-icecore.gif

http://www.ncdc.noaa.gov/paleo/abrupt/data3.html"
 
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  • #6
I have a hunch that the 1,470 year cycle is a permanent feature of the inner core acting dynamically against the fluid outer core. It could be thought of as the internal orbit of the inner core due to irregularities in formation.
 
  • #7
I want to remind everyone of our https://www.physicsforums.com/showthread.php?t=280637"
Controversial claims must be supported by evidence that comes from a scientific, peer-reviewed journal or a similarly reliable source, i.e., unsubstantiated claims are not allowed.
 
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  • #8
Mammo said:
I have a hunch that the 1,470 year cycle is a permanent feature of the inner core acting dynamically against the fluid outer core. It could be thought of as the internal orbit of the inner core due to irregularities in formation.
This sciencemag article shows that there is still a lot about the inner core which we are just beginning to find out about http://www.sciencemag.org/cgi/content/abstract/309/5739/1357
 
  • #9
Mammo said:
I have a hunch that the 1,470 year cycle is a permanent feature of the inner core acting dynamically against the fluid outer core. It could be thought of as the internal orbit of the inner core due to irregularities in formation.
Also, check out this interesting article newscientist: Different Gravity
 
  • #10
Global warming is a step in the Ice Age. Sounds ironic, but true...
 
  • #11
ndnkyd said:
Global warming is a step in the Ice Age. Sounds ironic, but true...

In this forum it is very important to use formal sources for claims like that
 
  • #12
Andre said:
In this forum it is very important to use formal sources for claims like that

In order to prove that we are heading into an ice age with global temperatures rising?
 
  • #13
We have entered a new climate epoch known as the http://en.wikipedia.org/wiki/Anthropocene" [Broken]

There is very little chance that the Earth will enter a new glacial epoch as long as humans are around. Even with extreme cutbacks in GHG emissions human activity will still provide enough positive loading of the carbon cycle to maintain a temperate to tropical Earth for at least the next million years.
 
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  • #14
Be careful; a million years is a long time.

Yellowstone National Park will likely erupt before then.
Even without that, after fossil fuels are exhausted, it will likely take less than 100,000 years for CO2 levels to lower significantly.
 
  • #15
As long as we are manufacturing refrigerants that get released into the atmosphere the enhanced greenhouse effect will overwhelm orbital forcings.

Humans will not allow another ice age to occur if they can help it, and they can. If the Yellowstone caldera blows there may no longer be a human civilization. So perhaps I should have said as long as human civilization exists the probability of another glaciation occurring is very remote.
 
  • #16
At present rate of consumption, there is only about 150 years of fossil fuel reserves. While CO2 levels are currently going up around 2 ppm/year, that is not sustainable forever.

CO2 levels are currently 386 ppm. Add another 300 ppm (2*150) and the maximum is around 686 ppm. After that, levels should start to decline. We could burn everything that grows, but since plants remove CO2 from the atmosphere, that in itself won't raise CO2 levels. Of course, there is also production of cement, but the economics aren't as lucrative.

Without fossil fuels, I just don't see how we can economically keep CO2 levels elevated. In a few hundred years, levels will stabilize and then start falling. Not sure how fast, but within a few thousand years, CO2 could be below 200 ppm and with the perihelion still in January, that's a recipe for growing continental ice sheets. Maybe not a full scale ice age, but enough to be a concern.
 
  • #17
Xnn said:
Without fossil fuels, I just don't see how we can economically keep CO2 levels elevated. In a few hundred years, levels will stabilize and then start falling. Not sure how fast, but within a few thousand years, CO2 could be below 200 ppm and with the perihelion still in January, that's a recipe for growing continental ice sheets. Maybe not a full scale ice age, but enough to be a concern.

Maybe there are ways we can do reverse sequestering.
 
  • #19
Fossil fuels are not the only source of GHGs, nor are they the most potent. HFC's have a GWP of ~10,000.

http://www.epa.gov/highgwp/scientific.html [Broken]
 
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What is global warming?

Global warming refers to the gradual increase in the Earth's average temperature, primarily due to the release of greenhouse gases from human activities such as burning fossil fuels and deforestation.

What is the difference between global warming and an ice age?

Global warming and an ice age are opposite climate phenomena. Global warming refers to a long-term increase in the Earth's temperature, while an ice age is a long-term decrease in temperature. Global warming is caused by an increase in greenhouse gases, while an ice age is caused by changes in the Earth's orbit and tilt.

Is global warming real?

Yes, global warming is a scientifically proven phenomenon. The Earth's temperature has been steadily increasing since the Industrial Revolution, and the majority of scientists agree that this is primarily due to human activities.

What are the consequences of global warming?

The consequences of global warming include rising sea levels, more frequent and severe natural disasters, loss of biodiversity, and disruptions to agriculture and water supplies. These effects can have significant impacts on human societies and ecosystems.

Can we stop or reverse global warming?

While it may not be possible to completely reverse global warming, it is possible to slow down and mitigate its effects through actions such as reducing greenhouse gas emissions, promoting renewable energy sources, and implementing sustainable practices. It is important for individuals, governments, and businesses to take action to address global warming and its consequences.

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