Global Warming

[mychells]

Hello All:

 

I have a major homework issue and your help would be greatly appreciated. Here's the question:

 

In what ways does volcanic eruptions and earthquakes affect global climate?

 

Thanks.

[iNow]

Where are you struggling?

 

Both events release carbon dioxide into the atmosphere. You might look to see how much on average is released by volcanos and earthquakes.

 

Carbon dioxide is a greenhouse gas, so you might look to see what impact having more of it in the atmosphere would have.

 

You might discuss the greenhouse effect, and why having more carbon dioxide in the atmosphere has the effect it does.

 

You might discuss the effect, and how it impacts other life.

 

Again, I'm not sure where you're stuck, so maybe the above will help free you from the researchers and writer's block.

[fattyjwoods]

In every way. Like iNow said, volcanic eruptions give out carbon dioxide (greenhouse gases). This causes the greenhouse effect.

 

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

 

If you want me to blab on about the greenhouse effect I will do so. When the sun’s energy enters the earth’s atmosphere most of the energy is reflected off back into space by the ozone layer. However some of the energy comes into the earth’s atmosphere and is absorbed by the land, trees, sun-bathers, etc. etc. Then some of the energy is reflected again back towards space, the atmosphere traps the heat and sends it back into earth (like a ping-pong match). However the ozone layer is breaking down because of the chlorofluorocarbons (CFCs) or Haloalkane emitted by fridges and batteries. These are dangerous and are the main cause of the decay of the ozone layer. More energy and light is entering into the earth and the ratio of carbon dioxide and oxygen is unbalancing. The CO2 is trapping the heat, as the heat rises our ice polar caps will melt, thus causing the sea levels to rise. Now you may think that is not a big problem, you just wait a couple of centuries and by that time when you walk to the corner store you will probably be waist high water flowing everywhere.

 

Earthquakes sometimes tear apart facilities that produce CO2, hence letting the gas escaping into the atmosphere. Earthquakes cause debris that pollute the water or land, thus killing trees, thus lowering the CO2 and oxygen balance.

[Chris C]

They do release a fair amount of CO2 but the abopve users are quite wrong in the conclusions (normally). Volcanic eruptions actually cause global cooling. CO2 is released as above users have pointed out, however, the carbon cycle quickly removes this CO2 and returns to equilibrium rather quickly. Humans release more CO2 per year and it accumulates year to year to year which is why you see a steady rise, but no abrupt jumps even at volcanic eruptions.

 

graph- http://www.globalwarmingart.com/images/thumb/8/88/Mauna_Loa_Carbon_Dioxide.png/700px-Mauna_Loa_Carbon_Dioxide.png

 

So why do they cause cooling? Volcanos typically emit large quantities of sulfate ejecta, which deflect incoming solar radiation, which causes a decrease in insolation (and temperatures) on the earth. This is not the same as "dust" which may have less significant impacts (ie Mt. St. Helens). The Mt. Pinatubo eruption in '91 caused a ~0.5 C degree cooling for a couple of years, but the cooling agents are also quickly removed in the atmosphere and significant climatic effects shouldn't be seen many years later.

 

I recommend this site for Volcanic relations to climate change

http://www.geology.sdsu.edu/how_volcanoes_work/climate_effects.html

 

Volcanic eruptions can be asociated with global warming especially in paleoenvironments with more intense and frequent volcano activity. A particular event was the Paleocene-Eocene thermal maximum (PETM) he massive outpouring of Siberian Trap Volcanoes at the Permian-Triassic boundary. However, what you say is generally the case in relation to smaller scale and individual eruptions

 

fatty,

 

your explanation of the greenhouse effect is wrong. For one thing, you are confusing "greenhouse gases" with "ozone." Ozone can act as a greenhouse gas (primarily in the troposphere) but the ozone layer is contained in the stratosphere and plays minimal role in global warming. Its main role, for our purposes, is to block UV radiation which causes sunburn, skin cancer etc. Without it, life on land and shallow water would not be possible. The depletion of the ozone layer is a separate topic, and is kind of fading away as it is actually in recovery and CFC's have largely been regulated since the Montreal Protocol.

 

In contrast, solar radiation (which peaks at the visible spectrum, not UV, which is why we see it) enters the atmosphere and goes though unblocked (almost) by the atmosphere. The Earth reflects some of it back out via clouds or other reflecting objects, and absorbs much of it. The visible radiation absorbed is emitted as infrared radiation (the wavelength of peak emission is inversely proportional to temperature by Wein's law and the Earth is much cooler than the sun so it emits in a different wavelength) and greenhouse gases in the troposphere (not the stratosphere where ozone resides) absorbs and re-radiates that infrared radiation. I don't want to get technical from here, because some can re-radiate upwards and sideways, but also downwards. Generally speaking, layers below will warm, and it is this effect that keeps the planet warm enough for life. So...

 

1) The ozone layer is in another layer of the atmosphere and regulated harmful UV emission, it plays little role in global warming

2) Greenhouse gases in the troposphere are what absorb and re-radiate infared radiation. You can say that the sun does not heat the atmosphere but rather it heats the surface which heats the atmosphere, so the suns effect is indirect. The problem is not depleted ozone but the increase of greenhouse gases which absorb more infrared radiation delaying its return to space.

 

Chris

[bascule]

Hi Chris C, nice to have you around. Given the sheer abundance of confusion that surrounds climate change (even around here), it's always great to see someone who's well-informed.

 

A couple other points of note:

 

Early 20th century warming can be partially attributed to a decrease in volcanic activity (due to reasons Chris C outlined above)

 

Anthropogenic CO₂ emissions are over two orders of magnitude greater than natural ones, including volcanoes

[fattyjwoods]

your explanation of the greenhouse effect is wrong. For one thing, you are confusing "greenhouse gases" with "ozone." Ozone can act as a greenhouse gas (primarily in the troposphere) but the ozone layer is contained in the stratosphere and plays minimal role in global warming. Its main role, for our purposes, is to block UV radiation which causes sunburn, skin cancer etc. Without it, life on land and shallow water would not be possible.

 

sorry, my bad, but I meant ozone as in when heat enters the earth's atmosphere some of the heat is deflected some some of it passes through.

 

The depletion of the ozone layer is a separate topic, and is kind of fading away as it is actually in recovery and CFC's have largely been regulated since the Montreal Protocol.

 

but they still exist and are still damaging the ozone. That is why the hole above the antartic region is getting bigger.

 

But still the volcanoes still produce CO2 and hence CO2 is a major contributor to global warming. Yes I have to agree with you that the ozone layer does not contribute much and yes burning of fossil fuels do contribute to global warming more than volcanoes.

 

But the problem is when the disaster happens (earthquakes) – buildings are destroyed and things explode, thus releasing harmful gases into the air. Then when aid arrives, all those vehicles containing food and medical supplies arrives. Heavy helicopters and ships burn fuel as well. And then the clean-up, trucks bulldovers, trucks and cranes all use huge amounts of fuel and diesel. Yes the effect is in-direct but still earthquakes cause global warming.

[Chris C]

if I was not clear on a particular point I will try to rephrase

[iNow]

if I was not clear on a particular point I will try to rephrase

 

There is little or no need for that. You did a great job, and I thank you for teaching me something new and correcting the error in my own post so the OP (and others) are not misled. Cheers.

[DrDNA]

But the problem is when the disaster happens (earthquakes) – buildings are destroyed and things explode, thus releasing harmful gases into the air. Then when aid arrives, all those vehicles containing food and medical supplies arrives. Heavy helicopters and ships burn fuel as well. And then the clean-up, trucks bulldovers, trucks and cranes all use huge amounts of fuel and diesel. Yes the effect is in-direct but still earthquakes cause global warming.

 

You're saying that earthquakes are a major factor in global warming because buildings explode and the exhaust gases from the medical/emergency/aid/resue workers' vehicles and heavy equipment? Well, I'll be darned.

[Chris C]

Hi Chris C, nice to have you around. Given the sheer abundance of confusion that surrounds climate change (even around here), it's always great to see someone who's well-informed.

 

A couple other points of note:

 

Early 20th century warming can be partially attributed to a decrease in volcanic activity (due to reasons Chris C outlined above)

 

Anthropogenic CO₂ emissions are over two orders of magnitude greater than natural ones, including volcanoes

 

Thanks for the welcome, I look forward to posting here. I've not heard of that argument in point 1 before (do you have a link I can look at?), but it looks like that warming from ~1900-1950 can be attributed largely to solar activity and some human forcing (but minimal) whereas the human forcing from about 1950 onwards is very strong.

 

The Lockwood and Frohlich paper (http://www.pubs.royalsoc.ac.uk/media/proceedings_a/rspa20071880.pdf) and Ammann et al. paper (http://www.pnas.org/cgi/reprint/104/10/3713) go over some of this, but personally I think that the trends are indicative of external forcing rather than internal stability; in other words, decrease of eruptions may partially explan why there is no cooling, but not why there is warming. If the lack of volcanic activity hypothesis held, than the 1950 baseline would be the temperature which the Earth was "supposed to" return to, which seems odd. Does look like an increase in volcanic activity, along with decrease in solar forcing was largely responsible for the maunder minimum though (time of our little ice age), so if volcanic activity declined, temperatures would have flattended out a bit but not raised abruptly.

 

I went over more on solar trends and why they are highly unlikely to have caused a large part of warming from about 1950 on in the "sunspot" thread in the ecology and environment forum.

 

An addition I want to make to my response of the OP- Actually, the 1940-1970 cooling in the graph above (which skeptics often use to show that CO2 does not cause temperature increase) was caused by increased aerosol usage which have a strong net negative forcing (and actually have partially mitigated warming trends today). The volcanic effects are similar to the large aerosol output in the more "dirtier" times of the industrial revolution- emissions go in the atmosphere and deflect solar radiation and cause surface cooling. This is what global dimming is all about.

 

With point 2, remember that the oceans and biomass are still a primary release of CO2 (in the sense that more CO2 is released naturally than by anthropogenic sources), but they are irrelevant in the CHANGE of CO2. The carbon cycle sequesters about as much is emitted by natural sources. When a skeptic hits you with the argument that natural sources far outweigh the human sources, tell them to remember the carbon cycle. CO2 cycles between the oceans, biosphere, atmosphere, etc so that what is released is removed at the same rate. What humans have done is change one side othe equation- which is why we call it an EXTERNAL forcing. Just for random numbers mathematically, it would look something like

 

100 from natural

4 from humans

 

but, the 100 from humans obviously doesn't keep acumulating otherwise the CO2 line would keep going to infinity, the same 100 units are removed via photosynthesis, oceanic uptake, etc...so

 

100 - 100 = 0 (so all you have is what is already in the atmosphere, or the pre-industral value which was stable over the entire Holocene from the last ice age)

 

Now add humans-

 

100 -100 + 4 = 4 (so now you have a rise in the line)

year 2- 104 -100 + 4 = 108

keep doing this on a yearly basis and it accumulates. I'm sure there is a lot of flaws in that simple set of equations, but that's the idea- humans are responsible largely for the variables, not the constants. Atmospheric CO2 concentrations began to exceed the narrow, naturally maintained range of atmospheric CO2 concentrations near the onset of the industrial revolution. See these graphs-

 

[bascule]

Thanks for the welcome, I look forward to posting here. I've not heard of that argument in point 1 before (do you have a link I can look at?)

 

http://www.nerc-essc.ac.uk/~olb/PAPERS/len19.pdf

 

Four possible mechanisms, individually or in combination, could have contributed to the early twentieth-century warming: anthropogenic effects, increased solar irradiation, reduced volcanic activity, and internal variability of the climate system.

 

[...]

 

From 1912 onward, volcanic activity entered a more quiescent phase and thus eliminated this climate cooling factor. Following the major eruptions at the beginning of the last century (Santa Maria in 1902, Ksudach in 1907, and Katmai in 1912) no substantial volcanic eruption occurred until Mount Agung in 1963 (Robock 2000). Of these eruptions Katmai was the most intense at least with respect to the anticipated effect on climate (stratospheric aerosols). Nevertheless, the eruption by Mount Pinatubo in 1991 was more powerful by about a factor of 2 when compared with Katmai (Robock 2000). We may therefore assume that the climate effect from Katmai was less than that from Pinatubo and we have no reason to believe that the effect should have lasted longer than the effect of Pinatubo. According to several modeling studies as well as to observational assessments, the cooling effect of Pinatubo had disappeared after a period shorter than 3 yr (Bengtsson et al.

1999). Consequently the cooling effect of Katmai could hardly have lasted longer than 1915.

[fattyjwoods]

 

You're saying that earthquakes are a major factor in global warming because buildings explode and the exhaust gases from the medical/emergency/aid/resue workers' vehicles and heavy equipment? Well, I'll be darned.

 

Well okay then, I'm wrong, theres no need for a clean-up procedure after a earthquake, theres no need to send aid-workers in to help the dying.

 

To Chris C

Don't worry, that goroth is just a little bit odd

[Fred56]

Another thing about earthquakes is they can cause major changes in geology, say by sinking some land below sea level, which then can cause major local climate change.

Also if there is a big undersea quake you get tsunamis, which aren't climate but they can do things like destroy forests and cause land change that way which then causes climate to alter.

[DrDNA]

Well okay then, I'm wrong, theres no need for a clean-up procedure after a earthquake, theres no need to send aid-workers in to help the dying.

 

I'm sorry but didn't you state that earthquakes cause global warming because of the exhaust or fumes from resue/clean up vehicles and equipment that are used in the aftermath? If I misunderstood that I appologize

...............................

...................................................but if I didn't misunderstand, ROFL.

[WintersGirl]

could someone please help me i need to get this done or i fail my class

[iNow]

could someone please help me i need to get this done or i fail my class

 

Help you get what done, exactly?

[ydoaPs]

could someone please help me i need to get this done or i fail my class

 

Like I told you before, use our Homework Help forum. That's what it's for. There's no need to derail the threads of others.

[DrDNA]

Like I told you before, use our Homework Help forum. That's what it's for. There's no need to derail the threads of others.

 

I think this is the Homework Help forum.

 

could someone please help me i need to get this done or i fail my class

 

Does this relate to mychells' topic?