Why worry about global warming?

Greatcloud said:

I like this one better because its the latest data. If it continues we won't have any more GW and will even go into global cooling.

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Your conclusion doesn't seem very robust if changing the start point by just 12 months gives a very different trendline.

We will just have to wait and see if the temperature keeps going down or not. I am betting that this modern period of global warming has ended, I think it has and we will have a cooling phase next. How long that lasts I don't know but its comming.



CO2

I've been following most of this discussion and I'm surprised no one has really placed any emphasis on the causation behind global warming or cooling.

GEOPHYSICIST HAT ON


Lets start with a basic lesson in the factors that could cause the Earth's surface temperatures to change. Forget the graphs and climate change research for a moment because we can all argue until the end of time about different graphs.

The Earth's surface receives heat from one primary source: The Sun. There are other factors (internal radioactive decay, tidal friction, earthquakes) but these contributions are all several orders of magnitude smaller than that of the sun.

A simple diagram:


This is founded on the basic principles of radiation, absorption, reflection and re-radiation used in physics and chemistry. Heat energy is just infrared waves and has the same properties as light. So this diagram is founded on the exact same reason why an apple is red: absorption and reflection. (An apple will also radiate light in a similar way to infrared but light radiation requires much greater energy input). The majority of heat energy that reaches us from the sun is immediately reflected off into space by our atmosphere and only a tiny, tiny amount reaches the surface directly. So, the Earth is warm and comfortable primarily because of radiation and re-radiation of the heat energy as it bounces around between the surface and the different layers of the atmosphere. If there was no atmosphere, then all the Sun's heat energy would hit us directly with no reflection and you would think we would be fried by all the intense heat, but without an atmosphere all the heat would immediately be radiated out without the convenient "bouncing around bit" between the atmosphere-surface duo. Without an atmosphere, the Earth would be chilly (about -18 degrees Celsius globally with fairly significant fluctuations between the night side and the day side).

So lets all agree that we need an atmosphere and we need greenhouse gases to keep the Earth comfortable. Greenhouse gases are defined as compounds in the atmosphere which are particularly adept at absorbing and re-radiating heat.

Now we are left with a few basic cause and effect situations.

A) If we change the amount of heat output by the sun directly while changing no other variables, then the Earth's surface temperature will logically also change. (Possible mechanism: sunspot activity. higher activity=less solar output)

B) If we change the amount of radiation/reflection coming off the Earth directly while changing no other variables, then the Earth's surface temperature will logically also change. (Possible mechanism: change in ice cover = change in albedo effect = change in radiation)

C) If we change the amount of re-radiation coming from the atmosphere directly while changing no other variables, then the Earth's surface temperature will logically also change. (Possible mechanism: change in greenhouse gas concentrations.)

This is a slightly simplified argument but even here we run into situations where all these if/then conditions are operating at the same time, potentially in conflicting ways to cancel each other out. (No wonder climate modeling requires some of the fastest supercomputers ever invented).

Okay, now that we have the cause and effects sorted out we can look at data.

A) Direct Solar Radiation:






We are currently going into the high activity phase of the sunspot cycle which could explain the downward trend in the last year or so with regards to climate change as compared to all the historic high temperatures we kept hitting in the years 2004-2007.

B) Earth radiation/reflection:

Albedo effect of common Earth landscapes:


We are losing sea ice and glacial ice, primarily in the Arctic. Ice and snow reflect anywhere from 3 to 10 times as much solar radiation than water. It creates an ice-albedo feedback loop.

C) Atmosphere Re-Radiation:

Even if some propose that the ocean acts as a carbon sink, no one can deny that greenhouse gas concentrations are rising markedly in the atmosphere.



Conclusion:

Global warming is occurring. All the mechanisms that can cause the Earth's temperature to increase are being activated. I am of the opinion that it is part of a natural cycle as the Earth comes out of the last ice age but this natural cycle is being accelerated by human causes. I don't think it would stop even if humans didn't exist; its natural. The Earth has been a lot warmer than this before and it has been a lot colder than this before (see picture below) and Earth's ecosystems (and even humans) did just fine. So global warming advocates that insist on the coming apocalypse due to catastrophic floods and mass famine need to calm down. And anti-global warming advocates insisting that global warming doesn't exist need to shut up. Even if you don't think it is caused by humans, at least acknowledge that the Earth is warming. I think the world needs to stop fighting about this and simply agree that human caused pollution of any kind is bad and unnatural and detrimental to the health of humans, animals and ecosystems whether it be atmospheric pollution, sewage, garbage or toxic dumping. In the 80s and 90s there was a big focus on recycling and reducing garbage pollution and there was a general consensus that this was a good thing regardless of political stance. Also, before the global warming debate, it was almost self-evident that air pollution was bad and cities like Los Angeles made a united effort to reduce air pollution simply because it's bad for your personal health. The world's voters and politicians need to wake up and simply realize that pollution is bad and who gives a rat's ass if it warms the planet or not.

And please stop using graphs that use the last 10 or 20 years to show climate change. Climate change is something that stretches out for centuries or millennia. A ten year graph is like zooming in on your bank account right when you get your pay day without zooming out to realize that you owe a $300,000 mortgage.



GEOPHYSICIST HAT OFF

***I apologize for any errors. This is all a simplification and there are more variables present but I have listed the major ones***

leftrightleftrightleft said:

***I apologize for any errors. This is all a simplification and there are more variables present but I have listed the major ones***

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So to be clear then, you feel that global warming is a natural cyle, mostly unrelated to man, and you are a GEOPHYSICIST?

Greatcloud said:

We will just have to wait and see if the temperature keeps going down or not. I am betting that this modern period of global warming has ended, I think it has and we will have a cooling phase next. How long that lasts I don't know but its comming.



CO2

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Assuming you believe the bible, that depends on how close to the end we are. The sun will be as several times hotter in the final phase....

leftrightleftrightleft said:

Global warming is occurring. All the mechanisms that can cause the Earth's temperature to increase are being activated. I am of the opinion that it is part of a natural cycle as the Earth comes out of the last ice age but this natural cycle is being accelerated by human causes.

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Nothing you posted supports the first part of this conclusion. We came out of the last ice age thousands of years ago. The Earth's climate has been relatively stable since then (with some changes, but nothing like we're likely to see in the coming decades). There are no natural drivers of climate that provide enough warming to explain more than a small fraction of the warming we have seen since about 1970.

Many people confuse Weather for Climate! They are not the same things! Also human activity does play a role in climate change simply because humans have added more variables that affect the outcome of climate change! How much? Well it all depends on the data we can collect.

It is true that Climate change is a natural phenomenon but hoe much humans can affect it is what worries me!

Chalnoth said:

Nothing you posted supports the first part of this conclusion. We came out of the last ice age thousands of years ago. The Earth's climate has been relatively stable since then (with some changes, but nothing like we're likely to see in the coming decades). There are no natural drivers of climate that provide enough warming to explain more than a small fraction of the warming we have seen since about 1970.

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I said the natural cycle is being accelerated by humans. I'm looking for a climate graph that shows the Earth's temperature over the last several million years. Can't seem to find one but it shows that we are still "coming out" of an ice age when you look at it on that scale. Stability for 5 thousand years looks less stable on a graph of a million years.

dad said:

So to be clear then, you feel that global warming is a natural cyle, mostly unrelated to man, and you are a GEOPHYSICIST?

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I said the natural cycle is being accelerated by humans.

leftrightleftrightleft said:

I said the natural cycle is being accelerated by humans. I'm looking for a climate graph that shows the Earth's temperature over the last several million years. Can't seem to find one but it shows that we are still "coming out" of an ice age when you look at it on that scale. Stability for 5 thousand years looks less stable on a graph of a million years.

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Except what we actually have is a period of dramatic deviation from the underlying natural variability. In just the last forty years the global average temperature has changed more than it's changed in at least the last 2000 years, probably much longer.

To say it's just an acceleration of a natural cycle is horribly misleading, because human activity, most especially the burning of fossil fuels, is a direct driver of climate change that doesn't much impact the normal natural drivers, which are generally the Sun (which, due to the orbit of the Earth, tends to cause climactic cycles on 46,000 year time periods), and major volcanic eruptions or asteroid/comet impacts (which, if large enough, throw lots of dust into the stratosphere, blocking sunlight and causing a significant drop in global temperatures). Our release of CO2 doesn't affect either of these things.

leftrightleftrightleft said:

I said the natural cycle is being accelerated by humans.

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I would tend to agree.

Chalnoth said:

Except what we actually have is a period of dramatic deviation from the underlying natural variability. In just the last forty years the global average temperature has changed more than it's changed in at least the last 2000 years, probably much longer.

To say it's just an acceleration of a natural cycle is horribly misleading, because human activity, most especially the burning of fossil fuels, is a direct driver of climate change that doesn't much impact the normal natural drivers, which are generally the Sun (which, due to the orbit of the Earth, tends to cause climactic cycles on 46,000 year time periods), and major volcanic eruptions or asteroid/comet impacts (which, if large enough, throw lots of dust into the stratosphere, blocking sunlight and causing a significant drop in global temperatures). Our release of CO2 doesn't affect either of these things.

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Ha, found your problem!

dad said:

Ha, found your problem!

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Dad, where did you find that HILARIOUS picture you have in your sig file! That is AMAZING!

The family looking heavenward with the flames behind them all smiles.

Oh that is PRICELESS.

Do you have a large format version that in your home????

That's so cool!

thaumaturgy said:

Dad, where did you find that HILARIOUS picture you have in your sig file! That is AMAZING!

The family looking heavenward with the flames behind them all smiles.

Oh that is PRICELESS.

Do you have a large format version that in your home????

That's so cool!

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That's a picture of the SECOND COMING, which occurs at the end of the Tribulation period, known as Armageddon.

I take it, it is a picture of a family rejoicing as Jesus comes back to put an end to this terrible battle, which is raging in the background.

I'm sure you would be smiling too, if you were them.

Chalnoth said:

Except what we actually have is a period of dramatic deviation from the underlying natural variability. In just the last forty years the global average temperature has changed more than it's changed in at least the last 2000 years, probably much longer.

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I'm not even sure what you're arguing with me about. I said it was being accelerated by humans, aka a deviation from the underlying natural variability.

Chalnoth said:

To say it's just an acceleration of a natural cycle is horribly misleading

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But that's what you also just said! You said its a "period of dramatic deviation from the underlying natural variability [due to human influences]".

I am saying that if humans didn't exist the Earth would still be warming but at a slower rate. If you agree with this then we are both saying the exact same thing.

I feel like we're saying the same thing but you are using stronger and more alarming language and you don't like the fact that I'm not using the same language.

leftrightleftrightleft said:

I am saying that if humans didn't exist the Earth would still be warming but at a slower rate.

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No, it really wouldn't be. Temperatures would have been quite stable without human activity.

leftrightleftrightleft said:

I feel like we're saying the same thing but you are using stronger and more alarming language and you don't like the fact that I'm not using the same language.

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Well, no. I'm saying it's wrong to claim that the Earth would be warming without us.

thaumaturgy said:

Dad, where did you find that HILARIOUS picture you have in your sig file! That is AMAZING!

The family looking heavenward with the flames behind them all smiles.

Oh that is PRICELESS.

Do you have a large format version that in your home????

That's so cool!

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Your name almost seems familiar. Reminds me of some guy that used to post here. Is that you? Licked your wounds enough to dare to do a few posts already? It's only been what...a few years? I would have figured you would need more time..

AV1611VET said:

That's a picture of the SECOND COMING, which occurs at the end of the Tribulation period, known as Armageddon.

I take it, it is a picture of a family rejoicing as Jesus comes back to put an end to this terrible battle, which is raging in the background.

I'm sure you would be smiling too, if you were them.

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There are two things that are wrong with that picture:

1 The parents are not blonde blue eyed and thus are not entitled to go to heaven.

2 Only whites go to heaven as no darker skinned person is depicted in the picture!

Oh well I guess Hell will be hard to enter with it being fully booked!

mzungu said:

There are two things that are wrong with that picture:

1 The parents are not blonde blue eyed and thus are not entitled to go to heaven.

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Chapter and verse for this racist comment?

2 Only whites go to heaven as no darker skinned person is depicted in the picture!

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So Moses married a dark woman, where will she go? How about the Ethiopian guy that got converted and went home to make his country the first Christian nation on earth..?

Oh well I guess Hell will be hard to enter with it being fully booked!

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Heaven ain't full, or the invites would not still be going out. Elementary.

dad said:

Chapter and verse for this racist comment?


So Moses married a dark woman, where will she go? How about the Ethiopian guy that got converted and went home to make his country the first Christian nation on earth..?

Heaven ain't full, or the invites would not still be going out. Elementary.

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Oh come on DAD even you can see that this poster comes from a time when racism was the norm. The picture is basically depicting the perfect Christian family and if we are to accept this then what of the other peoples? The poster is racist in the sense that what it depicts to the message it is trying to convey is purely racist!

dad said:

Chapter and verse for this racist comment?

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I think he's got the Bible mixed up with Mein Kampf or The Preservation of Favoured Races.