The Naked Scientists

The Naked Scientists Forum

Author Topic: Global Warming : The World Is On Fire  (Read 18380 times)

Offline davidjuliowang

  • Jr. Member
  • **
  • Posts: 19
    • View Profile
    • http://members.shaw.ca/robertwang
Global Warming : The World Is On Fire
« on: 17/05/2006 05:07:13 »
30 Degrees On Vancouver Island

It's May.
It's Spring.
It's been 30 Degrees Celsius for the past two days in a row and it will be so until Saturday.

The normal temperatures for this time are 15-18 degrees celsius.

Vancouver Island is an island.
Nanaimo is right on the water.
It should be cooler.
I don't want to think what it's like on the mainland, or especially in downtown Vancouver.

Construction

I work in construction.

It was sickeningly hot out.

Working in construction is taxing for me.

The site is still unpaved dirt and with the heat and the wind the dirt forms little clouds of choking dust.
A hose was used to wet the dirt to keep the dust from choking everyone.
The hose had a huge leak with water spilling out everywhere.
Did I say anything?
No.
Why?
I don't want to jeopardize my job, but...you know...I should have.
It's important for my coworkers to see that someone is aware that water is not an unlimited resource, and that wasting it is a sad act.

Speaking of waste: the construction industry is far too, far too wasteful.

Collecting garbage is a taxing activity for me.
So much plastic and paper and metal and styrofoam all thrown into one big bin destined to be buried and forgotten : a testimony to humanity's still as of yet unexamined belief in the unlimitedness of our resources.

It saddens me to a degree that almost distracts me from my work (but I hold on because work = money = survival).

I have a plan to tell my boss about a service which sets up bins to separate recyclables and insure that they are recycled, but I'm reticent because I don't think he'll go for it.

Don't worry though.
I will try regardless.

World Is On Fire : Sarah McLachlan

If you like a song with a message may I recommend Sarah McLachlan's.

She's a wonderful Canadian singer with a concinetous mind.

The video for the song is especially excellent.
She took the money usually dedicated to making a video and using "Frontpage" demonstrated what she and her studio did with the money in thrid world countries.
They fed people, schooled people, vaccinated people, sheltered people and simply helped a bunch of people.

The thought of somebody caring enough to sacrifice gain for giving brings a tear to my eye.

Give the song a listen and know that there's an artist out there who cares about more than themselves.

Be Worried, Be Very Worried

That was the coverpage from Time magazine back in April.

I intend to make a shirt out of the page which shows a polar bear stranded on an ice drift looking for another one to swim to (the sad thing is I know that she will have a hard time finding one because there are few around).
Dozens of polar bears are drowning because the ice is melting so rapidly.

Here in Canada the government is proud of Canadian diamonds with polar bears inscribed on them.

Too bad the real bears are dying and we're the cause.

Final Thought

Sorry for the rant, but, then again, not sorry.

We have to say it.
We have to say that things aren't right.
We have to say that petroleum has to stay with the dinosaurs.
We have to say that the word 'garbage' needs to be removed from human vocabulary.
We have to say it's too blasted hot and that cloudy, rainy days are blessings which keep our planet alive.
We have to say it's time to change the way we interact with our planet : now.


"When Given A Choice Between Two Paths, Take The Third Path." (Talaxian Saying)
« Last Edit: 17/05/2006 05:11:18 by davidjuliowang »


 

Offline davidjuliowang

  • Jr. Member
  • **
  • Posts: 19
    • View Profile
    • http://members.shaw.ca/robertwang
Re: Global Warming : The World Is On Fire
« Reply #1 on: 17/05/2006 05:31:22 »
Without Water There Is No Life

I shed a tear or two.

Doing what?

Watching the video for "The World Is On Fire".

You can see it too : newbielink:http://www.worldonfire.ca/ [nonactive]

Caring

I hope the day comes sooner than later that I free myself from my own hurts and replace them with caring.

"When Given A Choice Between Two Paths, Take The Third Path." (Talaxian Saying)
 

Offline Matthewsb

  • First timers
  • *
  • Posts: 4
    • View Profile
    • http://www.dme.gov.za
Re: Global Warming : The World Is On Fire
« Reply #2 on: 14/06/2006 18:05:27 »
We urgently need to limit carbondioxide and carbonmonoxide pollution in the atmosphere. We need to lobby internationally that all rich countries should lead by example.

Matthews Bantsijang
 

Offline Atomic-S

  • Hero Member
  • *****
  • Posts: 935
  • Thanked: 19 times
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #3 on: 17/06/2006 07:30:04 »
Desperate polar bears, take heart! More ice is on the way, even if we don't do anything ecologically correctly in the next few decades, according to National Review, June 5, 2006, pp. 35ff.
 

Offline tony6789

  • Neilep Level Member
  • ******
  • Posts: 1127
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #4 on: 22/06/2006 19:48:13 »
global warming is both our fault and natures fault. We humans have polluted the earth so badely that we have created a "greenhouse effect. the sun's rays go through the atmosphere then cant get out due to the pollution in the air. but another factor is in place: the sun is getting hotter. lets but the suns life on a clock. the sun is born at dawn. right now we r at 10:36. humans have been around for only about 1 second. at 11:31 the sun will be too hot for life to exist. so yes global warming is happening.

NEVER! underestimate youth
 

Offline davidjuliowang

  • Jr. Member
  • **
  • Posts: 19
    • View Profile
    • http://members.shaw.ca/robertwang
Re: Global Warming : The World Is On Fire
« Reply #5 on: 24/07/2006 09:30:26 »
Sorry

I apologize for the long absence.
Thankfully, the show has remained excellent in my absence.

Oh yes.
I voted on Podcast Alley!
God save the Naked Scientists!

30 degree weekend

I apologize for the subsequent gloomy reflections, but, perhaps I and whomever reads this can decide to look at the following statements as positive, in that they display awareness and contemplation of something that is important.
Perhaps, these statements even display, the beginnings of initiative to "do" something about this.

Here on Vancouver Island, British Columbia Canada, we had a near record high weekend of temperature.

The weather is typically in the low to mid 20's.
The temperature was in the low to high 30's.

The radio commentators blithely commented on how "isn't the weather great!"
Well, the poor fellows and fillies are paid to perpetuate obliviousness.
Saying something like,
"It's hotter than it should be. Consider switching to a low emissions vehicle and recycle all you can."
Would cause people to think about something that is uncomfortable.
Most poor people are stressed out and uncomfortable enough as it is.
...i guess it is unjust for me to be judgemental.
...i'm no hero either.
but.
i do care.
and i do want to hear radio commentators say,
"Hey! You know what kits and kats? It's really too darn hot."

An Inconvenient Truth

I saw it and I am going to try to do what Al Gore wanted.

Here's one of the things he asked me, and, everyone who watched the film to do:

"Hey there fellow human being. I would like to encourage you to watch the movie 'An Inconvenient Truth'. You hear all about Global Warming. Who do you trust? I don't know. But. I do trust Al Gore. Why? A feeling. My feelings. I trust them. Watch the movie. And when you consider your position, I say : trust your feelings."

There.
Now I have to:
1. Write my parliament.
2. Buy environmentally friendly lightbulbs (check)
3. Buy a low emissions vehicle (looking at a small Toyota pickup)
4. Do an energy efficiency assessment of the house.

I still have a few things to do.

Why do I want to?
Because watching the movie opened my eyes.
and.
i felt something.
what Al Gore said,
how he said it,
the look on his face as he said it,
felt right.
he cares.
i care.
i'll do what he asked.

Proposal for a Commercial

There's a cute commercial by Coca-Cola.

The Polar Bears.

Baby bear finds some penguins.
He's curious.
He goes among them.
Papa and Mama follow baby.
They're nervous.
They're surrounded by strange penguins.
Will they hurt baby?
No!
One of the penguins gives baby a bottle of Coke.
Baby happily drinks down the cool, refreshing beverage.
Mama and Papa look on happily.
[musically] Always Coca Cola.

Watching "An Inconvenient Truth" I learned that the Polar Bears are dying out there up North.
The ice is there home.
We're taking that away.
No home.
No living.

I propose a new commercial.
I propose it to anyone who can make it.
I'll make it myself someday, if it doesn't get made.

It's still nightime.
Baby bear is happily drinking a beverage from a bottle (assumably Coke, but not coke because they'd sue) along with all his penguin friends.
Papa and Mama come over to happily look on.
The sun starts to come up.
Everyone looks out to happily greet the new day.
The suns rays gently stretch out along the icy sheet.
The rays reach the soda bottles held in polar bear paws and penguin webbed wings.
The bottles sparkle and shine and refract the rays towards the ice.
and everything goes to hell.
Rays lance out from all the soda bottles and cut into the ice.
The terrified baby bear and the penguins toss the bottles onto the ice  sheet.
The bottles land on the ice but continue to collect the suns unforgiving energy and carve the ice mercilessly.
The bear family and the penguins watch in horror as geysers of water shoot out into the air and the ice sheet splits apart into countless small floes.
[cut scene]
The bear family is swimming.
They swim up to an ice floe.
Papa and Mama try to push baby on.
The floe breaks into two pieces.
They try to push baby onto one that is just big enough for baby.
It breaks.
The exhausted bears resume their desperate swimming but as the camera pans out...there is nothing but water...everywhere.

Apologies

I'm sorry.
Writing this brought tears to my eyes.
It's kind of nice though.
It's so rare for me to feel much.

Powerful things.

Hurrican Katrina.
Iraq.
These experiences have catalysed the American people to look at their leadership, themselves, and question their direction.
really question their direction.
Painful experiences.
Lots of people are dead.
They won't see if their deaths have taught the survivors anything.
Hopefully the survivors will remember for them.

Polar bears are dying out there.
It's global warming.
It's our doing.
It's our responsibility.
A powerful commercial can be another "thing" to catalyse us to question, really question, our direction.

oh yeah.
i don't drink coke (or any other soda). period.

"When Given A Choice Between Two Paths, Take The Third Path." (Talaxian Saying)

Please see Al Gore's Movie "An Inconvenient Truth". The earth is our home, our responsibility.
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #6 on: 24/07/2006 23:47:06 »
While you are suffering record temperatures in British Columbia, as we are here in British England, we have reports from Texas of abnormally low temperatures for the season, as England is warmer than the Med.  Is it thus really appropriate to talk of global warming, or just a shift of hotspots from one point in the globe to another?

Beyond that issue of extrapolating too much from too small a data base, one also has to ask about the assumption of causal link.  We know that weather has been getting warmer since the 1660's, and that this has been due to changes in solar output, and all the emission reduction in the world wont change that.

As for human pollution much of it may actually have helped cool the world, and the reduction in particulate matter caused by cleaner factories may actually have increased the amount of solar radiation reaching the soil.

All of the attempt I have heard about to model the climate based upon the assumption that greenhouse gasses play a significant part in global warming have singularly failed to accurately predict anything.  Ofcourse, it may be that just one little tweak in the model may get everything exactly right, but it is just as likely that the underlying assumptions are completely wrong.



George
 

Offline moonfire

  • Neilep Level Member
  • ******
  • Posts: 4597
  • Can't stand the heat, step away from the fire!
    • View Profile
    • http://www.m2global.com/stormdiamonds
Re: Global Warming : The World Is On Fire
« Reply #7 on: 25/07/2006 03:54:37 »
George this is true!  It has been cooler for us the last 2 days...90's...and cool breeze.

"Lo" Loretta
 

Offline Acoustic Samurai

  • Jr. Member
  • **
  • Posts: 19
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #8 on: 25/07/2006 03:58:54 »
Alright guys, im in need of some criticism.
Supposedly heat cannot be destroyed, correct?
It only dissipates from one cooler object or body of matter to another, so suppose that our global warming isnt attributed to the ozone effect but the fact that in the past century, human beings have created much more heat energy through forms such as industrialization and the growth of fuel burning products. Also take into account the increasing population which is constantly growing with each year. The chemical reactions that take place within our body create heat too, so could the increased population plus recent industrialization (recent in relation to the age of the earth) have anything to do with the increased global temperatures we are experiencing? I'm probably very misinformed and sounding like an idiot, but it was a thought that crossed my mind while sitting in physics class.

Anywayz, criticize away!

-Timmy-

"Science Rules"

            Bill Nye The    
             Science Guy
« Last Edit: 25/07/2006 04:04:35 by Acoustic Samurai »
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #9 on: 25/07/2006 04:40:29 »
quote:
Originally posted by Acoustic Samurai
so suppose that our global warming isnt attributed to the ozone effect but the fact that in the past century, human beings have created much more heat energy through forms such as industrialization and the growth of fuel burning products.



Minor correction much of the argument for greenhouse heating has little to do with the ozone issue I think you are confusing two different matters.

The Earth can cool itself down if it radiates heat out into space.  This is one of the arguments the proponents of the greenhouse gas theory claim, that an increase in CO2 that still is measured in a few hundred parts per million is sufficient to significantly handicap the Earth's ability to radiate heat out into space.

On the broader issue, it seems a more plausible argument to me than the greenhouse gas argument the question is whether we actually are producing enough energy to have much impact.

I did put forward a question to the forum that might give some indication whether we do produce enough energy to significantly increment the temperature of the planet - http://www.thenakedscientists.com/forum/topic.asp?TOPIC_ID=4841

If the energy we are producing were as much as 1% of the energy that the Earth receives from the Sun from fossil fuels, then it would mean that we may be raising the Earth's temperature by about 2.8 degrees celcius.

The question is whether human energy production is in that order of magnitude.

Ofcourse, if we do use that much energy, then it follows that there is absolutely no way we can substitute 'renewable' energy sources for our fossil fuel sources, since I think it unlikely that we could ever have access to even 1% of the solar energy reaching this planet, and if we did, we would have to deprive the rest of the ecosystem of the use of that energy.

quote:

 Also take into account the increasing population which is constantly growing with each year. The chemical reactions that take place within our body create heat too, so could the increased population plus recent industrialization (recent in relation to the age of the earth) have anything to do with the increased global temperatures we are experiencing?



It is unlikely that out population increase will have much impact on global energy production since for the most part we are removing other animal species from the planet at about the same rate, so I imagine the two processes would about cancel each other out.

quote:

I'm probably very misinformed and sounding like an idiot, but it was a thought that crossed my mind while sitting in physics class.



No more than the rest of us if you don't ask, you won't find an answer.



George
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #10 on: 29/07/2006 19:33:01 »
http://www.climateprediction.net/board/viewtopic.php?t=2723

covers the same ground. Not sure if the calculations are accurate but the conclusion was that CO2 is massively more important than that of all mankinds energy creation.
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #11 on: 29/07/2006 20:18:30 »
quote:
Originally posted by crandles

http://www.climateprediction.net/board/viewtopic.php?t=2723

covers the same ground. Not sure if the calculations are accurate but the conclusion was that CO2 is massively more important than that of all mankinds energy creation.



I have no way of knowing if the figures they quote are accurate, but it does indicate that our own energy production is still only a fraction of what the Sun is presently giving us, and thus of little concern.

The figures they have used are (as I said, I have no idea if they are correct):
quote:

Energy recieved from sun:

radius of earth = 10,000 km
energy in incident radiation = 2.4 kw/m2
proportion of incident radiation absorbed = 0.2

Total rate of energy absorption = 1.5 x 10^14 kw


Energy consumed by people:

No of people = 6bn
Energy consumption per head = 30 kwh/day (this is my wildest guess)
proportion released as heat = 100%

Total rate of heat production = 7.5 x 10^9 kw

Ratio of man made heat to solar heat = 5 x 10^-5



I do not see any figures there about what the actual level of reduced radiation into space would be if there was a doubling or tripling of the current 300ppm or so proportion of the atmosphere that is CO2 (in geological time, there have been 5 fold increases over this, and it has not caused a runaway greenhouse effect and although the increase in CO2 has historically been associated with rise in global temperature, it has not been demonstrated that it causes, rather than is caused by, rises in global temperature -and we know that factor other than CO2 are at least partly responsible for changes in temperature, and may even be wholly responsible for it).



George
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #12 on: 30/07/2006 20:33:32 »
You are right about the comparisons being between mankinds energy production versus solar energy so I should not have suggested the CO2 being massively more important based on that thread.

I agree that the historical correlation alone does not provide very good evidence of causality. There are even lags in a few places suggesting the initial rise is not caused by CO2.

However, the totality of the evidence is much greater than the historical correlation. The science of how CO2 acts as a greenhouse gas is well understood. Without feedbacks, we are sure there would be a positive feedback of approx 1C for a doubling of CO2. The feedbacks are less certain but the main ones we know of increased water vapour and ice albedo are positive. There are several independant lines of research that suggest the climate sensitivity is about 3C

http://julesandjames.blogspot.com/2006/03/climate-sensitivity-is-3c.html
http://julesandjames.blogspot.com/2006/03/new-improved-estimate-of-climate.html#comments

Dr Annan is clearly bored with climate sensitivity now:
http://julesandjames.blogspot.com/2006/07/mission-impossible.html

If you want to suggest there are negative feedbacks such that climate sensitivity might even be negative then you are going to have to come up with some important feedbacks that are currently unknown and provide reasons why all those different estimates are wrong. If there was no positive climate sensitivity, you would also have to explain the unpresidented rates of warming at coincidentally just the time we would expect rises if there was a positice climate sensitivity.



You are right about there being factors other than CO2 but we know more than nothing about many of them else we could not produce figure a of 12.7:

http://www.grida.no/climate/ipcc_tar/wg1/450.htm

A positive feedback does not necessarily lead to a "runaway greenhouse effect" so because we haven't had one at 5 fold the CO2 level this may provide confort we won't get one if the same conditions arose again. However, it doesn't mean that there are not positive feedbacks.

 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #13 on: 30/07/2006 20:36:12 »
See also:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

http://www.realclimate.org/index.php?p=13
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #14 on: 31/07/2006 03:14:34 »
quote:
Originally posted by crandles

See also:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

http://www.realclimate.org/index.php?p=13



This seems like a very selective interpretation of the data.  Ofcourse, being selective does not make it provably wrong, only that it makes it suspect.

There is a clear acceptance that the first 800 years of global warming (in the historic records of past warm periods) was not caused by CO2.  It then suggests we can ignore this 800 years when we look at the subsequent 4,200 years.  While it is true that we cannot prove that the subsequent 4,200 years have the same cause of warming as the preceding 800 years; but would not Occam's razor suggest that we should first look for one mechanism, rather than postulate two separate mechanisms.  Ofcourse, Occam's razor is not always right, but why assume it to be wrong before having shown it to be wrong?

Furthermore, since it is clear that historic CO2 levels have consistently risen after the initial rise in temperature, we may reasonably deduce that there are non-anthropogenic mechanisms within the biosphere that actually cause a rise in CO2 as a consequence of rising temperature.  To what extent can we even be sure that present rises in CO2 levels are actually caused by human activity, and to what extent are they themselves part of the mechanisms that have in the past been a response to increasing global temperatures (the fact that humans produce CO2 does not of itself prove that humans control the balance between CO2 and O2).



George
« Last Edit: 31/07/2006 03:29:38 by another_someone »
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #15 on: 31/07/2006 03:25:00 »
quote:
Originally posted by crandles
However, the totality of the evidence is much greater than the historical correlation. The science of how CO2 acts as a greenhouse gas is well understood.



There should be one very important piece of evidence that should be available to us to help indicate the magnitude of the greenhouse effect.  I have yet to find anywhere on the Internet any publication of this evidence.

If the current presumed rise in CO2 levels on Earth are reducing heat radiation into space, then we should actually see a significant reduction of emitted energy in the infra-red pictures of the Earth taken by weather satellites over the last few decades.  Is such a reduction in infra-red emission actually observed in satellite photos?

quote:

Without feedbacks, we are sure there would be a positive feedback of approx 1C for a doubling of CO2. The feedbacks are less certain but the main ones we know of increased water vapour and ice albedo are positive. There are several independant lines of research that suggest the climate sensitivity is about 3C


If you want to suggest there are negative feedbacks such that climate sensitivity might even be negative then you are going to have to come up with some important feedbacks that are currently unknown and provide reasons why all those different estimates are wrong. If there was no positive climate sensitivity, you would also have to explain the unpresidented rates of warming at coincidentally just the time we would expect rises if there was a positice climate sensitivity.



The climate is dynamic, but with multiple stable (transiently) states.  In order to be able to achieve such short term stability, there must be negative feedback loops.  In order to switch states, there must also be positive feedback loops.  I do not think one can discuss whether there are positive or negative feedback loops, but must inevitably accept that there are both, most of which we have not the slightest understanding of.



George
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #16 on: 29/07/2006 19:33:01 »
http://www.climateprediction.net/board/viewtopic.php?t=2723

covers the same ground. Not sure if the calculations are accurate but the conclusion was that CO2 is massively more important than that of all mankinds energy creation.
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #17 on: 29/07/2006 20:18:30 »
quote:
Originally posted by crandles

http://www.climateprediction.net/board/viewtopic.php?t=2723

covers the same ground. Not sure if the calculations are accurate but the conclusion was that CO2 is massively more important than that of all mankinds energy creation.



I have no way of knowing if the figures they quote are accurate, but it does indicate that our own energy production is still only a fraction of what the Sun is presently giving us, and thus of little concern.

The figures they have used are (as I said, I have no idea if they are correct):
quote:

Energy recieved from sun:

radius of earth = 10,000 km
energy in incident radiation = 2.4 kw/m2
proportion of incident radiation absorbed = 0.2

Total rate of energy absorption = 1.5 x 10^14 kw


Energy consumed by people:

No of people = 6bn
Energy consumption per head = 30 kwh/day (this is my wildest guess)
proportion released as heat = 100%

Total rate of heat production = 7.5 x 10^9 kw

Ratio of man made heat to solar heat = 5 x 10^-5



I do not see any figures there about what the actual level of reduced radiation into space would be if there was a doubling or tripling of the current 300ppm or so proportion of the atmosphere that is CO2 (in geological time, there have been 5 fold increases over this, and it has not caused a runaway greenhouse effect and although the increase in CO2 has historically been associated with rise in global temperature, it has not been demonstrated that it causes, rather than is caused by, rises in global temperature -and we know that factor other than CO2 are at least partly responsible for changes in temperature, and may even be wholly responsible for it).



George
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #18 on: 30/07/2006 20:33:32 »
You are right about the comparisons being between mankinds energy production versus solar energy so I should not have suggested the CO2 being massively more important based on that thread.

I agree that the historical correlation alone does not provide very good evidence of causality. There are even lags in a few places suggesting the initial rise is not caused by CO2.

However, the totality of the evidence is much greater than the historical correlation. The science of how CO2 acts as a greenhouse gas is well understood. Without feedbacks, we are sure there would be a positive feedback of approx 1C for a doubling of CO2. The feedbacks are less certain but the main ones we know of increased water vapour and ice albedo are positive. There are several independant lines of research that suggest the climate sensitivity is about 3C

http://julesandjames.blogspot.com/2006/03/climate-sensitivity-is-3c.html
http://julesandjames.blogspot.com/2006/03/new-improved-estimate-of-climate.html#comments

Dr Annan is clearly bored with climate sensitivity now:
http://julesandjames.blogspot.com/2006/07/mission-impossible.html

If you want to suggest there are negative feedbacks such that climate sensitivity might even be negative then you are going to have to come up with some important feedbacks that are currently unknown and provide reasons why all those different estimates are wrong. If there was no positive climate sensitivity, you would also have to explain the unpresidented rates of warming at coincidentally just the time we would expect rises if there was a positice climate sensitivity.



You are right about there being factors other than CO2 but we know more than nothing about many of them else we could not produce figure a of 12.7:

http://www.grida.no/climate/ipcc_tar/wg1/450.htm

A positive feedback does not necessarily lead to a "runaway greenhouse effect" so because we haven't had one at 5 fold the CO2 level this may provide confort we won't get one if the same conditions arose again. However, it doesn't mean that there are not positive feedbacks.

 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #19 on: 30/07/2006 20:36:12 »
See also:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

http://www.realclimate.org/index.php?p=13
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #20 on: 31/07/2006 03:14:34 »
quote:
Originally posted by crandles

See also:

What does the lag of CO2 behind temperature in ice cores tell us about global warming?

http://www.realclimate.org/index.php?p=13



This seems like a very selective interpretation of the data.  Ofcourse, being selective does not make it provably wrong, only that it makes it suspect.

There is a clear acceptance that the first 800 years of global warming (in the historic records of past warm periods) was not caused by CO2.  It then suggests we can ignore this 800 years when we look at the subsequent 4,200 years.  While it is true that we cannot prove that the subsequent 4,200 years have the same cause of warming as the preceding 800 years; but would not Occam's razor suggest that we should first look for one mechanism, rather than postulate two separate mechanisms.  Ofcourse, Occam's razor is not always right, but why assume it to be wrong before having shown it to be wrong?

Furthermore, since it is clear that historic CO2 levels have consistently risen after the initial rise in temperature, we may reasonably deduce that there are non-anthropogenic mechanisms within the biosphere that actually cause a rise in CO2 as a consequence of rising temperature.  To what extent can we even be sure that present rises in CO2 levels are actually caused by human activity, and to what extent are they themselves part of the mechanisms that have in the past been a response to increasing global temperatures (the fact that humans produce CO2 does not of itself prove that humans control the balance between CO2 and O2).



George
« Last Edit: 31/07/2006 03:29:38 by another_someone »
 

another_someone

  • Guest
Re: Global Warming : The World Is On Fire
« Reply #21 on: 31/07/2006 03:25:00 »
quote:
Originally posted by crandles
However, the totality of the evidence is much greater than the historical correlation. The science of how CO2 acts as a greenhouse gas is well understood.



There should be one very important piece of evidence that should be available to us to help indicate the magnitude of the greenhouse effect.  I have yet to find anywhere on the Internet any publication of this evidence.

If the current presumed rise in CO2 levels on Earth are reducing heat radiation into space, then we should actually see a significant reduction of emitted energy in the infra-red pictures of the Earth taken by weather satellites over the last few decades.  Is such a reduction in infra-red emission actually observed in satellite photos?

quote:

Without feedbacks, we are sure there would be a positive feedback of approx 1C for a doubling of CO2. The feedbacks are less certain but the main ones we know of increased water vapour and ice albedo are positive. There are several independant lines of research that suggest the climate sensitivity is about 3C


If you want to suggest there are negative feedbacks such that climate sensitivity might even be negative then you are going to have to come up with some important feedbacks that are currently unknown and provide reasons why all those different estimates are wrong. If there was no positive climate sensitivity, you would also have to explain the unpresidented rates of warming at coincidentally just the time we would expect rises if there was a positice climate sensitivity.



The climate is dynamic, but with multiple stable (transiently) states.  In order to be able to achieve such short term stability, there must be negative feedback loops.  In order to switch states, there must also be positive feedback loops.  I do not think one can discuss whether there are positive or negative feedback loops, but must inevitably accept that there are both, most of which we have not the slightest understanding of.



George
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #22 on: 31/07/2006 11:49:56 »
quote:
The climate is dynamic, but with multiple stable (transiently) states. In order to be able to achieve such short term stability, there must be negative feedback loops. In order to switch states, there must also be positive feedback loops. I do not think one can discuss whether there are positive or negative feedback loops, but must inevitably accept that there are both, most of which we have not the slightest understanding of.


What makes you so sure of this? Why cannot the appearance of multiple stable states be a result of the forcings applied  eg Milankovitch cycles. To first order, the most important consideration is that the hotter the earth the more heat it ratiates. This creates the stability in the same manner as the leaky bucket analogy. A steady state can be reached. Reduce the size of the hole and the water level starts to rise but it doesn't necessarily overflow the bucket a new equilibrium level is likely to be reached because the flow out of the hole depends on the height of water.

Since there appear to be net positive feedbacks at more than one point in time (eg current, LGM, and other times from which estimates of climate sensititivity have been made), it is possible that at another point in time the net feedbacks could be different but that doesn't mean they are likely to become negative and I suggest that the experts know enough to say they are very unlikely to become negative soon.
« Last Edit: 31/07/2006 11:51:06 by crandles »
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #23 on: 31/07/2006 12:09:45 »
quote:

This seems like a very selective interpretation of the data.  Ofcourse, being selective does not make it provably wrong, only that it makes it suspect.

There is a clear acceptance that the first 800 years of global warming (in the historic records of past warm periods) was not caused by CO2.  It then suggests we can ignore this 800 years when we look at the subsequent 4,200 years.  While it is true that we cannot prove that the subsequent 4,200 years have the same cause of warming as the preceding 800 years; but would not Occam's razor suggest that we should first look for one mechanism, rather than postulate two separate mechanisms.  Ofcourse, Occam's razor is not always right, but why assume it to be wrong before having shown it to be wrong?



George




This is actually funny. [:o)] Who is being selective? Is it the climatologists at realclimate for ignoring the other cause?

or could, just perhaps, it be the case that they are considering both causes of warming (one known to have a positive contribution and the other which is unknown whether it continues or not) and it is you being selective in wanting to consider only one cause of warming and deliberately ignoring the CO2 when that is the cause we know to have a greenhouse effect which will have a positive effect on temperature.

I don't think occam razor suggests ignoring a known cause in favour of an unknown one.
 

Offline crandles

  • Full Member
  • ***
  • Posts: 54
    • View Profile
Re: Global Warming : The World Is On Fire
« Reply #24 on: 31/07/2006 12:21:21 »
quote:
Originally posted by another_someone

Furthermore, since it is clear that historic CO2 levels have consistently risen after the initial rise in temperature, we may reasonably deduce that there are non-anthropogenic mechanisms within the biosphere that actually cause a rise in CO2 as a consequence of rising temperature.  To what extent can we even be sure that present rises in CO2 levels are actually caused by human activity, and to what extent are they themselves part of the mechanisms that have in the past been a response to increasing global temperatures (the fact that humans produce CO2 does not of itself prove that humans control the balance between CO2 and O2).



George




We are pretty sure. We are putting 7 gigatones of carbon into the atmosphere each year through burning fossil fuels and when we measure the atmosphere 4 gigatones per year are accumulating in the atmosphere. The ocean is disolving most of the balance causing it to become more acidic. Prior to the industrial revolution CO2 had been pretty much stable in the atmosphere. So to raise uncertainty about us being the cause you are going to have to find some pretty big natural sources to have started at just the right time as well as methods for our CO2 to be dealt with naturally.
 

The Naked Scientists Forum

Re: Global Warming : The World Is On Fire
« Reply #24 on: 31/07/2006 12:21:21 »

 

SMF 2.0.10 | SMF © 2015, Simple Machines
SMFAds for Free Forums
 
Login
Login with username, password and session length