Quote: Original post by LessBread
My understanding is that the wobble of the earth on it's axis is a greater factor in ice ages.

Ice Ages Blamed on Tilted Earth (2005)

Milankovitch cycles

Well,Milankovitch circles seems me too short for such "sluggish" system like Earth,of couse it could "modulate" an average Ice Age temperature,but the main grounds may be another.
AFAIK geology,almost everything depends from continents position and global ocean flows such as Al-Ninyo etc.We live in the times of "spliting" one huge continent (Pangea) to many parts,and after ~150 millions it caused Ice Age.It may be very long time,almost "Ice Age forewer",because splitting and "disbanding" will continue at least during next 100 million years.After this time the Sun itself will change because of evolution-i.e. we must take into account Sun itself as a star.Of couse,it has extremely stable light emission because of equilibrum gravity and pressure in the center where fusion reactions create energy,but everything changes slowly because the amount of hydrogen in Sun decreases.AFAIK,Sun could exist as a star of "main sequence" about 9 billion years,~5 billion has passed, next 5 billion will be other.Modern star models shows that after 100 millions years Sun emission can increase more than 1%.Another words,we live in the "ice minimum", past and future of the Earth must be more hot.
In addition Sun's magnetic field existance and their influence to energy emission depends from galaxy magnetic fields and hell knows what else.Sun orbits around galaxy center,enters into spiral branches ,interstellar gas and dust clouds , and so on.May be thats why the first Ice Age has occured more than 3 billion years ago though Earth surface was stil extremely hot.


Solar system evolution




[Edited by - Krokhin on September 5, 2010 6:22:58 AM]

Quote: Original post by Hodgman
The "greenhouse effect" has been known for a century - this is the name I knew "climate change" by when I was a kid, followed by "global warming". I wasn't told about it by politicians or the media, but by scientific periodicals, school teachers and history books -- it's old news. The reason it's exploded so much in the media lately and become an issue for politicians is because the denial movement came into existence in recent decades.

For half-a-century we've known that we're pumping an unprecedented amount of "greenhouse-gasses" into the air.
For decades we've recorded the effects of the changing composition of the atmosphere, and we've compared these measurements with the predicted changes due to the "greenhouse effect" - the predictions and observations line up.

Hogwash. It's a weak argument to take "climate change" and prefix "man-made" on the front. You're taking a strong argument that is well documented, and tacking something else on. It's the issue of how much man is to blame which is the big variable, and despite the greens spouting "it's obvious" that doesn't make it so.

Quote: Original post by Hodgman

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Quote: I think it's healthy to entertain dissenting views, especially when it's considered taboo.

It is exactly the same approach used when talking about new-earthers and scientists should know better.

It also reminds me a lot of the evolution vs. creationism debates.

What, in that new-earthers, creationists and climate-change-deniers are all challenging sound scientific theory with unfounded doubt and magical nonsense?

That's precisely the point I made. Talking from a position which implies the other party is stupid in order to dismiss their argument as 'crazy' without answering it is not science. When scientists start using emotion rather than facts, this is concerning. However, I don't know scientists do do this, because there are scientists on both sides of the argument... it's the people who actually know squat who decide one side is right and then call the other side stupid in order to discredit them, when as far as I can tell as in outside observer, the question is far from resolved.

It's not science if by the time kids get to school they've been told what the answer is, before the issue is even looked at. When I was at school, it was taught as a question of "what is happening" and "why is it happening", not "look what man did".

Going off on a totally different tack, I don't see anyone ever discussing why it's bad for man to affect the climate, it's taken as read that change is inherently wrong.
Given that more modern theories on climate change aren't just "it will get hot and everyone will drown" then why is exacerbating a natural phenomena 'evil'?

I prefer to think about man's affect on the planet in terms of pollution, deforestation and other invasive harvesting of resources. These seem able to cause much more clearly identified problems on a much shorter time-scale - health problems, extinctions, etc, etc. I wish all the green people would focus their energies on pollution rather than climate change.

Quote: Original post by LessBread

Quote: Original post by d000hg

Quote: Original post by Dreddnafious Maelstrom
I think it's healthy to entertain dissenting views, especially when it's considered taboo.

Absolutely. The climate-change brigade's biggest victory is not in how good their science is, but in getting everyone to believe that it's so obviously right, that only cranks would think otherwise. Phrases like "climate change deniers" are routinely used to ridicule those who don't share the prevailing view, in a clear attempt to discredit their arguments so that they can be dismissed without response. In the UK election, one candidate even accused another of "associating with climate change deniers" as if he were saying "holocaust deniers".

When the "skeptics" are unable to offer competing theories capable of explaining observations and continually dismiss the piles of gathering evidence and climate change predictions that bear out, they are behaving like holocaust deniers so labeling them in like manner is fitting.

Quote: Original post by d000hg

Quote: Original post by ddn3
It's so obvious that man made climate change is occurring

And there we go. The old "it's obvious, any fool can see it" argument. What is obvious and why? Because your local weather isn't nice, or because you've listened to people repeat it on TV, or because you've analysed the raw data, or because you've verified the raw data isn't adjusted to look good?

Melting glaciers, melting ice caps, disrupted rain patterns, increase floods, increase droughts, record breaking heat waves, increased forest fires, increased ocean acidity, increased ocean temperatures, expanding ranges of insects and diseases, ...

As I say, the hard part is showing this is due to us. As one example (which may be answered, it is only an example) wouldn't a single large volcanic event throw all the graphs out - actually I was wondering has the Icelandic volcanic ash cloud been analysed as to how it affects things?

Quote: Original post by d000hg
Going off on a totally different tack, I don't see anyone ever discussing why it's bad for man to affect the climate, it's taken as read that change is inherently wrong.
Given that more modern theories on climate change aren't just "it will get hot and everyone will drown" then why is exacerbating a natural phenomena 'evil'?

One of the big arguments seems to be that the coming climate change will increase the rate of extinctions and will therefore negatively affect biodiversity. It seems that the Greens don't much like the idea of another mass extinction, particularly one that is on human hands. I don't know enough about biology or ecology to explain why it is exactly that this is so bad, but I'm sure someone else here can chime in.

Quote: I wish all the green people would focus their energies on pollution rather than climate change.

Since anthropogenic climate change is believed to be caused by some pollution, in a way they're doing both. [wink]

Quote: Original post by Oberon_Command
Since anthropogenic climate change is believed to be caused by some pollution, in a way they're doing both. [wink]

For sure. Too many people forget about the giant hole in the ozone layer above the South pole, or the steps we took to help the situation long before anthropogenic climate change became a cool-ass meme:

http://www.aerosolproducts.org/

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A recent survey shows that 70% of Americans believe that aerosol products still contain the ozone harming chemicals chlorofluorocarbons (CFCs), but product manufacturers voluntarily stopped using them as propellants more than 30 years ago, before the U.S. Environmental Protection Agency banned them in 1978.

Quote: Original post by d000hg... because there are scientists on both sides of the argument...

Cool, here's my side. I think you'll agree there's some pretty hefty scientific weight behind that.

Where are the scientists on the other side? (Morons, idiots and raving lunatics don't count [grin]). In all seriousness, though I have yet to see any scientist on the denial side that hasn't been discredited almost instantly. See this thread for a prime example.

Quote: Original post by d000hg
Going off on a totally different tack, I don't see anyone ever discussing why it's bad for man to affect the climate, it's taken as read that change is inherently wrong.

As I've said before, the greeny-pinko-lefty-tree-huggy "OMG we're killing the earth" attitude is wrong. The earth (both as in a big ball of rock orbiting the sun and as a life sustaining eco system) will be fine long after we're gone.

What will be wrong is that lots of things we (i.e. humanity) like will be screwed up. Some info (yes, it's wikipedia, but you can read the references)

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I prefer to think about man's affect on the planet in terms of pollution, deforestation and other invasive harvesting of resources. These seem able to cause much more clearly identified problems on a much shorter time-scale - health problems, extinctions, etc, etc.

Same here, conservation and intelligent use of resources is a worthy goal and not reliant on contentious models and what ifs. Renewable energy is a worthy goal for multiple reasons. Sustainability is primary but if switching from a petrol economy will keep us from incinerating brown people willy-nilly then it's worth it on those merits alone.

Quote: Original post by d000hg
It's the issue of how much man is to blame which is the big variable, and despite the greens spouting "it's obvious" that doesn't make it so.

The last major IPCC report put the figure at half of observed warming. Your shouting "hogwash" would carry more weight if you showed the slightest bit of familiarity with the claims you seek to dispute.

Quote: Original post by d000hg
... when as far as I can tell as in outside observer, the question is far from resolved.

Perhaps it appears that way to you because you're observing the political discussion rather than the scientific discussion. See "Global Warming Deniers Aren't "Experts" At All" that I linked to earlier for a rundown of that distinction.

The conclusions produced by the cooperative work of almost 200 countries:

Quote: It is very likely that the observed increase in CH4 concentration is predominantly due to agriculture and fossil fuel use.

There is very high confidence that the net effect of human activities since 1750 has been one of warming.

During the past 50 years, the sum of solar and volcanic forcings would likely have produced cooling.

Human influences have:
* very likely contributed to sea level rise during the latter half of the 20th century
* likely contributed to changes in wind patterns, affecting extra-tropical storm tracks and temperature patterns
* likely increased temperatures of extreme hot nights, cold nights and cold days
* more likely than not increased risk of heat waves, area affected by drought since the 1970s and frequency of heavy precipitation events.

Spatial agreement between regions of significant warming across the globe and locations of significant observed changes in many systems consistent with warming is very unlikely to be due solely to natural variability.