Climate change?

[cee-dee]

Climate change is foremost on the lips of many people not least those "protesters".

The thing is..... over millions of years the climate on Earth has fluctuated with extremes of heat or cold and that was long before Man walked the Earth.

At one time the Mid-West (USA) was covered by a sea so the Earth must have warmed and it had nothing to do with "emissions" caused by Man.

At another time, most of the Earth was covered in ice so what caused those two extremes?

Is the answer that big Yellow thing out there..... the Sun?

There's many theories as to why the ancient climate changed and now Man is being blamed for the speed of climate change but if all supposedly "harmful emissions" stopped right now, would it make a ha-porth of difference?

Is (or was in times past) the change caused by a difference in our orbit around the Sun? Does our distance from the Sun vary over time causing the Earth to warm or cool? If that's so, there's absolutely nothing we can do about it? Cause for thought?

[**bustysinclaire**]

If that's so, there's absolutely nothing we can do about it?

Would we, if we could?

[cee-dee]

I wonder if those people chopping down the Amazon (and other) forests are concerned about climate change?

[cee-dee]

Thinking about the distance of the Earth from the Sun.......

One of the most powerful forces in the Universe is gravity soooooo..... when all the outer Planets are in a direct line as they're also furthest from the Sun, are they able to exert any gravitational pull on the Earth to cause it to drift a little further from the Sun?

Conversely, when all the Planets other than the Earth are on the opposite "side" of the Sun, will the Sun exert a bit of gravitational pull on the Earth to cause it to drift a little closer to the Sun?

[upthecreekyetagain]

Gravity is one of the weakest forces in the universe. 

[fallen-archie]

So many points made I would simply say this, what happened in the past is to be aware of however because as civilisation has developed, cutting down trees and belching toxins into the air surely there will be some impact? The internal combustion engine has only been around for a 120 years or so however the growth it experienced from the 50s has been phenomenal, are you suggesting that man made emissions have no impact, if so I remember the impact of smog in the late 50s. Early 60s, thing is you could see it we decided to introduce smokeless zones, not because of global warming but because of the impact on individuals health! There can be little doubt that our desire to continue blindly going into development and expansion brings with it problems. And yes if we all want to heat our homes to 20c + surely that will have some impact on external temperatures too!

[cee-dee]

Not so, when the distance is greater, so is the effect.

[garygee]

It is

The weakest of the known forces emf, nuclear 

And its effect is inversely proportional to sq of distance, proportional to mass, not as suggest elsewhere, as should be obvious really 

[cee-dee]

Going back to #4, I said Gravity was one of the most powerful forces in the Universe. I said that because it's not the most powerful.

Of the four fundamental forces, gravity (being the weakest of the four) operates at distance and as such is therefore more powerful than others which, although very powerful at atomic level don't have the effect of gravity operating on mass.

[garygee]

No, it's the weakest 

& its force is inversely proportional to the sq of the distance, not as above

The explantion of how it acts has changed, the basic maths remains the same

[cee-dee]

Getting back on the topic of my OP, it seems I wasn't far out with what I said.

Dr Jerome Chappellaz, part of a NASA team who drilled down through 3 kilometres of Antarctic ice when speaking about Ice Ages predicted that within 40,000 to 60,000 years an Ice Age will return and said that :-

"Our distant cousins – Saturn and Jupiter – are responsible. 

These two planets are so big that their mass periodically deforms the Earth’s orbit, making it more elliptic. 

Since the sun is further away, the energy we receive from it lessens.

The Earth’s orbit around the sun causes the quantity of the energy received at the surface of the planet to change with time.

If we take winter snowfall at out latitudes, there needs to be enough energy during the summer to make it melt but, if it is not strong enough, the snow will stay and form a glacier over summer.”

It seems obvious then that the converse must also be true. If we get closer (to the sun) it'll get hotter?

[upthecreekyetagain]

Changes in Earth’s orbit as well as inclination obviously do have an effect on the climate here on Earth, that does not mean that man’s activities don’t also contribute to climate change.

Indeed, consensus amongst the planet’s most respected scientists is that man is the major contributor towards climate change.

Just because we can expect the climate here on Earth to change over millennia due to solar and planetary movements does NOT mean that we can continue to behave in a way that is causing it to change in a matter of decades.

[cee-dee]

Man is the next most destructive happening on Planet Earth after cosmic events.

It's true that although Man has only been around for a short time (in cosmic terms) he had had a destructive effect more than anything else.

That said, similar effects on the Planet (and therefore the climate) have happened before (and before Man). There's all sorts of nasties on the ocean floors which have been "stirred up" and released causing climate change. 

Man is obviously not helping the situation but how do you "control" those who completely disregard any limits or restrictions?

Anyway, when're you gonna post more on Deno?

[upthecreekyetagain]

In the grand scheme of things man’s “behaviour” may be less “destructive” than cosmic events but it is causing changes on a far faster scale.

What man does is very unlikely in the long term to have any permanent effect on the future of the Earth whereas ultimately cosmic events will destroy it.

The relatively minor changes that man’s actions may cause however could well make the Earth uninhabitable for us as well as many other species.

[theelench]

ArielI'm not convinced that climate change will be such a disaster for the Earth as many make out.  As you say seas move around, so do deserts and forests.  Climate is continually changing, species rise and fall and some go extinct, it's Nature.

I was watching a program about Africa and its wildlife recently, it showed that the jungles have expanded and contracted for millions of years without mans interventions.

It's well documented that North Africa was wet, fertile and inhabited by animals now confined to the southerly plains into Roman times.  

If we are changing the climate quicker than usual I suspect that it is us that will experience the disaster as the Earth self-corrects.  Archeology in South America reveals that the collapse of most of the civilisations there was brought about by the rapid expansion of population, cultivation and chopping down of the forest.  

We are doing the same on a global scale again but as in South America the break-down of the ecology that was a disaster for humans will happen before we have completely wiped out everything else.  With most of the humans gone the small pockets of the "Natural" world will expand again covering our cities as it did the Mayans.

[**bustysinclaire**]

"I'm not convinced that climate change will be such a disaster for the Earth as many make out."

agreed.  It won't be 

[fallen-archie]

The real disaster will come from overpopulation we need to get that under control!

[**bustysinclaire**]

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@fallen-archie wrote:
The real disaster will come from overpopulation we need to get that under control!

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When you think how little of the planet is inhabited and how much of the planet isn't, there needn't be overpopulation.

Mankind's bad management?

[fallen-archie]

Yes but we share the planet with other species and they too are entitled to exist!

[upthecreekyetagain]

Without previous major events changing the Earth and wiping out species then we most likely wouldn’t exist nor would many of today’s other species.

As a viable species man has only existed for mere seconds relative to the current age of the Earth and is likely only to exist for a tiny fraction of the time the Earth has left.

We can’t harm our planet, all we are likely to do is make it unviable for us to live on it.