Or do we rely on the Earth's core to provide for any shortfall from the Sun's contribution?

that's why orcs and hobbits burrow…

we rely on sunshine from billions of years past, no?

If you mean is the sun capable of providing all the energy we need – yes. Something like 13 times more solar energy falls on the earth than we use. However, could we economically / feasibly harvest it – no. Not at current consumption rates anyhoo.

Only works during daylight hours

Ok, here's a clue.

Polar nights last 6 months, and even during the polar summer, the sun is further away than say, africa, or india. That whole "equator" thing.

And now, ask yourself, how cold is it at the equator? How much does heat from the earths core provide?

From o level geography, its an average of 4% of the total heat.

My question put another way is…if we didn't have the heat from the Earth's core what would the effect be on the temperature of our planet?

might have to put a jumper on 🙂

.if we didn't have the heat from the Earth's core what would the effect be on the temperature of our planet?

who can we sell it to ?

The Sun provides us with everything as it writes about Jordan, Posh and Gordon Brown. It even has a photo of a topless lady. Jeez, the youth of today 🙁

Any sensible answers? 🙂

The answer is 32 watts per square metre. Apparently.

http://www.madsci.org/posts/archives/oct98/905866177.Es.r.html

Thanks ernie.

If I'm reading this right this would mean that we actually need the heat from the Earth's core to survive.

Well according to that link "there is no significant energy received at the Earth's surface from any interior source. (Contrast this with Jupiter, which radiates about 10 times the energy it receives from the Sun.) "

Although as sweepy suggests – you might have to put a jumper on

I'm just thinking of volcanoes, lava and magma which are extremely hot and just below the surface. Even if you under ground just a little way the temperature rises. So I'm of the opinion that if the Earth was cold (frozen if you like) then the heat of the Sun would not be sufficient to sustain life. Am I wrong?

The answer is 32 watts per square metre. Apparently.

insolation is around 1000W per sq. metre at the equator…

Am I wrong?

yes. However, life may have started in hot undersea vents 🙂

Forgive me (like Winnie the Pooh I have only a bit of fluff between my ears) but does insulation = internal heat? I'm only considering at the moment external heat from the Sun and internal heat from the Earth's core.

the heat of the Sun would not be sufficient to sustain life

Well if what the Earth's core contributes is less than 10%, then I would have thought that heat from the Sun would easily be sufficient to sustain life. Although there might be a few things happening differently.

does insulation = internal heat?

😕 Are you worried about the Sun's heat getting "sucked into" the Earth's core ?

He typed insolation not insulation and yes, as in the link it comes from the sun (sol).

I apologise for using insolation, I thought its meaning was obvious!

32/1000 = 0.32% which ain't much…

Sfb is correct. Bugger all comes from inside the planet and radiates out, even though it's very hot in there.

Without the Earth's hot core wouldn't we loose our magnetic field and thus get our atmosphere 'poofed' by solar radiation?

32/1000 = 0.32% which ain't much…

But the 1000W per sq. metre at the equator is hardly an average. I understood the average solar energy input as 353 watts per square metre. So 32/353 = a bit under (cause I ain't technical 😉 ) 10%

yeah, I'm sleepy after a long ride and 32/1000 = 3.2% 🙂

But isn't the current Climate Change meant to be less than this and yet we're anticipating huge changes?

I see.

Who said that there wouldn't be huge changes ? 😕

The Earth's average surface temp. is about 14 degrees C. You could reduce that to say 10 degrees C, and the Earth could still easily sustain life – no bother. Although it would undoubtedly have a catastrophic effect on species throughout the planet. Including humans.

So in that case the heat from the Earth's core is crucial to sustaining life as we know it on our lovely planet.

life as we know it

It depends in what context you're using "life as we know it".

If it's as in "it's life Jim – but not as we know it", then no, a drop of a few degrees would not change life as we know it. But it would certainly wipe out species which have taken millions of years to evolve. And severely effect others that might which might manage to survive. Of course some at least, would undoubtedly find the change beneficial. Although I'm fairly confident that it would have a seriously negative effect on humans. The world is a fragile place, and so are the species that live within it.

I reckon that last statement is fairly true. Life would continue in some form but I doubt wimps like humans would survive it. Look how periously perfectly we are positioned, our poles are covered in ice, our equator is so hot it burns. Even a tiny change to that setup and it'd be WOOOP! Covered in ice all over.

Heat has a lot more celeb gos than the Sun, so clearly the answer is no.

So I'm puzzled as to how this planet of ours seems to be "just so". Do other planets have molten cores? If so, do they have atmospheres too?

Just having watched the prog on our wonderful Solar System I'm just amazed that everything in our world "just happens to be" and no real scientific explanation.

Just having watched the prog on our wonderful Solar System I'm just amazed that everything in our world "just happens to be" and no real scientific explanation

Coincidence? It's not like someone 'put' earth were it is, made the core molten etc.

Is that like the coincidence of the lunar eclipse with our moon being just the right size and distance?

tyger are you is trying to get us all to endorse intelligent design ???
Was this suggested at the latest marketting meeting of god childrens or something.

I'm just amazed that everything in our world "just happens to be" and no real scientific explanation.

so god did it I mean what other explanation could there be for the serendipity that led to life.
Does the rape and murder of small children help you with "just happens to be"?

Of course it is as it is the chicken and egg scenario if things changed radicaly say a 35% change in temperature life would still exist [ though many many species would be extinct] and it would still be amazing that everything just happens to be and fits so well. the things that can adapt tot he environement survive and the things that cannot die out. It will always look like it fits if you ignore all the dead stuff and the millions of planets that do not sustain life.

yes we are very lucky the moon is the exact size and distance to create eclipses. I assume you thought god decided we needed some random display of power every now nad agin to reminfd us of our place. I would have thought ending stravation or curing disease would be more useful demonstration

The thing is, if the planet were not 'just so' then we wouldnt be here to notice.

I didn't mention God, Junkyard, I'm just curious to know why things are the way they are. Like why are you so agressive?

Just having watched the prog on our wonderful Solar System I'm just amazed that everything in our world "just happens to be" and no real scientific explanation

Well, you must have watched a different programme to me. I thought he was trying to explain the workings of the solar system, and how it was formed, by using exampes of the same physics operating here on Earth on a smaller scale. I though he did so brilliantly, I understood every word of it, and I now have a far greater undersanding of where it all comes form than I did before 🙂

So in that case the heat from the Earth's core is crucial to sustaining life as we know it on our lovely planet.

It certainly is in Iceland. After their banks going bankrupt the last thing they need is someone turning off their geothermal energy supply.

Right, well there's this thing called anthropic reasoning, and it goes like this. Lots of things on earth are co-incidentally just perfect for life, but this isn't a co-incidence. Life could only evolve sufficiently to think about these things on a planet where everything was just-so.

Or, to put it another way – there could well be billions of other planets out there where conditions are not perfect for life, but no-one'd have evolved on them to start thinking about it.

So not a remarkable co-incidence at all, rather a pre-condition of this very discussion.

As for insolation, I seem to remember a figure of 1.5kw/m2 from uni. Maybe this was at the equator. If we say X is the amount at the equator, then the amount at a latitude L = X * cos(L).. If I could be bothered I could probably remember how to work it out using calculus, given the total output of the sun.

And I don't think that the earth's core has much to do with ambient temperatures on the surface other than providing us with a magnetic field (which is of course vital, keeping the atmosphere in place). I seem to remember reading that it gets pretty warm on the moon which has no hot core. Also space stations etc would get really really hot when the sun's on them – that's why they get covered in tin foil. So I'm guessing that heat from the core makes not much difference.