Is Global Warming a Natural Phenomenon?

[ChrisJB]

Originally Posted by FlyAgaric

Chris your not a spokesperson for Exxon by any chance are you?

All what you believe there, more than not comes from big oil company science, the same kind of science that tries to prove the creationist theory that the universe is only 6 thousand years old.

Nah, I'm a teacher (alas). But palaeoclimatology was a fair chunk of my degree course, and to be honest what I learned and studied there makes a lot more sense than the sensationalist tosh I keep 'encountering' in the media today.

Not six thousand years old?? I don't believe you! You'll be telling me it's billions of years old next!

Regards, Chris

[Interpreter]

This is a little tongue in cheek.

If cows and vegeterians are to blame for most of the greenhouse gasses being emitted today, what was happening 65 million years ago? How much CO2 would an 80 ton brontosaurus produce at one end and methane at the other and how many of these creatures could the earth support before global warming became an issue?

Just a thought.

[matt_xyz]

Originally Posted by Interpreter

This is a little tongue in cheek.

If cows and vegeterians are to blame for most of the greenhouse gasses being emitted today, what was happening 65 million years ago? How much CO2 would an 80 ton brontosaurus produce at one end and methane at the other and how many of these creatures could the earth support before global warming became an issue?

Just a thought.

What a thought. I suspect there were never sufficient numbers of the large dinosaurs around for this ever to have become an issue

It's not entirely accurate to say that cows and veggetarians are responsible for most of the greenhouse gases emitted today. Methane only contributes around 15-20% to augmented warming and only a proportion of that comes from cattle (21% in the US, for instance). And the role played by vegetarians is a bit of an urban myth (actually, if there were more vegetarians there would be fewer cattle, but that's another debate ).

Matt

[excoriate]

Originally Posted by Interpreter

This is a little tongue in cheek.

If cows and vegeterians are to blame for most of the greenhouse gasses being emitted today, what was happening 65 million years ago? How much CO2 would an 80 ton brontosaurus produce at one end and methane at the other and how many of these creatures could the earth support before global warming became an issue?

Just a thought.

Intensive agriculture.

[nikki cooper]

I think it is essentially a natural occuring process myself. When we look at the rings in old, old trees we can see naturally occuring changes in climate over thousands of years. Colder and hotter climatic evidence is present as the trees grow more during hotter episodes than cold (not to state the obvious) and the rings are bigger during these times. However, i do believe that we have a duty to look after this beautiful Earth. Many species have become extinct through human intervention and turning the earth into a vast rubbish dump is not what i have planned for my descendants to see. Hence i recycle and 'do my bit'. I feel its just negligence otherwise.

[Paul mabbott]

Tree ring sizes don't reflect "warm v cold", rainfall is extremely important - warm-wet years will show greater growth than warm-dry and cold-wet - cold-wet may fit somewhere into the pattern but also there are matters like length of the growing season .... so we cannot make simplistic judgments from dendrochronology. Also worth noting that rings show changes in *weather* rather than *climate* .....

However, there are much better indicators of anthropogenic climate change (glacial CO2 changes, for instance) which suggests that humans have accelerated climate warming irrespective of natural changes which, as I get tired of repeating, no one denies!

Pleased to see that you are taking appropriate action whatever the underlying cause. If only other people would take the same precautionary principle - if you might be contributing to the problem then stop it unless you can prove that you're not! So many people are taking the attitude that 'well it's not proven' to just do nothing and carry on with their polluting ways ....

Well done

Originally Posted by nikki cooper

I think it is essentially a natural occuring process myself. When we look at the rings in old, old trees we can see naturally occuring changes in climate over thousands of years. Colder and hotter climatic evidence is present as the trees grow more during hotter episodes than cold (not to state the obvious) and the rings are bigger during these times. However, i do believe that we have a duty to look after this beautiful Earth. Many species have become extinct through human intervention and turning the earth into a vast rubbish dump is not what i have planned for my descendants to see. Hence i recycle and 'do my bit'. I feel its just negligence otherwise.

[Strontium]

Hi, thanks for your input;

I was interested to hear about this -

Originally Posted by ChrisJB

Milutin Milankovitch, a Serbian astrophysicist, described subtle perturbations in the Earth's orbit, which govern how much sunlight reaches us at different latitudes. Consequently, we get periodic expansion and contraction of the Polar ice-caps. Seemingly, Milankovitch's theory seems to explain nearly every fluctuation in the Ice Age.
Regards, Chris

Could you provide a link or something to look at pls - sounds like a good bit of info?

I was watching some stuff on youtube about how some data analysts at Harvard University decided that the data used in the Inconvenient truth was selective, and did not properly account for the little ice age of the middle ages. There was a definite bias though (and they had dubious intentions), they didn't even mention a discussion of what they saw as credible evidence of a cycle. The debate also tries to argue that surface temperatures aren't even important, because the earth in high altitude does not even warm (what a load of claptrap). The only substantial point was that the suns output is changing quite a lot currently, and that the last cycle was very intense. This cycle we are in at the moment will be important for astrophysics, because many are predicting high output, but importantly different methods of prediction arrive at different outcomes. Another group have said this up and coming cycle of sun activity will not be as great as before.

[richardkm]

I'm not connected to Bush or an oil company.

I heard a letter read out recently from a fellow of the RGS to the Admiralty describing the enormous reduction in the level of ice in the NW Passage and judging by the amount of water in northern European rivers, owing to the melting of the glaciers.

This letter was dated in the 1800s (I can't remember the exact date)

We're just getting back to temperatures experienced before the "Mini Ice Age" that begun in the 14th Century and many experts consider that we are only just emerging from.

[russj1975]

Global Warming is quite clearly a natural phenomenon, but it is also quite clear that we are accelerating the trend.

you only need to go to the Lakes, North Wales, or Scotland, and ask yourself where all the glaciers have gone, and they didn't melt in the last 200 years! A warming event occurred in the past and at the time our mountains contained glaciers we must have been experiencing alpine temperatures at sea level, as our mountains are much lower than typical alpine environment. Now i'm not sure how long our glaciers lingered after the main ice age event, but its fair to say that the rate of melting of some glaciers today is quite alarming. It surely cannot be a coincidence that noticable changes in climate over the last 200 years are not linked to the industrial revolution....

[Strontium]

Originally Posted by richardkm

I'm not connected to Bush or an oil company.

I heard a letter read out recently from a fellow of the RGS to the Admiralty describing the enormous reduction in the level of ice in the NW Passage and judging by the amount of water in northern European rivers, owing to the melting of the glaciers.

This letter was dated in the 1800s (I can't remember the exact date)

Science back in that day, of meteorology was not even in its infancy, its not likely to be the most credible account of what was happening at the time. Experts don't say we are "emerging" from a little ice age, in fact we are well on the way to the reverse. When the permafrost in the tundra is in such massive decline, and ice sheets are being stripped away, this is not called "emerging", it is far from the nadir in global temperatures in the mini ice age. If you consider the net energy transfer to melt all that ice you will get what I mean.