Earth facing a mini-Ice Age 'within ten years'

[biffvernon]

I don't think the IPCC made any prediction. It just presented models. The difference may be subtle but it's important.

[snow hope]

I don't think the IPCC made any prediction. It just presented models. The difference may be subtle but it's important.

The difference may be important, but they are still wrong so far.....

[biffvernon]

The difference may be important, but they are still wrong so far.....

Ok, so you've not understood the difference. The model just says that IF **** THEN ****. Change the IF and you'll get a different THEN.

You might usefully argue that the IPCC did not use the right IF. For instance they did not include IF the oil depletes rapidly.

[snow hope]

I fully understand the point you are trying to make, but I do not accept it.

The IPCC draw conclusions (such as mankind being the dominant cause of global warming), they highlight 'evidence' of warming from various scientic reports, models, data collection from various meteorlogical organisations. They summarise their findings and provide advice for policymakers, etc.

They say we are causing the climate to warm. The graphs they drew up, and/or highlighted in some previous reports have not been borne out so far, by actual temperatures, despite the number of reporting stations and data collection being reduced dramatically over the last decade or two.

What part of that do you not understand? Or do you simply choose to ignore that fundamental problem, due to your absolute acceptance of AGW?

[biffvernon]

absolute acceptance of AGW?

Yep, about as absolute as rotundity of the Earth and downward effect of gravity on apples. There's no debate.

Have some bedtime reading: http://www.columbia.edu/~jeh1/mailings/ ... People.pdf

[snow hope]

There's no debate.

Thanks for verifying my point.

[An Inspector Calls]

Don Easterbrook? Don't make me laugh!

James Hansen? Don't make me laugh!

[kenneal - lagger]

...........and downward effect of gravity on apples. There's no debate.

Now that depends on how high you go. Go high enough and the apple will fly upwards towards the moon or sun!

[clv101]

... I don't believe that we have a full grip on the relationship between Solar effects and greenhouse gas effects. The mechanism for the way the sun heats the earth and affects the climate are not fully understood, the mechanisms for the Little Ice Age and the Grand Minima are not understood for instance.

It might be because there isn't much of mechanism there at all.

Here's a new paper linking the Little Ice Age with volcanism.

Abstract
Northern Hemisphere summer temperatures over the past 8000 years have been paced by the slow decrease in summer insolation resulting from the precession of the equinoxes. However, the causes of superposed century-scale cold summer anomalies, of which the Little Ice Age (LIA) is the most extreme, remain debated, largely because the natural forcings are either weak or, in the case of volcanism, short lived. Here we present precisely dated records of ice-cap growth from Arctic Canada and Iceland showing that LIA summer cold and ice growth began abruptly between 1275 and 1300 AD, followed by a substantial intensification 1430–1455 AD. Intervals of sudden ice growth coincide with two of the most volcanically perturbed half centuries of the past millennium. A transient climate model simulation shows that explosive volcanism produces abrupt summer cooling at these times, and that cold summers can be maintained by sea-ice/ocean feedbacks long after volcanic aerosols are removed. Our results suggest that the onset of the LIA can be linked to an unusual 50-year-long episode with four large sulfur-rich explosive eruptions, each with global sulfate loading >60 Tg. The persistence of cold summers is best explained by consequent sea-ice/ocean feedbacks during a hemispheric summer insolation minimum; large changes in solar irradiance are not required

[snow hope]

LOL Chris, at least you used the word "might"!

So that big yellow fiery thing in the sky that gives the Earth all its heat "might" not have anything to do with the cool (and warm) periods that the earth experiences over the decades, centuries and millenia?

Hmmmm, just strikes me as a little counter-intuitive........ would you not agree?

But say we accept that the period when the sun had practically no sunspots and that happened to coincide with the coldest part of the Little Ice Age, was really down to explosive volcanic periods blotting out the sun and causing cooling. What then caused the Medieval Warm Period or the Roman Warm period or other warm periods in the Middle Ages?

[UndercoverElephant]

LOL Chris, at least you used the word "might"!

So that big yellow fiery thing in the sky that gives the Earth all its heat "might" not have anything to do with the cool (and warm) periods that the earth experiences over the decades, centuries and millenia?

Hmmmm, just strikes me as a little counter-intuitive........ would you not agree?

Not really, no. Lots of things have affected the climate (atmospheric composition, orbit of the Earth, output of the sun, distributions of the continents on the Earth's surface...) - so it is a question of what has biggest the influence.

Now look at this graph:



Even taking peak oil into account, it looks increasingly likely that our CO2 emissions will screw up the climate BIG TIME.

[kenneal - lagger]

The sun's heat output doesn't vary enough to change the climate to the extent that happens, Snow. There are other factors at work which science can't, as yet, explain. We also don't know enough about trigger points and tipping points which can invoke an exaggerated response.

[UndercoverElephant]

What's the big scientific mystery you are talking about, Ken?

This isn't gravity we are talking about here. There's no missing Higgs Boson of climate science.

[clv101]

The sun's heat output doesn't vary enough to change the climate to the extent that happens, Snow. There are other factors at work which science can't, as yet, explain. We also don't know enough about trigger points and tipping points which can invoke an exaggerated response.

Sure - the reason I mentioned this paper is that it adds a little new insight into this open area.

[RenewableCandy]

The sun is heading into an unusual and extended period of hibernation

I think they were talking about the paper, not the big yellow shiny thing