When will this Interglacial end? + The "In the 1970s they feared an Ice Age" Myth.

Just when you thought this tripe was dead, it comes round again. Well, its winter at least in this hemisphere, and a bit chilly, so perhaps it seems plausible – the septics usually have trouble telling weather from climate.

Anyway, your reference is We’re number 1! which provises you a handy link to The Myth of the 1970s Global Cooling Scientific Consensus – the paper that the denialists are too scared to address.http://journals.ametsoc.org/doi/abs/...2008BAMS2370.1

1970s cooling, again – Stoat

Comment from John Mashey

There’s been much good research over last 10 years, and it is increasingly clear that without humans, we’d already be on the long slow (if jiggly) downward CO2 temperature path. if I recall aright, CO2 ought to be down around 240-260ppm by now. Archer, Chapter 12:

Very clear discussion of trigger points and CO2 levels, finishing with:

“If mankind ultimately burns about 2000 Gton C (this is about the business-as-usual forecast for the coming century), then it looks as though climate will avoid glaciation in 50 millennia as well, waiting until the next period of cold summers 130 millennia from now.”

The natural course of things is that Milkovitch Cycle that triggered the end of the Ice Age fizzles out, the CO2 released then and at the start of the interglacial starts slowly being absorbed by the sea and by rock weathering, causing the global climate to cool over a few millennia.

By releasing Gigatonnes of man-generated CO2 into the atmosphere, we have disrupted this cycle, and the next major glacial cycle is postponed, perhaps for a long time. Some CO2 might have been ok, but this time we may have overdone it, unless we put the brakes on in time.

Originally Posted by owedtojoy

The natural course of things is that Milkovitch[sic] Cycle ...

Say what?

Originally Posted by owedtojoy

By releasing Gigatonnes[sic] of man-generated CO2 into the atmosphere, we have disrupted this cycle, and the next major glacial cycle is postponed, perhaps for a long time.

Or perhaps not at all, no one knows.

Originally Posted by owedtojoy

Some CO2 might have been ok

How much, exactly?

Originally Posted by owedtojoy

but this time we may have overdone it

Do you mean, as opposed to last time?

Originally Posted by owedtojoy

unless we put the brakes on in time.

Different people are advising that it's already too late, whilst others are somewhat less catastrophist.

Originally Posted by owedtojoy

When will this Interglacial end? + The "In the 1970s they feared an Ice Age" Myth.

No, you are making the same mistake the those small handfull of scientists in the 1970s made. They looked at the Vostok ice core and assumed the same pattern would continue.

But the Milankovitch orbital calculations indicate that the current interglacial is going to be quite a long one, with or without the help of human kind. These kinds of calculations can be very reliably calculated by astronomers, as the orbital movements of the planets are very predictable. See here: ftp://ftp.soest.hawaii.edu/engels/St.../Berger-02.pdf. What they do predict however is that if CO2 gets to 750 ppm then we lose the Greenland and West Antarctic ice sheet.

Look at the EPICA ice core from Antarctica, it goes much further back in time than Vostok, you will see that the last few interglacial/glacial cycles that Vostok recorded are by no means the only type that happen. File:EPICA delta D plot.svg - Wikipedia, the free encyclopedia

I watched a TV programme a few days ago on this. It put the next interglacial at 60,000 years away barring man's activities that, on current form, would cancel it.

It concluded that of the three essentials, closeness in orbit, shape of orbit, and tilt, only one was in place at this time and that it would be 60,000 years before all three conjoined.

Originally Posted by brine

No, you are making the same mistake the those small handfull of scientists in the 1970s made. They looked at the Vostok ice core and assumed the same pattern would continue.

But the Milankovitch orbital calculations indicate that the current interglacial is going to be quite a long one, with or without the help of human kind. These kinds of calculations can be very reliably calculated by astronomers, as the orbital movements of the planets are very predictable. See here: ftp://ftp.soest.hawaii.edu/engels/St.../Berger-02.pdf. What they do predict however is that if CO2 gets to 750 ppm then we lose the Greenland and West Antarctic ice sheet.

Look at the EPICA ice core from Antarctica, it goes much further back in time than Vostok, you will see that the last few interglacial/glacial cycles that Vostok recorded are by no means the only type that happen. File:EPICA delta D plot.svg - Wikipedia, the free encyclopedia

I said the pattern of past Ice Ages had been disrupted by us dumping Gigatonnes of CO2 into the atmosphere that would otherwise have remained in the ground.

The David Archer quote seems about right:

“If mankind ultimately burns about 2000 Gton C (this is about the business-as-usual forecast for the coming century), then it looks as though climate will avoid glaciation in 50 millennia as well, waiting until the next period of cold summers 130 millennia from now.”

So, a Long Thaw from the last Ice Age, no matter what.

Archer, D.: The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate.

Climate science & evidence deniers are not into daft anti-semitic theories, are they ?

Apparently, well, some are.

Toxic legacies: Malcolm Roberts, his CSIROh! report and the anti-Semitic roots of the “international bankers” conspiracy theory | Watching the Deniers

Originally Posted by owedtojoy

Tamino (once again) shows that you cannot reject the null hypothesis of a 0.15C/ decade warming rate for the last 15 years.



He demonstrates a non-parametric method of estimating the trend.

Theil-Sen | Open Mind

Looking at the Tamino chart you can see that, while global warming continues, the warming rate has apparently slowed in the last few years. The long-term rate may not change, but a short-term fluctuation is certainly possible.

Some scientists are putting forward dust and aerosols from small volcanoes as the reason, and not industrial pollution from China and India, as a rival theory suggests.

A team led by the University of Colorado Boulder looking for clues about why Earth did not warm as much as scientists expected between 2000 and 2010 now thinks the culprits are hiding in plain sight -- dozens of volcanoes spewing sulfur dioxide. The study results essentially exonerate Asia, including India and China, two countries that are estimated to have increased their industrial sulfur dioxide emissions by about 60 percent from 2000 to 2010 through coal burning, said lead study author Ryan Neely, who led the research as part of his CU-Boulder doctoral thesis. Small amounts of sulfur dioxide emissions from Earth's surface eventually rise 12 to 20 miles into the stratospheric aerosol layer of the atmosphere, where chemical reactions create sulfuric acid and water particles that reflect sunlight back to space, cooling the planet.

Volcanic aerosols, not pollutants, tamped down recent Earth warming, says CU-Boulder study | e! Science News

Originally Posted by owedtojoy

Looking at the Tamino chart you can see that, while global warming
continues, the warming rate has apparently slowed in the last few years.
The long-term rate may not change, but a short-term fluctuation is
certainly possible.

Some scientists are putting forward dust and aerosols from small
volcanoes as the reason, and not industrial pollution from China
and India, as a rival theory suggests.

Volcanic aerosols, not pollutants, tamped down recent Earth warming, says CU-Boulder study | e! Science News

How does this argument go? Oh yes, "There's been no warming since 1995"
or something like that. Well. since 1850 temperatures have trended up about
3/4 degree Celsius and the current temperature is above that trend line.

Did you really need me to make the argument for you?

Originally Posted by owedtojoy

When will this Interglacial end? + The "In the 1970s they feared an Ice Age" Myth.



1970s cooling, again – Stoat

Comment from John Mashey



The natural course of things is that Milkovitch Cycle that triggered the end of the Ice Age fizzles out, the CO2 released then and at the start of the interglacial starts slowly being absorbed by the sea and by rock weathering, causing the global climate to cool over a few millennia.

By releasing Gigatonnes of man-generated CO2 into the atmosphere, we have disrupted this cycle, and the next major glacial cycle is postponed, perhaps for a long time. Some CO2 might have been ok, but this time we may have overdone it, unless we put the brakes on in time.[

What will exactly happen if we don't put the breaks on in time?

Originally Posted by owedtojoy

Looking at the Tamino chart you can see that, while global warming continues, the warming rate has apparently slowed in the last few years. The long-term rate may not change, but a short-term fluctuation is certainly possible.

Some scientists are putting forward dust and aerosols from small volcanoes as the reason, and not industrial pollution from China and India, as a rival theory suggests.



Volcanic aerosols, not pollutants, tamped down recent Earth warming, says CU-Boulder study | e! Science News

That very noble. These dedicated climate scientists seeking out the flaws in their theory that is patently evident because the observations don't fit the model. But strangely amidst this great truth seeking they insist that two things in particular are written in stone:

The cause is definitely not an overly extreme assumption for temperature sensitivity to CO2.

It is still a certainty we will get dangerous warming.

Check out a blog from one of the more reputable climate scientists on this from a couple of years back. A gentle mocking of her colleagues who would make a pretence of claiming to want to solve the problem of the failing theory and why the observations increasingly seem to disprove it.

Candid comments from global warming scientists | Climate Etc.