Carbon emissions 'will defer Ice Age'

[klr]

http://www.bbc.co.uk/news/science-environment-16439807

Human emissions of carbon dioxide will defer the next Ice Age, say scientists.

The last Ice Age ended about 11,500 years ago, and when the next one should begin has not been entirely clear.

Researchers used data on the Earth's orbit and other things to find the historical warm interglacial period that looks most like the current one.

In the journal Nature Geoscience, they write that the next Ice Age would begin within 1,500 years - but emissions have been so high that it will not.

"At current levels of CO2, even if emissions stopped now we'd probably have a long interglacial duration determined by whatever long-term processes could kick in and bring [atmospheric] CO2 down," said Luke Skinner from Cambridge University.

Dr Skinner's group - which also included scientists from University College London, the University of Florida and Norway's Bergen University - calculates that the atmospheric concentration of CO2 would have to fall below about 240 parts per million (ppm) before the glaciation could begin.

The current level is around 390ppm.

Other research groups have shown that even if emissions were shut off instantly, concentrations would remain elevated for at least 1,000 years, with enough heat stored in the oceans potentially to cause significant melting of polar ice and sea level rise.

Orbital wobbles

The root causes of the transitions from Ice Age to interglacial and back again are the subtle variations in the Earth's orbit known as the Milankovitch cycles, after the Serbian scientist Milutin Milankovic who described the effect nearly 100 years ago.

The variations include the eccentricity of the Earth's orbit around the Sun, the degree to which its axis is inclined, and the slow rotation of its axis.

These all take place on timescales of tens of thousands of years.

The precise way in which they change the climate of the Earth from warm interglacial to cold Ice Age and back every 100,000 years or so is not known.

On their own, they are not enough to cause the global temperature difference of about 10C between Ice Age and interglacial. The initial small changes are amplified by various factors including the release of carbon dioxide into the atmosphere as warming begins, and absorption of the gas by the oceans as the ice re-forms.

It is also clear that each transition is different from previous ones, because the precise combination of orbital factors does not repeat exactly - though very similar conditions come around every 400,000 years.

The differences from one cycle to the next are thought to be the reason why interglacial periods are not all the same length.

Using analysis of orbital data as well as samples from rock cores drilled in the ocean floor, Dr Skinner's team identified an episode called Marine Isotope Stage 19c (or MIS19c), dating from about 780,000 years ago, as the one most closely resembling the present.

The transition to the Ice Age was signalled, they believe, by a period when cooling and warming seesawed between the northern and southern hemispheres, triggered by disruptions to the global circulation of ocean currents.

If the analogy to MIS19c holds up, this transition ought to begin within 1,500 years, the researchers say, if CO2 concentrations were at "natural" levels.

As things stand, they believe, it will not.

Loving CO2

The broad conclusions of the team were endorsed by Lawrence Mysak, emeritus professor of atmospheric and oceanic sciences at McGill University in Montreal, Canada, who has also investigated the transitions between Ice Ages and warm interglacials.

"The key thing is they're looking about 800,000 years back, and that's twice the 400,000-year cycle, so they're looking at the right period in terms of what could happen in the absence of anthropogenic forcing," he told BBC News.

He suggested that the value of 240ppm CO2 needed to trigger the next glaciation might however be too low - other studies suggested the value could be 20 or even 30ppm higher.

"But in any case, the problem is how do we get down to 240, 250, or whatever it is? Absorption by the oceans takes thousands or tens of thousands of years - so I don't think it's realistic to think that we'll see the next glaciation on the [natural] timescale," Prof Mysak explained.

Groups opposed to limiting greenhouse gas emissions are already citing the study as a reason for embracing humankind's CO2 emissions.

The UK lobby group the Global Warming Policy Foundation, for example, has flagged up a 1999 essay by astronomers Sir Fred Hoyle and Chandra Wickramasinghe, who argued that: "The renewal of ice-age conditions would render a large fraction of the world's major food-growing areas inoperable, and so would inevitably lead to the extinction of most of the present human population.

"We must look to a sustained greenhouse effect to maintain the present advantageous world climate. This implies the ability to inject effective greenhouse gases into the atmosphere, the opposite of what environmentalists are erroneously advocating."

Luke Skinner said his group had anticipated this kind of reception.

"It's an interesting philosophical discussion - 'would we better off in a warm [interglacial-type] world rather than a glaciation?' and probably we would," he said.

"But it's missing the point, because where we're going is not maintaining our currently warm climate but heating it much further, and adding CO2 to a warm climate is very different from adding it to a cold climate.

"The rate of change with CO2 is basically unprecedented, and there are huge consequences if we can't cope with that."

[Gawdzilla Sama]

The next Maunder Minimum is supposed to slow down global warming a tiny bit, yes?

[ginckgo]

Well that contradicts previous research that points to an exceptionally long interglacial of up to 50,000 more years, based on the current configuration of Milankovic cycles

http://www.sciencemag.org/content/297/5585/1287

[Gawdzilla Sama]

Well that contradicts previous research that points to an exceptionally long interglacial of up to 50,000 more years, based on the current configuration of Milankovic cycles

http://www.sciencemag.org/content/297/5585/1287

I hope it lasts longer than 50,000 years, I hate cold weather.

[Seth]

Luke Skinner said his group had anticipated this kind of reception.

"It's an interesting philosophical discussion - 'would we better off in a warm [interglacial-type] world rather than a glaciation?' and probably we would," he said.

"But it's missing the point, because where we're going is not maintaining our currently warm climate but heating it much further, and adding CO2 to a warm climate is very different from adding it to a cold climate.

"The rate of change with CO2 is basically unprecedented, and there are huge consequences if we can't cope with that."

Of course, what this nitwit fails to say is what, exactly, these "huge consequences" might be...besides a slightly warmer global climate, absence of ice, various natural shifts in weather patterns that humans have been adapting to for tens of thousands of years, and some slowly-rising sea-levels that would eventually force a relocation of human populations away from present coastlines.

But what idiots like him want is for humanity to bankrupt itself and submit to environmental slavery trying to fix something right away that doesn't need fixing pretty much at all, and what does need fixing (like sea-walls and dikes and moving populations) can be done carefully, at leisure, without panic because the effects of global warming aren't going to be "catastrophic" for at least a hundred years. Sea level rising? Move your lazy ass uphill. Climate changing so you can't grow crops? Move your lazy ass somewhere else. Adapt or die.

Forty years ago idiots like this were shrieking that the "Greenhouse Effect" would turn Earth into Venus by now. They were alarmists and they were wrong. This nitwit is an alarmist and he's wrong too, along with the IPCC and everybody else who is using the undefined and extremely long-term threat of global warming as nothing more than a fearmongering method of power and control to create one-world global government that controls everything and everyone. Given the history of bad climate science and false predictions and the history of outright fraud at the IPCC and in the labs of government-paid scientists who have a vested interest in touting global warming so as to keep the grant money coming, it's no wonder nobody believes them.

To blithely hand-wave away the Hoyle/Wickramasinghe conjecture by saying it's an "interesting philosophical discussion" and that "probably we would" be better off with a warmer rather than glaciated climate and return to the dogmatic insistence that global warming is a bad thing is the height of tunnel vision ideological blindness and makes people even less likely to believe their hysterical sky-is-falling rhetoric.

Having the discussion is not "missing the point," it IS the point. It's an essential discussion that we must have out in full before hundreds of trillions of dollars are wasted trying to stop the very thing that could preserve the existence of the human (and many other) species.

[Tyrannical]

What next?
Cutting CO2 emissions will cause mass famines due to lower crop yields?

[Gawdzilla Sama]

[Atheist-Lite]

Why does Seth getignored when he talks perfect sense? There is no need to limit carbon emissions when they are more or less self limiting in a few decades. Better to adapt over a few decades with small targets than do everything at once and make a big mess? If you are gonna do anything it is after the horse bolted now....things in play are not going back to the way they were because you are being a good boy today. You are fucked no matter how nice a gloss you put on it.......

[Seth]

Why does Seth getignored when he talks perfect sense? There is no need to limit carbon emissions when they are more or less self limiting in a few decades. Better to adapt over a few decades with small targets than do everything at once and make a big mess? If you are gonna do anything it is after the horse bolted now....things in play are not going back to the way they were because you are being a good boy today. You are fucked no matter how nice a gloss you put on it.......

Precisely. There is absolutely no urgency in this whatsoever. If damage has been done, it's been done and will be with us for a century or more according to the IPCC. Things are not going to get radically worse if we take time to come up with real, effective, affordable answers to carbon reduction.

The latest news is that scientists are now suggesting something I was talking about years ago, which is not CO2 emissions, but methane, which is 16 times more harmful to the atmosphere than CO2. They are talking about capturing coal-bed methane and capping landfills to trap methane.

Problem is the biggest source of methane on the planet is termite farts in the Amazon. Next in line comes, I believe, decomposition products of dying boreal forests in places like Siberia and Canada. Then there's all the methane that will be released by decomposition of the organic components of permafrost when it melts.

I asked this question before: Which is better for the "global warming" problem, to allow the dead and dying pine forests in North America and Canada to rot and decompose, which produces methane, or to either vigorously log them and find uses for the wood or light a match to them and burn them off, which produces CO2 and particulates, but which is less harmful than methane?

Never got an answer to that question.

So yes, there's almost nothing of any significance that humans can do today, or in the next century to stop the inevitable effects of CO2 and methane in our atmosphere. It's going to happen, and there is no need to bankrupt economies and disrupt social stability with all the panic about it.

So, adapt or die. Start building sea-walls and polders. Begin the planning for moving the population of Bangladesh and other low-lying areas away from the ocean. Move infrastructure, plan for rising sea levels NOW and begin a calm, orderly, AFFORDABLE practical response to what is going to happen no matter what we do this year or next, or in the next 50 years.

The problem with the whole global warming industry is that it's exactly that, an industry, and there is a lot of money at stake so the stakeholders are being alarmists so that they can get more money. And the powermongers wish to use the "crisis" as an excuse to grab more power over individuals.

It's nothing to do with dealing with global warming and everything to do with power and control and enhancing it by creating an artificial immediate crisis that can be use to manipulate public opinion and behavior through fear.

[jaydot]

seth, seth, you're far too damn sensible. governments won't do any of that because the bwankers have dreamed up a nice new fiddle for making lots of dosh. it's called 'carbon credits'.

[Atheist-Lite]

seth, seth, you're far too damn sensible. governments won't do any of that because the bwankers have dreamed up a nice new fiddle for making lots of dosh. it's called 'carbon credits'.

That everyone obeys except the Chinese.

[Jesus_of_Nazareth]

MMGW = Man Made Global Woo

FACT

[Atheist-Lite]

Atheists want to live forever = fact.

[Warren Dew]

seth, seth, you're far too damn sensible. governments won't do any of that because the bwankers have dreamed up a nice new fiddle for making lots of dosh. it's called 'carbon credits'.

That everyone obeys except the Chinese.

So the politicians get what they want, and the Chinese save us from an ice age?

[Drewish]

Holy crap. So people on this board accept that global warming is real, but also think it's really nothing to be worried about?!

I'm home!