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Comment Re:And what most folks are missing... (Score 1) 437

Finding it hard to follow your train of thought, but if I understand you right...

There are multiple factors, not one "root cause". Orbital precession isn't enough by itself, but when combined with orbital eccentricity and obliquity AND favourable topology, then you get an ice age. That's why they don't occur at *every* orbital cycle - and why they can sometimes occur between cycles (e.g. if intense volcanism causes enough cooling to trigger an ice age by itself).

If you want a specific example, try this paper, which describes how, 116,000 years ago, a pattern of ice sheet formation and melting every few thousand years was triggered by the Bering Strait being shallow enough that whenever sea levels lowered sufficiently through ice formation, the Strait closed, which changed the salinity mixing of the Pacific and Atlantic oceans. This intensified the Atlantic's meridional current, which warmed parts of Greenland and North America sufficiently to melt enough ice to re-open the Strait - and the pattern repeated.

This pattern was eventually broken 34,000 years ago when (yes) we reached a point in our orbital cycle that kept temperatures cool enough, and the Strait closed long enough, to stabilise the climate, so that when it opened once more 10,000 years ago, the climate remained stable enough to allow our civilisation. So as you see, it's not so simple that there's a single "root cause" we can pin it on, but that doesn't mean we don't know what did it - we can see (and simulate) how multiple factors combined and interacted to result the ice ages we can see in the ice core record, which gives us a pretty solid explanation as to the causes of all the ice ages over the last 116,000 years.

Comment Re:Earth also has the potential (Score 3, Interesting) 137

The two are not linked. If we move off fossil fuels, our net CO2 emissions are cut to virtually zero, regardless of population (in fact, increased population acts as a carbon sink) or energy usage. Given enough cheap, carbon-free energy to distill seawater and power hydroponic stacks, we can support a far larger population if required.

Then all we have to worry about is excess waste heat, which will be a huge problem in 300-400 years. Though limiting ourselves to solar-derived energy can help a lot here.

Comment *Restricted* user profiles (Score 1) 244

What's new about the profiles is that now they can be restricted from certain apps or actions (with some granularity), for parental control.

Other new features include:

* Intermittent Wi-Fi scanning for location (saves battery)
* OpenGL ES 3.0 support
* Bluetooth 4.0 LE and AVRCP 1.3 support
* Autocompleting dialpad
* Virtual surround sound

There's more under the hood changes:

* SELinux MAC system support for the app sandbox
* Better WPA2 EAP and Phase 2 authentication support
* Hardware root of trust support
* Modular DRM support (e.g. allows 1080p Netflix)
* Hardware geofencing
* Media muxer and VP8 encoding
* And of course, further rendering and other optimisations

Still, it's no ICS or Key Lime Pie.

Comment Re:And what most folks are missing... (Score 1) 437

Google Translate didn't do an awesome job at that, but AFAICT it says we're not totally sure of all contributing factors, but puts it down to a combination of Milankovitch cycles, plate tectonics, topology changes that redirect air and water currents, and vulcanism.

Which are all described in the second link I gave, too. Like I was saying, most earth scientists have a pretty good idea of what causes ice ages. Orbital variations are often a significant factor (as evidenced by the timing correlations), but of course there are other factors too.

I don't think you could argue that "no one knows what caused the glacier periods" when we have identified numerous contributing causes that explain them all quite well. Are we 100% absolutely certain? No, nor can we be about anything (except mathematics), but the causes of glaciation are relatively well understood.

Comment Re:And what most folks are missing... (Score 1) 437

Did you look?

Three orbital variations contribute to interglacials... eccentricity.. obliquity.. precession.

There are other contributing factors of course, but orbital variations are the strongest and accepted explanation. From the first source:

Glacials and interglacials occur in fairly regular repeated cycles. The timing is governed to a large degree by predictable cyclic changes in Earth’s orbit

If you can cite studies supporting a better theory, or even studies throwing these studies into doubt, feel free. Or are you just going to fall back to the useless solipsist argument of "nothing is real, there are no absolutes"? Which is fine for the philosophy department's coffee room, but will cut no ice in the real world.

Comment Re:Honesty? (Score 1) 440

Don't forget the oceans - they're more than twice the area of the ground, and six times the area of the deserts.

I'd like a cited study that suggests capturing 20% of the energy from 5% of the globe and releasing it at a city nearby instead will "throw the climate into far more chaos than some CO2 ever did". Rather than leaping to conclusions like it's an Olympic event.

Comment Re:As temperatures rise, scientists continue to... (Score 1) 437

You're right, temperature isn't rising for me either. Though that might simply be because the sun just set here.

More relevantly, yes, the temperature is still trending upwards, despite natural cycles that slow or reverse this over shorter periods of time.

Let me direct you to this pretty graph that you might be able to understand.

Comment Re:More to the point... (Score 1) 437

That's true, but ice below sea level tends to float (as it is 9% less dense), so there'd be no net change (as with Arctic ice). There are sea ice shelves in Antarctica that wouldn't affect sea levels, but the GP's figures all refer to land ice.

Then of course there's Greenland to consider. Melting that would add another 7.2m to sea levels. And thermal expansion is not insignificant either.

Comment At what cost? (Score 1) 437

If "adapting" means "build a 1m seawall around New York", then sure, just as soon as people stop arguing. It's not going to happen around every coastal city & town in the US though, so that's a massive cost to relocate all those prime coastal buildings and infrastructure. But the real damage comes from occasional storm surges like Hurricane Sandy; add 1m to that and half the city would be flooded. And of course, strong storms like that will also get more common.

Then there's the developing world; no seawalls for them. Saltwater surges ruin essential cropland and will displace millions in places like Bangladesh, creating a flood of starving refugees and political turmoil. Some island nations are already becoming unviable (q.f. Tuvalu).

Yes, we can and will adapt. But it's sure as hell going to cost a freaking bundle to do so - and the price will be in human suffering for countries that can't afford the dollars. Far cheaper to mitigate the changes ASAP, as the costs are rising every year we delay.

Comment Re:Honesty? (Score 1) 440

billions of tractors


This doesn't have to happen overnight. All those cars & bulldozers have to be replaced in the next few decades anyway. Electric vehicles are mechanically simpler by far, and amortised full-lifecycle costs at full scale are significantly less than internal-combustion vehicles, even including current batteries.

As for land use, more solar energy than the entire world uses annually falls on just the deserts of the world - every six hours. And there's no reason to limit ourselves to only solar.

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