11 posts • joined Friday 7th January 2011 17:47 GMT
Re: pointless stupidity
A couple of points:
Absent any greenhouse effect, the Earth would on average be about 30 degrees C colder than it is now. It's not that hard to do the basic calculation, which is why the greenhouse effect was discovered in the 19th century. Calculating the proportion of anthropogenic impact on the greenhouse effect as a whole is misleading, because we only need to move it by a few percentage points to create a very large swing in average surface temperature.
I don't know where you get your 3% number for anthropogenic contribution to atmospheric CO2. Or are you quoting some other number? The pre-industrial level of atmospheric CO2 was about 300ppm. It's now about 400ppm, all of which is us. The natural sources of CO2 emission are in equilibrium with natural sources of absorbtion. The bottom line is that we've moved the level by 30%, and are moving it at an increasing rate.
Re: "heightened hydrogen-alpha sensitivity"
...or point it at a nebula. Most of the brightness in a nebula tends to be in the h-alpha emission line, which happens to be right on the edge of the UV/IR passband in a typical camera, causing you to lose most of it. As a result, a stock DSLR is significantly less sensitive than it could be in capturing many "feint fuzzy" objects.
There is a very active secondary market for modified DSLRs and modification services to swap out the UV/IR filter (that sits right on top of the sensor) with one that moves the passband slightly into the IR region to fix this problem.
You can also buy the filter and do it yourself, if you're a masochist. I've done it myself on an older model Canon DSLR, and I can't say I recommend it. It involves getting out a soldering iron and dealing with the tiniest connectors you've ever seen.
Re: Good HA filters..
"I didn't read it as it having a Halpha filter. I read it that the IR blocking filter now has a better pass characteristic for Halpha. Therefore, the camera is more responsive to Halpha."
Yes, that's exactly what they did; they did the same trick with the 20Da.
"The current level of CO2 in the atmosphere is about 0.0387% by volume. If it was to increas by "30%" it still only gets to 0.05031, which is still much lower than the levels it has been at many times in the past."
Please define "in the past". If you mean tens of millions of years ago, then sure.
"AGW bleaters like to focus on the last 100,000 years leading up through the industrial revolution (and it has NOT been static or in equilibrium during that period) as this gives them another nice hockeystick graph known as the Keeling Curve."
Yes, we do like to focus on the last 100,000 years. You know why? Because agriculture has only existed in that period, and is rather finely tuned to the specific set of conditions existing in the present time. Because London, the East Anglia, and, I don't know, Florida have not been underwater in that period. Because most of the species alive on the planet are finely adapted to their current ecological niches and wouldn't survive a sudden shift back to the climate of the cretaceous period.
You seriously don't think it's a problem that we've moved the needle on atmospheric composition (from 300ppm CO2 to 400ppm) by such an amount that you have to go back before humans existed to find a comparable, and we've done that in only fifty years?
Re: yes but
"Well, seeing as all human C02 emmissions make up a tiny 2% compared to those of nature herself,..."
This is one of the more ridiculous denier talking points. Those "natural" CO2 emissions to which human emissions are being compared are not *net*. Sure, there are natural processes that generate CO2. There are also natural processes that absorb CO2. These two sets of processes have been in equilibrium since before humans were around.
It doesn't really matter how big the human emissions are in comparison to the natural emissions, because there isn't a corresponding "extra" 2% natural absorption suddenly appearing to cancel out the now unaccounted for human emissions.
The net result of all of this is that atmospheric CO2, which has been stable for millions of years, has increased from about 300ppm in the middle of the last century to about 400ppm now. Not only that, but that 100ppm increase only accounts for about half the amount of CO2 emitted by humans; the other half has gone into the oceans, resulting in significant acidification.
There's really no mystery here; we know exactly how much carbon we burn (many people in the oil, gas and coal trading industry care a great deal about tracking this data) and we know where it goes.
Re: yes but
"The oceans are alkaline and that alkalinity has reduced ever so slightly in some areas. That is not, in any way, "acidifying".
So yes, New Scientist is talking out of its arse. Again."
The pH has reduced. No matter where you start, that is "acidification". Becoming less alkaline is the same thing as becoming more acidic...
Mean ocean pH has decreased by about 0.1 in the last hundred years or so. That may sound like a small amount, until you remember that pH is a logarithmic scale and that actually represents a change of 30%. This is a rate of change 100 times faster than anything seen in the last 20 million years.
No, not really
"dark matter" is postulated to exist because the observed rotation rate of galaxies doesn't match up with what we would expect to see based on our observations of where the mass appears to be and our understanding of how gravity works.
Multiple hypotheses have been proposed to explain this discrepancy (in fact, pretty much every combination of possibilities has been suggested). Many experiments have since been conducted in an attempt to eliminate one or more of those possibilities. The hypotheses include:
1. The effect is caused by Baryonic dark matter (ie regular matter that we just can't see because it's dark)
2 .The effect is caused by one of at least two different kinds of non-Baryonic dark matter (ie exotic particles, either of a type that we know about already or which we don't know about yet and might find in one of the ongoing supercollider experiments)
3. Our understanding of how gravity works is just wrong. A detailed proposal called MOND (Modified Newtonian Dynamics) adjusts gravity at long distances to explain the rotation rate discrepancy.
The thing about experiments like this is that they pretty much eliminate option 3. According to option 3, we shouldn't see light bend gravitationally around where the dark matter would need to be, because according to that hypothesis it doesn't exist.
There's much more you can find online. Google for terms like "MOND" and "non-baryonic dark matter".
Missing from the article...
Any discussion as to whether the conclusions of the report were correct. Isn't that part important?
As the report also notes, the methane hydrates under the polar ice (the stuff that might cause a problem) are mostly under only about 40 meters of water, meaning that most of it would bubble up to the surface before dissolving in the water (compared to the deep horizon methane which started out a mile under water). That would mean that the methantroph bacteria wouldn't get the chance to have much of an impact on the volume released.
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