Interesting that a historically rather serious recession can only cause a small decrease.
That's because recessions are not economically efficient ways to lower carbon emissions. They don't address the energy sector specifically, they don't specifically target low-emissions technology development or efficiency measures, etc. They just indiscriminately suppress economic activity, and obviously have effects far beyond the carbon-related sector.
For more on the economics of climate policy, see here and here.
It seems like cutting CO2 back to the levels needed to stop global warming would require or cause a much more serious recession.
That's probably true, which is why nobody is proposing to cut CO2 levels to stop global warming. Or at least, not stop it at current temperatures. Most want to stabilize it at 2 C above pre-industrial. That will still have serious costs (as would unstabilized climate change), but if appropriately designed to specifically promote low-carbon activity, it's not going to create a severe recession; see the above links.
TLS is the lower stratosphere, which is not where we live. (We don't live in the entire lower troposphere, either, but its average temperature trend is much closer to the surface trend than is anything which happens in the stratosphere.)
Note, by the way, that an enhanced greenhouse effect predicts lower tropospheric warming and lower stratospheric cooling. Which is in fact what is observed.
Warming rates are projected to increase over time as more CO2 is added to the atmosphere, for obvious reasons; the 21st century average rate is not the same as the current rate. The 6 C by 2100 projections are the product of very large emissions projections toward the end of the century. Current warming projections are for about 0.2K/decade, IIRC.
I found this paper which suggests 1.4 meters of sea level rise over 500-600 years 8500 years ago, the largest freshwater pulse into the North Atlantic in 100,000 years. However, some parts of that rise were rapid and they calculate that it could have caused massive flooding around the Black and Mediterranean Seas over a period of 120 years. I wonder if that's fast enough, recent enough, and global enough to account for global flood myths. The worst effects were localized around the Black Sea which would have been flooded, see here. But the last link suggests that the flooding wasn't so abrupt after all.
Actually, in my other comment I completely forgot about Meltwater Pulse 1A, about 14,500 years ago. Like the last interglacial event I mentioned, MP 1A also had average sea level rise rates of 4-5 centimeters per year, except it was sustained for 500 years instead of 50.
If you're talking about the Missoula Floods, they couldn't have contributed "several meters" of sea level rise. Lake Missoula only had a volume of about 2200 cubic kilometers. The Greenland ice sheet (2.8 million cubic kilometers) is thought to hold an extra 7 meters worth of sea level. Using that scaling factor and ignoring density differences between water and ice, that works out to about 0.5 centimeters of potential sea level rise from Lake Missoula. And it's also contested whether the whole lake could have drained "in a matter of days", or in smaller bursts spread out over a century.
I know of other abrupt drainage events as the last glacial period ended, which ultimately released volumes of water similar to Missoula (e.g., from Lake Agassiz). But I've never heard of and can't imagine any drainage event that could release millions of cubic kilometers of water in a matter of days.
This paper (summarized here) is of interest. It's not talking about "abrupt" drainage, but "rapid" sea level rise. It goes back to the last interglacial, i.e., after the end of the next-to-last glacial period. This was about 115,000 years ago, too early to be related to global flood myths. The paper describes evidence for 5 centimeter/year sea level rise sustained for 50 years, amounting to at least 2.5 meters (8 feet) of sea level rise over half a century. That's the fastest multi-meter sea level rise event I know of. It's really rather tremendous if you think about it, equivalent to a third of the entire Greenland ice sheet disintegrating in a few decades. It will be interesting to see if this interpretation is confirmed by other researchers.
Interestingly, people have used GPS to measure temperatures in the Earth's atmosphere. The idea is to precisely measure the Doppler shift of the GPS satellite signal. This is modified by the refraction of radio waves through the atmosphere. Atmospheric refraction is governed by the density of air, which in turn depends on its temperature. Thus, radio occultation measurements can be used to infer (a convolved integral of) the air temperature along the line-of-sight. Many such measurements can be used to extract spatial and temporal structure, and also infer information about atmospheric pressure and water vapor content.
Here is one early paper, and a review. This system is gaining increasing attention and may one day be a competitive alternative to existing ground- and satellite-based observation systems.
We have numerous alternative theories that explain, without resorting to saying the universe consists of 96% invisible voodoo, various anomalies such as gravitational rotation and the implied anisotropy of the CMB.
No. We don't. That's the whole point. Dark matter wasn't invented for the hell of it. Astronomers resisted it for decades. It was ultimately accepted precisely because it continued to pass observational tests and other theories didn't.
It's possible to cook up alternative theories to explain individual phenomena such as galactic rotation curves (e.g., MOND). But they all fail when you try to simultaneously explain multiple phenomena such as galactic rotation curves and CMBR anisotropies and early universe structure formation and galaxy cluster dynamics and... you get the idea.
The thing is that when you're just looking at data points as they come in, you can't tell if a distribution is well-behaved.
If you make distributional assumptions (e.g., "it's a power law"), you can put probabilistic bounds on the shape parameters. If you're near a boundary, yes, there's going to be a high probability that the true parameter is on the "bad" side of the boundary. If you're far from a boundary, then there's a low probability. This is obvious.
If you don't make distributional assumptions, there's little you can conclude about the nature of any distribution.
Generally they're talking about Pareto or power-law distributions, which aren't quite as degenerate as, say, the Cauchy distribution with no higher-order moments. You're right that they should check for the existence of the moments they care about; I presume they do, but I don't know.
Ed Belbruno's work in the early 1990s on the Hiten lunar transfer orbit (see his book) predates Lo's IPS work. Belbruno's calculations saved the Hiten mission which failed to achieve lunar orbit using conventional trajectory planning. Lo generalized the concept to non-lunar missions throughout the solar system.
Why would you want to put a space port in geosynchronous orbit? It's harder to get there than to LEO, and I don't see any benefit of locating a space port over a stationary point on the Earth's surface, which is the only advantage of GEO. ("Future endpoint of a space elevator" doesn't sound like a very practical justification to me.)
(And a space port would decrease the necessity to expend fuel to reach orbital velocity? As others have pointed out, whatever you launch from the port, or its raw materials, needs to get to the space port somehow, so you're not saving fuel that way. You might save fuel if you build everything on the Moon and ship it from there instead of from Earth, but that presumes a moon base or factory too.)
"The SoundSense software was able to correctly determine when the user was [...] brushing her teeth [...] Choudhury says that enabling the software to learn to recognize new sounds will be essential for practical applications. 'A system that can recognize sounds in a person's life can be used to search for others who have the same preferences'"
That sounds like great functionality. " If you like brushing your teeth, you may be interested to know that 21 out of 23 people on your Contacts list also enjoy brushing their teeth."
Look harder. Those RAND papers are advocating FOR reducing CO2 emissions, on the basis of economic cost-benefit analysis. This includes the costs of climate change.
I think there are some national security implications inherent in relocating all of Europe's electric power generation capacity to Africa. I hope nobody in Africa minds European armies building bases there to guard their energy sources.
Slashdot Mirror
Interesting that a historically rather serious recession can only cause a small decrease.
That's because recessions are not economically efficient ways to lower carbon emissions. They don't address the energy sector specifically, they don't specifically target low-emissions technology development or efficiency measures, etc. They just indiscriminately suppress economic activity, and obviously have effects far beyond the carbon-related sector.
For more on the economics of climate policy, see here and here.
It seems like cutting CO2 back to the levels needed to stop global warming would require or cause a much more serious recession.
That's probably true, which is why nobody is proposing to cut CO2 levels to stop global warming. Or at least, not stop it at current temperatures. Most want to stabilize it at 2 C above pre-industrial. That will still have serious costs (as would unstabilized climate change), but if appropriately designed to specifically promote low-carbon activity, it's not going to create a severe recession; see the above links.
TLS is the lower stratosphere, which is not where we live. (We don't live in the entire lower troposphere, either, but its average temperature trend is much closer to the surface trend than is anything which happens in the stratosphere.)
Note, by the way, that an enhanced greenhouse effect predicts lower tropospheric warming and lower stratospheric cooling. Which is in fact what is observed.
Warming rates are projected to increase over time as more CO2 is added to the atmosphere, for obvious reasons; the 21st century average rate is not the same as the current rate. The 6 C by 2100 projections are the product of very large emissions projections toward the end of the century. Current warming projections are for about 0.2K/decade, IIRC.
I found this paper which suggests 1.4 meters of sea level rise over 500-600 years 8500 years ago, the largest freshwater pulse into the North Atlantic in 100,000 years. However, some parts of that rise were rapid and they calculate that it could have caused massive flooding around the Black and Mediterranean Seas over a period of 120 years. I wonder if that's fast enough, recent enough, and global enough to account for global flood myths. The worst effects were localized around the Black Sea which would have been flooded, see here. But the last link suggests that the flooding wasn't so abrupt after all.
Actually, in my other comment I completely forgot about Meltwater Pulse 1A, about 14,500 years ago. Like the last interglacial event I mentioned, MP 1A also had average sea level rise rates of 4-5 centimeters per year, except it was sustained for 500 years instead of 50.
Again, though, it wasn't a few-day deluge.
If you're talking about the Missoula Floods, they couldn't have contributed "several meters" of sea level rise. Lake Missoula only had a volume of about 2200 cubic kilometers. The Greenland ice sheet (2.8 million cubic kilometers) is thought to hold an extra 7 meters worth of sea level. Using that scaling factor and ignoring density differences between water and ice, that works out to about 0.5 centimeters of potential sea level rise from Lake Missoula. And it's also contested whether the whole lake could have drained "in a matter of days", or in smaller bursts spread out over a century.
I know of other abrupt drainage events as the last glacial period ended, which ultimately released volumes of water similar to Missoula (e.g., from Lake Agassiz). But I've never heard of and can't imagine any drainage event that could release millions of cubic kilometers of water in a matter of days.
This paper (summarized here) is of interest. It's not talking about "abrupt" drainage, but "rapid" sea level rise. It goes back to the last interglacial, i.e., after the end of the next-to-last glacial period. This was about 115,000 years ago, too early to be related to global flood myths. The paper describes evidence for 5 centimeter/year sea level rise sustained for 50 years, amounting to at least 2.5 meters (8 feet) of sea level rise over half a century. That's the fastest multi-meter sea level rise event I know of. It's really rather tremendous if you think about it, equivalent to a third of the entire Greenland ice sheet disintegrating in a few decades. It will be interesting to see if this interpretation is confirmed by other researchers.
Interestingly, people have used GPS to measure temperatures in the Earth's atmosphere. The idea is to precisely measure the Doppler shift of the GPS satellite signal. This is modified by the refraction of radio waves through the atmosphere. Atmospheric refraction is governed by the density of air, which in turn depends on its temperature. Thus, radio occultation measurements can be used to infer (a convolved integral of) the air temperature along the line-of-sight. Many such measurements can be used to extract spatial and temporal structure, and also infer information about atmospheric pressure and water vapor content.
Here is one early paper, and a review. This system is gaining increasing attention and may one day be a competitive alternative to existing ground- and satellite-based observation systems.
We have numerous alternative theories that explain, without resorting to saying the universe consists of 96% invisible voodoo, various anomalies such as gravitational rotation and the implied anisotropy of the CMB.
No. We don't. That's the whole point. Dark matter wasn't invented for the hell of it. Astronomers resisted it for decades. It was ultimately accepted precisely because it continued to pass observational tests and other theories didn't.
It's possible to cook up alternative theories to explain individual phenomena such as galactic rotation curves (e.g., MOND). But they all fail when you try to simultaneously explain multiple phenomena such as galactic rotation curves and CMBR anisotropies and early universe structure formation and galaxy cluster dynamics and ... you get the idea.
Troy McClure agrees!
The thing is that when you're just looking at data points as they come in, you can't tell if a distribution is well-behaved.
If you make distributional assumptions (e.g., "it's a power law"), you can put probabilistic bounds on the shape parameters. If you're near a boundary, yes, there's going to be a high probability that the true parameter is on the "bad" side of the boundary. If you're far from a boundary, then there's a low probability. This is obvious.
If you don't make distributional assumptions, there's little you can conclude about the nature of any distribution.
Generally they're talking about Pareto or power-law distributions, which aren't quite as degenerate as, say, the Cauchy distribution with no higher-order moments. You're right that they should check for the existence of the moments they care about; I presume they do, but I don't know.
Ed Belbruno's work in the early 1990s on the Hiten lunar transfer orbit (see his book) predates Lo's IPS work. Belbruno's calculations saved the Hiten mission which failed to achieve lunar orbit using conventional trajectory planning. Lo generalized the concept to non-lunar missions throughout the solar system.
Impact armor was in Ringworld Engineers, not Ringworld.
Meltdown alert? Mad dog drill? Blimp attack? Ah... I think a good old-fashioned fire drill today.
I think a map is a graphical user interface for a map.
We don't know that we should be heading for a long-term cooling now. We could remain in an interglacial for 50,000 years (e.g. here).
There have been some studies, for example "The influence of large-scale wind power on global climate".
Yeah, we wouldn't want a rogue nation with zero-G toilet technology on the loose.
If you're going to deorbit it, why waste it on the ocean? At least drop it on a country we don't like. Or on Kenny.
Why would you want to put a space port in geosynchronous orbit? It's harder to get there than to LEO, and I don't see any benefit of locating a space port over a stationary point on the Earth's surface, which is the only advantage of GEO. ("Future endpoint of a space elevator" doesn't sound like a very practical justification to me.)
(And a space port would decrease the necessity to expend fuel to reach orbital velocity? As others have pointed out, whatever you launch from the port, or its raw materials, needs to get to the space port somehow, so you're not saving fuel that way. You might save fuel if you build everything on the Moon and ship it from there instead of from Earth, but that presumes a moon base or factory too.)
From TFA:
"The SoundSense software was able to correctly determine when the user was [...] brushing her teeth [...] Choudhury says that enabling the software to learn to recognize new sounds will be essential for practical applications. 'A system that can recognize sounds in a person's life can be used to search for others who have the same preferences'"
That sounds like great functionality. " If you like brushing your teeth, you may be interested to know that 21 out of 23 people on your Contacts list also enjoy brushing their teeth."
Look harder. Those RAND papers are advocating FOR reducing CO2 emissions, on the basis of economic cost-benefit analysis. This includes the costs of climate change.
RAND is actually rather non-partisan, and does serious work on climate change policy, e.g. here, here, here, here.
The original poster wasn't talking about beamed space solar. We were talking about ground-based solar located in Africa to power Europe.
I think there are some national security implications inherent in relocating all of Europe's electric power generation capacity to Africa. I hope nobody in Africa minds European armies building bases there to guard their energy sources.