Mass Extinctions from Global Warming? 348
uncleO writes "The current issue of Scientific American has an interesting article,
Impact from the Deep, about the possible causes for the five major global extinctions. It contends that only the most recent one was caused by a 'dinosaur killer' asteroid impact. Evidence suggests that the others were caused by 'great bubbles of toxic H2S gas erupting into the atmosphere' from the oceans due to anoxia." From the article: "The so-called thermal extinction at the end of the Paleocene began when atmospheric CO2 was just under 1,000 parts per million (ppm). At the end of the Triassic, CO2 was just above 1,000 ppm. Today with CO2 around 385 ppm...climbing at an annual rate of 2 ppm...to 3 ppm, levels could approach 900 ppm by the end of the next century."
Troll Food. (Score:5, Informative)
Just in case you actually belive your "research", here is a handy mythbuster [realclimate.org]. A bit of research on that site will set you straight, the link itself points to a search on the word "myth", I'm confident the results will cover your objections and questions.
BTW: If you can come up with an original myth I'm sure the boffins at realclimate will be happy to try and bust it for you, if they can't then you may just end up famous.
Re:Fearmongering is not the way to do this. (Score:3, Informative)
we'll cope with whatever comes our way, anyway. We always have; we always will.
No we haven't. The sixth extinction has started a few centuries ago and there's hardly anything we've done to cope with that, and more and more species are disappearing and there's hardly anything we can do to it. And whatever we do now we're in for a ride to the land of troubles, because as the unfreezing of permafrost and the acidification of the ocean due to its higher concentration in carbon release gigatons of CO2, these new gigatons of CO2 in the atmosphere contribute to the very unfreezing of permafrost and acidification of oceans, in other words even if we totally stopped emiting CO2 or methane if you like, the global warming would go on on its own.
You see what we gotta cope with is not simply the direct warming effect due to our emissions, what we rather have to cope with is our environment's kind of self-destruction process
just let a major volcano erupt and you'll see a temperature swing that'll get your attention
Oh man how I love to prove people wrong. Volcanoes actually cool down the atmosphere because of the aerosols they spray in the air. That's because of a volcanic eruption that we had a year without a summer [wikipedia.org]
Or let methane generation get completely out of hand, that'll put CO2 in perspective for you.
As much as methane can have a global warming effect, I think there's quite a difference between the volume of CO2 released and the volume of methane, both naturally and from our emissions, which makes CO2 a more important protagonist.
Re:Fearmongering is not the way to do this. (Score:2, Informative)
That's incorrect. See here: http://www.space.com/scienceastronomy/sun_output_
And for the record, a minor correction on my part, the increase in the Sun's activity isn't 10% in 15 years but rather 1.5-2.0% in 30 years. Regardless, my point is it's getting warmer which may explain why the Earth is also warmer.
Ignorance is not the way to do this. (Score:2, Informative)
CO2 is the central climate gas. No, it doesn't have the largest warming effect; water does, nor the largest effect per molecule; SF6 is the current leader with 22,200 times the greenhouse effect of CO2. CO2 is the central climate gas because it is the reason why the Earth's climate has been mostly stable over geologic history.
CO2 is released by volcanic action, and removed by rock weathering. Rock weathering is a temperature dependant process. If the climate is warmer than the equilibrium temperature, more CO2 is removed by rock weathering, cooling the climate. Volcanic activity varies somewhat, which changes the equilibrium temperature. Human releases of CO2 are about 150 times that of current volcanic activity. The good news is that there is only enough fossil fuels to continue such releases for a few hundred years, far shorter than the effective lifetime of free carbon (as CO2 in the atmosphere, carbon in living and dead plants, etc), so the climate will not reach the equilibrium temperature.
Water acts to magnify climate change, as warmer temperatures mean more water vapor, and less snow cover. Methane is the joker in the pack, but probably not a good disaster movie. SF6 is produced in such tiny amounts as to be almost a non-issue, yet with a lifetime of about a million years, tiny amounts will add up.
http://www.realclimate.org/index.php?p=227 [realclimate.org] http://en.wikipedia.org/wiki/Sulfur_hexafluoride [wikipedia.org]
Aside from all that, we'll cope with whatever comes our way, anyway. We always have; we always will. Barring asteroid impacts, of course.
RTFA: "Five times in the past 500 million years most of the world's life-forms have simply ceased to exist." Only one of these extinctions has a huge crater and other convincing signs of a killer asteroid. Perhaps there are even some events that might be harder to cope with than a killer sized asteroid. But H2S bubbling out of the oceans probably wouldn't make as good of movie as "Deep Impact".
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This is not a sig. If it was a sig, it would say something witty.
Re:One wonders (Score:4, Informative)
It's not like much electricity comes from burning oil or derivatives
Riiight [nationmaster.com], except that 80.2% of China's production of electricity and 71.4% of the USA's production of electricity is coming from fossil fuels, and that for the whole world 65.1% of electricity is produced from fossil fuels.
You're right, it's not that much, it's only two thirds.
Re:Fearmongering is not the way to do this. (Score:5, Informative)
Without going into a great deal of detail, let me provide a couple of pointers you can use to begin hunting stuff up on the net.
First, with regard to storage of nuclear waste. Passivated glass block storage solves all the storage problems. The waste is distributed in the block, the block will last longer than the waste's dangerous lifespan, the production of the block is easy and the stored materials will neither erode, progress chemically, or distribute themselves through the environment any other way. The technology is here now, and all it takes is using it to resolve the problem. In other words, money. The only down side is that once in said glass block, the "waste" is really waste, that is, we can't use it for anything else. This may not be optimum.
Second, with regard to accidents, modern reactor designs don't have those same kinds of problems. Neither do smaller, low-ish power reactors. For instance, look up pebble bed reactors [wikipedia.org]. Good design is important.
Re:Fearmongering is not the way to do this. (Score:5, Informative)
That was man made, according to this wikipedia article [wikipedia.org]:
"The Dust Bowl was the result of a series of dust storms in the central United States and Canada from 1934 to 1939, caused by decades of inappropriate farming techniques, with buffalo herds that fertilized the soil displaced by wheat farming, followed by a severe drought. The fertile soil of the Great Plains was exposed through removal of grass during plowing. During the drought, the soil dried out, became dust, and blew away eastwards, mostly in large black clouds. At times, the clouds blackened the sky all the way to Chicago, and much of the soil was completely lost into the Atlantic Ocean."
Get your facts straight, puhleeeaaase! Western civilization and productivist agriculture hold a nasty record in destroying the environment on a wide scale. You can't destroy entire ecosystems without suffering consequenses, short-term and long-term.
Re:Fearmongering is not the way to do this. (Score:1, Informative)
Actually, burping is a greater source, but doesn't create as much merriment!
Oversimplification (Score:5, Informative)
It's not because they are evil or apathetic. They are simply not rich, are commonly sleep-deprived (read: have children), and flat out do not have time to deal with it (read: have children).
As far as your "use stone instead of wood houses," that is a red herring. Yes, when starting from scratch, a stone house would be better; however, US homes are overwhelmingly built upon wood construction. Those homes don't just magically go away just because we decide stone homes are better. Even if all new construction were to be stone homes -- a long shot considering that most construction workers are familiar with wood construction, not stone -- it would be a minuscule proportion of the total number of homes.
In addition, what would you propose for earthquake-prone regions? Stone? I think not. A very good reason to build wood homes is that the wood home will sway in an earthquake instead of crumble. In 1989, a major quake hit my area. Many homes survived, but the chimneys were by and large ruined. You simply can't buy a home around here that doesn't have a cracked or repaired chimney.
The suggestion about smaller, more fuel-efficient cars is actually the most reasonable suggestion you've made. Far more so than the suggestion about wind power. Why? Check out wind density in the US [wikipedia.org]. Wind power completely excludes the south and most of the southwest. Just have one state sell to another? One word: Enron. Not gonna happen.
Also, let's look at your numbers. Possibly up to 10% by 2020 in Germany? In the US, we consume upwards of 4.8 trillion kilowatt-hours per year (with a 't'). The larger windmills generate up to 5 megawatts if the wind is blowing to full potential and the windmill is in perfect working order. That's potentially about 43.8 million kilowatt-hours per year. Those 5 megawatt jobs require about an acre of land apiece (they're really big!). Hmmm... Not only would it require 19,178 of those monsters to handle 10% of the US in the perfect case (hint: we live in the real world where perfect cases don't exist), but you'd have to factor in the maintenance costs associated with keeping such a decentralized power source in good repair. This requires -- you guessed it -- more energy. If you think the repair aspect is trivial, just remember the climate found in those northern states where the wind is so abundant. Hot summers and below freezing winters with hail and sleet in between.
Coal is currently the number one US electricity source: over 50% of our total electricity production. This is a problem. For reasons mentioned above, wind is not going to replace that. For reasons I haven't spelled out but you can research yourself, solar power can't displace coal either (1.367kWh/m^2 is the solar constant). The reasons are somewhat similar though: energy density and the demands of geography. So what's left?
Hydroelectric? We've already tapped that avenue. Microtidal? Over 90% of Earth's life exists within ten miles of a coastline. I'm a bit hesitant to mess with the energy transfer found in those ecosystems. Geothermal? The US is not Iceland. Biodiesel? The amount of cropland required to offset coal usage would significantly reduce the area available for food production.
What's left? Conservation? Even if we cut our usage in half -- 2.4 trillion kilowatt-hours per year, which incidentally will not happen in the US without an energy crisis afoot -- that's still a massive amount of power required.
And we haven't even factored in vehicle needs yet, which is necessary since oil won't last forever. Plug-in hybrids? Great idea. Gonna need more electricity for that.
What hasn't been discussed yet? Nuclear. Commonly
Re:One wonders (Score:3, Informative)
But that's NOT what the evidence shows. The evidence shows that the current cycle of global warming began about 30,000 years ago. Other evidences include the land bridges between Ireland and Britain, Alaska and Siberia disappearing as the oceans began to rise -- presumably from the melting of the ice caps from the previous Ice Age. And long before human activity had any effect on global climate
this is a strawman; nobody is saying that people are the cause of warming out of the last ice age. people are saying that humans are responsible for the warming above and beyond what is caused by natural means.
in the last 800,000 years, the world has gone through a number of climate cycles where CO2 has peaked at about 300ppm and then turned and lowered along with temperature. today, we've surpassed that peak and instead have continued climbing to almost 400ppm, something unseen in almost a million years of fossil records.
hence the belief that humans are screwing up the system; people point out that in ancient times CO2 was at ridiculously high levels, however nobody can point to a natural phenomenon which would be responsible for the extra warming and CO2 we see today.
Nuclear power is NOT the answer. (Score:2, Informative)
Yes, global warming is happening. Certainly the current fossil-based goin-on-all-guns economy isn't helping matters. Nuclear energy appears to be an appealing emmissions-free alternative. But, is it really?
1- Claims of greenhouse reductions made by nuclear power generation supporters focus primarily on only one aspect of the entire process, namely the power generation cycle, which gives off nearly no greenhouse emissions, while downplaying or ignoring greenhouse gas emissions throughout the remainder of the cycle, such as mining of uranium, uranium conversion and enrichment, plant construction, transportation of uranium and spent fuel, nuclear waste storage and nuclear power plant de-commissioning.
In order to produce enough enriched fuel to supply a standard 1GW reactor for one full-power year, about 160 tons of natural uranium must be processed. The hexafluoride method of uranium enrichment commonly employed during both enrichment and reprocessing of spent nuclear fuel releases greenhouse gasses in the form of halogens and halogenated compounds, such as Freon-114, with many times greater global warming potential than CO2. When the entire nuclear power cycle is considered, the argument that nuclear power reduces greenhouse gas emissions does not stand under scrutiny.
2- Nuclear power is not cost-effective. The nuclear power industry is the most heavily subsidised among all power generation technologies. Without these subsidies, nuclear power could not compete with other, less labor, time and capital intensive generation technologies. There is currently a backlog of high-level nuclear waste that has accumulated over the course of 60 years into a over a quarter of a million tons that are kept in storage in ponds in temporary storage containers, which have to separated by boron panels to prevent chain reactions. How much energy will be required to dispose of this waste is unknown, but in "Why Nuclear Power Cannot be a Major Energy Source" David Fleming suggests a rough guideline of one third of the total of all energy produced.
When the total life cycle of nuclear power generation, from mining to plant decommissioning is factored in, the cost of nuclear power is greater than the power generated. It is estimated that the energy requirements to create the lead-steel-copper containers required to package the spent nuclear fuel produced by a reactor is nearly equal to that required to construct the reactor.
3- Nuclear power generation decrease national security. Governments have been aware of the security issues raised by nuclear power generation since the inception of the industry. In the US, the FBI has long considered nuclear power plants to be "hardened" targets. After the 2001 terrorist attacks in New York City, the public became increasingly aware that nuclear power plants could be devastating targets for attack. In 2005, elected officials from counties neighboring the India Point nuclear power plant facilities in New York called for the immediate closure of the plant, citing a history of accidents and toxic leaks, and a growing concern that the dense local population within a fifty-mile radius of the plant, numbering close to 20 million, would be at great risk in the case of a terrorist attack on India Point.
Nuclear reactors are not the only potential targets for terrorists. Because spent fuel contains deadly radioactive particles that remain hazardous for so long, an attack on nuclear storage facilities could lead to a catastrophe on the same scale as an attack on a nuclear reactor. Since the 2001 terrorist attacks in New York, over $US 1 billion has been spent on security improvements by the nuclear power industry, in addition to the substantial sums which has already been spent before that time.
4- Toxic waste and pollution is created at every stage of nuclear power production. In mining operations, "in sutu leaching" is a common technique for reaching deeper uranium deposits by injecting hundreds of tons of sulphuric acid, nitric acid, a
Re:One wonders (Score:3, Informative)
If butterflies were natural you would expect them to look like other flies. Flies have dark bodies and translucent wings. Butterflies have light bodies and colorful wings.
Now, I can accept the idea that evolution has produced a variety of fly that looks different from the other members of its family. (Look at zebras and horses.) But butter does not occur in nature! Butter is only a manmade product! How can we accept that butterflies are natural when butter is not natural! Scientists and evironmentalists are ignoring the clear facts to stir up controversy.
Compound words [wikipedia.org] are not always compositional [wikipedia.org] in meaning. This is especially true of technical terminology [wikipedia.org]. If you want to participate in a debate, it is a good idea to learn what the words mean before doing so. (Hint:"Global warming" is not just about the globe getting warmer. It's more complicated than that.)
Re:Fearmongering is not the way to do this. (Score:3, Informative)
The above post is a troll.
Well, of course we won't dig up all the coal and burn all the oil.
Fossil fuel reserves are for economically producable oil and coal. There is roughly enough economically producable coal to take the CO2 level to very roughly 2400 ppm from the current 380 ppm. There is lots more fossil carbon that isn't economically producable, at least with current technologies. Like oil shales.
Because most of the rest of us can do math. To take the CO2 level up by 2000 ppm will indeed bring the O2 level down by 2000 ppm. Or 2 parts per thousand. Or from about 20.9% to about 20.7%. Complete non-issue.
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Error 696. Missing sig.
Re:Global warming is real (Score:2, Informative)
Re:Fearmongering is not the way to do this. (Score:5, Informative)
Someone took the time to assemble a bibliography of climate change literature from the 70s with reference to predictions of cooling [wmconnolley.org.uk]. In the scientific literature, as contrasted with Newsweek, the closest thing was a paper that pointed out the current interglacial could end in a few thousand years, or maybe even a few hundred. The overwhelming bulk reached the totally accurate conclusion that they didn't know enough to make a prediction.
The hard data on solar output from satellite measurements [nasa.gov] goes back fifteen years and is kinda-sorta constant over that period. Much earlier, and you're relying on horribly indirect proxy measurements like radionuclides. There are a lot of uncertainties about trends in solar output [realclimate.org], although some climatologists think it could account for 10-30% of the temperature rise we've seen.
Re:Fearmongering is not the way to do this. (Score:2, Informative)
Waste is not an issue, especially with designs like the Integral Fast Reactor [wikipedia.org]. It not only produces much less waste, but that waste is itself much safer. Beyond that, the design is highly efficient, and passively safe. Like the PBR, a meltdown is not possible.
The pebble bed reactor design is actually rather old though, and only solves the safety issue; it is not a sustainable source of energy. The IFR is the obvious solution for our long term energy needs. It is also the best way to curb emissions and pollution, through eliminating coal plants and enabling electric vehicles.
Re:Fearmongering is not the way to do this. (Score:3, Informative)
Some of your facts are wrong. (Score:2, Informative)
There are numerous proxies for temperature. Ice core studies use the proportion of deuterium to hydrogen in the ice is a sound local temperature proxy, since the water with deuterium in it requires more heat to evaporate it. This proxy correlates well with temperature measurements.
A mercury thermometer can measure relative temperature to within 0.1C. These have been around since 1714.
Indeed [sciencedaily.com] no [livescience.com]. About 0.07%. (Yes that's not 7% and a typo, that's 7 parts in every 10 000.)
100 years [wikipedia.org].
No, the earth is experiencing global warming. Jupiter is experiencing a redistribution of temperature. (from your link: As a result, areas around the equator become warmer, while the poles can start to cool down.)
Possibly. I don't think that observed changes on Mars over the past 7 years are a good reason to ignore the measured and predicted effect on increasing greenhouse gasses here on earth over the past 100.
No it's not. CO2 levels are the highest in several million years, and temperatures are hotter than any time in the Holocene, which represents 7 ice-age cycles. This is new, and we know why it's happening, because the physics of greenhouse gasses is well understood.