That is exactly the question. The simplest answer is “whatever it’s been during most of the history of civilization, because that’s what agriculture is optimized to.” That’s an oversimplified answer, of course, but to get any more specific, well, re-read Colibri’s post above.
“Change causes upset.” Think about that. Even change for the better causes problems. Economies, population centers, and agriculture are all optimized for current conditions. Changing conditions rapidly would be a disaster.
There’s lots of evidence that it’s not a very stable system. Iceball Earth, for example.
I am not understanding. Are you saying the Earth get a different amount of sun in the winter than it does in the summer? Is the summer solstice in June or December?
The biosphere releases almost exactly as much carbon to the atmosphere as it extracts. This is due to a balance between photosynthesizing plants and respirers (animals etc.). One way to understand the recent spurt in atmospheric CO[sub]2[/sub] is to compare the millions of years over which fossil fuels accumulated with the short span of their burning.
Examine the Earth’s temperature or temperature compared with CO[sub]2[/sub] levels over 100’s of million years and see that the Earth’s climate is NOT stable over long periods of time. I don’t know how well the drivers of transitions are understood, but we could be at a transition now.
There are both positive and negative feedback mechanisms at work. One negative feedback which kept temperature within a narrow band during the Quaternary is that melting ice leads to oceanic CO[sub]2[/sub] accumulation, reducing the greenhouse effect. Ice, already at a low level for the Quaternary, continues to melt, but the resultant equilibrium may have higher temperatures and more acidic oceans.
Which is it? Climate change isn’t happening … or climate change is good?
You know what I noticed here? Not a single citation. I mean, you make a lot of very tall claims, but you completely fail to back any of them up. Is this like your claims about solar power again?
Right. Which is why the climate never changes.
Ever.
It’s why the earth was not ever covered in ice, and when it was, it snapped back almost immediately.
It’s why the eocene thermal maximum never happened.
It’s why every time something happens that would affect the earth’s climate, negative feedbacks immediately change it back.
…
…Sounds kinda stupid when you say it like that, right? That’s because it’s wrong. It’s blatantly and obviously wrong. Yeah, there are negative feedbacks. But they are neither instant, nor bottomless. And there’s good evidence for positive feedbacks as well, and good reason to believe that some negative feedbacks (such as the ocean) are losing their ability to function as negative feedbacks as we get warmer.
Citation needed.
Citation needed.
Citation needed.
Citation needed that we’re ignoring it.
Everything you’re saying is wrong and you make absolutely no attempt to back it up with published research (because you can’t, because it’s wrong), appealing rather to our common sense. Just like it’s common sense that volcanoes must dwarf human CO2 output (wrong), that we couldn’t possibly affect the carbon cycle (wrong), that such a tiny portion of the atmosphere could not have a huge effect (wrong), and that climate has changed in the past, therefore we couldn’t be the cause of the current change (wrong wrong wrong wrong wrong). Stop appealing to common sense, and actually do some research. Your insistence that your assumptions about the natural world must be true is the reason that every single thing you’ve said about AGW in this thread is wrong.
Yeah! Which is really helpful when we completely lack the architecture in place to take advantage of it!
To come back to Colibri’s (completely accurate) point: modern human society is built around the climate that has existed for the past few centuries.
Our cities are built at the sea because that’s how shipping used to work - if the sea level rises or drops significantly, their position becomes precarious or useless.
Our farms and agriculture is centered around crops we know can grow well in the environments that are good for growing - if these environments become arid, there’s little guarantee that the new areas will not pose significant problems.
Our entire agricultural supply line (and believe me, this shit is really, really, really non-trivial in magnitude and cost to relocate/rebuild) is based around things like the grain belt - if we can’t grow there any more, we’ll have to move all of this around, and it’s going to be some really lean years until we pull it off.
Our population centers are often built around aquifers or rivers that run off from glaciers - if rising temperatures make these water supplies unsustainable, we will face migration and refugees.
Our entire modern society is based around the climate we live in. The problem is not “we’re away from the ideal CO2 concentration”, the problem is “the change in CO2 concentration leads to the infrastructure we’ve built over centuries needing to adapt faster than is comfortable for us”. And that’s ignoring the rest of nature, which doesn’t quite have the same tools we do to adapt to changes.
As has been said, even if some areas become better there would still be enormous costs involved in developing new infrastructure. If the best area for corn cultivation moves from the Midwest to Canada, you then have to build new roads, railroads, silos, and everything else to support it. Meanwhile much of the existing infrastructure for corn cultivation in the Midwest may not be suitable for sugar cane, or whatever the new crop is.
As has been said, even if some areas become better there would still be enormous costs involved in developing new infrastructure. If the best area for corn cultivation moves from the Midwest to Canada, you then have to build new roads, railroads, silos, and everything else to support it. Meanwhile much of the existing infrastructure for corn cultivation in the Midwest may not be suitable for sugar cane, or whatever the new crop is.
Or if you assume the oceans to be a massive, inexhaustible sink for CO[sub]2[/sub], then what about the resulting acidification? CO[sub]2[/sub] + water --> Carbonic Acid (H[sub]2[/sub]CO[sub]3[/sub])
IMO, the possible shift of agriculture from the US to Canada isn’t as troubling as, say, loss of agriculture from large parts of southern Africa and southern Asia. There is a fairly developed infrastructure in Canada, and the government is stable and prosperous enough to allow efficient development further to the north.
On the other hand, the Siberian steppes are vast and almost completely undeveloped. Somehow I doubt that a billion subsistence farmers from Africa and other parts of Asia can just pack up and start farming in the newly thawed permafrost in Siberia…
You guys are saying that climate science isn’t ignoring it, but one of the guys above JUST SAID that there are positive feedback mechanisms before the negative, or something like that
Oh yeah, right, that experiment where they built a time machine and slowly tracked all climate data for the past 1,000,000+ years
Oh right…
Oh, but stupid tree rings are just as good as that, right? Other kinds of science can only make claims they can actually experiment on, with exact precise data whose tiny variance is only allowed to be caused by imperfect measurement machines.
Every single interaction in physics and chemistry and electronics can be explained exactly by the relevant theories, and reproduced 100%. But climatologists get to look at some tree rings and I’m supposed to buy it 100%, and impoverish my entire country. That level of faith?
So, first we know that there’s global warming, that we know the future with super duper certainty, and now, on top of that, we know all the details too! Wow!
Sounds like a SECOND hypothesis that needs more proof, to me
Look, I get it. AGW is a theory, and there’s some evidence behind it. I get all of what anyone has said. You guys are just over-stating the meaningfulness of the evidence. If you’re honest, you’d never accept this kind of evidence to back up such intense claims to coerce people into spending such atrocious amounts of money, if it came to one of the other sciences.
I get it. All the AGW people have to get that you’re never going to make a full sale to the American people.
P.S., I could have responded to more, there was some more strawmanning up there, you guys putting words in my mouth, but whatever, I’m not really interested in dragging on this kind of shit
That is because the scientists investigated that before, please read about it in the links provided before telling us more baseless claims.
You are entitled to your opinions but not the facts, the CO2 that is released in the atmosphere by human activities is the same stuff as the past CO2 that is detected in the extracted ice cores, tree rings are not the only items used to get approximate temperatures from the past (three rings by the way are proxies to past temperatures, the estimated temperature they report from the past has limitations so other proxies are used to check them and for deeper timelines.)
National Geographic Teaching Guide:
The evidence for Tobacco causing cancer, fossil power plants and vehicles causing acid rain and industrial CFCs causing the loss of the ozone layer were accepted before. Then as now the same groups that oppose doing a concerted effort (that will take money, but not at the atrocious lebels the same groups misleadingly claim) are telling our politicians to ignore the science.
The latest polls show that even with groups like the Heartland Institute, The George C. Marshall Institute and FOX spewing misinformation the majority of the American People do think that the government should do something.
I noted that there are positive as well as negative feedbacks. This does not negate the existence of elements of the environment which are negative feedbacks. That said, the way you’re describing feedbacks is nonsensical. The climate has changed significantly in the past; where were these negative feedbacks then? Oh right, they were there, they just don’t work the way you think they do.
How do you feel about creationism?
We don’t have the most precise data. What we do have is multiple lines of concordant data. The tree rings. The ice cores. The silt deposits. We can get very precise measurements on things like CO2 concentration in the past, and fairly precise measurements on temperature in the past. From this evidence, we can piece together what the climate in the past looked like. No time machine necessary. Again, how do you feel about creationism? Because this is Ken Ham level reasoning right here.
Yep! Like Pluto’s orbit! We can totally reproduce that! :rolleyes:
No, you’re wrong. But more to the point, the fact that certain kinds of modern science can offer a more direct form of proof does not discount sciences that look at the past. We’re all capable of looking at evidence from the past and drawing valid inferences. If I showed you a picture of a city after either a hurricane, a tornado, an earthquake, or , and you had to either tell me what caused it, I betcha 99/100 times you’d get it right without any experimental confirmation. What you’re pulling is a straight-up creationist argument to try to attack all science that examines the past. It’s fundamentally dishonest and I am disappointed that anyone here would make such a bogus argument.
Well, you could examine the multiple concordant lines of data which have led to temperature reconstructions and CO2 reconstructions of the recent past all looking pretty much the same, with slightly different error bars. See, that’s one of those things in science. When you try two different methods and lines of evidence to find out what happened, and each of those ways gives you the same result, usually that’s a pretty good sign that the result is accurate. But again, you don’t understand this. You’re not looking at this evidence. You’re simply making bald-faced assertions with no understanding of the published scientific evidence. Case in point.
There is decent evidence that indicates that the economics of AGW are not negative, and very strong evidence that the economic impact of global warming is a big deal. That is, taking action now is not a bad thing for the economy, but not taking action could be catastrophic. There’s little to no reason to believe that fighting AGW would destroy the economy or impoverish the country.
Tell ya what. How 'bout you spend 5 minutes looking for the proof - five minutes looking at the evidence supporting these hypotheses - before you pretend there is none? That would be really swell. You think the evidence is not a strong basis because you aren’t looking at it! You have no idea what you’re talking about. It’s the solar panels thing all over again. You just make bald-faced assertions with no interest in what the actual peer-reviewed literature says, or what experts on the topic have to say. You’ve been demonstrably wrong quite often. At what point do you stop and say, “Jeez, maybe I should go learn something about what I’m talking about, rather than just flapping my gums about a subject I know nothing about?”
Excellent. Then don’t. Your opinion is completely unproductive to any discussion on climate change because, as previously stated, your understanding of the subject is less than zero.
Let’s not make this into yet another thread about the reality of global climate change. We have plenty of those already.
Frankly, I don’t think the OP is clearly enough formulated to permit a simple factual answer in GQ terms (other than that an optimum can’t really be determined), nor a focused debate in GD. My inclination is to close this, unless someone can address the OP in a relevant manner. Those who wish to debate any other aspects of anthropogenic climate change may contribute to the existing threads or open another thread on the questions raised by the OP in GD.
I am leaving this open for now but if it continues as a general debate on global climate change I will close it.
Not unless you consider current proposals to maintain CO[sub]2[/sub] levels to those we had in 1990 (~350 ppm). Current levels are at ~400 ppm
Is it doable? Yes. Is it economically viable that’s up for debate. http://www.aps.org/policy/reports/popa-reports/loader.cfm?csModule=security/getfile&PageID=244407 gives a value of ~$600/tCO[sub]2[/sub]. Youc an also read that as how crucial it is to either not emit in the first place, or to capture at the point of emission. It’s much for effective to capture CO[sub]2[/sub] at the coal plant vs. pulling it all back out of the air.
“The practical concern for humanity is the high climate sensitivity and the eventual
climate response that may be reached if all fossil fuels are burned. Estimates of the carbon
content of all fossil fuel reservoirs including unconventional fossil fuels such as tar sands, tar
shale, and various gas reservoirs that can be tapped with developing technology (GEA, 2012)
imply that CO2 conceivably could reach a level as high as 16 times the 1950 atmospheric
amount.”
For references 16 x 1950 CO[sub]2[/sub] would be >3000 ppm.
I’m pretty sure you addressed the OP pretty clearly, and so did I, taking your point further. The optimal CO2 level, at least for us, is the level needed to maintain the climate as we’ve had it for the past few centuries of astounding growth.
Plants “remove” a huge amount of our emissions already. Irrigating the worlds deserts, with solar power of course, would be the fastest and most economic way to remove carbon. Economic because the plants would have a huge economic value, as well as creating huge areas of land to live on. Making fuel from atmospheric CO2, using solar power of course, would also be good.
Since we don’t actually know how much fossil fuel there is, it’s unknown. There is also the issue of the huge amount being removed all the time. If the known coal reserves were all burned (which would be something like 5,000 years from now), as well as all the unconventional fossil fuels (such as tar sands, tar shale, and hydrofracking-derived shale gas) it could be as high as 1400 ppm, but that is a wild estimate, and meaningless to us at present.
Something I wonder about are the surprises we may get. Animals or plants in the ocean or on land that suddenly start to multiply faster with higher levels of carbon available, possibly affecting the food chain.
A long term well done study of trees in Maryland reported hard wood trees are growing two to four times faster now, and it is due to increased CO2 levels.
It’s one reason experts think the missing sink (where all the CO2 is going) might just be the forests.
Thats kind of where I was going wit this, could the living bio mass in the ocean increase by 30% for instance. How long would it take those living animals to die and decay back into free carbons.
Which is it? Climate change isn’t happening … or climate change is good?
![temperature compared with CO[sub]2[/sub] levels](http://astronomy.nmsu.edu/tharriso/ast110/carbondioxide.gif){kind=link}