Taking onto account that we may have to go through some changes while getting there has an optimized co2 level ever been attempted to establish?
Another related question, is the feasability of removing carbon from the air a real possibility at this time?
And if all the available fossil fuels are used up what is the projected co2 level when that happens?
Optimized for what?
Humans?
Human body? Which human body, healthy humans or the weakest and most sick? Or for our agriculture? Or industry? Human economy as a whole? Or safety from extreme weather?
Obviously we can only choose one number that has to be the best compromise for all. So for the health of planet earth and its inhabitants, slightly favoring humanity.
Sorry, this is still way too vague to permit any meaningful answer.
Higher CO2 levels could result in more of the planet becoming more habitable for humans, and more suitable for agriculture. Or it might not. We can make some predictions as to which areas will become warmer, and which rainier or drier. However, we can’t do it in such detail as to know what level will be “optimal” (in whatever sense you mean it). And what’s optimal for us isn’t going to be optimal for most other life forms.
The problem with rising CO2 and associated climate changes isn’t so much what levels they eventually reach, but their speed. We can no doubt adapt to higher CO2 levels and to climate changes; the problem is that they will make some areas that we now use unsuitable, and there will be enormous costs and disruptions in moving them to new areas that are suitable. Likewise with plants and animals. Given enough time they will adapt to changing climate. However, changes are likely to come too rapidly for plants and animals to shift their ranges in time or to adapt physiologically.
In a sense, the “optimal” level is that which most human societies are well-adapted to. Which is probably the CO2 level from (WAG) several decades ago, since cities and populations don’t move around very rapidly.
If, magically, the CO2 concentrations returned to pre-industrial levels tomorrow I’d bet that there would be lots of regional climate shifts that we wouldn’t be prepared for. There’d be agricultural regions that experience less rain than they’ve had recently, or cities that are colder than they are accustomed to.
(After that epic WAG… is there a good global map of, say, average precipitation in 1900 and 2000?)
the entire idea of thinking of the relationship as being “CO2 = more warmth” is overly simplistic. The earth, being a stable complex system, has negative-feedback systems, as this is the only way such complex systems can exist without going haywire. This is not really accepted in the global-warming model, but will come to be known as correct within the next hundred years as science advances and understands more about this obscure part of science (the study of systems and chaos and equilibrium. This is what Jeff Goldblum’s character in Jurassic Park was held to be a scientist/professor in, if you remember)
The forces that are at work on earth are massive. The only way this planet could still be existing without its atmosphere being blown off or all the water boiled off or whatever is if all the huge forces were balanced by negative-feedback systems.
So whatever happens, it will all be balanced out in some way. There would be trade offs depending on the region, but overall there could not be huge catastrophic effects, if by that you mean insane weather that’s unprecedented in Earth’s history
Since this is GQ and all, cite?
There are a lot of assertions here that are simply wrong and/or caricatures, so I’d like to know where you’ve seen this directly stated by climate scientists.
For example, feedback systems are directly addressed in the IPCC report.
As mentioned above, the argument is not that models don’t include feedback mechanisms or that they aren’t important but that rapid changes can’t be handled by them and that the basis for our lifestyle and economy is not equipped to deal rapidly with them either.
It’s a bad understanding and statement of negative feedback mechanisms anyway. There are tons of negative feedback mechanisms that can handle relatively gradual changes but can’t handle sharp transitions. For example, human body temperature regulation. Or human blood pressure regulation. We can handle reasonable (for a given value of "reasonable) variations in body temperature or blood pressure. But those negative feedback mechanisms can be insufficient or actively harmful in many emergency situations.
So, just because a negative feedback mechanism exists doesn’t make it a cureall either.
He told you it will be known within a hundred years. Just wait a bit.
You jest, but in this case that poster does not know that there has been more than a hundred years of investigations that also looked at those negative-feedback systems, in reality about 60 years ago a lot of the scientists had the idea that we should not worry even if they were aware of the effects of CO2 accumulating: they thought that nature would absorb a lot of the human made emissions, like the oceans would take care of the increase, just then real Galileos like Callendar got the disdain of the consensus then by proposing that we should not depend on those sinks or negative feedbacks.
By a combination of figuring out what were the actual absorption lines of CO2 in different layers of the atmosphere (Plass), and finding out that many of the expected carbon sinks and negative feedbacks were not as they expected then the realization came to the vast majority of scientists that this was a big problem.
For the long explanation with links to the scientific evidence one has to read the now free to read The Discovery of Global Warming by Spencer Weart Particularly the chapter on the long train of science and investigations made to conclude that The Carbon Dioxide Greenhouse Effect is one of the main drivers of the currently observed warming and that we control the knob.
The idea that some are still expecting, that there are great negative feedbacks or carbon sinks out there ready to save us from our irresponsibility, is the real wishful thinking.
As Carl Sagan told us (and back then he was aware of this issue too) “there is no hint that help will come from elsewhere to save us from ourselves.” The work we will have to do to control this issue is not impossible to do, it is just that the longer we wait, the harder and more expensive it will be to control or mitigate.
Bingo.
Science hasn’t determined an optimal CO2 level, but it has established that, in the past million years, the ecosystem in which we evolved seems to have coped quite well with gradual changes on the order of 1-4 ppm per century. The CO2 level is currently rising at more like 4 ppm per YEAR, which is a breakneck speed by historical standards.
My WAG is that 400 ppm might very well be a quite comfy level to be at if we had gotten here gradually and if it weren’t still going higher and higher.
That seems silly, given that all the forces on the earth are enormous and in the absence of negative-feedback systems we know would produce huge rapid changes. Indeed, they DO produce them, but they’re countered by negative feedback. Just the change in insolation from winter to summer is enourmous when you count the huge surface areas involved, and that it happens in less than a year.
The feedback mechanisms that we know exist are based on the levels of different things, not their rate of change. The higher the CO2, or anything, the more a negative feedback kicks in. I mean, think about it, both the oceans and the plants can absorb CO2. Can the sum of all human activity even remotely compare to all the plants in the world? The endless forests in Siberia, the still huge Amazon, the endless grasslands of Africa, all of which are dwarfed by ocean algae? Of course not. Even a marginal change in their growth rate would dwarf human output of CO2. Ditto the enormous oceans.
To ignore negative feedback mechanisms is to ignore that the climate is stable, that there is even a climate at all, instead of a violent fucking constant windstorm and massive temperature swing a la venus or whichever planet it is.
To say that the rate of change matters is to ignore all the massive changes that have occurred in the past of the earth.
Can you give any examples of “massive changes” that occurred this quickly?
The only one I can think of is the K-T extinction event which was involved a meteor strike. All the others I can think of (like the buildup of oxygen in the atmosphere due to the emergence of photosynthesis) happened very gradually, on the scale of thousands or millions of years.
I don’t think there’s much hope of convincing EdwinAmi differently, so this is for anyone else who stumbles onto this thread: this is completely wrong and ignores all scientific experiment and investigation. You need look no further than CO2 concentrations over the last century to see how patently false it is.
No one is ignoring negative feedback mechanisms! Please do some actual study of climatology before you spread this misinformation.
Nobody is ignoring negative feedback. I think you’re misunderstanding what it is, though. Negative feedback is not something that pushes a system back to the same original. If you change a parameter of a system, negative feedback causes the system to settle at a new, different equilibrium, which may be very different from the original condition.
Think of a basket hanging from a spring. If you add a weight to the basket, the basket starts moving down, and the spring will extend. But the more the spring extends, the more upward force it exerts on the basket. That’s negative feedback, and this prevents the basket from falling all the way to the floor. But the spring does not bring the basket back to the original height. The basket comes to a stop at a lower point.
By the way, the amount of CO2 created by burning fossil fuels is about the same amount as the total amount of CO2 in the atmosphere. That’s a significant input, and you would expect the system’s new equilibrium point to be very different from the original conditions.
Exactly this. The rate of change of CO2 we’ve experienced since industrialization is dramatically higher – by several orders of magnitude – than is usually seen in nature even during periods of climate transition, as can be seen here and here. Moreover, in addition to the ecological challenges you describe, the strong forcings generated by this rapid change are destabilizing, leading to more and more extreme weather events and significant changes to atmosphere and ocean circulation systems that can disrupt local climates in major ways. The idea that there is “no one ideal temperature” for the earth, and that a warmer earth might even be “better”, is a common tactic used by those seeking to undermine the public’s understanding of these biological and climatological stress factors caused by the unprecedented rate of change, the equivalent of trying to turn an aircraft carrier around on a dime.
This is complete garbage and exhibits a total ignorance of climate science. I love how those who obviously know nothing about climate science always have free advice for the researchers who have been studying the field for a lifetime. Climate system feedbacks are among the most important and well-studied areas in climatology and are crucial to assessing climate sensitivity. Equilibrium climate sensitivity is sufficiently well understood, for instance, that while there’s still a relatively broad range of possible values in the accepted consensus, there is no doubt that it’s dominated by positive feedbacks, with the majority of estimates centering around a factor of about 3.
Most important feedback responses to CO2 forcing are strongly positive – ice-albedo feedback, methane release from permafrost and hydrates, water vapor, and others. Negative feedbacks, like geo- and biosequestration and lapse rate feedback tend to be small. If it were not so, then there would not have been the kind of CO2-driven temperature increases we consistently see in the paleoclimate record – for example, during the Paleocene-Eocene Thermal Maximum.
Indeed.
and make other areas much more fertile/useful
The potentially more fertile area is dwarfed by the area that will become unsuitable for growing food and survival in the way we are accustomed. And that completely ignores animal and plant life that can’t move as easily as humans and will simply die out.
Please please please get some facts on this before posting misinformation.
The problem of the jump seen in the increase of CO2 in the atmosphere is that there is no guarantee that the new much fertile areas that will get warm enough for it will be stable for long, or/and it will take generations to figure out what, when and where to plant.
And then there is the issue of giving guys that will follow the steps of Putin the control of most of that land.
