Just one nit wolfpup. I think that humanity will survive even if not much is done, but I’m pessimistic about most countries not being able to drop their xenophobic act once we get hit with a wave of refugees just by the expected ocean rise alone.
Even if I agree on a possible stable warmer planet generations from now, I can’t see how a bottleneck before that “happy time” can be avoided if very little is done; and it will be thanks once again due to a group in government that claims repeatedly that there is no problem at all. That will only lead also to nations not being properly prepared for the changes, a double whammy IMHO.
Ignoring the issue, as recommended by a few skeptics and many fake ones, will not be cheap in the long run and it will be deadly to many members of our following generations.
Even ignoring the AGW of the future, it is interesting to try to understand the past glaciation cycles of the Pleistocene. Orbital fluctuations are inadequate, by themselves, to explain the size of the temperature fluctuations. Recently in messages in another thread there was a sub-debate between Mr. Brazil84 and myself. I see wolfpup’s explanation is the same as mine.
As I understand it, because cold water releases its CO2 when it freezes, negative feedbacks eventually take over and limit the glaciation. But over a broad range during the Pleistocene, temperatures and greenhouse gas concentrations track each other almost exactly. To me, this implied that positive feedback(s) (temperature–>CO2+CH4) was dominant over the intermediate range. Yet when Brazil84 challenged the point, I wasn’t sure how to articulate or find a “cite” for this intuition. What should I have told Mr. Brazil?
(Mine isn’t really a question about climate; it’s a general question about dynamical systems. Does the lockstep between two parameters imply positive feedback? If so, how does one articulate a proof?)
No disagreement there. I’m not seriously suggesting that if we don’t act to mitigate GHG emissions humans will soon be extinct (although that was the only non-serious part of my post! :D) However, there is ample evidence that we will be in for major economic and physical hardships directly proportional to the eventual level of CO2 stabilization (for example, per the IPCC WG2). Refugees from tropical regions are more likely in the short to medium term from food shortages than from sea level rise, as they will likely be the first to be hit with reduced crop yields. Yields may actually improve for a time in the northern latitudes (absent non-indigenous pest invasions) before reversing again. And then there’s all that extreme weather for which climate change is loading the dice.
I’m not sure if I fully understand your question, but I did read Mr. Brazil’s response, so let me throw out a few factoids and see if it helps at all. Beginning with the fact that he makes the unfounded and totally baseless assumption that for some mysterious reason known only to himself, “it’s more reasonable to hypothesize negative feedback with a complex system which has been around for a long time. Negative feedback should be the default assumption.”
What can I say except that he is stating baseless beliefs that are contradicted by the physics of the climate system. CO2 forcing is inferred directly from the spectral radiative transfer codes for which there is a good first-order approximation here. The relationship of this forcing to temperature change is expressed in terms of climate sensitivity, for which there is a “transient response” and “equilibrium sensitivity” metric. Equilibrium climate sensitivity (ECS) is by definition 1.0 if there is no net feedback, leading to a 1°C temperature increase at equilibrium for a doubling of CO2. It is less than 1 if negative feedbacks dominate.
Suffice to say that ECS is tightly bounded at the lower range at about 1.5, with upper values much more open to the range of 5 or even 8 or so when accounting for long-term feedbacks like the disappearance of polar ice. The exact value is a subject of much contention, but the general consensus is still somewhere around 3 – despite a certain amount of bad science clamoring about lower values.
So the idea the most feedbacks are negative is just BS with no basis in science.
My other general point is that tracking temperature and CO2 relationships over tectonic timescales (e.g.- millions of years) is fraught with peril for two reasons. One is that the proxy evidence for either temperature or CO2 has wide margins of error over such timescales, and the other is that over such timescales many other slow-response factors come into play.
What I think is much more significant is the tight temperature-CO2 correlation for the past ~600K - 800K years reconstructed with particular accuracy from the EPICA ice cores and others at Vostok and other Antarctic locations and others in Greenland. It shows that the onset of glacial terminations is always a warming that starts to release CO2 from carbon sinks like oceans after about 600 years or so, and that this drives the termination and eventually – as atmospheric CO2 levels rise – creates climates like today’s interglacial. It doesn’t really matter if one accepts the Milankovic cycle explanation as being the initial trigger or not; the atmospheric carbon dynamic (as exemplified by the above-linked radiative transfer equation for CO2) is recurrent throughout the earth’s climate history, whether it’s CO2 or, as in the case of the Paleocene-Eocene Thermal Maximum, possibly CH4.
One must also note of course that what is happening today is completely different in its initial dynamic from a glacial termination. We are already in an inter-glacial, we were already (before industrialization) at the typical inter-glacial CO2 maximum, and we are suddenly being hit with a veritable tsunami of suddenly elevated CO2 that has not been seen since possibly the Pliocene or even longer, possibly not for as long as 15 million years, but certainly never since the balance of the ecosystem on this planet was anything remotely like what it is today.
I agree with you for the most part, the exceptions primarily concern the complete waste of amino acids as used by semi-evolved rodents, belch that CO2 suckers, I dare you.
If I may ask for a few clarifications: Does carbon dioxide saturation levels decrease with increasing temperature of liquid water? That’s actually opposite what is more common, say sugar and water, where increasing temperature increases solubility. This is a surprising difficult fact to find on the internet, makes me suspect what you say is true. If you could please verify this, I’d be much appreciative. I’m not sure what you mean by “grossly different timescales”, this ice age started 30 million years ago. Maybe it’s just my inner astronomer talking, but 30 million years is a rather short time frame. Whatever the physics of 400 ppm that is true today must also be true for the Cryogenian period.
I’m completely baffled by your reference to Milankovic cycles. I’m not familiar with this work and if I’m to rely on the [url=http://en.wikipedia.org/wiki/Milankovic_cycles]Wikipedia entry, then I’ll have to challenge this. It doesn’t matter how the Earth is orientated to the sun, exactly half is exposed to the sun. What varies over time is the Earth’s distant to the sun, which involves the perturbations of the orbit. Things like unequal distribution of the mass of the Earth causes the baricenter to wobble, excluding the perfect elliptical orbit Keplar would predict. I offer this only to explain why we’ve been in an ice age these past 30 million years. septimus is correct that this fails to explain the 400 ppm we are currently experiencing.
My argument is centered on the certainty of your statements. Do we really have absolute proof that extreme weather will cause the demise of humans (and good ridden if you ask me)? Do we have absolute proof that we’ll see massive crop failures decade after decade? Sea level rise is but an inconvenience, a thing humans have prospered with over the past 25 feet rise, what is the definitive proof that this next 25 foot rise will be devastating?
BTW, do you buy into the prediction that rainfall rates increase due to global warming. Nevada was once a fertile grassland full of delicious herbavores …
If we are in mass global warming, how is it two icebreakers are stuck in Antarctica (During summer) and 95% of the United States is was below freezing (WELL BELOW) for the last two days??
We’re currently at solar sun spot maximum … and yes, this 11 year cycle of climate change is well documented as is separate from the discourse of 100K year cycles. The polar vortex spinning off energy is by no means unusual, just infrequent. For the record, I’ve been seeing rather warm weather this past week, it’s just the poor suckers east of the Sierra’s that are seeing cold temps.
What is positive feedback for global warming is indeed negative feedback for global cooling. Ice reflects solar energy, rather than absorbing it. This energy is lost to outer space as it occurs at wavelengths the atmosphere in transparent to. Reducing input energy reduces temperature causing more ice to form. This would be a “negative” feedback mechanism if the subject at hand was global warming.
Hardly BS … although admittedly it has negligible effect at the present time.
The problem is that the “cozy” examples of how things would look with a 25 feet rise is that it does not include things like what hurricanes will do to those locations even with the huge levees (Paid with what?) that would be needed to be built if it is decided to keep the cities.
But before that “happy” time of more Venice like cities,
Again, that is just thinking about the material costs, add to that the droughts and in various areas more precipitation leading to floods means less crops. That will lead to more displacement, I’m not an optimist that the timing will be perfect on the expected cropland in Siberia or Canada to be ready in time, nor that the people on places like Russia will be willing to accept the numbers of people affected.
I remember reading reports from researchers in Nevada, mostly they report that dryer conditions are becoming the norm.
No. The Earth’s orbit is always elliptical, and always has almost exactly 365.2-day period. There is some variation in the eccentricity; Earth will approach Sun more closely at perigee in an eccentric orbit, but it will also be further at apogee and, due to Kepler’s Laws, spend more time further away. (My calculus is decades too rusty to derive net heating as a function of eccentricity from first principles. :dubious: ).
I’ll bet any “barycentric wobble” is far FAR too insignificant to matter. Where Earth’s unequal terrain matters is in summer/perigee alignment due to differences between the Northern land and Southern ocean.
As to “absolute proof that extreme weather will cause the demise of humans”
[ul][li] I didn’t notice anyone here predicting “demise.” But more importantly,[/li][li] Denial-whiners lose all credibility when they suddenly switch from “AGW isn’t happening” to “AGW isn’t bad.” Pick one point and try to defend it. Don’t just jump around randomly parroting every Denial-whining YouTube you can find.[/li][/ul]
But you said it had plateaued. So is it increasing or has it plateaued? If you want to participate in Great Debates you should probably decide where you actually stand first.
The most entertaining thing about “environmentalists” is how conceited they are. To believe that anything our pathetic little species could do would ever affect this molten ball of stone and ore hurtling through the infinite vastness of space at nearly half a million miles per hour; I can only assume your tiny little mind can’t see past the fingertips of your tiny little hands.
This rock isn’t going anywhere and despite what you may believe, nature isn’t going anywhere either. Mother Nature survived far worse than this current infestation known as the human race - and she will long outlive us - until one day when the star that created her will reclaim her.
I have to correct myself - our solar system is only orbiting the center of our galaxy at about half a million MPH. Our galaxy, and therefore our solar system with our planet in tow, is traveling well over 1 million MPH.
Actually, it’s exactly the opposite. We can directly observe the effects we have on the globe. It’s not conceited to assume that you have power when you’ve punched a huge hole through an important protective layer of the atmosphere, vaporized entire cities in instants, turned the rain acidic to the point where it kills the trees it falls on, and hunted numerous otherwise-viable species to extinction. I’m sorry, but this argument is possibly the most vacuous crap I have ever heard. It’s almost impressive in how short-sighted it is. “We couldn’t possible affect something so big!” Yeah, well there’s 7 billion of us and we use some pretty advanced tools. We have affected something this big. And given the evidence, I’d say it’s you who can’t see past your own bizarre preconceptions.
Who here gives a fuck about mother nature? Yeah, nature will exist regardless of what we do. We could literally blow ourselves to bits with every nuclear weapon currently available and the radiation would still leave cockroaches and assorted other creatures around. But I care about us. The human race. What happens to us. And it just so happens that global warming is going to suck. Not for “nature”, it’ll be just fine, but for US.
Okay, but do you understand why this factoid is completely meaningless? You throw it out with absolutely no context, failing to denote that relative to us our motion is fairly stationary. Half a million MPH. That’s nothing on a cosmic scale, and on a local scale, not measuring relative to our movement is like claiming a bee is going 99MPH because you measured it from your sports car.
Depends on what time frame you’re referring to, doesn’t it.
Currently, the global temp has plateaued which makes the previous IPCC guesstimations wrong. Considering a much longer period of time, the Earth’s global temp has increased since the last ice age. If you look at the period between the last two ice ages, you’ll notice that the global temp increased until it began to decrease, which lead to the last ice age. And the cycle began again.
Absolutely. It’s amazing how little sense of perspective these left-wing “science” types have.
To give another example, a neighbor came down with dengue fever and the “doctor” blamed it on a mosquito! :smack: A mosquito that weighs … what? 3 milligrams? That it could have any effect on a 80 kilogram man. A man traveling millions of miles per hour, no less. Of course it’s even worse than that: then they even shift the blame from the mosquito to viruses! :rolleyes: Viruses which weigh a few femtograms each.
Left-wing pro-“science” thinkers are so amusing! Educated Americans know dengue fever is really caused by homosexuality.
Hahaha. Once again, everyone is ignorant except the “man-made-CO2-is-evil” zealots.
According to the “WORKING GROUP I CONTRIBUTION TO THE IPCC FIFTH ASSESSMENT REPORT CLIMATE CHANGE 2013: THE PHYSICAL SCIENCE BASIS
Final”:
Note: The final draft Report, dated 7 June 2013, of the Working Group I contribution to the IPCC 5th Assessment Report “Climate Change 2013: The Physical Science Basis” was accepted but not approved in detail by the 12th Session of Working Group I and the 36th Session of the IPCC on 26 September 2013 in Stockholm, Sweden. It consists of the full scientific and technical assessment undertaken by Working Group I.
the report you linked to hasn’t been vetted by the IPCC and couldn’t have been vetted by any other organization yet. It’s not like the IPCC hasn’t been wrong in the past so why should anyone assume that the IPCC is unquestionably correct this time?
A man traveling millions of miles per hour, no less. Of course it’s even worse than that: then they even shift the blame from the mosquito to viruses! :rolleyes: Viruses which weigh a few femtograms each.