There have been five extiction level events in earth's history. The worse was at the end of the Permian, where 95% of all life was eliminated. There are plenty of articles and research (with data and evidence) to support each event.
I'd like to hark back to the beginning of this thread and look at the correlations between atmospheric CO2 and the Mass Extinction Events in the past 500 million or so years.
The 5 main ones seem to be:
End Odivicial - 444 million years ago;
Late Devonian - 375 million;
End Permian - 251 million
End Triassic - 200 million
End Cretaceous - 66 million
And in each of those, total species losses ranged between 75 and 95%.
These MEE's correlate pretty well to the graph referenced by AstralTraveller(David) in #27 in this thread. A somewhat more detailed plot can be found in the attached which derives from Dr. Peter Ward’s book, “Under a Green Sky.” It reinforced David's basic point pretty well.
However, there is no room for complacency. That plot might be said to show that our current CO2 levels are bouncing along at historical low levels. Another way of looking at it is that MEEs have in the past occured when the CO2 levels exceeded 1 thousand PPM. The most recent 5 MEEs - i.e. in the past 200 million years have all occured when levels were between 1 thousand and 2 thousand PPM. How much comfort can you derive from knowing we are nearly half-way to a possible MEE?
" Dr. James Hansen, a leading climate expert points out in his book “Storms of My Grandchildren” that at the current rate CO2 will increase one hundred ppm in approximately 40 years. During past periods of abrupt change — the most recent one occurring approximately 50 million years ago — it took roughly a million years for CO2 to change by one hundred ppm. Thus it is now changing about 25,000 times faster than in known geologic history."
Now that puts a different spin on the issue, I think and makes it folly to hide our collective heads in the sand. This won't go away.
We are clever enough to work out that energy consumption comes at what you could call a life and death cost in the long term.
Yet the only responce from most humans is ... I dont care or how do I make a buck from this.
Over the last day I have been looking at the human excess in respect of toys...I find there is a twin v8 trike ( a motor bike with three wheels which cries for a twin v8 instalation) I find dragsters that race in mud..these things cost a fortune and money represents energy expended... I was going to make a youtube viewing list of the waste and sheer stupidity enjoyed by so many humans...all production contributes to the problem but we allow five motors in a tractor to pull a load down a track some simply so someone can boast he was the best. What mindless stupidity which I can tolerate but all these stupid things cost us..we will have to contribute by giving up our childrens future.
And then folk offer this solution or that to provide energy that has no harm factor simply so the tractor pulling and other nonsense can go on...perhaps stop the childish indulgence to stupid non productive toys could be a reasonable place to start.
No way..no one is going to take away my right to run a five motor tractor...
Sure the carbon footprint is evidenced and each year we receive confirmation that we have a problem...sure ok now lets go race our twin v12 mini bike in jelly.
These humans are less than children animals have more sense.
There is only one solution.
I should be put in charge of the new world government ... that is the planets only hope☺.
After the first week in office the only problem would be what to do with all the bodies☺
I predict a world wide collapse as the problem gets to a critical point...and then humans will be back in the stone age and everthing will be alright.
The pity is the message for 80% of the world is a certain entity will fix it...mmm there the most dangerous threat to humans..worse than everything else.
Abdication of personal responsibility...how wonderful.
Alex
I am watching the drag races..funny cars...what is the carbon footprint of a drag car? How much coal is burnt to produce one? How much coal is burnt to maintain and race one?
Some dragsters use 60 liters for a run..thirty to warm up and thirty down the short track...and apparently the engine life is under two minutes..so how much coal to build an engine that lives such a short life... so I wonder what their carbon foot print could be...why did they address light globes with filaments before they failed to address racing cars boats and planes.
Why wring our hands about the co2 and turn a blind eye to the wasteful consumption.
Why even bother to take readings each year as to the parts per million of co2...do we need more data to work out that wasteful consumption of resourses is a problem in itself...and so I brand myself a hypocrite..instead of refusing to watch the car racing and the tractor pulling I like so many other hypocrites look on rather than turn away and deny these idiots the attention they crave...so perhaps the first place to work upon the problem is to reject and outcast all those who greedily consume resources that I am sure our futher generations will need to exist.
I am taking the first step by turning off the drags so to deny them at least one little humans support and approval...just imagine if we could get everyone to treat greed with the disgust it deserves.
So lets do nothing other than gather more data and grizzle about a problem we refuse to address by stamping out greedy and wastful consumption.
" Dr. James Hansen, a leading climate expert points out in his book “Storms of My Grandchildren” that at the current rate CO2 will increase one hundred ppm in approximately 40 years. During past periods of abrupt change — the most recent one occurring approximately 50 million years ago — it took roughly a million years for CO2 to change by one hundred ppm. Thus it is now changing about 25,000 times faster than in known geologic history."
Hi Peter,
It's not clear what part of that quote is attributable to Hansen and which part to Englander, but one thing that is clear is that it is only partly correct.
Certainly based on extrapolations of the Keeling Curve (Manua Loa CO2 Concentration) it is not unreasonable to conclude that the atmospheric CO2 concentration will increase by 90 to 100 ppmv in 40 years IF the current rate of increase is maintained.
What however is not correct or misleading is that one has to look back 50 million years to see the a 100ppm change in the concentration of CO2 (which incidentally occurred over a time interval of "roughly a million years") in order to calculate the fastest historical rate (for comparison with today's rate of change of CO2 concentration) . This is simply not correct and clearly evident in ice-core data which disproves this.
There are circa 100ppm changes in the CO2 concentration at each of the glacial/interglacial transitions clearly evident as having occurred SEVERAL times in the last 420,000 years in The Vostok Ice Core CO2 Record and at a rate around two orders of magnitude FASTER than proposed in the Englander/Hansen quote. The Vostok record shows an approx 100ppm CO2 change at each of the several glacial/interglacial transitions occurs over a period of something like 15,000 to 30,000 years. The suggestion therefore that the modern day CO2 concentration is now changing 25,000 faster than ever seen in history is therefore not true. It is around two orders of magnitude SLOWER than that. Why the error or exaggeration? Is it poor science or activism?
Anyone that would like to check their (or my) claim, based on the real data, please refer to the CO2 reference raw data from CDIAC and calculate the rate of change of C02 concentration at the (several) glacial/interglacial transitions in the 420,000 year record: https://cdiac.ess-dive.lbl.gov/ftp/t...ok.icecore.co2
As an aside- One important additional thing to remember when looking at present day v historical CO2 data stretching back many millennia is that:
Present day CO2 concentration measurements (Manua Loa, etc) are direct measurements of CO2 collected by sampling the atmosphere in a few seconds by sucking it in to an evacuated flask for measurement, versus
Historical CO2 concentration measurements (at least Ice-Core based measurements) which are measurements of the CO2 trapped in ice core samples. This entrapment starts in/towards the bottom of the the firm layer of the ice , somewhere between the snow layer and the solid ice layers anywhere between typically 50 to 100 meters below the surface depending on location. The CO2 gradually becomes trapped over many decades or even centuries depending on the location as the firn layer compacts to become solid ice under the ever increasing pressure of season after season of snowfall.
What this means is that the historical CO2 record will be limited in its ability to measure sharp peaks in the CO2 data, as the CO2 sample is in effect sampled (averaged) over /during this extended entrapment time. Depending on many factors such as snowfall and temperature it takes many decades /centuries as the firn layer compacts to become ice and to trap the CO2. There are also chemical processes at work on the entrapped CO2 which can further smear the temporal resolution. A sort of many decade (or even maybe many century?) average of the CO2 concentration is the result. The time (temporal) resolution is also smeared by this as well. Despite this it is still possible to make some comparisons between past and present as long as care is exercised and the data is not blindly accepted, presented without explanation, or worse still misused.
I wonder if you could come up with a rule of thumb that would indicate how much CO2 is generated for each dollar spent...perhaps you would need catagories...
I must look into something I just thought about...surely the area of roads and buildings must hold heat more than a forest ... I often feel how hot a section of cement can be many hours after the Sun goes down. ..I wonder do such things add to the warming issue.
Alex
I wonder if you could come up with a rule of thumb that would indicate how much CO2 is generated for each dollar spent...perhaps you would need catagories... I must look into something I just thought about...surely the area of roads and buildings must hold heat more than a forest ... I often feel how hot a section of cement can be many hours after the Sun goes down. ..I wonder do such things add to the warming issue.
Alex
Absolutely right Alex. You've just described the Urban Heat Island Effect. It could easily skew conclusions with temperature data. It is something that needs to be controlled for in any proper analysis.
Maybe time to buy a property in Greenland☺
Actually if for no other reason cause light pollution would not be bad.
Actually for lack of light pillution North Korea seems ideal☺
Or move to Turkey into those underground cities..if anyone has not heard about them I suggest look into them...could accomodate 20,000 people and more than one...a mystery as to why..but they went underground with live stock and all.
Why did they do that?
Alex
It's not clear what part of that quote is attributable to Hansen and which part to Englander, but one thing that is clear is that it is only partly correct.
A quick search shows Hansen was talking about the rate of change of CO2 in the atmosphere leading up to past mass-extinction events - the last of which was at the Paleocene-Eocene Thermal Maximum some 56 million years ago (when the temperature rose 5 deg C in 15-20 thousand years - ie: slower than current temperature rise).
Hansen is completely correct.
Quote:
Originally Posted by JA
What however is not correct or misleading is that one has to look back 50 million years to see the a 100ppm change in the concentration of CO2 (which incidentally occurred over a time interval of "roughly a million years") in order to calculate the fastest historical rate (for comparison with today's rate of change of CO2 concentration) . This is simply not correct and clearly evident in ice-core data which disproves this.
There are circa 100ppm changes in the CO2 concentration at each of the glacial/interglacial transitions clearly evident as having occurred SEVERAL times in the last 420,000 years in The Vostok Ice Core CO2 Record and at a rate around two orders of magnitude FASTER than proposed in the Englander/Hansen quote. The Vostok record shows an approx 100ppm CO2 change at each of the several glacial/interglacial transitions occurs over a period of something like 15,000 to 30,000 years. The suggestion therefore that the modern day CO2 concentration is now changing 25,000 faster than ever seen in history is therefore not true. It is around two orders of magnitude SLOWER than that. Why the error or exaggeration? Is it poor science or activism?
There was no error nor exaggeration, no poor science nor activism. Hansen was stating a fact about emission rises leading up to extinction events.
It kind of looks like you have created a strawman here.
The fastest ever rises in emissions from the geologic record are still some 325-750 times slower than current human created rises in emissions.
Quote:
Originally Posted by JA
What this means is that the historical CO2 record will be limited in its ability to measure sharp peaks in the CO2 data, as the CO2 sample is in effect sampled (averaged) over /during this extended entrapment time. Depending on many factors such as snowfall and temperature it takes many decades /centuries as the firn layer compacts to become ice and to trap the CO2. There are also chemical processes at work on the entrapped CO2 which can further smear the temporal resolution. A sort of many decade (or even maybe many century?) average of the CO2 concentration is the result. The time (temporal) resolution is also smeared by this as well. Despite this it is still possible to make some comparisons between past and present as long as care is exercised and the data is not blindly accepted, presented without explanation, or worse still misused.
The low temporal resolution of ice-cores is well-known. I am unaware (I'm no expert of course) of any natural mechanism that could cause short term (< 100-200 year long) sharp "spikes" in atmospheric CO2 that wouldn't subsequently be detected by ice core sampling.
Climate science scepticism is a political campaign - originally funded by Exxon and now by Koch industries - where doubt and misinformation are spread via denialist blogs and amplified by conservative media outlets.
It has little to do with any real issues relating to the science. Science is never completely settled and there is always more that we can be known but the central tenets of greenhouse-gas theory are not in doubt by anyone with genuine credibility.
Climate science scepticism is a political campaign - originally funded by Exxon and now by Koch industries - where doubt and misinformation are spread via denialist blogs and amplified by conservative media outlets.
It has little to do with any real issues relating to the science. Science is never completely settled and there is always more that we can be known but the central tenets of greenhouse-gas theory are not in doubt by anyone with genuine credibility.
I think it's much simpler: These people are just lazy. Plain old laziness has always stood in the way of change. To call this attitude "scepticism" suggests some sort of reasoned, meaningful, active relation to the subject. The reality is that to deny climate change is to follow the path of least resistance, both in terms of educating oneself (watching youtube vids as opposed to reviewing scientific research, perhaps even using scientific methods), and personal action or lack thereof (driving to the shop instead of walking, for example).
I think it's much simpler: These people are just lazy. Plain old laziness has always stood in the way of change. To call this attitude "scepticism" suggests some sort of reasoned, meaningful, active relation to the subject. The reality is that to deny climate change is to follow the path of least resistance, both in terms of educating oneself (watching youtube vids as opposed to reviewing scientific research, perhaps even using scientific methods), and personal action or lack thereof (driving to the shop instead of walking, for example).
I agree on the laziness issue you cited Mirko, just not necessarily unilaterally. That's why I think it's very important to:
work from the raw data where possible for any analysis, as well as take in the relevant scientific literature rather than solely rely on the opinion of others, organisations or governments and
to discuss and argue a case with those who are prepared to do likewise.
To take your last point and to paraphrase: I think it's important to take personal action - kind of like running to the shops instead of walking, for example
I Wonder is anyone building data on the energy that is wasted on Toys�� How many solar powered homes do we need to support tractor pulling and darg racing etc etc.
And it seems that I am the only person who sees a problem the way I see it. I don't hear a cry to reduce wasteful consumption ever...no a tax or NP or alternative energy so a great percentage of it can be wasted...seems most human..
I notice there are some places where they are aware and acting on covering heat absorbing materials yet this approach never seems to make the news...like the government is raising a carbon tax so it can fund covering heat sinks with lawn.
Alex
