Inspired by the thread on global warming basics, I have 3 questions (Obligatory note : I have evaluated the science on global warming and agree with the conclusion that humans factors are a statistically significant factor in causing it) :
1> Is today’s science advanced enough to predict specific short term outcomes (of the global warming trend) that can be measured ? Some specific outcomes will be like - a> 5 years from now - CO2 concentration at lat /long XX/YY in the Atlantic ocean will be zz g/m3 (with 99% probability) ? b>The sea level at Tampa bay, in the next five years will go up 3 ft (with 99% probability) ?
2> Are the climate change models good enough to predict the specific changes to the global climate ? If I ask a scientist , whats the calculated probability that the Sahara desert will see rainfall will go up 6 times in the next 50 years, can she/he reasonably answer the question ?
3> What is a sustainable rate of CO2 emission (per year) and why ? Will cutting emissions now (by 10% or 20% or 30%) make any change to the trend ?
I’m sure others will give you answers to your specific questions, but I suspect that you’re thinking about this wrong.
If I have a 100 sided dice, I can predict with 99% accuracy that it will not roll a 42 the next time I roll it. If a 42 comes up, that doesn’t mean that my analysis was wrong, it means that the term “high accuracy predictions” don’t necessarily correlate with any ability to make a prediction.
Papers which analyze the climate usually offer several “predictions”, with widely varying results. Scientists can’t predict the future any better than a fortune teller can. All scientific frameworks allow are reasoned projections, based on some different, representative possibilities. Say for example that as the 3rd world modernizes over the next 50 years and their power usage increases, are they going to use nuclear, coal, or unknown future-tech to power themselves? Will their power needs actually grow all that much, or will technology start to use electricity so efficiently because of unknown future-tech 2 that Africa ends up being powered by a single coal plant that’s only active half the year? Will half of the habitable surface of the Earth end up being taken out by an asteroid or a megavolcano? There’s too many possible futures such that making any sort of prediction is basically going to be nonsense at some sort of quadratic rate, the further into the future you go. So scientists take a few reasonable possibilities and project out what happens, given those scenarios. There might end up being some happenstance situations where a 50 year projection’s base assumptions end up holding true, but that’s basically luck, not keen predictive insight on the part of the person who ran that projection.
So basically, I would suggest dropping the word “prediction” from your head and replacing it with “projection”. I think that holds a closer connotation to what is actually intended by most studies.
If there’s a 95% confidence level that climate change is happening, then you should ask yourself whether that means that the level of change is going to be within 5% of what they have projected, or if it means that of 100 parallel universes, in 95 of them, climate change will occur but in 5 of them, nothing will happen?
As to the specific effects, very hard predict. This is because a bunch of positive feedback loops are about to be set off. For instance, once the Canadian really starts to melt, lots and lots of methane will be released. And at that point the whole thing become unstoppable, and no one knows how bad it will get.
Certain regions are sure to be affected more than others. Costal zones, Australia, the America SW ect. Other areas won’t be hurt too bad, and some will likely become nicer.
As to how much carbon we can safely use…We are near the tipping point, and it is a few decades too late for any of that. I think the best action at this point is add additives to all the jet fuel that and create lots of contrails that will reflect sunlight away from the planet. Just a bandaid, it not help what the CO2 is doing to the oceans, or that we will not have the jet fuel to keep that up forever, but it is a start.
The most likely one is the ocean rise:
This is likely or very likely (in IPCC language this is between 66 to 90 percent probability)
(Click on the “Show More” comment area to see the cited scientific papers)
Ice is melting, ocean will rise more because of that, the most up to date published science reports that close to a meter of ocean rise is to be expected by the end of the century.
Basic physics tell us that including the thermal expansion of water means that will expand also 1 or 2 meters by the end of the century, but mind you, most of the papers cited in the video do not mention the latest finds from the loss of ice in the Antarctic.
The video points at the studies and models of the MET office regarding the regions that will get wetter and the ones that will get dryer:
IIUC to prevent even more dire scenarios, the target has been to keep the rise in temperature under 2°C, so we need to keep the emissions between 30 to 50 GtCO2eq by 2030 or reduce them even more if by them we are not doing much.
I think you have confused accuracy and precision. In general, if I have a model of a system, I can get the confidence range of the output, if I know the confidence range of the inputs and then run a monte carlo analysis.
That is a gross generalization. Scientists can and do predict the weather a day or two in advance with associated probabilities. Scientists can and do predict crop production for a given year quite successfully. Some areas are well understood and predicted - others are not. My specific question was if this area was well understood to have meaningful predictions.
I am very well aware of the current and future energy portfolio and specialize in analyzing and predicting world energy trading and trends. Your speculations reveal a very bad understanding of thermodynamics at the best.
I would suggest you read the basic books on scientific methods. Any output or projection unless measurable is not good science. It is one thing to say that models are not mature enough to predict - it is another thing to say that models CAN NEVER be mature enough to predict - which one are you claiming ?
Those words sound scientific but they are not. What specific variable is “climate change” here ? Is it the average global temperature ? or the average global precipitation or a vector of 10 different measurable climatic variables ?
I agree it is hard. I would like to know - how hard though.
Let me compare to a model of a Hurricane - you see a few days before a hurricane - scientists will predict the future path of the hurricane with probability bands and also give different models prediction. Is this as hard as this ?
I know that long term weather prediction is nonlinear (and am aware of the butterfly effect) - Is the long term climate change now under consideration like the butterfly effect? If so then doing anything to control CO2 does not make sense.
In general, I’d say to ignore my post. Most people posting questions like yours aren’t very technical, so really what they’re seeking is different from the question they asked. If you understand the difference between random and chaotic, then you’re well beyond the audience I was targeting.
My post was written to be understandable to any random guy’s grandma, not to be technically accurate, so while your complaints are all valid, neither my post nor your corrections appear to be relevant to anyone in this thread.
That is pretty much my view now. I am fairly convinced man will burn every last drop of oil no matter what. Just like a crack head will smoke every last rock. He knows he shouldn’t, and feels bad about it, but does it anyway. Anyone who thinks he won’t is a fool. This is the main liberal bias in climate …too much faith in humanity.
And, indeed, in a short amount of time the process is likely to become self sustaining. Enough peat in Canada thaws, and enough polar ice melts, and the switch is thrown.
So the time for plan B is now. Geoengineering and mitigation. Spray synthetic dust into the stratosphere, dump iron into the oceans, work on other sequestering methods,… maybe even nuke the moon to make the big dust cloud. Some of these are likely horrible ideas, but time to start thinking outside the box.
This is not good science since “continue to lengthen” is just weasel terms. If they said we are 60% sure that the growing season will lengthen by 1% over the next 10 years or 99% sure that it will lenghten by .0.2% over the next 10 years - that to me will be** science**.
Same comment as before. Define “more” - 1% per year or 10% per year ?
Same comment as before. Quantify largest increases.
Same comment as before. Quantify more intense, less intense…
Same comment as before. Quantify projected to increase - 10 more year , 2 more year , 1 more per 10 years
Same comment as before. “are uncertain and are being studied intensively.” - that typically means there’s someone with a government grant somewhere
This is a good quote - thank you.
This is a good quote - thank you.
I think thats a bad quote - as temperature rises, oceans are supposed to give up CO2 not absorb more.
This like most of the other points you are making here, they are just trying to dismiss science by making it more complicated that what the papers say in those cases. In those cases the way to falsify it is to come with evidence that the length of the season is not increasing and show in general that the reverse is happening or that the changes are not significant.
The keyword there was “current” that shows that they are aware of your complaint here, and what the oceans are likely to do BTW is one of the reasons why scientists are worried.
[QUOTE=GIGObuster]
Obligatory note : I have evaluated the science on global warming and agree with the conclusion that humans factors are a statistically significant factor in causing it
[/QUOTE]
Please read the OP. I have said that I agree with the evidence for anthropogenic causes to climate change. My OP was about the specific measurable predictions the climate change science can make.
Who is they ? and why are they worried ? Last I visited NOAA or any of the big University research scientists, they did not seem worried about this. In fact, my previous job title was scientist and I looked into it too - I was not worried. Many of the scientists actually are more worried about their grants being renewed or they not making Tenure.
Anyways - the question was not about the worries of scientists but specific measurable predictions that global warming science can make. So far, the research in this particular direction seems to be in infancy.
And the IPCC (that is the scientists that were consulted) made the note in the 2007 report that we were likely to get about a meter of a rise of the oceans, provided that no evidence on the acceleration on the loss of ice appeared.
As pointed out, it seems to me that it is too simple to just be a contrarian in the previous post, it is not hard to find the scientific papers with the measurements that can be dismissed just by pointing out at evidence that their readings are faulty.
And that indeed is a number that can be falsified by looking at the records, the weaseling you talk about is coming from a report that is made for the public that would be too unwieldy if all the data was reported, and for laziness on others not looking for the explanations and data that they point out to.
I believe that a word about how uncertain outcomes can be with weather is needed for perspective. Please bear in mind that “scientific models” are programs run on computers based on parameters. How these parameters are entered will affect the predictive range of the model. Unfortunately, it is impossible to determine every factor for a system like “the earth” which has numerous conditions that are averaged out then set as an algorithm within the program code. Anyone who has made measurements and been just a little off each time has discovered how error adds up. The same is true for weather models that go more than a few hours. From this view I conclude that the findings of those scientists may be very much in error. Far better to consider and model “climate shift” than “global warming” for the culprit to changes in weather.
I offer these observations about the atmosphere and its conditions we call “weather”.
First, air is a gaseous mass that is weakly coupled to the land and water masses it is in contact with. This allows some movement of air mass by land and sea but more movement is created within the air mass based on fluid dynamics. These dynamics are controlled by thermal dynamics and the energy flow through and between masses. Change of energy state to create an equilibrium of energy throughout all masses in contact with one another is what thermal action is all about. This balancing force is expressed on earth as “weather”.
Second, the energy state of the earth is created by the effects of gravity, mass, and pressure to form geothermal energies. Also, there is the radiation from the sun that reacts with the atmosphere changing the energy state of air over time. Part of the balance of this energy influx is re-radiation outward into space. A balance is formed by having the earth rotate on a daily basis. The day side warms the night side cools. If this did not occur so that heat in equals heat out we would be like Venus. This is where the “global warming” alarmists say we have shifted the balance to hold more heat because of “greenhouse gases”.
Third, motion is created in fluids like air and water because of temperature differences. Regardless of how hot a fluid becomes, if all other masses remain the same, then the patterns of convection and radiation will remain the same. This would indicate that a few hundredths or tenths of an “averaged” degree for the global temperature is not significantly affecting weather. Rather, changes in the land surface of earth is a larger influence on currents and radiation patterns. When areas are changed that were less reflective of heat or tended to store less heat into there opposite - a shift in currents will occur. Shifts of currents brings different “weather” to a location on earth.
Finally, I conclude that there are far more people interested in “pseudo-science” and poor scientific methodology than in understanding and using a controlled and well thought analytic style of the observed phenomenon. If you ask someone about there model - please ask them to disprove what I have
A great deal of simplistic outright nonsense there which I’m not inclined to spend a lot of time arguing about. Just two of the most egregious errors, aside from the gratuitous use of the word “alarmist” which I presume is supposed to describe climate scientists, not that I’ve ever known any to warrant such a dismissive label:
Projecting climate change is an entirely different proposition from predicting the weather. Chaotic events are predominant in weather, but not so in climate. The forcings from CO2 and other GHGs are well quantified and notwithstanding babble about how the earth radiates heat, the resulting net increase to the earth’s energy budget can be estimated as a basic matter of physics, and it’s that indisputable change to the total energy balance that really matters. The arguments about the accuracy of climate models relate to spatial and temporal resolution – how and when climate changes will affect specific parts of the globe. The most important general consequences – more severe weather, sea level rise, negative impacts on global agriculture, and many others – are not in dispute among reputable scientists.
Is anyone on this board supposed to believe this kind of sophomoric nonsense? Has a system like the earth ever, in its history, warmed or cooled uniformly? The Arctic alone is warming about four times faster than the global average. Vast changes in circulation systems are already being observed, along with consequent changes in local climates and weather.
I think this overstates the case in a subtle, but important way. But perhaps you have opportunity to speak with more scientists than I do.
Most “reputable” scientists agree that the climate models are based on the best science we have. There is general agreement that the consequences you mention are likely to trend in the directions you mention.
But what will actually happen is still a matter of conjecture, and we don’t have a good history of projecting those kinds of consequences very far out. We can try, for example, to validate CO2 forcings by seeing if the modeling parameters can be tuned such that they “predict” the overall patterns to date retroactively, thus validating the parameterization. We don’t know what we don’t know for future feedback loops and consequences, and it’s common in science to re evaluate predictive modeling as new data becomes available.
For example, the idea that we can create a good model for the net effect on agriculture is something that “all reputable scientists” might agree on, but not necessarily bet their personal pocketbooks on (at least, the ones I get a chance to chat up). Ditto w/ sea level rises (one of my closest friends is a PhD Oceanographer from a highly reputable program who generally accepts the overall scientific approach but is very wary of actually predicting sea levels, even though his thesis was around that topic).
The plea to “science experts” is legitimate. The expansion of the idea that, because “most expert scientists agree” means the current predictions are “not in dispute” at any kind of useful level–i.e., selling your beachfront–overstates the case.
It’s sort of a personality argument, I guess. For example, here is Kerry Emanuel, who is an ardent supporter of current models and the need to take decisive action:
*
“…we should also be wary of our own collective ignorance of how the climate system works…We are humbled by a sense of ignorance…” * (Paraphrasing: it may be worse than we think or not as bad as we think)
(From “What We Know About Climate Change,” second edition.)
I cannot think of any arenas where we did a great job predicting 50-100 years into the future, much less further than that. Nor can I think of many times we were able to predict what ended up being the worst of all possible catastrophes accurately.
Yet many expand the general agreement of scientists for current scientific paradigms around ACC into a general agreement on the accuracy of a prediction that relative catastrophe will occur and that ACC will be our greatest challenge.
We’ve discussed Emanuel before, and I specifically talked about this here and here and here.
And since you now know and acknowledge yourself what I’ve been saying about Emanuel – that he is a staunch advocate of decisive action on climate change – I’m not sure what you think there is to be gained by continuing to quote him out of context to try to defeat his position with his own quotes! You’re not understanding the context of that quote, which isn’t that we don’t know enough to be actionable, but the ignorant recklessness with which we’re continuing to abuse the climate with a relatively poor understanding of the many hazards we’re creating. When almost none of the destabilizing influences we’re creating are beneficial, and when many are potentially catastrophic, our lack of quantitative understanding of some of them is much more a dire warning than it is a reprieve. This is what Emanuel is telling us, and why he makes frequent references to the parable of Phaeton, despite your propensity to misinterpret what he is saying.
This seems to be typical of a common argumentative approach on this topic: challenge the quantitative precision of any climate prediction, and conclude from that whopper of a red herring that we may as well just sit back and do nothing until we have a whole lot more data, preferably the kind of data that we can never actually have! I’ve never claimed that sea level rise is easy to predict; in fact it’s one of the hardest phenomena to get right because so many significant contributing factors are involved. But we do know how fast the sea has been rising on average, and we have reasonable predictions of where it will be by the end of the century under various emissions scenarios, which are themselves one of the big variables.
If we basically continue to do nothing and follow the RCP 8.5 trajectory, we can expect between half a meter to almost a full meter average rise by 2100 relative to a 1980s baseline, somewhat lesser amounts under the other RCPs. In the meantime every year creates another inexorable small rise that adds to the damage of storm surges, all of which the IPCC, the insurance industry, the National Climate Assessment, and many other agencies have studied and quantified. So your friend doesn’t think we can accurately predict sea level rise? Within many reasonable definitions of “accurately”, he’s right, for many reasons. So what? We can confidently predict it within sufficient bounds to know that it’s a looming hazard.
If it seems paradoxical that climate scientists on the one hand tell us how much we still don’t know and aggressively pursue new research, while on other hand the vast majority are strongly supportive of decisive action on carbon mitigation, well, as I’ve tried to explain, it isn’t paradoxical at all. Many like Kerry Emanuel, the late Stephen Schneider, James Hansen, Gavin Schmidt, Michael Mann, and many others have indeed become prominent public spokespersons for what they regard as one of the most significant problems that humankind has ever faced.
