Friday, August 15, 2014

On Global Warming ... Interview with a Meteorologist, Part 4

Here's the final instalment of my interview.
 
So where do we go from here? What action items do we take?

I'm not into politics. I do think it's clear we don't want to be dumping this much CO2 into the atmosphere for the next 500 years. However I do think we have more than enough time to research this more closely, pay close attention to the observations, and improve the climate models to where they can make better predictions on independent data. In the mean time we are inching our way where we need to go with more efficient cars, stricter EPA regulations, and trending toward cleaner fuels. The next 10-20 years will be important and should make the issues more clear. If global temperatures start up-ticking again toward the climate model projections then that would be a big red flag saying we need to take more serious immediate action. However before it gets to that point I am hopeful that we'll come up with technological solutions to the problem.

Any other recommendations?

Well just one. When a new study appears on the news regarding a recent climate change study, it's best to treat it like you would a new study from one of the medical journals. You know the kind "people who eat oatmeal for breakfast lower their heart attack rate by 65%, etc." Treat new climate change results the same way. That is, don't discard them in the trash, because they might actually be right, but don't take them so seriously that you rush to the store to clear oatmeal off the shelves. It's not that I want to intentionally downplay everything, but rather it's just my experience dealing with these studies (that are solely derived from output of numerical models) which often fly in the face of what's really predictable and what's not given the current state of the art.

What good has come out of the debate over climate change?

The first thing is awareness of a potential problem. Even though some climate change skeptics (or "deniers") are overly critical of climate change activists (or "alarmists"), if it wasn't for the loud voices on the side of the activists then we run the risk of business as usual for too long before taking remedial actions, and that could be a problem.

The second one is advancement of science. Even though some climate change activists are overly critical of climate change skeptics, the net result is better science because it forces the scientists to go back, re-look at the data and make sure there are no holes in their work. 

What things do you dislike about the climate change debate?

I guess the thing I hate the most is when there's a bad storm and the news media (or even some scientists who should know better) attribute the storm to global warming. There is no evidence despite all the warming the last 100 years that there have been more stronger storms. Even the IPCC admits as such in their reports. Here is the latest study on the subject which looks at global frequency of hurricanes and the total accumulated storm energy:
http://policlimate.com/tropical/frequency_12months.png
http://policlimate.com/tropical/global_running_ace.png

In actuality, whether or not we get stronger storms really will depend on where the warming occurs (if in fact the earth's atmosphere does get warmer). If most of the heat increase is at ground level or in the oceans then that could lead to more intense hurricanes as long as other factors don't change. If most of the heat increase is higher up in the atmosphere than that would stabilize the atmosphere leading to fewer strong storms. Right now I don't think the models are reliable enough to trust what they say in that regard.

I also detest the overt scare tactics, like when someone who should know better says that we only have 4 years (this was back in 2009) before we reach the point of no return and that New York City will be partly under water by 2020. That really gives me heartburn. I also detest the use of labels (e.g., "denier", "warmist").

Is there any aspect of a warming planet that does concern you?

To be honest, I'm more concerned about global terrorism than global warming. That said, I won't be buying any property in Miami Beach because of rising sea levels, LOL. But even in that case the worst that will happen is people would have to re-locate, and it would happen so slowly over time that it's not like people will die all of a sudden. The other effects ... stronger storms, increased droughts, more wild fires, more floods, food shortages, mass extinctions by 2050, 20-foot sea level rises I don't take seriously at this time due to lack of evidence or lack of track record at making such predictions.

Any parting words?

Yeah, don't use the phrases like "greenhouse effect" or "greenhouse gases", they're wrong! Greenhouses stay warm in the daytime for a totally different physical reason (lack of convective mixing) than how the earth would stay warm through increased CO2 (absorption & re-emission of long wave radiation). I'm surprised so many scientists still use these terms.

This concludes the "interview". Thanks for reading!


Wednesday, August 13, 2014

On Global Warming ... Interview with a Meteorologist, Part 3

Continuing with my interview of myself ...

Sounds like you have an agenda to drive a stake in the hearts of climate activists.

Not at all, I'm just conveying the reality and what the data shows. I have no personal agenda or any skin in the game. Of course I also don't want to imply that we should throw the baby out with the bathwater either. The science of weather & climate modelling has advanced tremendously in the last 30 years since I was in school and we need to keep up the research effort. Moreover, just because there are obvious problems also doesn't mean that humans aren't causing any global warming. In all likelihood, we probably have at least to some extent.

However, the reality is the climate forecast models are just not that good yet, and we really don't know, or at least can't precisely specify, all the feedback mechanisms and interactions involved in the atmosphere/ocean system. There are literally dozens of different climate models in use today, each has their own set of physics, and they are all continually being modified and improved. If there was scientific consensus on the physics of the atmosphere and oceans then there would only be one climate model and it would be fixed forever.

Climate prediction is still very young and it's nowhere near an exact science. So all I'm trying to convey is that there is still significant uncertainty exactly how much humans have contributed toward global warming the past 100 years and how much they will contribute the next 100 years, regardless of what the news media and sketchy surveys suggest.

On top of that it has to be realized that our climate can change either advantageously or destructively all by itself even if humans cease burning fossil fuels tomorrow. There are so many things that can influence our climate that have nothing to do with CO2:  changes in solar activity, earth's tilt, earth's orbit, volcanoes, ocean currents, plate tectonics, albedo, land use, etc. Thus any effort of humans to temper our climate could ultimately be a waste of time and capital.

Lastly, has anyone even defined what is the optimal climate? Why should today's climate happen to be the best and any change from that is bad? I would think that any debate over climate change should begin with a healthy discussion on what our optimal climate should look like.

I don't know, it still sounds like you're a climate change denier in sheep's clothing who's in bed with all the big oil companies.

No I'm definitely not a denier and I'm not receiving any tithes from big oil, but perhaps I can make this all a bit more clear with what I call the "97% Challenge".

The 97% challenge? Are you making fun of the climate change surveys?

Not making fun of the surveys, but after I'm done with the challenge hopefully it'll be easier to see that the science is not settled with a 97% confidence level implied by those surveys.

OK, so what's the challenge?

Quite simple, if climate scientists and activists are so confident regarding global warming then they should have no problem making the following wager. Specifically the climate scientists and proponents would wager 97% of their total net worth (house, car, bank accounts, IRA, social security payments, furniture, everything) and if the earth is warmer in say 10-20 years compared to the last decade then they would win the wager and essentially double their net worth. BUT ... if the earth doesn't get appreciably warmer in that time period then they lose 97% of all their possessions!

Mathematically if the survey results are correct about the 97% confidence, then the bet should be a no-brainer because of the positive financial expectation to make money. Yet, I don't think any person in their right mind would take such a wager and risk their life's savings which is an implicit admission that deep down inside we know there is a significant amount of uncertainty in the field of climate science & prediction, regardless of what the surveys suggest.

To be continued ...

Monday, August 11, 2014

On Global Warming ... Interview with a Meteorologist, Part 2

Here is part 2 of my interview with myself on global warming.

So, then how do climatologists conclude that the increased warming is due to increased levels of carbon dioxide?

Simply stated, climatologists run computer models that simulate the physics of our atmosphere and oceans, initializing the models at some time in the past where the data history is known. Computer simulations are run both with and without increasing the CO2 concentrations from the starting point. Results show that when increasing carbon dioxide amounts over time the temperature output in the models is warmer and also in line with observed readings in the past century. Results also show that the warming did not occur as the result of any known natural source.

So tell me more about these climate models.

Climate models are very similar to the numerical weather prediction (NWP) models that are run every day to make short term (0-7 day) forecasts. They each start with an initial state where conditions are known and use a complicated series of physical equations to determine how the initial conditions will change over time. The main differences are that climate models use a more course resolution (that's so forecasts can be made decades in advance instead of just a few days), and climate models contain additional physical processes that are germain for long-term prediction, especially those for handling ocean circulations, land/sea ice, vegetation, aerosol chemistry, and so forth.

Since the computer models say the warming is due to human activity then the science is settled, right?

It increases the probability, but the model simulations don't prove anything conclusively. Unfortunately the devil is in the details, and there are many problems that need to be addressed. First and foremost, when dealing with direct output from short-term NWP models, every experienced forecast meteorologist knows that those forecasts contain significant biases and errors even on forecasts just a couple of days out. This is especially true of surface weather parameters like temperature and precipitation. NWP models also suffer from "model drift" (or climate drift), which means they get artificially hotter or colder or more wet or more dry over time. As a result of these deficiencies, scientists at the NOAA's meteorological development lab apply statistical corrections to short-term (0-7 day) NWP model forecasts (called MOS for Model Output Statistics). These statistical models correlate the NWP model predictions to actual observed surface weather. The improvements of the statistical post-processing are substantial, and in terms of temperature forecasts the error rates are cut in half. For example, see the 2nd chart in the link below comparing temperature forecast errors directly from NWP models (DMO) vs. statistically post-processed forecasts (MOS):
http://www.atmos.umd.edu/~ekalnay/syllabi/AOSC630/Antolick2013.pdf

Unfortunately, no such statistical post-processing is applied to climate models, and that is a huge problem. If short-range NWP models have significant biases and errors on just a 1-2 day forecast, then I can't imagine that long-term climate models running out 50-100 years in advance wouldn't have even deeper issues. Not only does this mean we're dealing with potentially sub-standard and biased predictions from climate models, but without the statistical post-processing there is no way to estimate the certainty level in the climate predictions. As a result, there is a good chance that some climate scientists may be attaching way too much confidence in the simulation results and predictions that are generated by climate models.

But at the top didn't you say that climate models successfully simulated observed temperatures the last 100 years? Doesn't that mean they are good enough to conclude that humans were responsible for making the planet warmer?

Not so fast. First of all, even though the climate models successfully simulated the global mean observed temperatures over the last 100 years, when the historical temperature & precipitation records at individual stations are compared with the climate model backtest simulations for those stations, the errors are grossly large. Since the global average historical temperatures were successfully simulated that means all the large errors at the individual stations cancel out. That there are such large errors at individual stations obviously means something significant missing in the model physics. Certainly if I was a forecaster and predicted a high temperature of 80* in New York and 60* in Denver but the observed ended up 70* in both places I'm not so sure I'd be bragging about my success even though the average of the two forecasts matched the average observation.

Secondly, there is a huge difference between simulations on historical data (called hindcasts) and forecasts on new independent data. In climate prediction models (and in short-term NWP models as well) there are literally thousands of tunable parameters that can be tweaked to calibrate that parametrization to match the past observed data. These tunable parameters exist because we may not know the exact physics involved or we may need to approximate the physics due to resolution scale of the model (i.e., certain radiative transfer processes). However, with so many tunable parameters it's pretty easy to find at least one configuration that will simulate history quite accurately. In statistics, this is a condition called "over-fitting". The real test for the quality of a model is how well it performs on new independent data that was never previously considered when calibrating on the historical (training) data set.

So how accurate are real-time climate predictions on new data?

Well, so far not that good. Climate models continue to significantly over-forecast the amount of warming compared to observed future temperatures, and that is a big problem which has been going on the last 15-20 years. See link:
https://ktwop.files.wordpress.com/2013/10/73-climate-models_reality.gif

Moreover, the places that were to receive the most amount of warming according to the climate models (mid levels of the atmosphere in the tropics) haven't received any warming. So the climate models are getting that wrong too.

Researchers have been scrambling trying to find a cause for the errors and, while a number of explanations have been proposed, nothing has been shown conclusive. Even the IPCC (Intergovernmental Panel on Climate Change) has conceded in their latest report that they will likely have to adjust the models to make them less sensitive to CO2. The implications of this are enormous. If real-time climate forecasts over-predict the warming on independent data, then that *could* mean that humans have contributed less to the amount of warming observed over the past 100 years than what was previously thought by climate scientists, and that would also imply natural variations have played a more important role in our recent past climate than figured by climate models. It also reduces the certainty of future climate predictions which has all sorts of implications regarding political policy and what future actions are required.

To be continued ...

Thursday, August 7, 2014

On Global Warming ... Interview with a Meteorologist, Part 1

Well, since the previous post got me started on the climate change kick I thought for this post I'd continue on the same theme and interview myself in Q&A style and provide some additional insight on the topic of global warming. Rather than make one really long entry, the "interview" will be broken up into several posts.

Bob, are you one of the 97%'ers?

Ha, nice question to start. No, I am not one of the 97% ... but I'm not one of the 3% either. Rather I was never asked to respond to a survey on climate change, along with thousands of other meteorologists. None of my colleagues that I know were surveyed either, a couple of whom are esteemed atmospheric scientists with an incredibly long list of publications and are nationally recognized & respected in the field (i.e., when they talk people listen). I'm not exactly sure who was polled as there are several of these surveys floating around, but you could probably classify all of them in the same category as "4 out of 5 dentists surveyed recommend sugarless gum". For one, I don't doubt that 97% or more of atmospheric scientists would agree with a simple survey question like "human activity probably caused some of the warming the last half-century". However the problem with that result is it doesn't mean those same scientists are going to share the same level of agreement on the myriad of more important hot button issues within the global warming debate (like whether the observed warming is ONLY the result of human activity, or whether additional warming will cause stronger, more destructive storms, or more wild fires, or more droughts, or cause mass extinctions, or flood cities, etc.). In other words, the survey question does NOT address the primary issues of contention that divide climate change skeptics from the supporters. Unfortunately certain media outlets, politicians (and even some scientists) will run with that 97% survey result, take it out of context, and apply it to those other contested issues regarding climate change. In some instances it's an intentional deception on their part and done solely for the pursuit of a political agenda, scoring some ratings points, or garnering more popularity which is unfortunate. Other times the mistake is completely unintentional, but either way the net result is that the public gets misled. Therein lies the main problem and is why the 97% survey result is utterly meaningless. Second, it doesn't matter whether 97% or 100% agree. What matters is if the science is right. I've already seen instances in this field which once had 100% backing but were later shown to be bunk by better science.

Can you give me an example?
 
Sure, my pet peeve ... positive vorticity advection (PVA). PVA is hailed in all the text books and shoved down the throat of every student taking atmospheric dynamics and synoptics classes [and that is still the case today by the way]. PVA is also mentioned in every weather map discussion in university meteorology seminars and forecast classes (often times so that the speaker would give the appearance of knowing what they were talking about, LOL). We were also taught that PVA is the #1 factor for predicting severe thunderstorms and is the leading cause of arthritis flare-ups in senior citizens (OK, just kidding about the arthritis, but you get the idea). Yet when creating models that actually forecast the weather for a given location, PVA never shows up as a meaningful contributor ... because it doesn't work! That said, I don't want to create a straw man here. To be clear, just because there have been past truths in the atmospheric sciences that were later debunked by better science doesn't mean the science behind global warming is at risk to be debunked. But I do want to point out the atmospheric sciences are young, we're learning new things all the time, and there's much we don't know. For sure, the physics are not as exact as the physics which tell us there will be an eclipse on May 20, 2055 at 9:01am. So the bottom line really it's the quality of the science, not the surveys which are important.

So who cares what you think about climate change? Are you a climate specialist? What could you possibly offer to the discussion.

I'm not a climate specialist. Climatology is one of many sub-disciplines under the atmospheric science umbrella. My area of expertise is in short-term (0-7 day) weather forecast modelling and probabilistic prediction. I'm intimately familiar with numerical weather prediction (NWP) models, like the kind climatologists use to predict future climate. So I'm fully aware of how they work, their strengths, weaknesses, capabilities and their limitations. I've also performed extensive work in the area of forecast verification which is full of land mines, and that makes it easier to sniff out weaknesses in a given study or experimental design that generates predictions.

OK, let's deal with specific questions regarding climate change. Is it even possible that humans can change the earth's climate? After all, isn't the earth just too big to be affected by mere humans?

There is absolutely no sliver of doubt that humans *can* alter the climate on our planet. Anyone can verify this for themselves. Just watch the evening news and notice how the night-time temperatures are always colder in the outlying suburbs compared to a populated city. In many cases there can be 10-15 degrees difference especially in winter. Of course this is on a small spacial scale and none of that is related to increases in carbon dioxide, but nonetheless it shows in a simple way that humans can affect the weather.

Has the earth gotten warmer in the last century?

Yes, global temperatures have risen about 1* C the last 100 years.

Has the amount of carbon dioxide increased in the period as well?

Yes, total C02 concentrations have increased over 30% in the last 100 years.


So what's the controversy? Doesn't this prove global warming is real and caused by humans?

Well, it may seem intuitive to think that at first, but I recommend some caution. First, correlation does not equal causation. Ice cream sales have also increased the last 100 years, but nobody is going to blame warmer temperatures on ice cream. Second, while there is indeed a strong physical link relating carbon dioxide and global warming (CO2 is transparent to incoming solar radiation but absorbs outgoing long-wave radiation), the ultimate relationship is not so simple. There are countless feedback mechanisms and interactions with clouds, plants, and oceans which complicate matters greatly. Here's a simple analogy of how a feedback mechanism works. Eating a sugary food causes your blood-sugar level to rise temporarily but a healthy pancreas then responds to secrete enough insulin to maintain stable blood-sugar levels. So in the end despite consuming sugar the blood-sugar level remains the same. There are a "gazillion" of these type of interactions & feedbacks that go on in the atmosphere. So the contribution of increased CO2 toward global warming can't be accurately measured unless all the interactive effects are taken into account. Third, there are instances in our past history when temperatures have risen greater than this without any human intervention, and that makes it a very difficult problem to separate natural (or random) fluctuations versus what humans have contributed.

To be continued ...


Sunday, August 3, 2014

Creationists vs. Climate Change Deniers

A recent article published at EarthMagazine.Org makes a claim that there is a link between creationists and climate change deniers. The gist of the article is that (i) both creationists and climate deniers reject mainstream science, and that (ii) both creationists and climate change deniers distort facts in a way that misrepresents science. The link to the full article is provided here:
http://www.earthmagazine.org/article/voices-defending-science-link-between-creationism-and-climate-change

While the article attempts to point out similarities between the two camps, I'd like to point out several differences, especially in terms of the science. [BTW, I'm not a fan of the phrase 'climate change deniers', but since the article uses the term I'll follow along with that phraseology].

First, there is a big difference between how the two groups feel their respective subjects should be taught in school. For example, consider the case of two of the bigger climate change deniers (meteorologists Joe Bastardi and Roy Spencer). I don't think either one would be against the teaching of climate physics in the classroom or would be against increasing our understanding of climate through the scientific method. In contrast, two of the most strident creationists (Ken Ham and Kent Hovind) are clearly against teaching evolution in school and would love to take it out of the text books if given the opportunity and instead have them filled with heaps of creationist propaganda!

Second, while the definition of a creationist is pretty clear cut, the article doesn't really define "climate change denier". Climate change can cover a whole array of hot button topics, much of which is clearly not "settled science". For example, how many times has it been said or written that global warming will result in stronger storms? In fact, every time there's severe weather it seems to get blamed on global warming. So if someone rejects the thesis that global warming will result in stronger storms should that person be labelled a "climate change denier" [even though there is zero observational evidence that warming has resulted in more frequent or stronger storms]? How about people who challenge whether 1700 US cities will be under water by the year 2100? What about those who don't believe that 1 million species on earth will be extinct by 2050? What about those who disagree with irresponsible statements such as "we have only four years left to act on climate change"? What about those who questioned Al Gore's prediction of 20-foot sea level rises by 2100? What about those who laughed at James Hansen's 1989 prediction that NYC would be partly under water by 2020? Should those who challenge such outrageous claims be labelled a "climate change denier"? I don't think so.

So unlike the science that refutes Biblical creation (which shows that the universe is very old, that the earth didn't form before the stars, that all animals were not 'created' at the same time, and that there was no global flood 4000 years ago), there are several aspects of global warming that are by no means conclusive (especially when addressing the potential consequences of global warming). So to lump those who question the more controversial areas of global warming in the same boat as creationists who 'deny science' is inappropriate to say the least and done merely to grab headlines, raise new research money or to pass an agenda.

Third, if I was to ask "what is the chance that the earth is really greater than 10,000 years old", nearly all credible geologists & astronomers would say 100% probability that it is older than 10,000 years. If I was to ask what is the probability that the first stars formed long before earth, nearly all credible cosmologists would say 100% probability that the earth formed long after the first stars. If I was to ask "what is the likelihood that all animal species were NOT created at the same time", nearly all credible scientists in the field would say 100% likelihood. However, if I was to ask "what is the probability that the earth will be warmer in the year 2050 compared to the last decade", I suspect you would find that most atmospheric scientists would shy significantly away from a 100% probability (and vote somewhere between 60-80% probability), especially if they had to wager a large percentage of their personal assets. Therein lies the difference between climate science and that used to prove an old universe or disprove biblical creation. In 50 years I'm sure the universe will still measure a lot more than 10,000 years old. However in weather there is a huge amount of uncertainty regarding the future 50+ years out. Long-range climate prediction is unlike other scientific disciplines and is nowhere near an exact science, unlike the physics which can predict the exact time of a solar eclipse 50 years in advance. Our climate can change with or without human activity in either direction whether we like it or not for natural reasons, just like it has done many times in the past. There may also be technological innovations down the road that curb any problem of CO2 emissions. Furthermore, climate physics are not completely known. There are feedback mechanisms and interactions that clearly are not handled properly in climate models as evidenced by the fact that these models have largely overpredicted the amount of actual warming in real-time forecasts on independent data. So unlike the science that is used to determine the age of the earth/universe or to show that different life forms evolved over millions of years, there are significant uncertainties in the field of climate prediction. Numerical weather prediction (NWP) models also suffer problems of "climate drift" and local biases, which have been known by operational meteorologists for 40+ years. That is why NOAA applies statistical post-processing to short-term predictions (1-7 days) to get these physical models back to reality. Ironically, no such post-processing occurs with climate change models. To label someone as a "denier of science" for pointing out such deficiencies in the models or by casting similar doubt as to our climate future is not appropriate because those uncertainties are genuine. Moreover, the science of climate prediction is still quite young, especially when compared to evolutionary theory or radiometric dating that is used to disprove creationism. There is still a lot to learn about our atmosphere and oceans, and the climate prediction models are far less complex than the real atmosphere. So the next time there is a new report in the news like "new study by climate scientists suggest that global warming will result in crippling snowstorms for the northeast US and prolonged droughts in the plains", well that can be treated similar to new medical studies that make headlines (i.e., eating oatmeal each morning will reduce the risk of heart attacks by 75%). In other words don't toss it out like garbage cause it may be right, but don't treat it as "settled science" either and label those who are skeptical of such claims as deniers of science either.

Fourth, interestingly enough most climate change "deniers" actually agree that the earth has gotten warmer the last 100 years and that humans are probably at least partly to blame. These are the two issues that formulate the "97% consensus" of climate scientists". However, these are not the issues that divide skeptics and "deniers". Rather the contentious issues are in regard to the effects of a warmer planet and whether they will be catastrophic (more storms, droughts, mass extinctions, etc..), and these are far from settled science. Unfortunately some politicians take that "97% consensus", misapply it to topics where there is no consensus, and then label those who disagree on those topics as "deniers". I can guarantee that 97% of climate scientists don't agree that Al Gore's 20 foot rise in sea level by 2100 will happen.

Finally, on the charge that climate change deniers distort science like creationists, well I've also seen it go the other way as well where climate change activists (and some scientists) distort the science in their favor for their agenda. A really good example is the bogus Whitehouse National Climate Assessment report from 2014, which is fraught with errors. Other good examples are most anything said by James Hansen and Al Gore. So this is not a compelling argument used by the authors of the magazine article.

So in summary, while I think the article attempted to make a comparison between climate change deniers and creationists, I think it misses the boat because the author equivocates the science used to refute creationism and the science used to support climate change. Unfortunately, not all science is created equal, and therein lies the problem with attempting to compare the two groups. I have personally witnessed in the meteorological field long-standing "certainties" in textbooks that got shoved down our throats as students which were later shown to be nonsense. So in terms of any discussion on climate change, we just need to do the research, argue over it, validate it, have it pass the smell test, take appropriate action and not waste time trying to label people or make connections between them.