Bike Tour of Climate Impacts in DC

[DismalScientist]

Scientific “truth” is not determined by consensus, but rather by not being found false through experimentation or other relevant empirical observation.

Once again, I have not stated my personal opinion on global warming as it would be irrelevant; I have neither the time nor inclination to go through all relevant theories on how humans can affect the global climate nor the empirical work on these effects. I do note, however, that empirical work must necessarily be done with one observation over a significant time period. Relevant empirical work would need to distinguish rural and over-water temperatures changes from urban changes (which reflect urban heat island effects, which are by definition not global). Currently, early rural and over-water temperature data appear to be predicted based on contemporary “urban” data. Using these data to determine how global temperatures have changed over time may determine underlying global warming or it may only determine the method by which earlier rural and over-water temperatures were backcasted.

[Steve O]

@DismalScientist 190514 wrote:

Scientific “truth” is not determined by consensus, but rather by not being found false through experimentation or other relevant empirical observation.

Once again, I have not stated my personal opinion on global warming as it would be irrelevant; I have neither the time nor inclination to go through all relevant theories on how humans can affect the global climate nor the empirical work on these effects. I do note, however, that empirical work must necessarily be done with one observation over a significant time period. Relevant empirical work would need to distinguish rural and over-water temperatures changes from urban changes (which reflect urban heat island effects, which are by definition not global). Currently, early rural and over-water temperature data appear to be predicted based on contemporary “urban” data. Using these data to determine how global temperatures have changed over time may determine underlying global warming or it may only determine the method by which earlier rural and over-water temperatures were backcasted.

As to your last point, should we alert the climate scientists, “Hey, you guys!! Didn’t you know cities are hotter than the countryside? There’s this guy on a bike forum in DC who just pointed that out. Wow! Who knew?!” C’mon.
(https://www.forbes.com/sites/marshallshepherd/2019/05/06/urban-heat-islands-dont-explain-climate-change-heres-the-bigger-problem/#176b6f7c4c26). Let me assure you that whatever “bias” or “error” or “question” you raise has been thought of by the real scientists long ago and already accounted for. Before spouting off some other canard, doublecheck it at skepticalscience.com. It’s sort of like checking Snopes before reposting some email you got, only about climate change instead.

Decision makers virtually always need to make decisions in the face of uncertainty. Policies are made, or should be at least, based on the best decisions one can make using the best information at hand. Right now the best information on hand is that we need to take pretty significant actions to avoid the worst effects of climate change. If you want to get your panties in a knot over an article about whether floods might be 8 feet or only 5 feet, well, go ahead. The gist is that extreme weather along with rising sea levels is going to make things worse than they are now, whether or not the details are spot on or not.

The Intergovernmental Panel on Climate Change, the officially created scientific body that advises the nations of the world on the science of climate (created in 1988) has been informing decision makers worldwide on the best science for 30 years. If you are, in fact, interested in the most well researched and highly regarded synthesis of the science of climate, I highly recommend you read the summaries (no need to read the entire reports). Journalists often get the gist but not the nuance right of these reports, so if all you read are articles, you may get somewhat incorrect notions. You will note that when you read them they present their findings in a probabilistic manner (likely, highly likely, more likely than not, etc., with each of those terms defined as a % confidence). So decide for yourself what that means in relationship to your definition of the word “settled.” You will also note, if you start with the 1992 report and look at them all, that the science continues to get both more robust and scarier with each report.

@DismalScientist 190470 wrote:

It’s nice to know that settled science can be reached so easily

That you used the word “easily” indicates that you really have no clue. The study of the science of climate spans many decades (going back even to John Tyndall and Svante Arrhenius from the 19th century if you like), tens of thousands of studies performed by thousands of scientists investing millions of hours of effort. There is no “easily.” The work that has gone into understanding the climate, its effects and how it will effect us in the future has been enormous.

[lordofthemark]

@DismalScientist 190514 wrote:

Scientific “truth” is not determined by consensus, but rather by not being found false through experimentation or other relevant empirical observation..

No, but laypeople, who do not have the time or ability to analyze all the relevant scientific questions themselves, are left to look at what actual qualified scientists think. Ergo for them, determining the consensus of scientists is quite relevant.

[peterw_diy]

@DismalScientist 190514 wrote:

Scientific “truth” is not determined by consensus, but rather by not being found false through experimentation or other relevant empirical observation.

Once again, I have not stated my personal opinion on global warming as it would be irrelevant; I have neither the time nor inclination to …

Blah, blah, blah. Congratulations, you’re now the second person added to my Ignore List.

[DismalScientist]

You should really read my posts before ranting about how I am denying climate change.

I originally compared the consensus value of sea level rising with the scare statement in the original post. Some politicians these days are saying that the world will be wiped out in 10 to 12 years because of climate change. You people complain that too few people care about climate change as an issue. Perhaps the problem is not with me, a non-denier that you claim “denies science,” but rather with all the alarmist rhetoric that does not actually reflect the published scientific consensus. Perhaps you are your own worst enemy.

[Steve O]

@DismalScientist 190635 wrote:

You should really read my posts before ranting about how I am denying climate change.

I originally compared the consensus value of sea level rising with the scare statement in the original post. Some politicians these days are saying that the world will be wiped out in 10 to 12 years because of climate change. You people complain that too few people care about climate change as an issue. Perhaps the problem is not with me, a non-denier that you claim “denies science,” but rather with all the alarmist rhetoric that does not actually reflect the published scientific consensus. Perhaps you are your own worst enemy.

Not sure who you are directing this towards, but I do not believe I accused you of denial. What I did accuse you of, based on your use of the words “settled” and “easily,” is that you don’t know much. And your faux discussion of urban heat island, that you are reading the wrong things.

That “scare statement” is actually based on some pretty solid science from NOAA, the National Climate Assessment, the IPCC and the Army Corps of Engineers among others. You can read about it here: https://riskfinder.climatecentral.org/place/washington.dc.us?comparisonType=place&forecastType=NOAA2017_int_p50&level=8&unit=ft

[DismalScientist]

@Steve O 190721 wrote:

Not sure who you are directing this towards, but I do not believe I accused you of denial. What I did accuse you of, based on your use of the words “settled” and “easily,” is that you don’t know much. And your faux discussion of urban heat island, that you are reading the wrong things.

That “scare statement” is actually based on some pretty solid science from NOAA, the National Climate Assessment, the IPCC and the Army Corps of Engineers among others. You can read about it here: https://riskfinder.climatecentral.org/place/washington.dc.us?comparisonType=place&forecastType=NOAA2017_int_p50&level=8&unit=ft

Thank you for that website as it proves my original statement. If you fiddle with the assumed level of sea level rise you will find that there is a 65% chance of an 8 ft flood by 2050 under a “medium rise” scenario. Under a “slow rise” scenario, that chance falls to 60%. Under a “fast rise” scenario, it is 70%. In other words, the chances that we see an 8 ft flood by 2050 is barely related to the speed of sea level rise, which was my original statement. What probably matters most is the “average” track of hurricanes and the probability of them coming straight up the Chesapeake.

You tacitly accused me of denial in post #21 when you suggest I might to want to purchase some land on the Eastern Shore since by implication I did not believe that sea levels were rising or land subsiding. (And it is interesting to search the internet for the relative rates of both.)

I only used the word “easily” in a sarcastic manner when characterizing how easily climate change has been called settled in light of climate being a complex system and the inherent difficulty obtaining a long enough time series of data to verify its predictions. I don’t think the word “settled” should ever be used in the context of any scientific statement. No scientific theory can ever be completely verified, but can only be consistent with data. In my view, scientists should always be skeptical. The essence of science is the testing of hypotheses, which is problematic if you have already settled on the hypothesis being true.

My only discussion of the heat island effect was in the construction of earlier inferred temperature data necessary to estimate the magnitude of global warming from a long time series of temperature data. This is simply a matter of proper statistical inference and not a function of me “reading the wrong things,” whatever the hell that means. I actually haven’t read any of these wrong things. It just results from the logical decomposition that any change in urban temperature is due to the aggregate change due to global warming and that due to urban heat island effects.

This brings me to you calling SkepticalScience a fact checking site. The website was explicitly set up to make counterarguments to global warming deniers. That said, the discussions in the comment sections of various pages on the site tend to be thoughtful and useful.

[Steve O]

@DismalScientist 190726 wrote:

I only used the word “easily” in a sarcastic manner when characterizing how easily climate change has been called settled in light of climate being a complex system and the inherent difficulty obtaining a long enough time series of data to verify its predictions. I don’t think the word “settled” should ever be used in the context of any scientific statement. No scientific theory can ever be completely verified, but can only be consistent with data. In my view, scientists should always be skeptical. The essence of science is the testing of hypotheses, which is problematic if you have already settled on the hypothesis being true.

The scientists themselves do not use the word “settled,” so I’m not sure what you mean when you use it.
@DismalScientist 190726 wrote:

My only discussion of the heat island effect was in the construction of earlier inferred temperature data necessary to estimate the magnitude of global warming from a long time series of temperature data. This is simply a matter of proper statistical inference. It just results from the logical decomposition that any change in urban temperature is due to the aggregate change due to global warming and that due to urban heat island effects.

There is nothing new in what you say. Scientists and statisticians are entirely aware of all such effects and have taken them into account in their estimations of past global temperature datasets. You seem to imply that there is insufficient or incomplete data or something like that. Go ahead and read the 5th Assessment report of the IPCC and you will see the rigor with which scientists approach these types of issues. Whatever lack of data may exist is accounted for in their probabilistic statements and conclusions. It is all very scientific.

[lordofthemark]

@DismalScientist 190635 wrote:

You should really read my posts before ranting about how I am denying climate change.

I originally compared the consensus value of sea level rising with the scare statement in the original post. Some politicians these days are saying that the world will be wiped out in 10 to 12 years because of climate change. You people complain that too few people care about climate change as an issue. Perhaps the problem is not with me, a non-denier that you claim “denies science,” but rather with all the alarmist rhetoric that does not actually reflect the published scientific consensus. Perhaps you are your own worst enemy.

In fact IIUC what the IPCC has said is that we have 10 to 12 years to take steps to prevent a 1.5 degrees C rise in temp. And there is great danger from a rise of that magnitude, including considerable uncertainty about feedback loops that might cause warming to accelerate.

Given that we have politicians who do deny human caused global warming, or even (by antics like taking snowballs into congressional hearings) implicitly deny warming period, its hard for me to get worked up about people who confuse the above statement with “the planet will die in 10 years”.

[lordofthemark]

@DismalScientist 190726 wrote:

Thank you for that website as it proves my original statement. If you fiddle with the assumed level of sea level rise you will find that there is a 65% chance of an 8 ft flood by 2050 under a “medium rise” scenario. Under a “slow rise” scenario, that chance falls to 60%. Under a “fast rise” scenario, it is 70%. In other words, the chances that we see an 8 ft flood by 2050 is barely related to the speed of sea level rise, which was my original statement.

Wouldn’t you need to test fast rise against zero rise? Slow rise still assumes some global warming.

[DismalScientist]

@lordofthemark 190731 wrote:

Wouldn’t you need to test fast rise against zero rise? Slow rise still assumes some global warming.

The website is very opaque on the assumptions underlying the different scenarios. I don’t know how to get predictions for a zero rise.

Here’s an interesting graph from the EPA:
https://www.epa.gov/climate-indicators/climate-change-indicators-sea-level

My interpretation is that a zero rise null hypothesis might be inappropriate.

[lordofthemark]

@DismalScientist 190733 wrote:

The website is very opaque on the assumptions underlying the different scenarios. I don’t know how to get predictions for a zero rise.

Here’s an interesting graph from the EPA:
https://www.epa.gov/climate-indicators/climate-change-indicators-sea-level

My interpretation is that a zero rise null hypothesis might be inappropriate.

It seems possible that the modest difference in flood risk between the slow rise scenario and the fast rise scenario reflects that any reasonable low end estimate of global warming leads to a significant rise. Ergo, OP’s initial statement may not be at all misleading.

I sympathize that it is difficult to do the analysis to challenge the implications of the OP’s statement (not the statement itself, which is clearly true) – in that case it seems like the best thing would be to just leave the OP’s statement alone.

[DismalScientist]

@lordofthemark 190734 wrote:

It seems possible that the modest difference in flood risk between the slow rise scenario and the fast rise scenario reflects that any reasonable low end estimate of global warming leads to a significant rise. Ergo, OP’s initial statement may not be at all misleading.

I sympathize that it is difficult to do the analysis to challenge the implications of the OP’s statement (not the statement itself, which is clearly true) – in that case it seems like the best thing would be to just leave the OP’s statement alone.

When I altered the size of the flood rather than its likelihood, my original “analysis” actually did assume zero rise.

[Brett L.]

I’m not sure what you are even arguing………. Original post stated:
“Did you know that DC has a 65% chance of seeing a flood over 8 ft in the next 30 years?”

It then followed up and stated the climate change is spurring sea level rise. That’s not the same thing as saying that sea level rise will be the predominate driver of the 8-ft flood………………. (I seriously can’t use enough ‘……’ )

Looking at the published Flood Insurance Study for Washington D.C. (hosted by FEMA, linked here: https://msc.fema.gov/portal/advanceSearch#searchresultsanchor), the Potomac River and the Anacostia River have a 1:50 year (2% Annual Exceedance Probability) flood stage of roughly 8.8-ft (datums are important). Over 30 years, the chance of a 2% AEP event NOT occurring is 54.5%. So based upon the best available data for these two major flooding sources, it is reasonable to suggest that a flood with a stage in excess of 8-ft NAVD88 has greater than 45% chance of occurring at least once. The 25-year (4% AEP) flood stage is 7.4-ft – 29.4% chance of not occurring.

So…… 45% chance of flood greater than 8.8-ft in the next 30 years, 70% chance of flood greater than 7.4-ft. 65% might be a little generous, but it’s not out of the realm once we look at future impacts.

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