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## Wednesday, February 5, 2014

### Anthony Watts thinks an asteroid catastrophe is more likely than rising seas!

Sou | 9:18 PM

Anthony Watts is a big brave man.  He's not scared of climate change.  He's especially not scared of storm surges or rising seas.  Today he wrote (archived here):
Oh my! Climate change threatens to cause ‘trillions’ in damage to world’s coastal regions
New research predicts that coastal regions may face massive increases in damages from storm surge flooding over the course of the 21st century.
Yes, and a asteroid could hit us, and some errant jihadist might get a nuke and set it off. I worry about those things more than I worry about coastlines and the affluent who build there, especially since Global Tropical Cyclone activity is at 33-year lows.

As usual, Anthony didn't link to either the press release or the paper itself.  HotWhopper readers are in luck, because I have.

First of all, the paper about which Anthony was putting on a brave face was written by Jochen Hinkel and others and was published in PNAS (open access). (Climate blog readers may be interested to know that one of the authors is Richard Tol, who has a bit of a reputation for acting up, acting out and generally acting oddly, to put it mildly).

The authors were attempting to estimate costs associated with selected strategies relating to the expected increase in coastal flooding over coming decades.  It looks as if there are no easy answers.  The estimates of flood damage and cost have a fairly wide range.  In the opening paragraph the authors wrote:
Without adaptation, 0.2–4.6% of global population is expected to be flooded annually in 2100 under 25–123 cm of global mean sea-level rise, with expected annual losses of 0.3–9.3% of global gross domestic product.

There are lots of unknowns which is one reason for the range to be rather broad.  It wouldn't just be the unknowns of how quickly we'll shift to clean energy and start to cut back CO2 emissions, or how quickly the ice sheets will melt.  There would be unknowns of just what would global gross domestic product be under a scenario of lots or little climate change.  I mean if we keep increasing emissions over the next couple of decades, by the end of the century GDP could be much closer to zero so 9.3% of global gross domestic product could be 9.3% of practically nothing.

The researchers were a lot more thorough than I and have spelt out their assumptions and scenarios.  They've obviously put some time into the "what if" part of the analysis.  They only consider sea level rise up to 123 cm by the end of this century, and of course seas won't stop rising on the 31 December 2099.

I'm sure this won't be the last bit of research attempting to work out the costs of adapting to sea level rise vs the costs of not adapting.  Here are more conclusions from the paper:
Damages of this magnitude are very unlikely to be tolerated by society and adaptation will be widespread. The global costs of protecting the coast with dikes are significant with annual investment and maintenance costs of US$12–71 billion in 2100, but much smaller than the global cost of avoided damages even without accounting for indirect costs of damage to regional production supply. Flood damages by the end of this century are much more sensitive to the applied protection strategy than to variations in climate and socioeconomic scenarios as well as in physical data sources (topography and climate model). Our results emphasize the central role of long-term coastal adaptation strategies. These should also take into account that protecting large parts of the developed coast increases the risk of catastrophic consequences in the case of defense failure. ### Can we hold back the rising seas? It reads as if the authors are urging nations to try to stem the rising seas by building dykes and barriers etc. On the other hand, see the last sentence, particularly with the sort of talk that's been going on in England with the flooding there. (Many people are saying that in some parts of England the best strategy is to let the sea come in rather than try to stop it). Anyway, the scientists are urging nations to take action of one kind or another. From the press release: "Countries need to take action and invest in coastal protection measures, such as building or raising dikes, amongst other options," urges Hinkel. With such protection measures, the projected damages could be reduced to below$80 billion per year during the 21st century. The researchers found that an investment level of $10 to$70 billion per year could achieve such a reduction. Prompt action is needed most in Asia and Africa where, today, large parts of the coastal population are already affected by storm surge flooding.

Whatever nations decide, it's going to be costly.  Whether it's costs of relocation or costs of trying to hold back the water. Neither choice will be easy or cheap. Holding back the water will be a temporary solution at best.

The paper touches on a few other points that can't be predicted easily - though they could be "directed" by policy decisions.  These include questions around how people will respond to rising sea levels.  Will they relocate and to where, particularly as there are expected to be another two billion people in the world by mid-century.  Will people keep building in areas that will be inundated this century?  It's reasonable to assume that the trend to urbanisation in countries most at risk will continue.  What about the impact of groundwater depletion?  The paper points out:
Another major source of uncertainty is human-induced subsidence as a result of the withdrawal of ground fluids, in particular within densely populated deltas, which may lead to rates of local relative sea-level rise that are 1 order of magnitude higher than current rates of climate-induced global-mean sea-level rise.

The paper probably raises more questions than providing answers.  They are important questions.  While I'm not necessarily persuaded by arguments to build and maintain dykes etc, it's good to see issues like this being addressed and attempts made to cost different strategies - even at the broad-brush level of this particular study.

### Likelihood of an asteroid strike vs likelihood of rising seas and storm surges

Back to Anthony Watts denial.  He's being very silly and showing his lack of knowledge of the world around him when he writes:
Yes, and a asteroid could hit us, and some errant jihadist might get a nuke and set it off. I worry about those things more than I worry about coastlines.
That's what I call alarmist.  How much and how many times since the likely asteroid impact 65 million years ago, have seas risen and fallen compared to the number of catastrophic impacts by asteroids hitting Earth?

Anthony Watts is more worried about something that currently has only a very remote (miniscule) chance of happening, while not being concerned about something that is a dead cert.  He lives a fair way from the coast and a much longer distance from coastlines in the most vulnerable countries.  And he has no talent whatsoever for assessing risk.

Now if Anthony Watts had said he was more worried about the worst drought in California in 500 years, or a massive earthquake, I would have understood.  The biggest worries are closest to home.

The question about sea level rise is not how much it will rise - it's virtually certain that the West Antarctic and Greenland ice sheets are going to eventually melt with this episode of global warming, raising seas by more than ten meters. The main question is over what period they will melt and how suddenly.   (If all Antarctica and all Greenland melt, seas will be something like 60 meters higher - but that would probably take thousands of years.)

You may also have noticed by now that Anthony didn't bother reading the paper he wrote about, because he talked about "coastlines and the affluent who build there".  The researchers on the other hand made it quite clear that it's the poorer nations and people who are most vulnerable to rising seas, sinking land and storm surges.

One of the more hypocritical and offensive memes of science deniers is that mitigating climate change will hurt poor people.  Anthony can't afford to let on to his readers that if we don't mitigate climate change, poor people will be hurting way more than people who live in more affluent countries like the USA and Australia.

There wasn't even a faint spark of insight or knowledge of the wider world in the comments I read.  Admittedly I didn't make it through all of them.  They are archived here.  Below is a small sample.

Bob Greene doesn't seem to think that we should plan for dead certs and says:
February 4, 2014 at 4:40 pm
Wow, what glittering generalities! I missed a prediction of how much the sea level will rise sometime in the distant future. One of the things they seem to ignore is the fact that humans have adapted to real climate change for 200,000 years. If the worry is the water rising over the next 86 years, I bet even a fat old man like me can walk or wheel his way ahead of it.
What do you think? More than 6,000 people couldn't "walk or wheel" their way ahead of this storm surge. Could Bob Greene do it?

Donna Quixote doesn't know that the seas are going to rise and societies will need to adapt and says:
February 4, 2014 at 4:45 pm
This is the religion of could, might, maybe, if.

Chris4692 has a simple(ton) solution and says:
February 4, 2014 at 4:48 pm
Want to stop weather related damage along the coasts? Stop building by the coasts.

Les Johnson thinks the scientists overestimated global population and GDP for 2100 and for some odd reason thinks the IPCC estimated zero growth in population over the coming century and says:
February 4, 2014 at 4:48 pm
Interesting numbers they have. 60,000,000 people affected? 5% of the population? Thats 12 billion people.
100,000 billion damages? Thats 20% of total GDP by then.
The IPCC, in its projections (which Castles and Henderson showed to fatally flawed), had global population at 7 billion in 2100. GDP is 522 trillion.
Wow. Talk about inflation. These guys need Bernanke to control it.

(That's not to say that global warming won't kill off huge numbers of people this century.  It might indeed do that, directly or indirectly.)

Curious George asks why the Netherlands isn't alarmed and says:
February 4, 2014 at 5:03 pm
Why aren’t Dutch people alarmed?

They probably are very concerned.  Thing is, because they are way up north the seas won't rise there nearly as much - see this video to find out why that is so.

ilma630 indulges in circular thinking and says "sea level won't rise because there is a low bridge somewhere":
February 4, 2014 at 5:24 pm
Flew into SFO yesterday and noticed that the San Mateo bridge is mostly a causeway at just above sea level. If the US gov’t or CA state were that worried about sea level rise, they would be raising it up well above sea level.

There are quite a few comments from people who have not got the first clue about human settlement beyond the beachfronts in Florida or California. For example, Speed says:
February 4, 2014 at 5:37 pm
In 1870, 70-80 percent of the US population was employed in agriculture. As of 2008, less than 2 percent of the population is directly employed in agriculture.
http://en.wikipedia.org/wiki/Agriculture_in_the_United_States#Employment
When people realized that there was no future in agricultural rural America, they moved away. If people see no future living near the ocean then sometime in the next 100 years, they will move away. Problem solved and no taxpayers were harmed.

ossqss is another one who has not the first clue about the world we live in and says:
February 4, 2014 at 6:35 pm
Ummmm, did I miss any reference to susidence and or building in flood plains or landfill construction on the water?
What percentage of the population lives near the water (any water) globally. Is it really 80%.
Perhaps I dont see how one can complain when most water threats are really an elective choice made by those who made that choice in the first place.
Just sayin……….
Ignorance and greed is no excuse.

I don't know about greed, but the people who inhabit WUWT sure have a lot of ignorance.

J. Hinkel, D. Lincke, A. T. Vafeidis, M. Perrette, R. J. Nicholls, R. S. J. Tol, B. Marzeion, X. Fettweis, C. Ionescu, A. Levermann. Coastal flood damage and adaptation costs under 21st century sea-level rise. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1222469111

1. Anthony Watts has been watching too much of the movie channels on cable TV. Killer asteroids were featured in movies like Deep Impact (1998), Armageddon (1998) and Asteroid (1997). It will be fascinating to see how he or a guest poster weaves the movies Sharknado (2013), Stonados (2013) or another Rotten Tomatoes movie shocker into a future science-challenged article.

2. The Netherlands surely is alarmed and they invest a lot in climate change adaptation to make sure that the country stays save.
http://www.deltacommissaris.nl/english/

1. Actually it is the Delta Commission who are quite up to reality. They have a say, they get the funds - but Netherlands as a whole including government proper are lagging.

3. If astronomers actually discovered an asteroid with a 95% of hitting Earth in,say, 2030, requiring prompt action and major tax-expenditure to counter the threat, how would Watts react? My money would be on instinctive denial and a witch-hunt of "alarmist" astronomers who are just in it for the funding.

I'd certainly put a bet on the US Republicans denying it, but I doubt anyone would take it.

1. Not to mention the fact that the asteroid orbit models are all wrong: instead of hitting Wyoming, it comes down in Wisconsin.

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