Archive for the ‘Climate Change’ tag
On thursday morning I sat into the “communicating climate change” session, which is not directly related with my work, but is timely, and relevant. It turned out that I saw some of the best talks of the conference so far in this session. As before I will post here some of my notes, again no guarantee for completeness.
M. Mann’s talk
- The scientific basis for climate change has been around for longer than many think, mostly since the early 19th century:
- Jim Hansen has been one of the first people to try and validate a climate model – and he didn’t do poorly
- there is a thing called the “Luntz Memo“. It is a memo written by a politician called Luntz who outlines in this memo how to argue against climate change in the public. Similarly, there are other politicians who are against climate change, including Senator James Inhofe and Sara Palin. This is nothing new, but was interesting in this clearness. Palin recently established a thing called “Climate Gate” in which she called for president Obama to boycott Copenhagen. Not to confused with Watergate.
R. Alley’s talk
- to be a scientist is one of the greatest jobs available: you discover things that nobody knew before, you share, and you help. On the other hand, scientist argue like crazy every time. Which might be necessary to “keep shaking the info until it’s solid”. To non-scientists, this usually looks like scientists do nothing else other than arguing. And that’s not good!
- The National Research Council was established to “investigate, examine, experiment, and report upon any subject of science or art”. Later came similar institutions for health and engineering. Now, after the initial IPCC report, the US government asked the NRC, if the IPCC predictions might be ok. The NRC responded that yes, the IPCC predictions look good.
- Then he got into sea-level rise, the main topic of his talk
- in 2001, sea level rise was predicted, excluding dynamics. In 2007, “scientists went like ‘Oh crap'” — sea-level rose faster than they expected. — “There’s the big gorilla out there that we don’t understand”
- “it’s not hard to get 1m sea-level rise by 2100”
- the underlying science: “all piles tend to spread, if you crank up the heat things melt, and if it snows it might accumulate”
- Sara Das does cool research in Greenland
- The Larsen B ice-shelf was one flying buttress for the ice of Greenland. Without a flying buttress, some ice might move up to 8x faster than with one. The less flying buttresses there are around Greenland, the “faster the whole thing goes”
- melting goes up faster than increased snow fall
- Regional Meteorological–Marine Reanalyses and Climate Change Projections by Weisse et al., 2009 in BAMS
- Geochemistry and the understanding of ground-water systems by Glynn and Plummer, Hydrogeology Journal 2005
- What indicators can capture runoff-relevant connectivity properties of the micro-topography at the plot scale? by Antoine et al., 2009 in AWR
- Zhu and Lin, 2009: preferential flow paths via EM in HESS
- Hydrodynamic Dispersion by Rose in Soil Science
- The original Pfannkuch, 1963 paper seems to be in french, not available online, but cited by many
- Berkovitz and Scher, 1995 in Water Resources Research
The Stuttgarter Zeitung recently published two articles related to water:
The first article describes the flood-protection measures for a part of the city of Tübingen. The city council just agreed to start building a dam in 2010. This dam will be able to stand in a flood with a 20-year return period.
A normally relatively small creek, the “Goldersbach“, has lead in the past after extreme precipitation events to extensive flooding and related destruction. The dam is part of a multiple-level protection strategy, which is outlined in this publication. The dam is a good thing, however it won’t withstand any substantial floods, that is floods bigger than with a 20-year return period. This is why the warning time is critical for the citizens living in the area! The article states that the warning time is five hours. It would be interesting to get to know details on how they estimate five hours as the warning time. Measurements have to be made, submitted, and calculations and predictions have to be made, involving fair amounts of uncertainty.
The second article describes how NASA researchers found out while working with GRACE data that groundwater levels are declining in India since 2002, even though the precipitation patterns have been fairly normal.
These are two practical examples that illustrate how extreme events are critical and need special attention!
Recently, I ran into the word geoengineering quite frequently. I kind of thought of it as a form of geotechnical engineering, but it seemed like the things that were talked about had not very much to do with geotechnical engineering.
This blog post will try and shed some light into what geoengineering implies. As [wikipedia] points out right at the start of its article on “geoengineering“, this term is not to be confused with “geotechnical engineering”! To keep confusion at a minimum level, let’s start with some definitions:
To clarify things, here are a few related important definitions from wikipedia:
Geoengineering: manipulate the Earth’s climate to counteract the effects of global warming from greenhouse gas emissions.
Planetary engineering is the application of technology for the purpose of influencing the global properties of a planet. The goal of this theoretical task is usually to make other worlds habitable for life. Geoengineering ti the application of planetary engineering techniques to Earth.
Terraforming is a type of planetary engineering by which a planet’s surface conditions are altered to be more like those of Earth
Geotechnical Engineering is the branch of civil engineering concerned with the engineering behavior of earth materials
One of the blog posts I came across recently which talk about geoengineering was a post by Miriam Goldstein at The Oyster’s Garter. She discusses the risks and benefits of geoengineering, especially a type of geoengineering called “iron fertilization”. This proposal involves “deliberately stimulating plant growth in the ocean with the aim that the excess material will be permanently sequestered in the deep sea. This would remove carbon from the atmosphere”. For German speaking readers, here is a nice summary. Other types of geoengineering she discusses include stratospheric aerosols, cloud whitening, atmospheric carbon capture, and geochemical carbon capture.
Probably, Miriam is talking about the same iron fertilization project as the german news-magazin “Der Spiegel” in its article from January 14th, 2009. “Der Spiegel” reported then that the project has been halted due to “environmental concerns” – the same concerns which have been raised by Miriram. On January 27th, the german federal research ministry allowed the Polarstern to conduct the experiment (see also this report). The AWI already posted first measurement results. I am not a remote sensing expert, but I kind of believe this map showing that more algae live in the area where the iron was put into the ocean. However, the total range of chlorophyll concentration on the map is from 0.1mg/m3 to 3mg/m3. That’s one order of magnitude. Map taken from here
Another set of measurements made available by the Alfred Wegener Institute are depth profiles of dissolved oxygen, silicate, ammonium and chlorophyll taken at two different moments in time: before the iron was put in place and four days after. Again, I am not a biologist or oceanologist, but the changes do not seem extremely high. But then, it’s only after four days.
To conclude, I guess it’s too early to conclude if the experiment was successful or not. However, it seems a very risky and monetary intensive experiment.
Here are two more posts dealing with geoengineering:
James Hrynyshyn at “Living on an Island of Doubt in a climate of change” posts some similar doubtful concerns about the effectivity of geoengineering. He writes:
As Lenton and Vaughan write, geoengineering really only makes sense as a part of a larger strategy that includes cutting back hard on greenhouse gas emissions.
Wired reports on a “Carbon Burial” project, also referred to as “geological sequestration”, that will deposit a million metric tons of carbon dioxide into the ground by 2012. This is such a hot topic, it probably deserves an individual post.
After all these novel approaches, an interesting side-node from some classic geotechnical engineering, with an interesting outcome – Wired reports:
Drillers accidentally hit a pocket of molten rock underneath a working geothermal energy field in Hawaii, a lucky break for geologists that could allow them to map the geological plumbing that created everything we know as land.
update Wednesday; April 15, 2009: Wired has an article from a researcher on board a boat in the southern ocean.
I’ve spent a fair bit of my time as a grad students trying to model groundwater systems. There have been long discussions on modelling and its philosophy. Today was a PhD defence of such a grad student. Typical thoughts afterwards tend to be “… if we only had more data… ” or “… if we only knew the underlying processes better and could describe them… ” or “… if we only had more computing power available… ” .
I think a key trait of an environmental modeller should be his or her awareness of the quality of the data and the limitations regarding the quality of the predictions of the model. So when I read the headline “Climate Models Trump Financial Models” I was a bit worried. Sure, climate change is a pressing problem, and there is a lot of effort put into improving climate models. However, for me as an environmental engineer it seems that global financial markets should be better understood than global warming. And if it’s only because finance has been around for longer than environmental engineering! 🙂
I had never put much thought into how financial models might work, so this article brought up an interesting point for me, even though I’m not quite sure what I think about it:
“Climate models are very complex but you more or less understand the basic physics or chemistry,” said Derman. “[Finance papers] look like physics but a lot of the similarity is syntactic more than semantic.”
For example, stock options are priced with the Black-Scholes model, which says that stock price movement can be seen to move like the random movements of particles suspended in a liquid, i.e. Brownian motion. But stock price models differ from particle models because they describe the aggregate actions of people.
I guess quite a few processes are modelled like Brownian Motion. Why not stock option pricing. This just means though that we don’t know the underlying processes of stock option pricing better, so we could model the pricing in a more deterministic way. Then I thought a bit and it occurred to me that if you asked me, I probably couldn’t explain to you what is going on in the financial world these days. Why are we having this crisis? What are the underlying processes? Then I found this wicked little movie that explains these processes:
Based on this video, this seems to be a fairly straight forward process… 🙂 But I agree, there is a human factor involved, which admittedly doesn’t make things easier. I wonder what would happen, if you would throw an environmental modeller, a psychologist, and a finance person into a room for a while!
It seems like Weird was on a roll writing about financial models: They also point out, that the length of the finger of a trader is an indication for his degree of success. For me, that seems a little far-fetched! However, there’s again one interesting thought:
But leading up to the crisis — and underlying public acceptance of the mistakes and wrongdoing that produced it — was a widespread belief in the fundamental rationality of free markets and economic behaviors. That assumption may need to be revisited.
Air temperatures in Germany vary with a weekly cycle: wednesdays are the warmest days, saturdays the coldest. These results were produced by Bernhard Vogel and Dominique Bäumer at the University of Karlsruhe, Germany, as is reported by Die Tageszeitung. They point out that this is not a local phenomenon, since they found the same phenomenon at fairly remote stations, in the German Alps for example. Additionally they argue that such a strict weekly phenomenon could not originate in nature, and they blame little particles in the air (aerosols) that are emitted mostly during work-days from factories and traffic. Similar results were subsequently found in China and in the USA.
Die Tageszeitung proceeds to describe how this is not unanimously accepted in the scientific community. Harrie-Jan Hendricks Franssen from the ETH Zürich. He compared Swiss data from Zürich and Lugano with the German data used by Vogel and Bäumer, trying to figure out if precipitation and temperature behaved similarly in Switzerland as in Germany as reported by Vogel and Bäumer. Lugano is south of the Alps and hence should be influenced from different weather mechanismns than Germany. Additionally, Lugano is located in the vicinity of Milano, which exhibits Smog frequently.
Both Lugano and Zurich never showed a persistent weekly cycle for precipitation and sunshine duration for the investigated period. In addition, only 4 of the calculated 28 anomalies for the period 1991 – 2005 (2 stations x 2 variables x 7 weekdays) were statistically significant (statistically 1.4 anomalies are expected). Only one of the four statistically significant anomalies had the same sign as observed by BV07. The anomalies were analyzed further in a Monte Carlo study. The stochastic simulation experiments suggest that none of the anomalies was significant; even the largest anomaly (the anomaly of Saturday precipitation in Zurich of 18.0%) occurred in 9% of the experiments due to purely random effects. In addition, for 21% of the stochastic experiments a weekly cycle in precipitation in Zurich is found due to random effects.
Vogel and Bäumer respond on Hendrick’s finding in a comment published also in the Geophysical Research Letters. Die Tageszeitung points out that there are additional studies being conducted in Spain and in the USA, all to evaluate the role that aerosols in the air play related to weather. It’s great to see that sometimes research is well published in newspapers for the public!
A couple of weekends ago I went with my girlfriend on a long guided tour through a forrest. We spent a few hours wondering around and exploring what’s crawling and living there: little bugs that are quite strong, different growing stages of trees, fungi and other living beings on dead trees. It turned out that the guy who gave the tour was a beekeeper. He made some delicious honey, trying to put a bee colony or two in the center of an area where mostly a certain type of tree grows. Say a kind of wild cherry tree. Then he sold that essentially authentic honey to us for a few Euros per 500g glass.
A few things came to my mind: a) real honey is delicious and b) I have noticed quite a few insects this year (it’s warm and relatively moist), but very few honey bees. The cherry tree in our garden had extremely many flowers, but only about a quarter of the flowers turned into actual cherries.
I talked to some people, and after I asked them they all agreed, that they have noticed very few bees around this year. I started to look a bit around and found this scary blog post from “bootstrap analysis”: There is a pesticide called clothianidine, which is sold by the brand “Poncho” by Bayer, that is linked to the deaths of honeybees in 11,500 colonies. In early June, Germany halted the sale of Poncho, but in July the ban was lifted. There are similar other pesticides still on sale and being used, in Germany and in other parts of the world.
This is not directly linked to water (yet). But who knows the pathways? I guess reading “Silent Spring” is not enough. But what can you do? Not buy the corn that was planted using Bayers chemicals?
Update 27. August 2008: bootstrap analysis published an update on related pesticide issues and how we don’t learn from history
Climate Change picks up pace, reports [SWR]
The independent has a little text for one example that demonstrates how the climate is changing: Reindeer herders in northern Scandinavia see in their daily lives how fast climate changes, and how they experience weather types that they have never experienced at the given times of the year, rain in winter, f.ex.
The Independent reports how Barcelona is “importing” drinking water with ships. This is a first to me!
Seems like the Independent is onto very novel stories: it also reports that the major of a Russian town of 70,000 suggests abandoning it and settling at a new place — the current location is just too polluted