Posts Tagged ‘climate change’

I’ll march for science, because the truth and the pursuit of truth matters. A lot.

April 20, 2017

This saturday 22 April a global March for Science will take place in around 500 hundred cities worldwide. I’ll take part in the Amsterdam March for Science, taking place between 12:00 and 16:00 on Museumplein. You can find me in the “discovery” tent with some posters about climate change and sustainable energy.

Science and rational thinking has brought a lot of good to the world. Facts and a good understanding of the situation are important input for making wise decisions. Scientists should be able to do their work in freedom, not being hindered or silenced by political pressure. Science is not just another opinion. I value the truth and the pursuit of truth. That’s why I will join the march for science.

Great 4 minute video by Neil deGrasse Tyson about the value of science:

Other reading:

FAQ on the America March for Science website.

I’m a Scientist. This is What I’ll Fight For. Strong, US-centered essay by Jonathan Foley:

“The War on Science is more than a skirmish over funding, censorship, and “alternative facts”. It’s a battle for the future, basic decency, and the people we love.”

He wrote quite a few more readable pieces on the war on science.

No, you’re not entitled to your opinion.

“You are only entitled to what you can argue for. (…) false equivalence between experts and non-experts is an increasingly pernicious feature of our public discourse. (…) If ‘Everyone’s entitled to their opinion’ just means no-one has the right to stop people thinking and saying whatever they want, then the statement is true, but fairly trivial. No one can stop you saying that vaccines cause autism, no matter how many times that claim has been disproven. But if ‘entitled to an opinion’ means ‘entitled to have your views treated as serious candidates for the truth’ then it’s pretty clearly false. And this too is a distinction that tends to get blurred.”

Climate inertia

August 9, 2016

Imagine you’re on a supertanker that needs to change its direction in order to avoid a collision. What would you do? Would you continue going full steam ahead until you can see the collision object right in front of you? Or would you try to change course early, knowing that changing a supertanker’s course takes a considerable amount of time?

The supertanker’s inertia means that you have to act in time if you wish to avoid a collision.

The climate system also has a tremendous amount of inertia built in. And like with the supertanker, this means that early action is required if we want to change the climate’s course. This inertia is a crucial aspect of the climate system, both scientifically but also societally – but in the latter realm it’s a very underappreciated aspect. Just do a mental check: when did you last hear or read about the climate’s inertia in mainstream media or from politicians?


The inertia of the climate system could be compared to that of a supertanker: if we want to change its course, it’s important to start steering the wheel in the desired direction in time.

Why is it so important? Because intuitively many people might think that as soon as we have substantially decreased our CO2 emissions (which we haven’t), the problem will be solved. It won’t, not by a very long shot. Even if we reduce CO2 emissions to zero over a realistic timeframe, the CO2 concentration in the atmosphere – and thus also the global average temperature- will remain elevated for millennia, as can be seen in the figure below. The total amount of carbon we put in the atmosphere over the course of a few hundred years will affect life on this planet for hundreds of thousands of years. And if we want to reduce the amount of warming that we commit the future to, we need to reduce our carbon emissions sooner rather than later. The longer we postpone emission reductions, the stronger those emissions reductions would need to be in order to have the same mitigating effect on long-term warming.

That’s why climate inertia is so important.

Zickfeld 2013

Modeled response of the atmospheric CO2 concentration (panel b) and surface air temperature compared to the year 2000 (panel c) to prescribed CO2 emissions (panel a). The CO2 concentration remains elevated long after CO2 emissions have been reduced, because the long-term sinks for CO2 operate very slowly (see e.g. IPCC FAQ 6.2 for an explanation of these carbon sinks). Since CO2 impedes infrared heat loss, for millennia the globe will remain warmer than it was before CO2 concentrations rose. The temperature lags behind the CO2 concentration because of the time it takes for the oceans to warm up. Figure from Zickfeld et al (2013).

As I wrote before: Postponing meaningful mitigation action until the shit hits the fan comes with considerable risk, because many changes in climate are not reversible on human timescales. Once you notice the trouble, it’s only the beginning, because of the inertia in the various systems (energy system, carbon cycle and climate system). The conundrum is thus that those who caused the problem are in the best position to solve it, but since the full consequences will not materialize until much later, they have the least incentive to do so.

Over at Bits of Science two Dutch science journalists, Rolf Schuttenhelm and Stephan Okhuijsen, published an interesting piece that focuses on the same issue: we only see a portion of the warming that we have committed ourselves to, due to the thermal inertia provided by the oceans. Just as a pot of water doesn’t immediately boil when we turn on the stove, the oceans take time to warm up as well. And since there’s a lot of water in the oceans, it takes a lot of time.

They included the following nifty graph, with the observed surface temperature but also the eventually expected temperature at the corresponding CO2 concentration (which they dub the ’real global temperature’), based on different approaches to account for warming in the pipeline:

real-global-temperature-graph - Bits of Science

Observed and eventually expected (“real”) temperature at concurrent CO2 concentration, via Bits of Science

This is a nice way to visualize the warming that’s still in the pipeline due to ocean thermal inertia. From a scientific point of view the exact execution and framing could be criticized on certain aspects (e.g. ECS is linearly extrapolated instead of logarithmically; the interpretation that recent record warmth are not peaks but rather a ‘correction to the trend line’ depends strongly on the exact way the endpoints of the observed temperature are smoothed; the effect of non-CO2 greenhouse gases is excluded from the analysis and discussion), but the underlying point, that more warming is in store than we’re currently seeing, is both valid and very important.

Timescales, timescales, timescales. Why art thou missing from the public discussion about global warming?

Update: ClimateInteractive has a good simulation of how this inertia works out in practice. By moving the slider at the bottom the figure you can choose between different emission scenarios. In the graphs above you then see the effect this has on the CO2 concentration, the global average temperature, and the sea level, and how this response is damped. The further down the cause-effect chain, the more damped – or better: the more slowed down- the response is. The sea level will continue to rise the longest (even long after the temperature has stabilized or even starts decreasing), but will take a while to get going. This simulation only runs to the year 2100 though.

A Dutch version of this post can be found on my sister blog KlimaatVerandering.

Consensus on consensus: a synthesis of consensus estimates on human-caused global warming

April 13, 2016

Most scientists agree that current climate change is mainly caused by human activity. That has been repeatedly demonstrated on the basis of surveys of the scientific opinion as well as surveys of the scientific literature. In an article published today in the journal Environmental Research Letters (ERL) we provide a review of these different studies, which all arrive at a very similar conclusion using different methods. This shows the robustness of the scientific consensus on climate change.

This meta-study also shows that the level of agreement that the current warming is caused by human activity is greatest among researchers with the most expertise and/or the most publications in climate science. That explains why literature surveys generally find higher levels of consensus than opinion surveys. After all, experienced scientists who have published a lot about climate change have, generally speaking, a good understanding of the anthropogenic causes of global warming, and they often have more peer-reviewed publications than their contrarian colleagues.

Scientific consensus on human caused climate change vs expertise in climate scienceFigure: Level of consensus on human-induced climate change versus expertise in climate science. Black circles are data based on studies of the past 10 years. Green line is a fit through the data.

The initial reason for this review article was a specific comment by Richard Tol on John Cook’s literature survey as published in ERL in 2013. Cook found a 97% consensus on anthropogenic global warming in the scientific literature on climate change. This article has both been vilified and praised. Tol argued that Cook’s study is an outlier, but he did so by misrepresenting most other consensus studies, including the survey I undertook while at the Netherlands Environmental Assessment Agency (PBL). To get a gist of the discussion with Tol see e.g. this storify I made based on my twitter exchanges with him (warning: for climate nerds only). Suffice to say the authors of these other consensus studies were likewise not impressed by Tol’s caricature of their work. This is how the broad author team for the current meta-analysis arose, which shows that Cook’s literature survey fits well within the spectrum of other studies.

The video below provides a great overview of the context and conclusions of this study:

Surveys show that among the broad group of scientists who work on the topic of climate change the level of consensus is roughly between 83 and 97% (e.g. Doran, Anderegg, Verheggen, Rosenberg, Carlton, Bray, Stenhouse, Pew, Lichter, Vision Prize). If you zoom in on the subset of most actively publishing climate scientists you find a consensus of 97% (Doran, Anderegg). Analyses of the literature also indicate a level of consensus of 97% (Cook) or even 100% (Oreskes). The strength of literature surveys lies in the fact that they sample the prime locus of scientific evidence and thus they provide the most direct measure of the consilience of evidence. On the other hand, opinion surveys can achieve much more specificity about what exactly is agreed upon. The latter aspect – what exactly is agreed upon and how does that compare to the IPCC report- is something we investigated in detail in our ES&T article based on the PBL survey.

As evidenced by the many –unfounded- criticisms on consensus studies, this is still a hot topic in the public debate, despite the fact that study after study has confirmed that there is broad agreement among scientists about the big picture: our planet is getting warmer and that is (largely) due to human activity, primarily the burning of fossil fuels. A substantial fraction of the general public however is still confused even about the big picture. In politics, schools and media climate change is often not communicated in accordance with the current scientific understanding, even though the situation here in the Netherlands is not as extreme as e.g. in the US.

Whereas the presence of widespread agreement is obviously not proof of a theory being correct, it can’t be dismissed as irrelevant either: As the evidence accumulates and keeps pointing in the same general direction, the experts’ opinion will logically converge to reflect that, i.e. a consensus emerges. Typically, a theory either rises to the level of consensus or it is abandoned, though it may take considerable time for the scientific community to accept a theory, and even longer for the public at large.

Although science can never provide absolute certainty, it is the best method we have to understand complex systems and risks, such as climate change. If you value science it is wise not to brush aside broadly accepted scientific insights too easily, lest you have very good arguments for doing so (“extraordinary claims require extraordinary evidence”). I think it is important for proper democratic decision making that the public is well informed about what is scientifically known about important issues such as climate change.

More info/context/reflections:

Dutch version at sister-blog “klimaatverandering”

Column by first author John Cook in Bulletin of the Atomic Scientists

Stephan Lewandowsky on the psychology of consensus

Collin Maessen tells the backstory starting with Richard Tol’s nonsensus

Ken Rice at …And Then There’s Physics

Dana Nuccitelli in the Guardian

Sou at HotWhopper

Amsterdam University College (AUC) news item


Andrew Dessler’s testimony on what we know about climate change

January 19, 2014

In his recent testimony, Andrew Dessler reviewed what he thinks “are the most important conclusions the climate scientific community has reached in over two centuries of work”. I think that’s a very good choice to focus on, as the basics of what we know is most important, “at least as to the thrust and direction of policy” (Herman Daly). This focus served as a good antidote to the other witness, Judith Curry, who emphasizes (and often exaggerates) uncertainty to the point of conflating it with ignorance.

Dessler mentioned the following “important points that we know with high confidence”:

1.  The climate is warming.

Let’s take this opportunity to show the updated figure by Cowtan and Way, extending their infilling method to the entire instrumental period (pause? which pause?):

Cowtan and Way - Global Avg Temp 1850 - 2012

2. Most of the recent warming is extremely likely due to emissions of carbon dioxide and other greenhouse gases by human activities.

This conclusion is based on several lines of evidence:

– Anthropogenic increase in greenhouse gases

– Physics of greenhouse effect

– Observed warming roughly matches what is expected

Important role of CO2 in paleoclimate

– No alternative explanation for recent warming

Fingerprints of enhanced greenhouse effect (e.g. stratospheric warming cooling, which was predicted before it was observed)


Thus, we have a standard model of climate science that is capable of explaining just about everything. Naturally, there are some things that aren’t necessarily explained by the model, just as there’re a few heavy smokers who don’t get lung cancer. But none of these are fundamental challenges to the standard model.

He goes on to explain that the so-called “hiatius” is not a fundamental challenge to our understanding of climate, though it is “an opportunity to refine and improve our understanding of [the interaction of ocean circulation, short-term climate variability, and long-term global warming].”

What about alternative theories? Any theory that wants to compete with the standard model has to explain all of the observations that the standard model can. Is there any model that can even come close to doing that?


And making successful predictions would help convince scientists that the alternative theory should be taken seriously. How many successful predictions have alternative theories made?


3. Future warming could be large 

On this point I always emphasize that the amount of future warming depends both on a combination of factors:

– the climate forcing (i.e. our emissions and other changes to the earth’ radiation budget)

– the climate sensitivity (the climate system’s response to those forcings)

– the climate response time (how fast will the system equilibrates).

Internal (unforced) variability also plays a role, but this usually averages out over long enough timescales.

4. The impacts of this are profound.

In the climate debate, we can argue about what we know or what we don’t know. Arguing about what we don’t know can give the impression that we don’t know much, even though some impacts are virtually certain.

The virtually certain impacts include:

• increasing temperatures

• more frequent extreme heat events

• changes in the distribution of rainfall

• rising seas

• the oceans becoming more acidic

Time is not our friend in this problem.

Nor is uncertainty.

The scientific community has been working on understanding the climate system for nearly 200 years. In that time, a robust understanding of it has emerged. We know the climate is warming. We know that humans are now in the driver’s seat of the climate system. We know that, over the next century, if nothing is done to rein in emissions, temperatures will likely increase enough to profoundly change the planet. I wish this weren’t true, but it is what the science tells us.

Peter Sinclair posted a video of Andrew Dessler’s testimony. Eli Rabett posted Dessler’s testimony in full.

A key distinction in the two senate hearings was that Andrew Dessler focused on what we know, whereas Judith Curry focused on what we don’t know (though “AndThenTheresPhysics” made a good point that Curry goes far beyond that, by e.g. proclaiming confidence in certain benign outcomes (e.g. regarding sensitivity) while claiming ignorance in areas where we have a half-decent, if incomplete, understanding, e.g. regarding the hiatus). I have argued before that emphasizing (let alone exaggerating) uncertainties is not the road to increase people’s understanding of the issue, where what we do know is much more important to convey (if your goal is to increase the public understanding of scientific knowledge). Alongside that I argue that much more attention is needed to explain the nature of science, which is needed to e.g. place scientific uncertainties in a proper context.


Herman Daly said it as follows, in a quote I’ve used regularly over the past few years:

If you jump out of an airplane you need a crude parachute more than an accurate altimeter.

Arguing whether the altimeter might be off by a few inches is interesting from a scientific/technological perspective, but for the people in the plane it’s mostly a distraction.

Long term persistence and internal climate variability

April 30, 2013

After a long hiatus, Climate Dialogue has just opened a second discussion. This time it’s about the presence of long term persistence in timeseries of global average temperature, and its implications (if any) for internal variability of the climate system and for trend significance. This discussion is strongly related to the question of whether global warming could just be a random walk, a question vigorously debated on this blog (incl my classic  april fool’s day post three years ago).

Invited expert participants in the discussion include Rasmus Benestad (of RealClimate fame), Demetris Koutsoyiannis and Armin Bunde. The introduction text here slightly differs from that posted on


Documentairy “Thin Ice” now available on the web

April 22, 2013

The documentairy “Thin Ice“, with spectacular images and interviews with a few dozen of well-known and lesser well-known climate scientists, is available for viewing tonight on their website (which features lots of other interesting content btw). At the same time, various public screenings are being organized all over the world (unfortunately not in the Netherlands, mea culpa). The free viewing via their website is probably temporary, though I don’t know for how long (my guess is a few days). The premiere has of course been timed to coincide with Earth Day.

Climate Science Survey – the questions

October 8, 2012

In the spring of 2012, a large scale climate science survey was held amongst 6500 scientists studying various aspects of global warming. The survey was spearheaded by the Netherlands Environmental Assessment Agency (PBL), where I was responsible for the execution and analysis during the first half of 2012.

The objective of this study is to gain insight into how climate scientists perceive the public debate on the physical scientific aspects of climate change. More info about the survey was posted on the PBL website at the time, which has recently been updated to include a link to the survey questionnaire. Please note that the survey is no longer active.

Some confusion has arisen over the status of this survey. I responded at WUWT in an attempt to clarify:

We undertook a survey in March/April of this year (which, as Hans Labohm mentioned in a comment on WUWT, had been previewed by a variety of people with different viewpoints). Some respondents, e.g. Timothy Ball, asked to see the questions again. After internal consultation, we decided to publish the survey questions on the institute’s website, so that they are viewable to all. We contacted the survey respondents to inform them of the questions being available to view. I informed Dr Ball of this as well, to follow-up on my earlier email to him.

Our email to all respondents, informing them of the fact that the survey questions are available on the web, was apparently misunderstood to mean that we were again soliciting responses to a survey; this is however not the case. Roger Pielke Sr had already put a notice about the survey on his blog, which he has since updated after an email clarifying that this is an inactive survey, to which he had previously responded.

Below we (Bart Verheggen and Bart Strengers) reply to some of the more substantive questions regarding the survey questions raised on WUWT. However, we will not discuss results or the survey sample at this point in time. We will do so when our manuscript has been accepted.


Climate survey discussion

January 3, 2012

On the previous post a discussion about climate surveys erupted. Please continue here. I’ll chime in when I habe more time.

I’m curious to hear what you find good or not so good about a particular survey and why. If you have contributed to the discussion on the previous thread, perhaps you want to condense your main arguments in one comment so that we can start a more structured discussion. If succesful, I’ll follow up with a post including the various contributions. Call it crowdsourced blogging if you wish.

A noteworthy survey that has not been discussed much is the one by Brown, Pielke Sr and Annan that I wrote about before:

A recent survey of scientists having authored a recent journal article on climate change found that the majority concurred with the IPCC position. A sizeable minority was of the opinion that the IPCC reports overstate the importance of and/or certainty regarding CO2 compared to other forcings (both natural and anthropogenic!). Only very few respondents were of the “skeptical” opinion that warming is predominantly natural. Nobody denied that the globe is warming. A large minority found the IPCC too cautious, understating the human influence on climate and/or the seriousness of the problem. Note that the authors do not claim that their survey is representative; less then 10% of the 1800 scientists contacted replied. Moreover, the positions that respondents had to choose between were sometimes a little ambiguous.

Others that have been discussed a lot include those by Bray and von Storch and the recent one by Doran and Kendal-Zimmerman.

What are the pros and cons of reducing CO2 vs other warming agents?

December 15, 2011

That is the question I’ve been pondering earlier this year and which’ pontifications you can now read on Planet3.

The difference is mainly in the timescale: CO2 lasts a lot longer in the atmosphere than most of the other warming agents (e.g. black carbon, ozone, methane). This means that the temperature will decrease faster when the emission of shortlived compounds is decreased, as compared to that of a longlived compound such as CO2.

The other side of the coin is that for long term warming, the cumulative emissions of CO2 are dominant, even if in the short term changes in its emission are relatively ineffectual. Other important aspects in this discussion are health effects from air pollution (e.g. soot and ozone) and political practicability (gridlock in global climate negotiations).

So the question is: Are you more concerned about the short term or the long term effects of climate change? Which is a similar question that is often implicitly present in climate debates: Weighing the right of this generation to economic wellbeing (through cheap fossil energy) with the right of future generations to a pleasant planet to live on (through us not using too much cheap fossil energy). Strangely enough, that central and deeply ethical question is usually embodied in the discount rate (as used in economics when comparing investments with the expected rate of return).

My conclusion:

It’s clear that for long term climate stabilization, cumulative CO2 reductions are paramount, and that for the short term, reducing other forcings can offer faster results and offer other benefits as well. So the answer to the question “what should we focus on” is “all of the above”. I would applaud more attention to the non-CO2 forcings in the International policy arena. However, let’s not forget that there’s a hefty price and/or climate tag to pay in the end for delaying CO2 emission reductions.

You can read the whole thing over at P3.

Planet3 is a community new(s) blog, aptly described by main driving force Michael Tobis (in an interview with Andy Revkin) as
opinionated yet skeptical, informed yet passionate
Conflict of interest statement: I live on the planet in question.
(via Elmar Veerman)

To publish BS or not, that’s the question

November 11, 2011

Richard Tol levied a strong accusation at Judith Curry for highlighting two seriously flawed papers (via twitter):

Its wrong, but with @JudithCurry lending her authority it becomes disinformation

Judith defended herself in a post where she tries to shift the blame to the mainstream scientists:

 Here is a quiz for you.  How many of these disinformation tactics [a list containing a mix of logical fallacies and avoidance tactics] are used by:

  • JC (moi)
  • Public spokespersons for the IPCC
  • Joe Romm
  • Marc Morano

If that’s not a dog-whistle I don’t know what is. 

Keith has a nice rundown of the discussion, and the ensuing thread over there contains many good comments. He’s got a knack for hosting interesting discussions.

Richard has since laid out his argument as to what’s wrong with the papers in a guest post over at CE.  Basically they’re methodologically flawed:

Using “detrended” fluctuation analysis to study “trends” was a dead giveaway that something is not quite right with these papers.

Tol goes on to write: 

7. There is a substantial body of climate research that is credible — even if it reaches opposite conclusions — but there are also papers (left, right, and center) that are just flawed.
8. If flawed papers reach a certain prominence, they should be debunked. Prominent but flawed research does damage as it misinforms people about climate change. Publicly criticizing such research hardens the existing polarization.
9. If flawed papers linger in obscurity, they should be ignored. The papers are wrong but do no damage. Lifting a flawed paper out of obscurity only to debunk it, is no good to anybody.

Curry takes especially issue with the last statement:

Yours isn’t a statement about science, but about playing politics with science, and reinforces the gatekeeping mentality in climate science that was embarassingly revealed by the CRU emails. (…)

Of course scientists don’t want the public to be misinformed about the science! So If I’m concerned about public understanding of science, I’m automatically “playing politics with science”? Then I sure hope every scientist is.

Judith rightly says that “Of course there are flawed papers that get published.” But why shining the spotlight on them? What’s gained by doing so?

It’s true that these discussions don’t occur about science without policy relevance. Research on the mating behavior of fruit flies won’t result in argument whether a flawed paper should be promoted in the public sphere or not.

The differences are that 1) such research is not present in the public sphere, because the public isn’t interested, and 2) even though flawed papers exist in any field, the more its conclusions clash with ideologies, the more attempts will be made to reach opposite conclusions and thus the more deeply flawed/biased papers will be published. It’s not a coincidence that there’s no fruitflies-version of EIKE or Heartland. 


Most people don’t come to climate etc. to reinforce their prejudices (there are far too many echo chambers where this is much more satisfyingly accomplished). They come here to learn something by considering the various arguments.

The general tone of comments at CE makes me strongly doubt this last statement.


I would agree with you [no harm done by highlighting flawed studies] if climate blogs were exclusively read by well-intentioned, well-informed, and intelligent people.

Richard further shows his mastery in the tweet-universe with one-liners such as

I argue for self-censorship. It is what separates adults from children.

Over at CaS, Roger Pielke Jr makes the point that wrong or bad articles can be a useful teaching tool. And indeed they can. But as Stoat rightly says,

within a managed class structure with someone guiding the discussion, it is fine to discuss flawed texts, for the reason given: it encourages critical thinking. That wasn’t what Curry was doing.


Curry took two papers that almost nobody had read, and put them in the limelight.
The papers say 2+2=5.
There are a lot of people who would like to believe that. It is not true.
So now there is yet another dogfight about whether the answer is 3, 4, or 5. We can do without that.
There are plenty of real issues to argue over.

Jonathan Gilligan, consistently thoughtful, writes:

Pielke has said that he views blogs as more like the kind of discussions people conduct over beers at the neighborhood bar, and from that perspective Richard’s criticism makes no more sense than telling the crowd at the pub to leave sports commentary to the experts. 

Tol makes some valid points here, but Pielke is more persuasive. People will read these blogs or not as they choose, and when a blog repeatedly calls attention to crap, its credibility and its audience will adjust to reflect this. Climate Etc. is not The Wall Street Journal, so the greater danger in Curry’s gushing over crap is to Curry’s reputation, not to the public understanding of science.

I have also compared blogs to bar-discussions (quoting Bob Grumbine), but that comparison is about the presence (or lack) of quality control. As Tol rightly says, 

With academics blogging and tweeting, and journalists, and prime ministers, and institutes, departments, agencies and companies, I don’t think there is a one-rule-fits-all.

At CE, thousands of people are listening. Judith’s opinion and her writings make their way to the general public and politicians via mainstream media and Senate hearings as well. By the scale of those who are engaged in the conversation, that is orders of magnitude different from a discussion in a bar. That also means that the risk is twofold: Both to Curry’s reputation (her problem) and to the public understanding of science (everyone’s problem, even though Curry tries to belittle that).

Whereas Tol argued based on methodological flaws, Fred Moolten explains why the papers’ conclusions are unsupportable on physical grounds and I made a similar argument:

Conservation of energy precludes the climate to wonder off too far in any direction without being “forced” to by changing boundary conditions. Unless of course the energy is merely being redistributed within the system. Which it isn’t, since all other compartments of the climate system are gaining energy.

The paper’s conclusion that the observed warming is “predominantly a natural 100-year fluctuation” is at odds with conservation of energy.

All very reminiscent of the random walk saga and the Harry Potter theory of climate.

%d bloggers like this: