I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.
By: RickyRood, 6:17 PM GMT on September 22, 2012
The Free Market and the Climate Model: Models, Water, and Temperature (8)
I am returning to my series of blogs on models, water, and temperature (see Intro, and previous entry). The earlier entries in the series are linked at the end.
The previous blog was a diversion from the series and reported on A National Strategy for Advancing Climate Modeling. Accompanying the publication of that document a new website was published Climate Modeling 101, which is an introduction to modeling more anchored in scientific language than the series I am currently writing. Give it a try.
Doing Science with Models 1.5: I have used the example of balancing a checkbook to write about the balance of energy at the center of the study of the Earth’s climate. I have shown that despite the simplicity of balancing the budget of a single account, there are many ways in which complexity emerges.
Let’s look at just one of these exchanges of energy, say between the atmosphere and ocean. We have wind in the atmosphere, which as it blows over the ocean, exerts a stress that causes waves and large surface currents, for example, the The Gulf Stream. The Gulf Stream is a warm-water current that carries heat from the Gulf of Mexico to the high latitudes of the Northern Hemisphere. At high latitudes, heat is transferred from the warm water of the Gulf Stream to the air. This heat keeps western Europe far warmer than would be the case if warming came only from the Sun. We have here the transfer of energy by motion of air and water, referred to as kinetic energy, as well as the transfer of heat or thermal energy between air and water.
Rain also represents energy transfer. We naturally think of rain as a source of water. However, in order for water to get into the atmosphere from the ocean, it must evaporate – turn from liquid to vapor. This takes energy, just as you have to add energy to a pan of water to boil it. This type of energy is latent energy, because it just sits in the water vapor until it gets cold enough to give up that energy as it condenses back to liquid water or ice, maybe many thousands of miles from where it evaporated.
If you focus on evaporation, then the heat from the Sun that is absorbed at the Earth’s surface is one source of the energy that evaporates water. So in our accounting problem, we account for some energy from the Sun that is absorbed at the ocean’s surface, which evaporates water, transferring energy to the atmosphere that is released in the atmosphere when it rains.
Hence, as we break down the problem to understand the accounting of energy between the ocean and atmosphere, we find several types of transfers that can occur. If we extend our consideration to the land, then we would consider trees, which take up energy from the Sun to drive photosynthesis and move liquid water from the soil to water vapor in the air through their roots and leaves. If we are doing an accounting of what trees do, then we have to take into the specifics of different types of trees: oaks behave differently from pines and bristlecone pines behave differently from loblolly pines. Trees behave differently from grasses, which are different from cacti, which are different from mushrooms.
The diversity of the natural world presents us with enormous complexity when we desire to describe it quantitatively. But at the foundation of the accounting is the budget equation for energy
Today’s Energy = Yesterday’s Energy + Energy Gained – Energy Lost
We write an energy equation for the atmosphere, and that energy equation will include how much energy is lost to the land surface over grassy surfaces, tree covered surfaces, and sandy deserts. There will be contributions to the energy equation for each process on Earth that our point of view brings us to. The total energy accounting is computed by adding up all of these energy transactions.
I want to return, now, explicitly to the budget equation for money. I made the point in Ledgers, Graphics, and Carvings that many of us have become familiar and comfortable with the idea of using computers to do our accounting and account balancing. The budget equations that represent our checking and savings accounts and the transfers between them are managed by software like Quicken or in spreadsheets like Excel. It is possible to do monthly accounting to the penny. If we think about our credit union, it manages thousands of accounts with near-perfect accuracy. A large bank manages millions of accounts, and a credit card company manages billions of transactions. Therefore, it is routine to accumulate millions of accounts and billions of transactions into large calculations. This sort of accounting problem is large and complex and requires diligence, rigor, and checking to get correct. The same is true with climate modeling. Each of the sales and returns and the transfers are, individually, simple, and in their total, complex. All of these financial accounting challenges are shared with climate modelers. The fact that we can do this financial accounting should demystify climate modeling. The complexity is a challenge, but it does not suggest impossibility. There is no magic that has to be invoked in the building of a climate model. (And, yes, you could write a climate model in Excel.)
As we collect information from all of our financial accounts, we start to describe our economy. In the United States, we imagine that we want a free market, one whose behavior is described by the law of supply and demand. If there is low supply and high demand for gasoline, the price is high. If there is high supply and low demand for terrier sweaters, then the price is low. Our purchase of gasoline and terrier sweaters is a loss of money to us, but a gain of money to their respective industries. We also make money itself a marketable item; we loan and lend for a price. We find these relations that emerge, for instance, when money is tight, then it costs more to borrow. Again, it is an issue of supply and demand, which is viewed as a defining law of markets and economies.
It is at this point of my comparison of financial budgets with energy budgets that an important difference emerges. It is in principle easier to predict the Earth’s climate than it is to predict how our economy will evolve. Why? Behavior. In financial transactions and our economy, people make decisions based upon necessity and whim. The fortunate among us might spend vast amounts on terrier sweaters, simply because we want terrier sweaters. The energy transactions in the Earth’s climate are far more boring: they are constrained by physical laws of conservation. The amount of rain cannot be just any number. It can be no more than the amount of water vapor that is available in the atmosphere to condense and fall out. The sea ice in the Arctic requires a certain amount of energy to melt. Once that melting has occurred, additional heat warms the ocean, and some of that heat expands the water. There are strict limits on behavior of the individual parts of the Earth’s climate, which do not hold true when buying and selling.
For the Earth’s climate, a strong constraint in any quantitative description is the amount of energy provided to the Earth by the Sun. The Sun is relatively stable in the amount of energy that it emits. Over the life of the Sun, its energy emission has increased by about 25 percent (Newman and Rood (Robert)). Over the span of a human life, the Sun varies up and down only a percent or so. But this is not true with money. We print money as our economies and populations grow. We try to engineer a stable economy, which actually means an economy that is growing fast enough to provide employment to an increasing population. This requires exploitation of new resources, innovation, fashionable ideas, or, perhaps, printing more money.
There is no denying that quantifying the observed behavior of our climate is a problem of immense complexity. It is, however, not a problem that is difficult to conceive. We have simple relationships based on calculating budgets of energy: production, loss, and transfers. These relationships define and constrain behavior of the processes that make up the climate as a whole. There is no free will, no credit, no overdraft protection to behave outside of these constraints. Arguments that the climate problem is too large and too complex to model and understand are simply spurious. We just require diligence, rigor, and checking our work in our accounting.
Models, Water, and Temperature
Models are Not All Wet: Series Introduction
Models are Everywhere
Ledgers, Graphics, and Carvings
Balancing the Budget
Point of View
Looking Under the Cloak of Complexity
Updated: 3:52 PM GMT on October 20, 2012
By: RickyRood, 5:27 AM GMT on September 12, 2012
New Report: A National Strategy for Advancing Climate Modeling
In late 2010 and 2011, I was writing about organizing U.S. climate modeling. I combined and posted some of the WU blogs over on ClimatePolicy.org as Something New in the Past Decade? Organizing U.S. Climate Modeling. I want to revisit those issues in light of the release of a National Academy of Sciences Report, A National Strategy for Advancing Climate Modeling (2012).
I am a co-author of this Academy report. In this blog, I am writing not in my role as a co-author, but from my personal perspective. This blog fits in with many of the themes I have written about in the last few years.
First, I want to explain the role of the National Academy of Sciences. The Academy is a private, not-for-profit organization created by President Abraham Lincoln at the height of the Civil War. Lincoln and others at the time realized the importance of science and technology to the United States and wanted a way to get independent advice on issues important to policy. Almost 150 years later, this importance is greater, but the role of science is an increasingly controversial political issue – especially when scientific investigation comes into conflict with how we might want to believe and to act. (see, here or edited here ) So one role of the National Academy is independent review – a role that is at the heart of the scientific method and the culture of scientific practice.
Second, how does the Academy decide what to write about? The Academy serves as adviser to the government, and so organizations within the government ask the Academy to evaluate a specific set of questions or issues surrounding a body of science-based knowledge about a particular subject. Often, as in this report, there is a forward-looking aspect of the problem, such as an outline for a strategy. One example of a past report is an analysis President George W. Bush requested soon after his inauguration, Climate Change Science: An Analysis of Some Key Questions. This report is famous, partly, because it took one-month from start to finish. It found that the science of climate change was robust. In June 2001, President Bush gave a speech noting, “Climate change, with its potential to impact every corner of the world, is an issue that must be addressed by the world.” (see speech)
The current report on modeling strategy had many sponsors, notably among them the U.S. Intelligence community, a user not a builder of climate models. An early talk to the writing panel was given by Rear Admiral David Titley (Titley talks about climate and national security). In his presentation, he highlighted numerous concerns of the U.S. military, ranging from patrolling an open and disputed Arctic Ocean to threats of rising sea level to billions of dollars in assets. Other issues of national security are related to the stability of nations, the access to resources, and the volatility of commodity markets. A basic question to the panel is on the improvement of predictive skill, to address questions such as, when will we have to rebuild the dry-dock in Newport News, Virginia, and how high will it have to be?
Next, how does a panel like this actually work? The National Research Council is the operational part of the Academy. If you look on the Policies and Procedures link, you will see its rules of operations on, say, conflict of interest. The Academy selects a chair and a panel to answer the sponsor’s questions from a broad range of experience and points of view. Practically, members of the panel are assigned as lead authors on some chapters, secondary authors on other chapters, and reviewers and deliberators on the entire document. In addition to the panel, the Academy assigns staff members to manage the integration of the document as well as to assure the document is written according to Academy protocols. The staff is attentive to moving the document away from personal points of view towards a document that represents the collective view of the panel. That’s the process.
In this report, it was recognized that I was old, and therefore I wrote history - the first draft of Chapter 2, Lessons from Previous Reports on Climate Modeling. Also, having been a co-author on some of those earlier reports, I provided continuity. For this blog, I am going to write from the perspective of someone who has advocated the need for our community to address a set of important organizational challenges. Or given a more than 20-year history of repeated recommendations and a series of Academy reports that re-identified the same problems, as stated in Chapter 2, “A challenge, therefore, to the current committee is how to disrupt the inertia of the U.S. climate science enterprise: going forward, what do we do differently?”
Because of the disruptive consequences of global warming, the scientific study of climate change has, long ago, moved out of the domain of curious scientists driven to explain the world around them. Climate change requires more than interpretation and guidance in order to be relevant to policy. Stated differently, to be directly usable by society, there is a requirement for scientific investigation focused on specific questions or classes of problems. Addressing these problems requires the use of complex software systems, multidisciplinary scientific information, rigorous and transparent evaluation, and interpretation of the knowledge produced and its uncertainty. Therefore, addressing these problems requires the combined efforts of many individuals from several professional backgrounds. There needs to be a process of planning, coordination, and execution.
We need, therefore, to coordinate activities that are, traditionally, scientific, computational, and organizational. My experience as a manager of scientific efforts is that organizational coordination is far more difficult than the challenges of computational and scientific coordination. Standing alone, coordination of computational and scientific efforts is stunningly difficult. Therefore, the new, perhaps overarching, recommendations of this report are focused on ideas that the committee viewed as helping to advance coordination, integration, or synthesis.
One of the report’s overall recommendations is “to evolve” towards a national software infrastructure for climate modeling. I think the word “evolve” is important because the reports from a decade ago also recommended software and information system infrastructure. In fact, following those reports, there has been investment and progress, both substantial, in the development of infrastructure. This is documented in the report, with the recognition that the organizational achievements are as notable as the technical achievements. Throughout the report, there are calls to build upon these successes, to utilize the communities that have made the progress of the past decade. To quote, “The Committee recommends a community-based design and implementation process for achieving a national common software infrastructure. While this goal has risks, costs, and institutional hurdles, the Committee believes they are far outweighed by its benefits.”
Another major recommendation is the formation of a modeling summit to promote “tighter coordination and more consistent evaluation” of climate models. This, to me, is perhaps the most novel and most important recommendation. Why? Previous reports have struggled with organizational issues and have made recommendations about re-organizing government agencies or re-focusing governmental organizations. At the same time earlier reports, as well as this report, express reservations about centralization and bureaucratic structures. What this recommendation recognizes is the need for a community-based organization that needs to find its niche within the federal agency structure, the interagency organizations, and the growing community of users. It recognizes the value of increased community-based planning and, hopefully, execution. And it, once again, recognizes the progress of the past decade of community building.
The next key recommendation is to “nurture a unified weather-climate modeling effort that better exploits the synergies between weather forecasting, data assimilation, and climate modeling.” This subject, too, has been flirted with in previous reports, and it is a recommendation that is more controversial than one might imagine. These two communities, weather and climate, have come to the modeling problem from different perspectives. Their practices of science have some distinct differences. There is also in the United States an idea held by many that weather forecasting is “operational,” and that “operational” comes at the expense of “science.” This recommendation from the Academy panel is based on the facts that 1) “operational” does not have to come at the expense of “science,” and 2) rationalization or unification of the different practices of science come with the benefit of more robust science-based products.
The final overarching recommendation is about the development of a new type of professional, the climate interpreter. This recommendation follows from other Academy reports and a growing body of research into the barriers of the use of climate information by scientists and practitioners who need climate information in their research, applications, and decision making. This recommendation explicitly recognizes the importance of formalizing the interfaces between climate modeling, more broadly climate science, and the usability of climate information by society as a whole.
These new recommendations are supported by a series of recommendations, which are, again, focused on pulling together the community: the scientific efforts, the computational efforts, and the interfaces to society as a whole. These supporting recommendations focus on continuation and strengthening of important activities that are of especial importance.
I want to also point out a few things that the report is not. It is not a list of important scientific questions. Many such lists have been made, and they are often the natural product of a group of scientists thinking about strategy. It is not a recommendation that if the government reorganizes in some way or simply provides more money, then we will address all needed climate services. We have no way to reorganize the government, and we are smart enough to know the challenges of money. And, finally, this report is not a call to centralize through reorganization. As a government manager, for years I studied centralized organizations, federations, and anarchist groups. I feel that centralization in a field and environment like ours is, primarily, a process that leads to increased risk. I feel that federated, community-based responsibility is the best path to assure success. It is also the most difficult.
As a final comment: I am a co-author of the report writing a blog that is my point of view. If I were asked to interpret the report in a strategic sense for a program manager, this is where I would start. One of the lessons I have learned, it having been recognized that I am old, is that this report is now in the hands of the public. Some people will interpret the report to support their agendas, sometimes their prejudices. I looked at past reports that I have been involved with, and I have seen recommendations cherry-picked for both good and bad reasons. The message of this report is synthesis, integration, and coordination. For the report’s message to become reality, those with the power to act and to implement need to focus on synthesis. We need to go forward more as a whole than as a thousand points of expertise brought together in grand exercises of climate-science assessment.
Updated: 3:10 PM GMT on September 19, 2012
By: RickyRood, 6:04 AM GMT on September 01, 2012
Looking Under the Cloak of Complexity: Models, Water, and Temperature (7)
This is a series of blogs on models, water, and temperature (see Intro). The earlier entries in the series are linked at the end.
Doing Science with Models 1.4: In this series I have used the example of balancing a checkbook to talk about the balance of energy that is at the center of the study of the Earth’s climate. In one of the earlier entries I wrote about the cloak of complexity that obscures climate science, and I made the statement that climate science was, in fact, simple physics (energy balance) but in a complex system. In this entry I want to explore complexity. I will stick to the budget equation for money.
Here again is the budget equation for the amount of money that I have.
Today’s Money = Yesterday’s Money + Money I Get – Money I Spend
The equation looks pretty simple, but … when I first started to think about how to write about models, rather than “Money I Get,” I wrote down “Income.” After I thought about that for a moment, I saw that the Money I Get might come from several places. If I use the model of a 1040 Tax Form, for instance, I might have income, and royalties, and gambling winnings. If I get lucky, I might just find some money. I’ll ignore the various methods of ill-gotten gains. The point is that the Money I Get can come from a number of places. It can get pretty complicated if, say, I have a couple of jobs, get paid for some piecework, sell my jars of homemade pickles, receive vouchers for health insurance, and hurry to collect every penny of Social Security that I can.
Then there is Money I Spend. That should probably have been Money I Get Rid Of, because I might drop some money, get robbed, or lose my retirement investment because I bought into a good-sounding geoengineering project to cool the planet using tunnels in the ocean. Again there are a lot of ways that things can get complex simply by the way I get and the way I get rid of money.
The comparison of the budget equation to the Earth’s climate and climate change is that there are many ways the Earth can gain energy or get rid of energy. Even if you say, “The Earth gets energy only from the Sun,” then if you think about how to count that, there is energy from particles like electrons and protons and there is energy from radiation, like visible light. Then there is that question point of view, are we really interested in how much of that energy reaches some boundary of Earth at the edge of Space, or are we interested in the amount of energy at the Earth’s surface? The answer is, scientifically, both of these places, but for the climate that matters to the humans on the surface of the Earth, we have to know what energy gets to surface of the Earth. So we start to add and subtract: We have the Sun's energy at the top of the atmosphere minus the energy that goes into charging up the ionosphere minus the energy that breaks up oxygen atoms to make ozone minus the energy reflected back to space by clouds … you get the point. Simply calculating the budget of energy that gets to and goes away from the surface of the Earth is a challenging accounting problem.
Point of View: In the previous blog I wrote about the importance of point of view. What does the stick man on Simple Earth see?
Figure 1: Simple Earth 1: Some basic ingredients of the Earth’s climate.
First, let’s look into his accounts. He has a checking account to pay his utilities and a checking account to buy knitted sweaters for his terriers. There are a couple of savings accounts, retirement accounts, and because of his years as a highly paid scientist, a large mutual fund of ethically based, environmentally sensitive companies. At the end of every month, if there is money left in his utilities account, then he puts half of that into one of his savings accounts and the other half into that account for the terriers’ sweaters.
So let’s think about that transfer. From the point of view of the sweaters-for-terriers account, the transfer from the utilities account is Money the Terriers Get. It is a source of money – production. From the point of view of the utilities account, this is Money the Utilities Spent. From the point of view of the stick man, money is conserved; the total remains the same. Looking at the level of the accountant, the transfers between accounts are losses in one account and gains in another account, but the total worth remains the same.
Bringing it back to the stick man’s climate, he sees energy going from the ocean to the atmosphere (perhaps in a hurricane), energy going from the atmosphere to the land (perhaps blowing over trees), energy going from the ocean to land (surf on the beach), energy going from the atmosphere to ice (melting the glaciers in Glacier National Park). These are all transfers within the accounts of the Earth. When the winds make waves in the Gulf of Mexico, the atmosphere loses energy and the ocean gains an equal amount of energy. We build up more and more complexity, but we are still just balancing a budget.
There is one more source of complexity that I want to explore -Time. Let’s start with credit. One month, a simply fabulous terrier sweater appears on the web, and I charge it on my Usurious Bank credit card. Usurious lets me take years to pay and only charges me 5 percent per month. So now rather than What I Spend happening instantly, I have already spent some of the Money That I (will) Get. Of course, it costs me a little more than the actual money I paid for the terrier sweater; there is that interest rate. Every month, an extra bit of money is added to the debt that I will eventually have to pay.
We add complexity to our accounts by spreading out our income and expenses over time. If I were fortunate enough to lend money and receive interest then someone else's debt would look like income to me, but spread out over time. We do this all the time; we invest; we buy on credit; we buy items that we hope will become more valuable, like terrier sweaters of the Hapsburg’.
Where does this element of Time fit into the climate? Everywhere. Energy (heat) and carbon dioxide can stay in the ocean for a long time compared to how long they stay in the atmosphere. How long? That, too, is an issue of complexity, but think about the interest rate in that loan. If the interest rate goes up, it costs you more, and if you pay the same amount every month, then it takes you longer to pay off the debt. If you increase the Time that the atmosphere holds energy (heat) near the surface of the Earth, then it takes a little longer for that energy to get back to Space, to leave the Earth. Therefore, the surface of the Earth is warmer. We change the transfers between accounts. It still, however, only requires us to balance the budget to understand what is happening.
Interesting Research: Recent Warming Reverses Long-Term Arctic Cooling - This past week saw a record low in Arctic sea ice. (nice blog in Washington Post) The previous record low was in 2007. There are those who dismiss this as a record low of sea ice because it is from “satellite data,” which are only about 30 years of observations. But I would argue that we can make a pretty convincing argument that these are record lows for, well, thousands of years. It’s really quite profound.
The paper that I want to highlight in this entry is a couple of years old. It is “Recent Warming Reverses Long-Term Arctic Cooling” which was published by Darrell Kaufman and co-authors in Science in 2009. ( Correction, 2010 ). This paper looks at the energy budget and temperature of the Arctic over the past 2000 years. The data that are used to represent temperature are from tree rings, lake sediments, and ice cores. All of these are valid proxies for temperature, and we rely on some type of model to convert the original measurement, for example, the amount of biological detritus in lake sediment to temperature.
Lake sediments provide a remarkable measure of temperature. Because of the extreme cold of the winters, and the lack of biological activity, the biological part of the sediments is a measure of summertime temperature. Biologically rich, summertime layers are separated from each other by biologically poor sediments from other seasons. This allows numbering the years with high confidence.
If you focus on the Arctic for the last 2000 years and count up the energy budget, an important part of that budget comes from the energy provided by the Sun. Because of the way the orbit of the Earth around the Sun changes, for most of the last 2000 years there has been a decreasing amount of sunlight in the Arctic summer. If only solar heating was considered, the Arctic should still be cooling. This is documented in the paper.
Starting in the 20th century, the warming of the planet associated with increasing greenhouse gas has countered the cooling associated with decreasing solar heating. This signal has increased in the more recent years, with the graph beginning to look like a variation on the hockey stick. Here is a version of one of Kaufman’s summary figures from the website of Scott Mandia at SUNY Suffolk entitled Global Warming: Man or Myth?
Figure 2: Summary picture of Arctic mean temperatures for the past 2000 years from Kaufman et al. (2009) (Correction, 2010). This figure was redrafted by the University Corporation for Atmospheric Research. The figure shows a decline in temperature that is consistent with a decline in solar heating. Though the solar heating suggests a continued decline in temperature, this decline (loss of energy at the surface) has been overwhelmed by warming (gain of energy at the surface). The warming is attributed, primarily, to carbon dioxide buildup.
So again and again, climate scientists use this accounting to understand the energy present in the different accounts that make up the portfolio of Earth’s energy budget. The story is consistent: the surface of the Earth is warming. The Arctic is the most stunning example of this warming. There has been enough energy to melt ice that had accumulated over many years. And in the past five years, we have seen two record lows of ice extent; ice mass declines. These years are amongst the warmest in the last 2000 years. The ice will continue to decrease with weather systems causing the ice amount to vary up and down a little bit. There is no reason to expect systematic cooling and recovery. The Navy will need a new fleet for the open waters.
Models, Water, and Temperature
Models are Not All Wet: Series Introduction
Models are Everywhere
Ledgers, Graphics, and Carvings
Balancing the Budget
Point of View
Updated: 1:19 PM GMT on September 21, 2012