The Next Problems
The Next Problems:
I am about to start to teach my climate change class for the fourth time. When I started teaching this course I did not know what to expect. I went into the course thinking that the discourse needed to change. Most of the conversations that I heard were about Kyoto, and often the conversation was about the Bush administration’s failure to sign the Kyoto Protocol. There was this idea that if the U.S. signed the Kyoto Protocol, then the climate problem would be solved. There was this idea that the solution resided in some movement of federal policy.
What struck me was that all of the conversations were polarized – this or that. Similarly they were stunningly simplistic. I found that the general knowledge about climate change was quite high. In fact, with regard to the knowledge of the Earth’s climate as a whole, the non-scientists in my class often knew more than the scientists. Therefore, it was not a lack of knowledge of the climate that was the issue. It was the realization that the climate change problem is completely intertwined with society. There was climate and policy, climate and energy, climate and public health, climate and agricultural, climate and this and that. And all of these issues are related, and climate and energy are, today, completely correlated, and energy use is at the core of economic success. It’s a complex problem. It’s a problem motivated by science, but once past the motivation, science comes into relation with all of these other interests. Often science does not bring immediacy to it all. We are faced with this enormous, long-term environmental problem, wrapped up with the immediacy of energy security and at the whim of markets and the economy.
We are at a governmental transition that, with respect to science (not just climate science), looks to be about as different as it can be. People are positioning themselves, planning for what might be and what they might want to be. With that, I want to return to the science, and what are the science issues that are evolving as the most consequential.
Here is my list:
1) Land (and sea) ice is melting faster than predicted in the IPCC Assessment Report 4. This is due to the over simplification of the melting of ice in previous models.
Rignot, E. and P. Kanagaratnam, 2006: Changes in the velocity structure of the Greenland ice sheet. /Science/.
Rignot, E. and K. Steffen, 2008: Channelized bottom melting and stability of floating ice shelves. /Geophysical Research Letters/.
2) Because of the underestimation of ice melt, sea level rise has been underestimated. We are committed to sea level rise, and we need to plan accordingly.
Shepherd, A. and D. Wingham, 2007: Recent sea-level contributions of the Antarctic and Greenland ice sheets. /Science/.
Horton, R., C. Herweijer, C. Rosenzweig, J. P. Liu, V. Gornitz, and A. C. Ruane, 2008: Sea level rise projections for current generation CGCMs based on the semi-empirical method. /Geophysical Research Letters/.
3) The terrestrial and ocean sinks of carbon dioxide are likely to be less effective than previously stated. (Be on the look out for a new paper by Jorge Sarmiento.)
Behrenfeld, M. J., R. T. O'Malley, D. A. Siegel, C. R. McClain, J. L. Sarmiento, G. C. Feldman, A. J. Milligan, P. G. Falkowski, R. M. Letelier, and E. S. Boss, 2006: Climate-driven trends in contemporary ocean productivity. /Nature/.
Polovina, J. J., E. A. Howell, and M. Abecassis, 2008: Ocean's least productive waters are expanding. /Geophysical Research Letters/.
4) The acidification of the ocean is likely to be more disruptive sooner than expected.
J. Timothy Wootton, Catherine A. Pfister, and James D. Forester, 2008: Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset, /Proceedings National Academy of Sciences/.
Orr, J. C., V. J. Fabry, O. Aumont, L. Bopp, S. C. Doney, R. A. Feely, A. Gnanadesikan, N. Gruber, A. Ishida, F. Joos, R. M. Key, K. Lindsay, E. Maier-Reimer, R. Matear, P. Monfray, A. Mouchet, R. G. Najjar, G. K. Plattner, K. B. Rodgers, C. L. Sabine, J. L. Sarmiento, R. Schlitzer, R. D. Slater, I. J. Totterdell, M. F. Weirig, Y. Yamanaka, and A. Yool, 2005: Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. /Nature/.
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Given our poor representation of the physics of melting in land ice, abstracting this to a tendency to underestimate changes that are associated with phase changes of water, melting of permafrost and release of greenhouse gases stored in permafrost is likely to be underestimated.
We must pay increased attention to adaptation. There is no reason to believe that we can mitigate our ways out of the above. We need to develop the capability to do Climate Impact Assessments for both 'geo-engineering" and the geo-engineering that we will do because of energy policy and land-use and the vagaries of billions of people. This leads to a type of modeling that is different from the type of modeling that most scientists advocate.
As I have stated before, our knowledge of climate change gives us unprecedented knowledge of the future. We have opportunity. We have responsibility.
Thanks for all of the feedback from this blog, and I am looking forward to the next year.
r
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Updated: 9:06 PM GMT op 14 januari 2009
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Cold in a Warm World:
Cold in a Warm World:
I am returning to science in this blog, and ultimately, what I might call a “thinky” problem, thinking about, “how can it be so cold in such a warm world?” We are in the midst of a cold spell that stretches pretty much from coast to coast, north to south, across most of the United States. Of course this has caught the attention of Mr. Limbaugh, who paid wunderground.com a high compliment. (Some have suggested to me that he is not familiar with all of the content on the web site.) First, I want to (re)state something about form of argument. The attribution of a particular warm event or extreme hurricane to global warming is generally not founded in scientific analysis. People, who maintain the argument that global warming is not real, often point this out in their refutations. Similarly, being cold for a while does not stand as proof that global warming is somehow, bogus. If it is your passion to argue that global warming is not real, then it is disingenuous to use the same fallacious form of reasoning as is sometimes used in the attribution of a particular event to global warming. That said - let’s think about how it can be so cold in such a warm world.
As stated in this climate change blog over a year ago, the fundamental role of weather in the climate system is to transport heat from the equator to the pole. This role is complicated by the importance of water and the energy associated with the phase changes of water. Indeed, our notion of climate stability is anchored in the notion of a global-scale balance of the ice, liquid, and gas phases of water. The differential heating between the equation and the pole drives a circulation to reduce the temperature gradient. The dynamical systems that develop also transport water. The range of temperatures that are common to the atmosphere causes phase changes of water, which in turn significantly impact the spatial and temporal distribution of energy.
Also recall that in the absence of greenhouse gases, especially water and carbon dioxide, the Earth would be much colder; it would be frozen and unpleasant. Hence, one could imagine something like a spring that is “pulling” the temperature down towards this “radiative equilibrium” temperature. The surface warming due to green house gases pulls on this spring.
Just because there is more carbon dioxide and water vapor in the atmosphere does not mean that it does not get cold. The Earth is still tilted on its axis, and the Sun still does not rise on the winter pole. Hence the solar heating is absent in the winter, and the surface and the atmosphere cool down.
Many of the wunderground.com audience are familiar with the idea of “air masses.” Air masses were commonly used to describe the climate and weather, especially, before the 1950s. They remain a useful concept. The basic idea is the following. Large areas of air reside over, for example, continents or the sea, and take on the characteristics of the surface that sits under the air. This leads to large regions of air of similar characteristics. Classic air masses are, for example, tropical maritime which is warm and wet, and continental polar which is cold and dry. Storms, the weather, take place along the boundary of air masses.
If the atmosphere becomes “stuck,” and there is not a lot of mixing between air masses, then the air masses take on extreme conditions. For example, imagine an air mass that forms over Canada in the winter. There is no sunlight; it will get colder and colder. Then when this air mass does get pushed southward, or just grows large enough to extend southward, it will be very cold in places where it generally is not so cold. “Canadian air” will come to the United States. These cold air outbreaks have been around forever, and in the eastern part of the U.S. are often called Alberta clippers
I lived in Tallahassee, Florida in 1976 and 1977, and that was a winter when it was REALLY cold in Southeast. I remember it snowed in Tallahassee and people tried to rake up the snow so they could take pictures. And even better, people who missed the shiny ice on trees put sprinklers in the yard, covered the trees and broke off all of the limbs. We’re just never satisfied are we?
Back to the thinking, it gets us to a couple of questions. What are the reasons that the atmosphere “gets stuck” and air masses take on their most extreme characteristics? That requires a complex answer, and there are still research questions to be addressed. Conceptually, however, we can set up the reasons. If you look at the weather maps of the Northern Hemisphere, in winter and summer you see some “average conditions” that repeat year after year. These are patterns of gigantic highs and lows, like the Aleutian Anticyclone and the Bermuda High. There are two major factors that contribute to average location of these mega-features. These are the contrast of temperature between the land and the ocean and the placement of the mountain ranges. How these mega-features in middle latitudes vary from year to year is the complex part that we don’t completely know. We can find relationships to other mega-features like the El Nino / La Nina cycle. And there are some aspects of the details that might, in fact, be properly described as “chaotic.” But on average, the temperature of the land and the ocean and the mountain ranges set the stage.
There is no doubt of the observation that if the atmosphere gets stuck, a characteristic sometimes known as a “persistent anomaly,” that the air can take on more and more extreme characteristics. (For those who are serious about the weather, look up ideas such as “blocking,” and “cut-off lows.”)
A second question that is begotten in this thinking exercise is, “what is role of climate change?” A warming climate will warm the ocean. The ocean temperature does not vary as much from winter to summer as the land temperature because the ability of the ocean to hold heat, the heat capacity, is much larger. Even in a warming Earth, when the sun goes away for the winter, the land will continue to get very cold. The land’s heat capacity is low compared with the ocean’s. It is reasonable, therefore, to expect that the contrast between land and water, one of the major factors in determining the position of those mega-highs and mega-lows that lead to air masses, will change. As I write this, remember this is a thinking experiment and for better or worse, it is, more or less, a stream of consciousness, it occurs to me that in the Northern Hemisphere the sea ice has changed tremendously in the last 30 years. Reduction of sea ice changes, drastically, the behavior of the surface temperature of the Arctic Ocean. Suddenly I see this isolated North American and Siberian land, cooling its little heart to space after the sun goes down, surrounded by warmer and warmer ocean water. I have not analyzed or researched this problem, but I would expect it to change the behavior of the highs and lows in a very real way.
In my class on climate change I teach that the following are robust: The surface of the Earth will warm, sea level will rise, and weather will change. I don’t say exactly how the weather will change, because it is not easy to quantify, not easy to reduce to a few adjectives, and the answer is not well known. We believe for sound physical reasons that extreme events will get more extreme, persistent patterns of drought and flood will amplify. These changes in extreme events are consistent with persistent anomalies becoming more persistent.
That it has been cold this week in Detroit, Chicago, and Denver gives me comfort that it can still get cold, that the physics of it all holds together, but it gives me no indication what so ever to doubt that the planet is warming. For now, it still has to get cold in the winter.
r
Previous blog on persistent anomaly and drought. This one includes other links.
Dry 'Lanta // SoCal Fires and Climate?
Here is a list of links to basic definitions used in climate.
IPCC Glossary
Arctic Climatology and Meteorology Glossary
Wikipedia Climate Definition
World Meteorological Organizations Climate Theme Page
Figure 1: Air mass tutorial from the University of Illinois.
Cold in a Warm World:
Cold in a Warm World:
I am returning to science in this blog, and ultimately, what I might call a “thinky” problem, thinking about, “how can it be so cold in such a warm world?” We are in the midst of a cold spell that stretches pretty much from coast to coast, north to south, across most of the United States. Of course this has caught the attention of Mr. Limbaugh, who paid wunderground.com a high compliment. (Some have suggested to me that he is not familiar with all of the content on the web site.) First, I want to (re)state something about form of argument. The attribution of a particular warm event or extreme hurricane to global warming is generally not founded in scientific analysis. People, who maintain the argument that global warming is not real, often point this out in their refutations. Similarly, being cold for a while does not stand as proof that global warming is somehow, bogus. If it is your passion to argue that global warming is not real, then it is disingenuous to use the same fallacious form of reasoning as is sometimes used in the attribution of a particular event to global warming. That said - let’s think about how it can be so cold in such a warm world.
As stated in this climate change blog over a year ago, the fundamental role of weather in the climate system is to transport heat from the equator to the pole. This role is complicated by the importance of water and the energy associated with the phase changes of water. Indeed, our notion of climate stability is anchored in the notion of a global-scale balance of the ice, liquid, and gas phases of water. The differential heating between the Equator and the pole drives a circulation to reduce the temperature gradient. The dynamical systems that develop also transport water. The range of temperatures that are common to the atmosphere causes phase changes of water, which in turn significantly impact the spatial and temporal distribution of energy.
Also recall that in the absence of greenhouse gases, especially water and carbon dioxide, the Earth would be much colder; it would be frozen and unpleasant. Hence, one could imagine something like a spring that is “pulling” the temperature down towards this “radiative equilibrium” temperature. The surface warming due to greenhouse gases pulls on this spring.
Just because there is more carbon dioxide and water vapor in the atmosphere does not mean that it does not get cold. The Earth is still tilted on its axis, and the Sun still does not rise on the winter pole. Hence the solar heating is absent in the winter, and the surface and the atmosphere cool down.
Many of the wunderground.com audience are familiar with the idea of “air masses.” Air masses were commonly used to describe the climate and weather, especially, before the 1950s. They remain a useful concept. The basic idea is the following. Large areas of air reside over, for example, continents or the sea, and take on the characteristics of the surface that sits under the air. This leads to large regions of air of similar characteristics. Classic air masses are, for example, tropical maritime which is warm and wet, and continental polar which is cold and dry. Storms, the weather, take place along the boundary of air masses.
If the atmosphere becomes “stuck,” and there is not a lot of mixing between air masses, then the air masses take on extreme conditions. For example, imagine an air mass that forms over Canada in the winter. There is no sunlight; it will get colder and colder. Then when this air mass does get pushed southward, or just grows large enough to extend southward, it will be very cold in places where it generally is not so cold. “Canadian air” will come to the United States. These cold air outbreaks have been around forever, and in the eastern part of the U.S. are often called Alberta clippers
I lived in Tallahassee, Florida in 1976 and 1977, and that was a winter when it was REALLY cold in Southeast. I remember it snowed in Tallahassee and people tried to rake up the snow so they could take pictures. And even better, people who missed the shiny ice on trees put sprinklers in the yard, covered the trees and broke off all of the limbs. We’re just never satisfied are we?
Back to the thinking, it gets us to a couple of questions. What are the reasons that the atmosphere “gets stuck” and air masses take on their most extreme characteristics? That requires a complex answer, and there are still research questions to be addressed. Conceptually, however, we can set up the reasons. If you look at the weather maps of the Northern Hemisphere, in winter and summer you see some “average conditions” that repeat year after year. These are patterns of gigantic highs and lows, like the Aleutian Anticyclone and the Bermuda High. There are two major factors that contribute to average location of these mega-features. These are the contrast of temperature between the land and the ocean and the placement of the mountain ranges. How these mega-features in middle latitudes vary from year to year is the complex part that we don’t completely know. We can find relationships to other mega-features like the El Nino / La Nina cycle. And there are some aspects of the details that might, in fact, be properly described as “chaotic.” But on average, the temperature of the land and the ocean and the mountain ranges set the stage.
There is no doubt of the observation that if the atmosphere gets stuck, a characteristic sometimes known as a “persistent anomaly,” that the air can take on more and more extreme characteristics. (For those who are serious about the weather, look up ideas such as “blocking,” and “cut-off lows.”)
A second question that is begotten in this thinking exercise is, “what is role of climate change?” A warming climate will warm the ocean. The ocean temperature does not vary as much from winter to summer as the land temperature because the ability of the ocean to hold heat, the heat capacity, is much larger. Even in a warming Earth, when the sun goes away for the winter, the land will continue to get very cold. The land’s heat capacity is low compared with the ocean’s. It is reasonable, therefore, to expect that the contrast between land and water, one of the major factors in determining the position of those mega-highs and mega-lows that lead to air masses, will change. As I write this, remember this is a thinking experiment and for better or worse, it is, more or less, a stream of consciousness, it occurs to me that in the Northern Hemisphere the sea ice has changed tremendously in the last 30 years. Reduction of sea ice changes, drastically, the behavior of the surface temperature of the Arctic Ocean. Suddenly I see this isolated North American and Siberian land, cooling its little heart to space after the sun goes down, surrounded by warmer and warmer ocean water. I have not analyzed or researched this problem, but I would expect it to change the behavior of the highs and lows in a very real way.
In my class on climate change I teach that the following are robust: The surface of the Earth will warm, sea level will rise, and weather will change. I don’t say exactly how the weather will change, because it is not easy to quantify, not easy to reduce to a few adjectives, and the answer is not well known. We believe for sound physical reasons that extreme events will get more extreme, persistent patterns of drought and flood will amplify. These changes in extreme events are consistent with persistent anomalies becoming more persistent.
That it has been cold this week in Detroit, Chicago, and Denver gives me comfort that it can still get cold, that the physics of it all holds together, but it gives me no indication what so ever to doubt that the planet is warming. For now, it still has to get cold in the winter.
r
Previous blog on persistent anomaly and drought. This one includes other links.
Dry 'Lanta // SoCal Fires and Climate?
Here is a list of links to basic definitions used in climate.
IPCC Glossary
Arctic Climatology and Meteorology Glossary
Wikipedia Climate Definition
World Meteorological Organizations Climate Theme Page
Figure 1: Air mass tutorial from the University of Illinois.
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Updated: 9:01 PM GMT op 14 januari 2009
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Preparing for the Next IPCC
Preparing for the Next IPCC: This blog continues the series (linked below) where I have tried to give some visibility into the management and politics within the climate community. This one is about how the community is preparing for the next Intergovernmental Panel on Climate Change (IPCC) Report … The next report for the IPCC Working Group I, who are the physical scientists, is scheduled for release in June of 2013. In climate centers around the world, they are already configuring the models that will be used so that they can undergo extensive evaluation before they are run in IPCC experiments.
For the most part, scientific development and the community of scientists are not strongly managed. One of the big changes in the climate community, as the results of the scientific investigation take on more and more importance in society as a whole, is the need to provide “products” for particular purposes, such as the IPCC assessments. In the beginning these assessments were treated like an “add on” to the research activities that had been funded for, more or less, basic research. Today, in the U.S. there is a sub-culture of the community that is directly interested in and funded to assure the U.S> participation in IPCC. There is a constant tension between the need for basic research and the requirement to produce the products necessary for the scientific assessment of climate change. (More on that, next time. Science is managed differently in other countries.))
As suggested in the previous blogs there are a variety of ways that the community organizes to meet the need for IPCC assessments. For the next assessment, named Assessment Report 5 (AR5), it is anticipated that new types of numerical simulations will be needed. Rather than running an array of scenarios to outline what will happen, there will be more consideration of what can and will be done to stabilize the climate.
One way that the community is organizing is through a program called the Climate Model Intercomparison Project. (CMIP) . This will be CMIP number 5; hence, CMIP5. The CMIP projects follow from the Atmospheric Model Intercomparison Problem which was started in 1990. There is also an even longer history of model intercomparison and assessments in the stratospheric ozone community.
These intercomparison projects are an important part of model evaluation, but they are just part of the testing and evaluation that is done in assessing the strengths and weaknesses of models. They all have basically the same steps. Observations are the foundation of any evaluation. Hence, there is the need to identify a set of observations that will be used in the evaluations. There are hundreds of possibilities, and over the community as a whole, virtually any credible observation set that provides useful information has been used. However, there are a few that rise to stop as standard. A couple of examples are the surface temperature observations as, for example, compiled and validated and maintained by the Hadley Center and the Goddard Institute for Space Studies. Another classic example are the cloud and radiation observations that come from the Clouds and the Earth’s Radiant Energy System (CERES) instruments that fly on several satellites. (Here’s where you can get some data.)
Observations sit at the foundation, but there are several other critical elements in model evaluation. One of those critical elements is to have at least one group of independent researchers mode up of members NOT responsible for the model development. This is a group that can look at models with objectivity. In the U.S. the Program for Climate Model Diagnosis and Intercomparison is such a group. (This group is sponsored by the Department of Energy’s Office Biological and Environmental Research.)
Also critical to the process is the design of numerical experiments. (Yes, some scientists argue that there is no such thing as a “numerical experiment,” but it is possible to set up robust scientific experimentation with numerical models.) For example, in the Atmospheric Model Intercomparison Project, all of the models simulate from 1979 – 2000 using observed monthly mean sea surface temperatures. This time span was chosen because of the presence of global satellite observations. There are several standard runs in the climate model intercomparisons. An example is the “modern industrial era,” approximately the past 150 years.
Another element of the evaluation is the selection of objective measures for the evaluation and intercomparison. One of the standard measures is called the Taylor Diagram, which is an accumulation of statistical information from many data sources and many models. Here is an example of a Taylor Diagram.
Figure 1: Taylor Diagram: (primer) The plot is constructed based on the Law of Cosines. The observed field is represented by a point at unit distance from the origin along the abscissa. All other points, which represent simulated fields, are positioned such that the variance is the radial distance from the origin, the correlation is the cosine of the azimuthal angle, and the normalized root mean square difference is the distance to the observed point. When the distance to the point representing the observed field is relatively short, good agreement is found between the simulated and observed fields. In the limit of perfect agreement (which is, however, generally not achievable because there are fundamental limits to the predictability of climate), the root mean square difference would approach zero, and and correlation would approach unity.
Finally, this is an example of organizing and planning in the climate community. The process works from both the bottom and the top. Some scientists see the need for both coordination and the need to have controlled experiments across many organizations. They self organize, then seek funding from the agencies. Sometimes the agencies see the need for organization, and then offer incentives and opportunities for scientists to organize. I want to point you to an interesting document for next major IPCC assessment. This is a strategy document developed by part of the modeling community. It is an example of scientists trying to take part in the definition of the best experiments to support the assessments. Here’s A Strategy for Climate Change Stabilization Experiments with Atmospheric Ocean General Circulation Models and Earth System Models. And here are the objectives as quoted from this document.
1. Identify new components that are currently under implementation or will be ready in the next six months for inclusion as first generation Earth System Models in Atmosphere-Ocean General Circulation Models (AOGCMs).
2. Establish communication through WCRP, IGBP, IPCC, the climate impacts community, and integrated assessment (IA) modeling teams to coordinate activities in preparation for climate change simulations that will be performed with this next generation of climate system models for a possible IPCC AR5.
3. Propose an experimental design for 21st century climate change experiments with these models (near term and longer term time frames).
4. Specify the requirements for these new models in terms of time series of constituents from new stabilization scenarios (particularly with regard to impacts, mitigation, and adaptation).
Links to relevant blogs.
Importance of Justification
Buying Big Computers
Fragmented Climate
Organizing the Fragments
This series of blogs collected.
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Updated: 5:24 PM GMT op 05 oktober 2010
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