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, 5:42 AM GMT on December 29, 2013
Best Possible Future
In a couple of weeks I will be starting my climate change problem-solving course. I didn’t teach last winter as I was working on a project called the National Climate Predictions and Projections (NCPP) Platform. My participation in NCPP follows from my class, and NCPP is focused on how to improve the usability of climate change knowledge in planning and management. We recently had a publication in Eos, called the Practitioner’s Dilemma. I also worked on an adaptation plan for Isle Royale National Park. You can get a copy of the report at this link. Working on that report we came to the realization that in many cases we really cannot look to the past, look to conserve the past, but that we need to look to manage the best possible future with a warming climate and changing rain and snow.
Starting in 2011 I quit teaching about “avoiding dangerous climate change,” which was the policy statement that we might control our emissions well enough to keep the average surface temperature from rising more than 2 degrees Celsius. I starting teaching that we needed to prepare for a world with at least 4 degrees Celsius warming. We’ve already passed 400 parts per million carbon dioxide, and there is no indication that we “collectively” are going stop our rate of emissions anytime soon.
I believe that it is far more likely that we will take action to reduce our emissions if we use the current information that we have in planning. Take the Isle Royale project, for example. A unique aspect of Isle Royale is its isolated wolf-moose, predator-prey ecology. Even without the challenges of climate change, the future of this ecosystem is fragile. The Park Service faces contentious decisions about managing the wolf and moose populations. There is nothing from a warming climate that works in favor of the wolf-moose ecosystem. Isle Royale is already at the southern edge of boreal forest. Disruptions to the forest due to extreme weather events will occur, and after these events, the ecosystem will be recovering in a climate that is warmer, where snow cover is changing, surrounded by Lake Superior, which has been warming more quickly than the land. There is no reason to expect that the ecosystem will be the same after the disruptions that will surely occur. This will change the browse that the moose rely on; the ecosystem will be different. Thinking about these problems in terms of plausible scenarios makes the impact of climate change far more real.
A revelation from the Isle Royale work was the need to think more about the best possible futures rather than preserving the past. Weather has always been disruptive, and we have always behaved with the idea that the weather of the future will be, mostly, like the weather of the past. If we continue to rebuild and plan with the assumption that the future will be like the past, then we will be making mistakes that we do not have to make. In the case of Isle Royale, a small isolated ecosystem, there is little reason to believe that left to what occurs naturally that the ecosystem in 100 years will be much like the ecosystem of 100 years ago. The same is true for more human constructs, like the City of New Orleans. The challenges of keeping New Orleans and the energy infrastructure that surrounds New Orleans viable, much less vital, will become greater and more expensive.
As I have changed my class over the years, I talk less and less about national and international policy options. I read an interview of Robert Stavins in the Harvard Graduate School of Arts and Sciences Alumni magazine, Colloquy. ( Here is a PDF of the current issue with the interview.) Professor Stavins is a leader in environmental economics and policy. In the interview he stated optimism that the world is moving slowly towards climate policy. There were a number of reasons for guarded optimism, but he viewed that the most fundamental was that negotiators had moved away from putting “the world into two groups: the industrialized world and the other countries,” which assured that nothing would happen. Still with regard to policy to mitigate greenhouse gas emissions effectively: “International climate policy development, for a whole set of scientific, economic, and political reasons, is a very gradual process.”
I have expressed optimism in previous blogs. My optimism has largely been based on my students, and their willingness to take on these problems of planning and adaptation, while dismissing the arguments of climate-change denial as disruption founded in political, emotional and financial self interest. I find that more and more cities and regional planners realize that they need to take climate change into account if they are to make the best decisions they can make for the communities and organizations they care about. They understand that their weather-related vulnerability is changing.
We may or may not be moving towards mitigation of carbon dioxide emissions. If we are moving forward in a very gradual process, this means that “dangerous climate change” is unavoidable. Dangerous climate change can be far less dangerous if we use the knowledge that we have now in our planning. The exercise of using this knowledge changes how to think about the knowledge generated by scientific research. It leads to research questions on what is important to improve the usability in real-world problems, often a far different perspective than the questions to improve our fundamental knowledge of the Earth's climate.
Updated: 3:25 PM GMT on December 29, 2013
By: RickyRood, 4:16 AM GMT on December 16, 2013
Klima Abruptus (1): Introduction
I have been waiting for some time for the new National Academy Report on abrupt climate change (Abrupt Impacts of Climate Change: Anticipating Surprises, there is a free PDF download). I am interested in how those most expert in the field would frame the problem. In 2007 I wrote a short blog on abrupt climate change, and in late 2012 I wrote a couple of long blogs about why I think climate change is moving fast rather than slowly and incrementally. A major difference between this and an earlier Academy Report is that this report discussed impacts on ecosystems services and built infrastructure more thoroughly. I expect to come back to this document several times in the next few months.
In this report abrupt means that the changes “come faster than expected, planned, or budgeted for, forcing more reactive, rather than proactive, modes of behavior” (old blog adaptive vs reactive). The length of time that is considered as abrupt is years to decades.
I am going to start with the table in the document’s summary, which you can page through starting with this link. The report lists a set of potential abrupt changes and a near-term outlook. The near-term outlook is whether or not there is likely to be an abrupt change in current trends that will need to be incorporated into planning and management during the next century. The likelihood is listed as low, moderate and high. The list of moderate includes, decrease in ocean oxygen; increase in intensity, frequency and duration of heat waves; increase in frequency and intensity of extreme precipitation events (droughts / floods / hurricanes / major storms); and rapid state changes in ecosystems, species range shifts and species boundary changes. Listed as high likelihood are late-summer Arctic sea ice disappearance and increases in extinctions of marine and terrestrial ecosystems (earlier blog on extinction). In this short-term, 100 years, the panel has concluded that rapid destabilization of ice sheets leading to greatly accelerating sea level rise is of low likelihood.
I have seen the conclusion on ice sheets and sea level rise listed as “good news.” However, if you look at the time horizon beyond a hundred years, many of those abrupt changes that are listed as low, move to high. And, for things such as heat waves, abrupt means a rapid acceleration of current trends. There will be significant disruption from the present trends. Therefore, this report should not be viewed as one of good news allowing us to lessen our concern about climate change.
Ocean oxygen? I like seeing this in the report. The loss of ocean oxygen, leading to rapid ecosystem changes, comes from the combination of nitrogen pollution from runoff, ocean acidification and rising temperatures (a blog with nitrogen and acidification). Too often these environmental problems are treated separately and disconnected.
I was surprised that the “changes of patterns of climate variability (e.g., ENSO, annular modes)” was listed as low likelihood. Aside from the fact that I am currently intrigued by this particular form of climate change, the document lists a couple of other changes that might have significant impacts on circulation - notably all that is going on in the Arctic.
As a final piece of this introduction, at the American Geophysical Union there was a session introducing the National Academy Report. The abstracts are there now, and I think that the talks might show up there as well. I’ll pick out some highlights over the next few weeks.
Klima Abruptus: OK, In my family I would be accused of mixing my Greek and my Latin. I know. So I did it on purpose.
Glaciers and Global Warming by Jeremy Bassis. Give it some hits!
Updated: 5:07 AM GMT on December 16, 2013
By: RickyRood, 6:25 AM GMT on December 08, 2013
Cold Weather in Denver: Climate Change and Arctic Oscillation (8)
I’ve been living with this cold weather in Colorado this week. If you look around at the Wunderground personal weather station sites, we’ve seen a lot of about -10 F at nights. It’s been causing a lot of grief for homeless people, animals and pipes. There have been a few record lows set. The whole Arctic air mass is starting to move east, which means it will get a lot more press. According to Jeff Master’s blog 80% of the country will be below average.
I thought I had finished my series of blogs on the Arctic Oscillation a couple of weeks ago, but this cold air out break takes me back. It that series I wrote about cold air in the Arctic that is isolated because of barriers caused by streams of rapidly moving air that flows around polar latitudes. I described wobbles in the streams that caused cold air to move south and warm air to move north. Here is one of the figures that I used.
Figure 1: This figure is from the point of view of someone looking down from above at the North Pole (NP). This represents a weak, wavy, wobbly vortex displaced from the pole. The vortex encloses cold air, represented as blue. The line surrounding the cold air is the jet stream or the edge of the vortex. (definition of vortex)
Figure 1 shows an idealized schematic of the North Pole as viewed from above. This is the weak vortex case, when there is a large wobble. In this case, the point X is cold and the point Y is warm. In a case of a stronger, more circular vortex, then the case would be reversed, with point X warm and point Y cold.
Here is a figure from the European Center for Medium-Range Weather Forecasts (ECMWF), that I have marked up a bit. The colors are the temperatures at the 850 hecto-Pascal surface, which is about 1.5 kilometers above the surface. The 850 hecto-Pascal temperatures are a good indicator of where it is hot and cold at the surface.
Figure 2: This figure is from the point of view of someone looking down from above at the North Pole (NP). The contour lines on the figure are the height of the 500 hecto-Pascal surface, which is between 5 and 6 kilometers above the surface of the Earth. The colors are the temperatures at the 850 hecto-Pascal surface, which is about 1.5 kilometers above the surface. The 850 hecto-Pascal temperatures are a good indicator of where it is hot and cold at the surface. Figure from the European Center for Medium-Range Weather Forecasts (ECMWF)
I drew a blue arrow showing that the cold air at the pole has wobbled off of the pole and it is pushed towards Colorado. To the west there is warm air, red arrow, pushing up towards Alaska. So while it has been cold in Colorado, it has been quite warm in much of Alaska. Though a less prominent signal, there has also been warm air moving up the East Coast of the U.S. The Alaska – Colorado contrast is a nice real-world example of what I showed in Figure 1. For completeness with my example, the big, black dashed line is the jet stream of air flowing around the pole.
There were several points in my series on the Arctic Oscillation. The first important point is that even in a world that is getting warmer, the polar latitudes become isolated as the Sun goes down for the winter and jet stream intensifies. In this isolation it gets cold, because there is no heating from the Sun and the polar latitudes have a barrier between themselves and the warmer lower latitudes. The second important point is this wobble, the pushing of air off of the pole in some direction. In this case the coldest air is over Greenland, Canada and the U.S. If there is sufficient wobble to push the air far to the south or if it gets pushed to some place it did not get pushed before, then it is even likely to have record cold. These points are all work together and are not correctly viewed as independent events. (I was recently annoyed by the parenthetical dismissal of global warming in this otherwise nice prediction of early strong lake effect snow in Michigan. The statement was essentially pockets of cold Arctic air should not exist.)
I will finish with the Arctic Oscillation. The Arctic Oscillation Index from the Climate Prediction Center is shown in Figure 3. The discussion in my Arctic Oscillation series focused on the positive and negative phases of the Arctic Oscillation Index. Much of the attention was on the eastern U.S. The negative phase was when it is likely to be very cold in the eastern U.S.
Figure 3: Arctic Oscillation Index for early August 2013 until December 7, 2013 from the Climate Prediction Center
In this measure of the Arctic Oscillation Index, the most recent times have been weakly positive, tending towards negative. (Perhaps suggesting movement of the cold air towards the U.S. east coast?) Perhaps more important Figures 2 and 3 together show that large undulations with warm air pushing far northward and cold air displaced off the pole can occur in other parts of the world when the index is weak. As pointed out many other times over the years of this blog, what goes on in the U.S. is not good instantaneous editorial content for climate change.
Climate Change and the Arctic Oscillation 2
Climate Change and the Arctic Oscillation 1
Wobbles in the Barriers
Barriers in the Atmosphere
Definitions and Some Background
August Arctic Oscillation presentation
CPC Climate Glossary “The Arctic Oscillation is a pattern in which atmospheric pressure at polar and middle latitudes fluctuates between negative and positive phases.”