Arctic is Extreme
Arctic is Extreme
A couple of blogs back in August I talked about this summer’s sea ice in the Arctic and the implications of an ice-free Arctic Ocean on national security. Jeff Masters recently had a blog that updated both sea surface temperature and Arctic sea ice. The ocean is still warmer than ever observed, and sea ice was the third lowest observed. The last three years have been the three lowest of a relatively short sea ice observation record.
In the last few weeks there have been a number of reports about the Arctic. Since the 2007 IPCC Report, there has been increased analysis of the uncertainties in the predictions of Arctic climate change and the behavior of ice sheets. There has also been more scrutiny of the observations, and an entire campaign to investigate polar regions (The International Polar Year).
The paper by Darrell Kaufman and many colleagues, entitled Recent Warming Reverses Long-Term Arctic Cooling (Science, 2009), is an elegant analysis that puts together many pieces. This paper uses observations from ice cores and tree rings, and especially, lakes across the Arctic. Sediments are used from the lake. These sediments are laid down and there is a temperature dependence of the sediments. There are both physical and biological reasons that there is temperature dependence. The easiest process to understand is the presence of creatures and creature detritus in the sediments, which is related to the biological activity of the spring and summer. (There are good references in the paper if you want to know more – here’s one: Smol et al. PNAS 2005 , and a simple web resource varve analysis) Therefore, we can get good records of not only each year for the last couple of thousand years, but differences between the warm season and the cold season.
The paper looked at several pieces of the puzzle. One piece is the fact that the orbital parameters of Sun and the Earth are such that there should be less solar heating of the Arctic. Therefore, based on the Sun, the Arctic should be cooling. This is found to be true for much of the last 2000 years, essentially to 1900. For the last century, however, they find systematic and strong warming. The signal sticks out like a sore thumb. So the paper establishes, from observations, that not only is there warming, but the warming overwhelms the cooling expected from the wobbles in the Earth’s motion about the Sun. The paper does not, however, stop here. The authors also add a long model simulation looking to see if the same signal is found in the models. The answer is yes, and it is a remarkably robust signal. The robustness of the signal is likely due to the strong signal found in the Arctic, and the sensitivity of that signal to snow on the land and sea ice. Remember, if there is less snow, less solar energy is reflected, more is absorbed, and the warming is amplified. The amount that the warming of the Arctic in the twentieth century lies outside of the 2000 year average is stunning.
This analysis reminds me of another analysis that I felt especially convincing, that of Osborn and Briffa (see blog)that established that the geographical extent of twentieth century warming was the greatest of, at least, the last 1000 years.
The Arctic is warming, and the magnitude of that warming is so far outside of the natural variability that it is, like the IPCC report said, “unequivocal.” It’s still a hard trip, but two German merchant ships went from Korea to Siberia in the Arctic Ocean, and they are already planning to do it again in 2010.
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Arctic Sea Ice Extent from Snow and Ice Data Center Daily Update
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Updated: 04:03 GMT le 24 septembre 2009
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Public Health Challenges in India
Public Health Challenges in India
On the Road (3): Home
I want to finish this series motivated by my trip to Goa, India to a conference on public health and climate change in India. In this one I will give an overview of some of the issues that were discussed at the meeting; that is, how people are thinking about the public health impacts.
There were a series of talks that focused on malaria, cholera and water borne diseases, air pollution, and extreme weather events. As someone coming from a physical climate background there was a lot for me to learn.
The interface of climate change to problems of public health brings, yet another, level of complexity to be addressed. With a disease like malaria, for instance, there is large sensitivity in the transition regions that separate wet and dry climate zones. In regions that are normally dry, flooding rains lead to outbreaks of mosquitoes, and the possibility of malaria outbreaks. There are also the oft cited issues of malaria moving into regions where it is currently too cold for the mosquitoes and protozoan parasites that cause malaria to live. Of note in India, this means that higher altitude regions become more vulnerable. What was most new to me was the realization that the life cycle of the protozoan, itself, was temperature dependent – it can reach maturity faster at higher temperatures.
Also of special note to those interested in climate change is the fact that the bacteria that causes cholera is sensitive to the salinity of water. Cholera is usually transmitted by consuming contaminated water or food. Issues of climate change and cholera bring attention to the coast, intrusion of salt water into river deltas, and coastal inundation associated with sea level rise and extreme storms.
When I was growing up, I was schooled about the importance of public health to very fabric of society in the United States. Much of this schooling was on sanitation and how efforts of basic sanitation in the U.S. in the early part of the 20th century led to reduction of many diseases and afflictions. I am in fact old enough, and Southern enough, to remember being lectured about hookworm and rickets. The national effort for polio vaccinations was a big deal, and we were so happy when there were Sabin sugar cubes, rather than needles. I bring the role of the practice and execution of public health forward because it helps to place the role of climate change into context.
If you look at differences between the U.S. and India, or if you travel to different parts of India, even different parts of New Delhi, one is struck by the manifest importance of clean water. Many people in India are exposed to contaminated water. Even in the presence of contaminated water, families can help control water borne diseases using personal filtration and treatment; hence, highlighting the importance of education, availability of tools, and training in how to use the tools. This is true today, right now, and developing the capacity to address public health problems today helps to build the capacity needed to address changes that might come from climate change.
It is this development of societal resilience and/or adaptive capacity that is the focus of those who are planning for expected impacts of climate change. In many places, planning for climate change becomes linked to planned or needed development projects; that is, projects that are needed to develop basic infrastructure and the capacity to address existing problems. This linkage between development and adaptation to climate change is a growing concept; it makes sense, and does not appear as a risky investment.
This is an approach that works in the case where climate change poses an incremental change to an existing problem. A more difficult problem is when climate change might lead to vast changes or the emergence of new problems. For example, there are many millions of people in South Asia who live and grow their crops in low lying river deltas. There will, with certainty, be more intrusion of salt water into these regions, which will not only displace people, but it will ruin agricultural land. There are also diseases such as dengue fever, for which explosive spread might be possible. (Here’s a link to dengue in Mexico to bring it a little closer to home.)
This trip to India changed my perspective on climate change – it made it far more real. For the country as a whole, Indian agriculture is highly sensitive to the climate and the onset of the monsoon. The bulk of the water comes in a relatively small number of days of precipitation. River flow is highly seasonal, and it will become more seasonal, higher high flows, and lower low flows, because of changes in snowpack in the northern mountains. This natural sensitivity sits together with a large population and a large portion of this population that is highly vulnerable to their environment. This vulnerability ranges from exposure to contaminants and pathogens, to sensitivity to crop failures, to exposure to extreme weather and coastal flooding. The consequences of climate change in India, Pakistan, and Bangladesh will be significant and will have international consequences. Tough problems will be made tougher.
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posted from Ypsilanti.
Figure 1: Here is a greeting card sent to meeting participants by Dr. Ashwani Kumar of India’s National Institute of Malaria Research (ICMR). Credit for the figure is Bayer Environmental Science.
Here is a .pdf to a good article on climate change and public health, with a emphasis on the U.S. Lead author is Howard Frumkin, who gave a great overview talk at the meeting. Frumkin et al.: Climate Change Public Health. From American Journal of Public Health
Previous blogs in this series:
On the Road (1)
On the Road (2)
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Updated: 16:52 GMT le 12 septembre 2009
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Interface of Climate Projections and Public Health
Interface of Climate Projections and Public Health
On the Road (2): Goa
I want to follow on from my last entry. At the conference in Goa, India, I gave a talk on climate change in India. My target audience was the interface between public health officials, public health researchers, meteorologists, climatologists and some from nongovernmental organizations and the United Nations. First, let me state, I am not an expert on climate change in India, and this was well known by the conference organizers. But let’s assume that even with this knowledge of lack of expertise, there was a reason that they asked me to speak on this subject. The response to my talk was positive, and interesting enough that I think it is worth writing about.
One issue that plays very large in the global warming community is the interface that sits between the knowledge base of climate change and a whole suite of needs to use this knowledge in applications such as public health and policymaking. There are traps that people fall into at this interface and those traps are based on not understanding the culture and needs of the communities that sit on either side of the interface. Alternatively, one could say that the interface is important, and the interface requires work, and there need to be interface experts. It is unreasonable to expect that there is just some sort of cable plug with the right number of pins to connect fields. Think about that for a minute, if it was like a connection between a printer and a computer, it is not really that the number of pins and sockets line up; it is that they line up with information (signal) sent across from the right place to the right place.
Thinking about an interface, and faced with the need of giving a talk on climate change in India, in a room in India where there are many more expert on Indian climate change than me, I decided to focus on that interface.
You could imagine a couple of ways that climate information might interface with an applications specialist. Let’s imagine an expert in malaria modeling. They know that in certain regions heavy rains are associated with outbreaks of malaria. Therefore, they want a time series of rain events. You can imagine generating such a thing from a climate model, and people do, but the readers of this blog would go crazy about the generation of daily time series from a climate model at the airport weather station 50 years from now. This is a process full of known errors and uncertainties. Still, it is a straightforward approach to a problem and, with careful caveats and methodologies, it is possible to advance our understanding.
Another approach is less detailed. Rather than generating a hourly time series of weather parameters at a set of stations, can we evaluate what are the more robust and what are the less robust aspects of climate projections? It is my opinion that we can, and that we must. I will come back to must below.
If we consider the underlying mechanisms that are responsible for weather phenomena, then we can do an analysis that provides useful guidance to decision makers. For example, in the case of the South Asian monsoon, this is forced by BIG things; the contrast between Asia and the surrounding Ocean, the difference between summer and winter, and mountains, some of them 6,000 meters high. The gross characteristics of these forcing mechanisms are well represented in models, and we are rewarded with a somewhat credible representation of monsoonal flows.
On the other side of it all, there is enormous complexity in the monsoon. There are embedded storms at several spatial scales. There are definitive, but ambiguous, relationships with tropical weather and climate patterns that are not well modeled. There are land use changes, and changes to the land from climate change (snow melts).
So in my talk (This is 15 MB powerpoint. Want it before you click!) , I pose an analysis based on this duality of simplicity and complexity. From my analysis, I think that one can rationalize, meaning place on a rational basis, the prediction that the South Asia monsoonal flow will, with some reliability, continue to supply a lot of water to South Asia. With some certainty, we can conclude that water availability will be affected because of the change of the balance between rain, snow, ice and glaciers. The transition areas are likely to change a lot. (If there is a real devotee of my blog some will remember a series of on the fringe (transition) blogs.) In India one fringe area is the northwest, and I think that the basic underlying meteorology suggests that this area will get dryer. Or perhaps, the risk of this area getting much dryer is so high that it should be planned for.
I also conclude that our knowledge of the details of the organization of tropical convection, the Madden-Julian oscillation, and El Nino will limit our ability to make definitive statements about the variability of the onset of the monsoon.
This type of analysis does not really drive scientific investigation; in fact, some of my friends would maintain that these are obvious textbook generalizations. The analysis does help the decision maker and those with applications required to make plans. It places climate knowledge in context of many other factors, and this is, often, what is needed. The public health official is usually dealing with an existing problem. Therefore, they are looking at how climate change might change their approach to that problem. They need to decide now and cannot wait 20 years until climate modelers are satisfied with their representation of tropical convection. Those details don’t make or break the deal.
It is a fact that those responsible for the infrastructure to support, public health, resource management, agriculture, etc. must always be making decisions that matter for the next 10, 20, 50 years. We must, therefore, be able to analyze the climate knowledge and help inform their decisions. Otherwise, they will either use old information or no information, and that presents a risk that is unnecessary.
There is a big concept at work here. Namely, for both the decision maker and the climate scientist we are working from a place where we have something that exists. When we look forward, plan, we need to decide whether our plans can be incremental changes to that which exists or whether or not something radically different is required. The analysis I pose for the South Asia monsoon is based on the idea that the major forcing mechanisms are such that we can look for incremental changes around the existing state. We can also identify places where we just don’t know, but those places of lack of knowledge do not require us to dismiss that we, in fact, have information that we can use to make rational decisions. It is important to remember that the climate of the Earth is not just some random state of the atmosphere and ocean. It is anchored to the geography and geology of the Earth and strength of the Sun’s heating. There is a chaotic element of the climate, but that does not make climate, fundamentally, chaotic.
OK, back to the talk and my vanity. This analysis was, unless people lie to me, well received. It ranged from policy people telling me it was the first time he had seen a modeler saying that we “know something,” to those far more expert than me on the climate, able to argue details, but saying that the basic foundation made sense. This, to me, is useful
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posted from Dubai.
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Updated: 19:44 GMT le 09 septembre 2009
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