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Interface of Climate Projections and Public Health

By: Dr. Ricky Rood, 4:34 PM GMT on September 01, 2009

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


posted from Dubai.

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.