THINK GLOBAL, ACT LOCAL

by Erica Rex

Although mathematical modelling of climate trends and weather patterns tells us a great deal about climate change, it has an inherent flaw:  we tend to substitute the map for the territory.  Climate models are good at showing trends on a large scale, the same way a map of North America tell us about large-scale geographical features.  A map depicts mountain ranges, rivers, deserts, plains and estuaries, but it doesn’t tell us anything about rainfall variability in Toledo, Ohio, nor about the 106 degree temperatures in Tranquility, California.  A mathematical model, likewise, can calculate how severe an El Niño year might be.   It can predict the likelihood of certain catastrophic events occurring within a given time frame, such as the summertime disappearance of the Arctic ice sheet. But climate models do not give an accurate picture of what happens at the local level.

The Hot Zone spoke with Rasmus Benestad, Senior Scientist, Norwegian Meteorological Institute, and a regular contributor to the climate blog, RealClimate. We asked him to identify issues he thinks are most important in confronting climate change. Among other things, Dr. Benestad believes that there is a need for local scale climate observation to complement and augment the global picture offered by mathematical models.

THZ: What are the most important issues we should be thinking about in terms of climate change?

Dr. Benestad: We need more precise modelling at the local level. This entails a limited area model – a model of a physical location with very high resolution.

THZ: Why is this important?

Dr. Benestad: For instance, if the sea ice in the Arctic Ocean disappears in the summer, seasonal temperature fluctuation in Norway and in Europe will be affected. In turn, storm patterns will change, and seasonal forecasting will be affected. Fisheries will also be affected, which has economic implications.

THZ: How will you obtain accurate observations in local areas, areas we’d consider remote, like Madagascar or parts of Indonesia – places that simply would not have access to the same scientific data gathering infrastructure we have in the US or in the EU?

Dr. Benestad: Countries which have the scientific infrastructure will have to collaborate with those that don’t. The organizations would have to hire local people to do local observations. This requires an economic commitment as well as a commitment to maintaining the infrastructure locally.

THZ: What are the other issues that might be standing in the way of accurately assessing and communicating the impact of climate change?

Dr. Benestad: We need to bring together the disciplines. The people who study the stratosphere generally don’t talk enough with other flavours of experts. There is too little interaction between different related disciplines: physicsists and statisticians or between meteorologists and oceanographers. We need to bring these people together. The issues are very inter-related.

THZ: A bit self-referential, in other words? What I’d call “chimneying?”

Dr. Benestad: Yes.

THZ: Are there other aspects of the discussion you’d consider important?

Dr. Benestad: There are too few people with physics degrees involved in this kind of work. There are too few people involved in this kind of work at all. Compare the number of people who work in finance in Oslo with the number of people who work in scientific disciplines.

THZ: Oslo and everywhere else.

Next time, conversations with Dr. Anastasia Romanou, Associate Research Scientist at NASA GISS and Dr. Watson Gregg, NASA/Goddard Space Flight Center, Global Modeling & Assimilation Office about ocean modeling and the Ocean Biogeochemical EOS Assimilation Model.