Climate change models omit key component
University of Guelph | February 27, 2014
Climate models used to study temperature change from greenhouse gases are missing a key ingredient — economics, according to a new study by a University of Guelph professor.
Economist Ross McKitrick, an expert in environmental policy analysis, says most models ignore the effects of socioeconomic change on land use changes, making those models inaccurate.
The study, co-authored with Lise Tole of Strathclyde University, was published online in the journal Climate Dynamics.
McKitrick has studied how land use changes from urbanization, agriculture and other surface modifications affect temperature trends around the world. Past research suggests these effects might account for some of the warming patterns in weather data. Climate modelers assume that the effects are filtered out at the data processing stage, he said.
“As a result, when researchers look for explanations of regional patterns of climatic changes, they rule out things like urbanization by assumption and give greater weight to global factors like greenhouse gases and solar variations,” McKitrick said.
The study examined data from 22 sophisticated climate models used by the Intergovernmental Panel on Climate Change (IPCC). The researchers compared how accurately those models would have predicted spatial warming patterns over land between 1979 and 2002 with predictions from a much simpler model using data on regional industrialization and socioeconomic growth.
“The contrasts were striking,” McKitrick said. Twenty of the IPCC models made predictions that were no better than random guesses or that contradicted the observed patterns, he said.
“Only two of the 22 models showed any explanatory power for the temperature changes over the same period.”
By contrast, the simple economic model made much more accurate predictions.
Using various statistical techniques to compare modeling approaches, the researchers found that usually the economic model was essential and the climate model could be dropped, but never the other way around.
One technique involved searching more than 537 million combinations of climate model outputs and socioeconomic data for the best possible mix. The research team found that combining three of the 22 climate models and a small number of socioeconomic indicators best explained the spatial pattern of surface temperature trends.
“By assuming the socioeconomic effects are not there, a lot of climate researchers are ignoring a key feature of the data,” McKitrick said.
The researchers also found that the best climate models aren’t necessarily the most well-known ones. The best models came from labs in China and Russia and from one American institute; models from Canada, Japan, Europe and most U.S. research labs lacked explanatory power, either alone or in combination.
The study has important implications for policy-makers, McKitrick said. “Computer forecasts of regional climate changes between now and 2030 can look impressive in their detail, but it would be wise not to make major policy decisions without first looking into the model’s forecast accuracy.”
The findings are also important for researchers, especially those using climate data sets. “A lot of the current thinking about the causes of climate change relies on the assumption that the effects of land surface modification due to economic growth patterns have been filtered out of temperature data sets. But this assumption is not true.”
Originally published on June 20, 2012 by the University of Guelph. Ross McKitrick speaks at the What Matters Now event in Thunder Bay on March 4.
Adjusting goals is not ...
Deborah Durbin | January 12, 2015On January 1st many people set bold exercise goals for themselves as part of their New Year resolutions. Come Valentine’s Day, though, most of those goals have fallen by the wayside, tossed aside along with empty heart-shaped candy boxes. read more »
Let shopping be your ...
Noreen Fagan | December 18, 2014Here’s a fun fact – Canadians eat more sushi than the Japanese. At least that’s what Mark Cleveland says, and he should know. Cleveland is a professor of marketing at Western University. His research focuses on the integration of cultures on a global scale and the effects of cosmopolitanism, which according to Cleveland is, “the cultural openness and the ability to successfully navigate between different cultural groups.” In other words, people who want to understand and experience other cultures do so by fully immersing themselves in that culture. “You want to live the life of cultural authenticity, by trying to understand the culture through that culture’s eyes,” he says. Cleveland’s interest in cultural openness started when he was a Master’s and then a Ph.D. student at Concordia University in Montreal. He started researching how new immigrants, primarily ethic minorities, adapted to Canadian culture by finding ways to combine their traditional identities, culture and values into mainstream society. “I have always believed that just because you learn another culture does not mean you give up the original culture. You can be bicultural or multicultural and the two can reinforce each other,” says Cleveland. “Not only are minorities affected by cultural exchange but the majority are as well.” Canada’s multiculturalism prompted Cleveland to extend his research into globalization, with a focus on how global cultures affect majority populations around the world. In the last decade Cleveland has conducted research in 15 to 20 countries exploring cultural exchange and cosmopolitanism. He says a person no longer has to travel abroad – although it helps – to become cosmopolitan. A person can experience different cultures in the comfort of their own home or neighbourhood, simply by watching TV, surfing the Internet, playing videos on You Tube or buying and consuming different products. “When we buy products, and types of brands and the reasons for buying them, they are like extensions of ourselves,” he says. So how do the sushi–eating Canadians fit into all of this? Cleveland believes if a person wants to experience cultural authenticity they will gear their shopping towards achieving that aim. In other words, a person is not going to go for the North American version of sushi (think Californian Roll), when they can get the real thing – think Unagi. He says there is probably a general global trend towards cultural openness as people become more educated and have more exposure to other cultures but he warns, there is another side. “A lot of people are really opposed to what is happening with Globalization and they see their culture as under threat,” says Cleveland adding that the threat is heightened when people feel insecure. If people are feeling secure in their surroundings (financially, emotionally and physically), the more open they are to cultural exchange and the more cosmopolitan they become. Being cosmopolitan however, does not mean buying local is a thing of the past; in fact what makes cosmopolitans stand out is that they strive for cultural authenticity. “The more cosmopolitan you are means you are not only interested in preserving differences but also interested in the environment, like getting the best locally,” says Cleveland. In terms of cosmopolitanism Cleveland thinks Canadians are more accepting of other cultures. “We are a new country, most of us go back two or three generations and have one or two grandparents born somewhere else. We have a more fluid identity,” he says, adding that as large cities go, Toronto is well integrated. “We are not just living in these areas dominated by our own ethic group, there are more opportunities to mix, and I think that allows us to become more open-minded.”