Climate change models omit key component

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.

Tagged: Economy, Nature, Blog, Events, Stories

Share: Print

Leave Comments

Blog Posts

Manipulus florum

From manuscript to search ...

Guest blogg by Chris Nighman | October 23, 2014

Long before the advent of the Internet, and well before Gutenburg invented moveable type, medieval intellectuals devised information technologies to take advantage of a growing mass of Big Data repositories known as “manuscripts.” In the 13th century, the florilegium was the state-of-the-art technology for making the wisdom of great thinkers more accessible – a sort of aggregator site for manuscripts. A florilegium is a collection of proverbs and short extracts from famous philosophers and theologians, organized so readers could immediately find (statim inuenire) what they were seeking. Thomas of Ireland’s Manipulus florum (“Handful of flowers”) is the most prolific and probably most influential Latin florilegium. Containing some 6,000 Latin quotations organized under 266 alphabetically organized with an elaborate cross-referencing system, the Manipulus represented the cutting edge of information technology when it appeared at Paris in 1306. It was systematically reproduced by the Parisian stationers’ companies, surviving in nearly 200 manuscripts and printed at least 50 times between 1483 and 1887. In 2002, I began work on a searchable online edition of Thomas’s florilegium which I completed in 2013 with the help of many talented students at Wilfrid Laurier University and two computer scientists at the University of Waterloo. While Thomas created his florilegium as a handy resource for theology students at the Sorbonne to pursue their intellectual and spiritual development, I wanted to use digital technologies to make it even more accessible. I worked to make the database especially helpful to Latin philologists and historians wishing to trace the influence of the Manipulus on later texts. We developed Janus, an “intertextuality search engine” that works differently from conventional search engines, which only allow users to search according to keywords. Janus enables scholars to compare a long digital text to the entire edition of the Manipulus in a single search query to find all overlapping passages. For those who don’t read Latin, the website provides English translations of portions of the Manipulus, and there are plans to translate the entire text. Readers are invited to access my translations of Thomas’s preface to the Manipulus and the 29 quotations on marriage: Clearly, Thomas chose quotations that are mostly very critical of marriage, but I don’t think he was against marriage itself, nor was he necessarily a misogynist, though most of the 30 quotations he gathered under the topic Woman (Mulier) definitely are. Rather, I believe that he wanted to dissuade male university students from taking a wife, as explictly expressed by one particular quotation against marriage. Janus was an essential tool in my research for a forthcoming article in which I discuss Thomas’s treatment of marriage and women and show how a 15th-century author used the Manipulus to create the stereotype of the female witch. He did this by employing misogynist quotations from Thomas’s florilegium to “prove” that women are more susceptible than men to being seduced by demons into practicing black magic, an early example of how writers’ intentions can be twisted by readers to their own purposes.

If you’re happy ...

Cathy Majtenyi | October 22, 2014

Brock University recently launched a series of monthly podcasts covering a wide range of themes. As part of our own package of “Belief” related blog posts, Research Matters is pleased to present this exclusive interview with Brock Associate Professor of Psychology, Michael Busseri. Busseri will join two other colleagues to explore this topic in Brock’s January 2015 podcast, “What gives us a sense of wellbeing?” (Busseri is no stranger to Research Matters, having answered one of the great questions asked of the Curiosity Shop, “Why is the grass always greener on the other side?”)   BU: How do you define wellbeing? MB: Historically there have been two broad traditions. One looks at things like satisfaction, enjoyment, pleasure and not pain. That’s called the Hedonic Tradition. The second tradition is about finding meaning, purpose and growth; that’s called the Eudemonic Tradition. Where the rubber meets the road for most people is the question of, ‘How can I get more of that, whatever it is?’ It all sounds good: who wouldn’t want a meaningful life, a purposeful life, an enjoyable life? One camp says, you know what? Happiness, wellbeing – regardless of the type – is determined by the genetic lottery of life. It’s more like a personality trait. They may fluctuate around that day-to-day, moment-to-moment, but if you check in with them every year and do that for 10 or 20 years in a row you find a lot of stability. The other camp says, well, that might be true for many people but there’s still a significant chunk of individuals who experience radical changes as a result of, unfortunately, largely negative life events: the death of a spouse; the loss of a job; a tragic injury; horrible crime. The impact of that event can last years for some individuals. BU: Can we become happier? MB: Short-term: there’s lots of evidence that people change their wellbeing; moment-to-moment, day-to-day, week-to-week. Longer term: it’s harder to find people who show the golden pattern of continuous increases. Where there are long-term changes in wellbeing, it tends to be on the down side. The ratio is almost two to one. But even those people who experience the lasting decreases – they are rare. We can be talking no more than 10 per cent of the population. The vast majority of us over the long term tend to be stable.   BU: Should we be discouraged or encouraged by those statistics? MB: The argument is, this is actually a positive thing! It shows how adaptive and resilient people are. The high highs, the people who experience lots of positive experiences in our lives are also the individuals who tend to experience lots of lows. In the extreme, we tend to think of these as “manic” individuals. Usually, this idea of huge fluctuations in wellbeing is not something we would recommend. BU: Is there any part of our wellbeing we can control? MB: Most of us want a satisfying and meaningful life beyond simply saying, well, you may win or lose the genetic lottery of life. But we can choose how we spend our time. Moment-to-moment, day-to-day, week-to-week, we can have some influence by choosing certain activities or choosing to spend time with people who are meaningful and important to us. Even if we realize that that boost is going to be temporary, who cares? For those moments that we’re experiencing it, we’re happy! BU: Can we “bank” these happy moments to draw upon when we feel sad? MB: Another controversial issue. Some people have argued that what you experience moment-to-moment gets stored in a separate bank than the part of you that holds the beliefs about your life. Daniel Kahneman, a Nobel prize-winning psychologist, has suggested we talk about this as two “selves.” The “experiencing self” is the you that, moment-to-moment, is experiencing life. The other self is the “story-telling self,” which has beliefs about how your life is going. Often those beliefs don’t align very closely with your experiencing self. It turns out there are cultural myths about wellbeing that influence our stories. One of these is that young adults tend to believe life gets better and better, and older adults tend to believe that life gets worse and worse. Both are myths, but you find these myths around the world. They’re wrong because for most individuals, the “real life story” is one of stability, not one of inclines and declines.

Lucid dreaming depends on ...

Trent University Staff | October 21, 2014

New research by Trent University Oshawa Anthropology professor Roger Lohmann and graduate student Shayne Dahl indicates that cultural learning shapes the kind of awareness and control people can experience while dreaming. “Scouring the ethnographic record on dreaming for hints of lucidity under Professor Lohmann’s guidance, I found something surprising: that lucid dreaming is widely thought to have serious consequences,” said Dahl, who completed his M.A. thesis, “Knowing Means Connecting with the Source of Life: Knowledge and Ethics among Blackfoot Traditionalists” at Trent in 2012. (He is now a Ph.D. candidate at the University of Toronto.) “As one of my Blackfoot informants put it, ‘You could die in your dream.’” Lohmann and Dahl’s findings were published in the 2014 collection, Lucid Dreaming: New Perspectives on Consciousness in Sleep. Lucid dreaming – waking consciousness arising during a dream – has been a hot topic of scientific research in recent years. According to Lohmann and Dahl, the common assumption that dreams are products of isolated imaginations has distorted our understanding of lucidity’s variation in form, function, and real-world outcomes. Pop culture portrayals in films such as Avatar and Inception present fantasies where lucid dreaming enables marvelous real-world powers. Many traditional and religious cultural worldviews take the relationship between waking and dream worlds as reality rather than fantasy. Lohmann’s fieldwork in Papua New Guinea among the Asabano people explored how they used dreaming as evidence for and contact with supernatural beings. “Asabano converts often told me that seeing dreams of Jesus or Heaven convinced them that what the missionary told them was true,” said Lohmann. “It struck me that they had to believe their dreams were more than figments of their own imaginations to reach that conclusion, and that I, for example, would not be convinced by the same experience because of my different cultural background.” Similarly, Dahl’s fieldwork in Alberta included encounters with Aboriginal medicine men who practiced lucid dreaming. “Shayne’s field experiences and his search of ethnographic literature brought home to us that lucid dreaming has profound potential for people who think it’s more than just a fantasy. We found that descriptions of lucid dreams are radically different in form, function, and outcome depending on the cultural assumptions of the dreamer,” said Lohmann. Their research revealed evidence that in some cultures, lucid dreaming is unknown, while in others it is a commonly taught skill. In some, lucidity is tacit rather than acknowledged, but people nevertheless believe that they actively undertake goals in their dreams. Lohmann and Dahl found that this implicitly lucid “volitional dreaming” commonly appears in ethnographic accounts of dreaming. In cultures where “generative” theory holds sway, dreaming of something is understood to cause it to happen in the waking world. This leads people to experience lucid dreams as opportunities to create or do magic. By contrast, people who believe dreams are what one sees during “soul travel” use lucid dreams as an opportunity to spiritually visit real places. “Even when we consciously disbelieve our dreams,” Dahl said, “They still affect us at a deeper, emotional level that we can’t easily control with reason.” “All of this shows that cultural dream theories are multiple, that people invoke them in complex ways, and that they are at the very core of what lucid dreaming is and what it makes possible,” said Lohmann. This story was originally published by Trent University on, July 15, 2014. Is has been edited for style, brevity and clarity and appears here with permission.

In money we trust

U of T Staff (With introduction by Patchen Barss) | October 20, 2014

A few years ago, late, late at night, I was tooling around the streets of Ottawa in the back seat of a Jeep being driven by former Bank of Canada Governor David Dodge. American economist and Nobel Laureate George Akerlof was riding shotgun. read more »
digital wallet

Phony shoppers

Marianne Koh | September 30, 2014

Cash gave way to magnetic strips, which gave way to chip-and-PIN, which gave way to “tap-and-pay” credit card scanners. Get ready for the next thing. read more »
More Blogs »