…so why is it still being debated?
On a clear day in late October, sunny, blue skies over the Berkeley university campus warmed the afternoon to a comfortable 68 degrees Fahrenheit (20 °C). It was one degree colder than the thirty-year average that afternoon when the Berkeley Earth Surface Temperature study released its findings on global climate change.
They emphasized in their findings, however, that only a large data set from many locations can provide an accurate picture of the global situation. While one-third of data collection sites around the world reported temperature cooling over the last century, two-thirds of the sites showed that temperatures had increased. It might be this unbiased approach used by the Berkeley scientists that will finally sway people who too easily dismiss the doomsday rhetoric that is often used to describe the threat of global warming.
The Berkeley Earth Surface Temperature study has ultimately only confirmed what prior studies had proposed, but it is the first study on climate change to use such a wide range of available data—about five times as much as previous studies. It will take more than reporting what everyone has already heard, however, to convince people that global warming is real.
According to a University of Michigan study published early last year on the opinions of climate change, what people believe is in part dependent on how it is phrased. This divide in understanding shouldn’t be ignored by scientists reporting on global temperature trends. Among self-identified Republicans surveyed in the United States, 60 percent said that “climate change” was real while only 44 percent said that “global warming” was real. (There was no discrepancy among self-identified Democrats who were surveyed, 86 percent of which agreed on the reality of global warming whatever it was called.)
This wording bias has to be expected among a skeptical population. It stems in part from the terms’ meanings. While the word “change” recognizes that there is an issue, its ambiguity finds allies among those who are uncertain about what is actually happening to the world’s climates. The other choice, the word “warming,” decidedly takes a stand that global temperatures are in fact increasing overall. People who are hesitant to use the word warming are at odds with the entire scientific community who insist global warming is the current trend in climate change.
Berkeley Earth was not the first study to report that the change the climate is facing is in fact is a trend of warming temperatures, but a Gallup poll in 2011 reported that 48 percent of readers believed that global warming concerns were exaggerated. This is up from 31 percent of those polled in 1997. Likely heavily overlapping with those people who are hesitant to agree that global warming is real, many feel that this trend isn’t of great consequence even though scientists continue to express their concerns.
What could cause such a widespread rejection of temperature analysis and an increased skepticism of corresponding scientific warnings? Another study has reported that exactly how scientists and governments phrase their concerns over global warming can have a large effect on whether or not those concerns are believed.
Psychologists at the University of California, Berkeley found that doomsday-style threats about global warming can increase skepticism. Their study found that people who view the world as “fundamentally stable and fair” were likely to reject dire warnings about climate change. In comparison, they were more likely to accept positively-worded messages that focused on possible solutions to the global temperature issue.
The study emphasized that “fear-based appeals, especially when not coupled with a clear solution, can backfire and undermine the intended effects.” The more dramatically warnings about climate change are worded, the more skeptical people become. The study insisted that the majority of people are more open to accepting the logic behind proposed solutions than sensationalist warnings of disaster.
Scientists, however, cannot be held responsible for failing to look at the whole picture when they issue warnings about climate change. Looking at both the causes of and solutions to global warming in an attempt to provide a positive message is outside the scope of any one scientific study.
The study released by Berkley Earth, for instance, only seeks to prove that there is a general trend of rising temperatures in the world. It refuses either to speculate on the causes of that trend or to propose a solution.
It is up to interested groups to combine the results of several studies so that they may propose solutions to global warming at the same time as they admit to the crises. In this way, they are not dismissed as mere doomsayers by global-warming skeptics.
Scientists Long Cao and Ken Caldeira from Carnegie Global Ecology have proposed exactly such a solution to one of the aspects of global warming. An increase in global temperatures can cause dry areas of the world to get even drier, which leads to droughts and famine. These scientists released a study in March of last year that shows how reducing the concentration of carbon dioxide in the atmosphere will increase precipitation in those areas.
This is a cure for only one of the symptoms of an increase in global temperatures, but Cao emphasizes that while it might take many decades for the climate to cool again, “we would see precipitation increase within the year … if we could cut carbon dioxide concentrations now.” Presenting solutions like this one alongside analysis of the trends of climate change helps to outline that global warming doesn’t spell disaster for a prepared society.
Rather than commenting on possible solutions to global warming, the study released by Berkeley Earth tries to sway public opinion of climate change with the legitimacy of its data. Its entire data set and corresponding analysis has been made available for peer review.
In addition, it is the first study to openly address the issues of data selection and bias in their results. The scientists considered, for instance, that many data collection sites located within urban environments would obviously report a general rise in temperature, but this corresponds to the growth of cities over the last century. This is known as a heat “island” effect because increases in the ambient temperatures of cities is not indicative on its own of an overall warming in global temperatures.
Robert Rohde, the lead scientist for Berkeley Earth, emphasized in his comments on his work that data from no one area can be conclusive evidence of global trends. The climates of local areas do contribute to skepticism surrounding global warming however. He suggested that “the large number of sites reporting cooling might help explain some of the skepticism of global warming.”
Despite what every study is reporting about the world-wide trends, the Berkeley Earth study reveals that a noticeable minority of areas have reported global cooling. People who have felt cooling temperatures in their area or who have heard of that shift reported by their local weather office are less likely to be convinced of a global trend of warming temperatures.
Even factoring in the areas that have experienced cooling, the Berkeley Earth study found that average world land temperature has risen by approximately one degree Celsius since the mid-1950s.
Their study is the latest contribution to the ongoing debate with skeptics about the concerns of climate change, but according to Berkeley Earth’s findings, there should be no debate over the legitimacy of global warming. By more thoroughly analyzing the data of temperature collection sites around the world, Berkeley Earth has hoped to prove once and for all what the scientific community is already agreed upon: global temperatures are rising. What should be done about it, however, is still up for debate.