In this blog post, I’d like to summarize my thoughts on how to distinguish between the claims I want to believe and objective evidence when examining social issues, as well as my reflections on the various arguments surrounding global warming.
Our Attitude Toward Social Issues
We encounter countless social issues throughout our lives. Some, like the U.S. eavesdropping on Germany, the Senkaku Islands dispute between China and Japan, the Dokdo dispute between South Korea and Japan, and global warming, are frequently covered in the media, while others receive little attention in our daily lives. We tend to pay even more attention to these issues when they involve our own country or are likely to directly affect our personal lives and interests.
For example, we tend to pay more attention to issues that could affect our lives—such as global warming—rather than issues that have almost no direct impact on the daily lives of South Korean citizens, like the Senkaku Islands dispute between China and Japan. We also naturally focus more on international disputes in which South Korea is directly involved, such as the Dokdo issue, the “Northeast Project,” and the “comfort women” issue. Furthermore, when confronted with issues that stir patriotism, most people end up supporting the position of their own country.
Taking the Dokdo issue alone, many South Koreans believe that Dokdo is Korean territory and that Japan is making baseless claims. I, too, couldn’t help but reflect on what my own stance is regarding such issues. However, when I stop to consider whether I can accurately explain the reasons behind my beliefs, the story changes.
Even among the people around me, while most hold the belief that Dokdo is South Korean territory, few can explain the specific grounds for why they think that way. Most people accept the arguments they encounter in the mass media without much critical scrutiny and do not delve deeply into whether the data presented by those media outlets as evidence is actually reliable or consistent with the facts.
If we think objectively, we need to question whether South Korean mass media can always report on such international disputes or social issues with perfect objectivity. In reality, however, it seems that many people choose the direction indicated by the majority opinion or the argument that appeals to them psychologically, rather than meticulously scrutinizing the objectivity and reliability of the evidence.
This problem can also be found in the debate surrounding global warming. Arguments that global warming is caused by carbon dioxide emissions from human activity are pitted against claims that current climate change is due to natural climate fluctuations rather than human activity. As I read through the relevant materials, I came to believe that rather than readily accepting one side’s argument, I should first examine how objective and reliable each piece of evidence is.
The Argument That Global Warming Is Caused by Human Activity
Those who believe global warming is caused by human-generated carbon dioxide emissions primarily cite the IPCC’s climate reports as evidence. The IPCC is a consultative body jointly established by the World Meteorological Organization and the United Nations Environment Programme to address issues related to global environmental change.
The IPCC’s Fourth Assessment Report, cited in the materials at the time, clearly states that concentrations of greenhouse gases in the atmosphere are increasing due to human activities and explains that the warming effect caused by rising greenhouse gas levels is greater than that caused by changes in solar radiation. It also states that global temperatures have risen by approximately 0.76°C since 1900, and that the rate of temperature change over the past 50 years—1.3°C per century—is higher than the rate of 0.74°C per century observed over the previous 100 years.
This data is used as evidence to support the claim that global warming is actually occurring. In particular, when examining temperature graphs estimating past temperatures in the Northern Hemisphere—derived from ice cores, tree rings, and microscopic rock fragments from glaciers—one can observe a sharp rise in temperature toward the end of the time series.
The fact that such abrupt temperature changes are occurring raises questions about whether current global warming can be explained solely by natural climate variability.
Claims that human activities are influencing climate change are also raised based on this data.
So, what arguments are being made by the opposing side? While researching relevant materials, I realized that the debate surrounding global warming is not simply centered on the single fact that “the Earth’s temperature is rising.” There were differing interpretations regarding the causes of current temperature changes and the data and methods that should be used to determine those causes.
The Argument That Natural Changes, Rather Than Human Activity, Are the Cause
Those skeptical of global warming argue that the Earth’s current temperature changes are caused by natural factors rather than greenhouse gases emitted by humans. Fred Singer and Dennis Avery present this argument in their book ‘Don’t Be Fooled by Global Warming’.
One piece of evidence they cite is the periodicity of past global temperature fluctuations. They note that past temperature changes on Earth followed a cycle of approximately 1,500 years, which closely aligns with the cycle of variations in solar activity. Therefore, they argue that rather than attributing the current warming solely to human activity, it can be viewed as part of a natural climate fluctuation occurring in cycles of about 1,500 years.
Another piece of evidence is the temporal relationship between carbon dioxide and temperature changes. According to the greenhouse effect theory, an increase in atmospheric carbon dioxide should lead to a rise in temperature. However, some analyses suggest that changes in Earth’s climate lag behind changes in carbon dioxide levels by about 800 years. Based on this data, it is also possible to interpret that atmospheric carbon dioxide concentrations increased as Earth’s temperature rose.
Furthermore, it is argued that warming similar to what we see today was measured even before carbon dioxide emissions increased significantly due to human industrialization. The fact that global temperatures actually showed a declining trend up until 1975—a period of high carbon dioxide emissions—is also cited as evidence casting doubt on the link between human-generated carbon dioxide emissions and global warming.
While examining these debates, the “hockey stick graph” particularly caught my attention. This graph, depicting temperature changes in the Northern Hemisphere and created by Dr. Michael Mann, was used in the IPCC’s Third Assessment Report. It is called the “hockey stick graph” because the sudden, sharp rise in temperature since 1910 resembles the shape of a hockey stick.
However, Singer and Avery question the graph’s accuracy, arguing that the data used in its final segment includes a significant amount of urban data heavily influenced by the urban heat island effect. Additionally, Stephen McIntyre and Ross McKitrick of Canada claim that when they reprocessed Dr. Mann’s data, they obtained results different from those of the original graph. In the graph they produced, global temperatures in the early 15th century were higher than those in the 20th century, where the hockey stick curve is currently located.
If this claim is accepted at face value, it leads to the conclusion that the original hockey stick graph contained errors in the data processing, and that current warming may also fall within the range of natural temperature variations.
Doubts about the IPCC report also extend to climate models. Singer and Avery cite a 2001 NASA report to argue that climate models at that time did not adequately reflect reality, and they question the extent to which such models should be trusted.
Is it easy to determine what the truth is?
After examining all these differing data sets and arguments, it actually becomes even harder to reach a judgment. Looking at data from just one side, the argument seems very persuasive, but reading the opposing data makes a different conclusion seem possible.
It is particularly difficult for the general public, who lack specialized knowledge in the field of climate science, to review all this data and determine which argument is correct.
This is because one must understand the methodology behind each study, how the data was collected and processed, and even how the graphs were created.
Nevertheless, we often jump to conclusions too quickly when it comes to complex issues. Take the issue of global warming, for example: many people naturally assume that global warming is caused by human industrial activity and that we must therefore strive to solve it.
Of course, we cannot simply conclude that such a conclusion is wrong in itself. What I found important while reading this material—regardless of whether the conclusion is right or wrong—was the process by which that conclusion was reached. When we believe a claim, do we sufficiently examine whether its evidence is objective and reliable? Or are we simply more inclined to accept data that aligns with what we already believe?
Why do we tend to believe the claims we want to believe more readily?
In this regard, we can consider the term “regression to the mean.” Regression to the mean refers to the tendency for results to converge toward the average when predictions are made based on a large amount of data. However, in human psychology, there are times when the exact opposite phenomenon seems to occur. This is especially true when we observe how people’s opinions on political leanings or social issues tend to polarize easily.
Let’s assume there are two claims, A and B, and that evidence supporting each is presented in roughly equal measure. Normally, one would compare the evidence from both sides to determine which is more valid. However, people tend to accept as true the evidence that supports the position they already believe in, while being reluctant to trust evidence that supports the position they do not believe in.
Ultimately, even when both sides are given equal evidence, that evidence can actually be used to reinforce the position they originally held.
From the perspective of “regression toward the mean,” it would seem that Opinions A and B should converge toward a middle ground to some extent as they examine each other’s evidence. However, human psychology does not necessarily work that way. Instead, people may cling to what they want to believe, causing the outcome to skew toward either extreme.
Reflecting on this, I realized that when considering social issues, it is more important to first examine why I believe a certain claim rather than simply what claim I believe.
