Issues Addressed in this Document

In recent years, awareness of global warming has been on the rise worldwide, alongside concerns for achieving Sustainable Development Goals (SDGs) and maintaining biodiversity. Countries, corporations, and local governments are implementing measures through their own creative efforts, and this is considered a positive trend. However, even among those actively involved in such initiatives, there may be a lack of detailed knowledge about the phenomenon of global warming.

"Is global warming real?" debates are commonplace in today's society, especially with the prevalence of social media. Amidst such discussions, there is a plethora of information where the authenticity is often unclear. While some information may seem convincing at first glance, a closer examination often reveals vague foundations and sources that are difficult to trace. In reality, comprehensively understanding and delving into the theoretical aspects of global warming involves considering an extremely wide range of factors. It is not a topic that can be easily resolved with a quick online search for the average person. Various factors are involved, such as the following:

• Several hundred million years ago until the present day, there have been ice ages, and periods with much higher levels of $CO_2$ concentration than the present. What distinguishes those periods from the present? Are they similar, and how did we arrive at the current environmental conditions?

• How have factors like plants, rocks, ancient deposits, biological activities, and volcanic activities, which absorb or emit $CO_2$, influenced the Earth's environment?

• The mechanisms of ice ages, interglacial periods, and their relationship with $CO_2$.

• The increase in $CO_2$ post the Agricultural Revolution, the rise in greenhouse gas emissions due to human activities post the Industrial Revolution, the reduction in carbon dioxide absorption sources due to deforestation, and their global impacts on temperature and climate.

• In essence, how does the emission of $CO_2$ contribute to the increase in temperature?

Understanding the mechanisms of global warming is naturally challenging, as it arises from a cumulative understanding of the wisdom gained by researchers who have dedicated years of study to individual domains. However, does this mean that the general public should remain uninformed? Is it acceptable to unquestioningly accept information flowing from the media and social media? Among such information, there are likely to be messages driven by political motives or vested interests. Is it okay to remain unable to discern whether such information is correct or distorted? No, there is no acceptable reason for that.

In today's society, where people determine the future of the world through voting, there is a risk that the collective and somewhat shallow wisdom of the masses might lead to disastrously incorrect choices, and once made, these choices may become irreversible.

However, the average person faces urgent challenges in their own lives and is busy with daily activities. While they may be aware of the term "global warming," they don't have the time to independently verify information by consulting literature or papers and determine whether certain knowledge is accurate or suspicious. Acquiring knowledge that requires extensive study over dozens of hours is practically impossible. Yet, being uninformed might lead to unwittingly accepting commonly heard information as true. People might find themselves relying on information like "It is stated in a United Nations report" without thoroughly verifying it.

The information that is frequently heard or seen has been disseminated with some strong intention by the sender, often involving significant financial investments to reach people. Such information may not necessarily be accurate in the context of the original purpose of addressing the global warming issue, and there is a risk of believing information with intentions contrary to justice. Once this happens, correcting people's knowledge later becomes a high-cost endeavor. Therefore, it becomes extremely important to initially acquire correct knowledge.

While this document covers fundamental themes, it does not adopt the stance of believing in information solely because it is presented by international organizations. Instead, it aims to convey scientific evidence as clearly as possible by referencing academic papers and other sources in response to basic questions based on observed facts. As a result, readers will be better equipped to discern the possibility that even information presented by international organizations might be a product of political compromise.

Until now, there has been a lack of comprehensive and specialized literature on global warming that is both interdisciplinary and accessible to the general public. To compile such literature, it is necessary to delve into scientific papers from various specialized fields, as well as government publications. However, this task goes far beyond the scope that an expert in one field can cover, making it impractical for a single specialist to compile information from multiple domains.

On the other hand, if, for instance, a team of 10 experts attempts to collaborate on such a compilation, it may result in a mosaic of explanatory articles from each specialist's field, making it challenging to maintain a cohesive narrative throughout the entire document. Moreover, even with 10 specialists, there may still be areas left uncovered. Adding to the complexity is the fact that if assumptions or disagreements between, for example, meteorologists and physicists are not properly addressed, readers may find it difficult to discern the essential information.

While it might seem perplexing to the general public, the reality is that consensus on theoretical aspects of the same observational facts is not always guaranteed between meteorologists and physicists.

Exactly, this task involves one person crafting the overall narrative, considering coherence and balance, while organizing the detailed scientific knowledge. The goal is to fairly verify whether what is being said in the world is correct. This requires a meticulous examination, and it needs to be achieved in as simple a manner as possible!

Indeed, it is believed that there has been a scarcity of consistent and textbook-like literature that describes the significant problem of global warming, from its scientific mechanisms to the implications for humanity's choices. While the documents from the Intergovernmental Panel on Climate Change (IPCC) represent a culmination of international efforts, the political nuances in international coordination raise questions about placing absolute trust in them.

For these reasons, this document compiles the "basic wisdom necessary for people to believe in their own intellect, make judgments, and choose the future regarding global warming." Additionally, it has been organized with the aim of satisfying the intellectual curiosity of the readers. I hope you enjoy exploring the content.

For example, how would you respond to the following questions?

Firstly, there are common assertions in the theory of global warming:

1. As a result of human activities, the concentration of $CO_2$ is increasing.

2. Since $CO_2$ is a greenhouse gas, an increase in atmospheric $CO_2$ leads to global warming.

3. With global warming, the melting of ice in the Arctic and Antarctic, rising sea levels, and unstable weather conditions causing heavy rainfall and droughts occur. This, in turn, rapidly deteriorates human living environments and leads to a loss of biodiversity.

Claims challenging these assertions (skepticism) – stating that "the above claims are actually incorrect" – are a periodic theme on popular social media platforms like YouTube. When asked about the specific details of such claims, non-experts may find it challenging to discern what is accurate.

In reality, even readers of this document might find it difficult to confidently answer whether the above assertions are correct, along with the reasons behind it.

Moreover, how about the following claim commonly seen in skepticism?

"Do you know how much of the air is composed of $CO_2$? It's only $0.04\% $! Almost negligible. With such a thin gas, a slight increase shouldn't cause global warming. Increasing $CO_2$ won't lead to warming."

The assertion here regarding the thinness of $CO_2$ concentration at $0.04\%$ is roughly accurate. While a person with knowledge can provide a correct counterargument, it is not easy to refute the above statement accurately.

How about this one?

"Everyone talks about $CO_2$, but why is carbon dioxide the only one getting singled out? Nitrogen, which makes up 80% of the atmosphere, oxygen at 20%, and other gas molecules don't have a greenhouse effect. It seems strange that only carbon dioxide, which has a concentration of just $0.04\%$, has a special greenhouse effect. Maybe the claim that carbon dioxide is the cause of global warming is just a ploy by the pro-nuclear power lobby or politically distorted information?"

It's not surprising if someone hears this and thinks, "Well, now that it's mentioned, it does sound strange." Without correct knowledge about the principles of greenhouse gases and empirical evidence in the atmosphere, refuting such statements is not easy.

Moreover, how about claims that appeal to emotions like the following?

"The story about polar bears being in danger of extinction because the Arctic ice is melting due to global warming is a lie. In reality, polar bear populations are increasing. Everyone is just being manipulated by fake information. So, of course, global warming is also fake."

It's not uncommon for someone to think, "I was concerned about those adorable polar bears disappearing and thought we needed to help, but wait, they are increasing? Was what I believed a lie? Does that mean global warming is a lie too?" It is true that scientific research results indicate an increase in polar bear populations. However, whether this implies that global warming is a lie is a separate argument. To gain a correct understanding, thorough investigation of literature is necessary, but easily accessible explanations of such literature are not often found.

Let's explore a few more skeptical claims.

"Yes, warming is happening, but it's just part of the natural cycle following the end of the previous ice age. Human activities and $CO_2$ are not the causes."

Arguing against such claims without a variety of basic knowledge can be extremely challenging. There are also claims like:

"If warming causes the melting of ice in Antarctica and the Arctic, leading to a rise in sea levels, the increased moisture evaporating from the sea to the atmosphere will result in higher precipitation and snowfall. Consequently, snow will accumulate in Antarctica and the Arctic, returning things to normal. If it rains more, plants will grow better, absorbing $CO_2$, so there's no need for people to worry in the end."

Imagine hearing such an explanation from the knowledgeable bartender at your favorite bar. It wouldn't be surprising if many people thought, "Well, if it's put that way, it does make sense." It's important to note that such seemingly understandable claims can be relatively easily accepted by people.

Up until now, many of the claims have been less scientific, but what if a professional scientist makes a skeptical statement like the following:

"The IPCC (the authoritative global organization on the issue of global warming) states that 'global warming increases in proportion to the total emissions of $CO_2$ released by humanity,' but in reality, it increases logarithmically. In other words, global warming progresses at a much slower rate than what the IPCC suggests. There is a possibility that the sense of crisis is unduly inflated by organizations dissatisfied with the inadequacy of global warming measures worldwide."

At this point, for an ordinary person, it would be challenging to determine what is accurate and to what extent. The scientific explanation here is indeed correct. However, understanding how to interpret this claim might be confusing.

On the other hand, what if a reputable newspaper made the following statement:

"Despite increasingly alarming warnings about global warming and a series of wildfires and worsening weather conditions attributed to it, a new public opinion survey reveals that residents of this state consider climate crisis less seriously than three years ago. In such a situation, a greater shift in consciousness is needed to refrain from emitting carbon dioxide."

While this statement is not skeptical, it is more in line with generally accepted claims. However, it also represents a typical structure that could be sensationalizing and not scientifically accurate. By continuing to read this document, one should be better equipped to approach such issues with common sense.

Scholars' Response to Skepticism

Scholars, being experts in the field, naturally possess the knowledge to address skepticism and identify errors in claims like those mentioned above. However, there seems to be a tendency among scholars to refrain from explaining these issues to the general public. Some typical opinions expressed by scholars include:

• Changing the opinion of those who believe that increased $CO_2$ is not the cause of global warming is challenging.
• Providing a thorough explanation is too technical for the general public.
• Attempting to simplify the explanation results in oversimplification, making it less understandable. Consequently, scientists might opt for explanations like "the majority in the scientific community believes this," but countering arguments like "majority consensus doesn't guarantee correctness" can be discouraging.

These opinions are valid and reflect the challenges faced by scholars. However, the author believes it is essential to convey a simple and accurate understanding as much as possible. In this document, an effort is made to simplify the mechanisms of global warming and highlight issues related to its solutions to a level understandable by individuals with the intelligence of a middle school student.

Background Information

The goal was to create a text that could be understood by Japanese middle school students. However, there are sections, particularly in the mathematical modeling and interpretation of observed values, that assume a level of mathematical and chemical knowledge equivalent to high school level. Upon reading this document, one may realize that various topics studied in middle and high school unfold extensively, demonstrating the importance of school education in understanding global warming.

There's a common belief that subjects like mathematics and science are not useful in adulthood and, therefore, not worth studying. This is far from the truth. Studying these subjects is crucial for understanding important issues in our future. Once understood, people's behaviors naturally change.

Additionally, this document utilizes mathematical models to perform various calculations. The scripts for these calculations are written in Python, a programming language. Detailed explanations of these scripts are compiled in the last installment of the series, in the "Appendix."

Structure

The progression of this document is as follows. To understand a single concept, it is essential to first grasp the overall picture. Therefore, we start with significant themes such as history before delving into a detailed understanding of the greenhouse effect mechanism. Additionally, in the first half, we confirm the mechanism of global warming using an original, simple mathematical model and verify whether the current recognition presented by international organizations is valid.

In the second half, we summarize crucial points about the future impact and damage estimates. Furthermore, we discuss important aspects such as the current global power generation composition and whether we are on the right path for climate change mitigation. We explore what is clear and what remains uncertain. Finally, based on the discussions, we make recommendations.

Access to the series

• The Truth of Global Warming: Part 1 - Do You Truly Understand "Global Warming"?
• The Truth of Global Warming: Part 2 - History of Research
• The Truth of Global Warming: Part 3 - History of Earth's Atmosphere
• The Truth of Global Warming: Part 4 - Global warming and the energy balance of sunlight
• The Truth of Global Warming: Part 5 - Verification of global warming through mathematical models