Nobel Prize in Physics Awarded to Climate Field for the First Time - Tokyo's Vision for the Planet

Relationship Between Greenhouse Gases and Global Warming

Global warming refers to a phenomenon caused by the emission into the atmosphere of large amounts of gases called greenhouse gases, such as carbon dioxide, methane, and chlorofluorocarbons.

The Earth's surface is warmed by the sun's rays as they pass through the atmosphere. The warmed surface radiates heat, some of which is absorbed by these atmospheric greenhouse gases. Because the gases have a property that causes them to release the heat they have accumulated, the absorbed heat is returned to the ground and causes temperatures to rise.

Fortunately, the heat that is not absorbed is released into space, so the temperature of the Earth is maintained at a consistent level. The Earth's average temperature is currently around 14 degrees Celsius, but if there were no greenhouse gases, some calculations suggest that the average would drop to around 19 degrees below zero.

Greenhouse gases are often treated as "the bad guys" for causing global warming, but in fact they are important gases that greatly affect temperature. It is thanks to greenhouse gases that the Earth remains within a temperature range under which humans are able to survive.s

So, what exactly is the problem? The answer is the increasing concentration of greenhouse gases in the atmosphere.

As more greenhouse gases are added into the atmosphere, more heat is absorbed. In turn, more heat is returned to the ground, which increases the temperature of the Earth's surface. In other words, the key to solving global warming is achieving a balance between greenhouse gas emissions and their absorption (carbon neutrality).

Dr. Manabe's Research Helped Unravel Climate Change

Among greenhouse gases, the rapid increase in the concentration of carbon dioxide in particular is considered problematic. This concentration increased by more than 40% over the 260 years between 1750 and 2013; that is to say, the dramatic increase began with the start of the Industrial Revolution. Since carbon dioxide is emitted by burning fossil fuels like oil and coal, there have been growing movements in recent years to reduce carbon dioxide emissions through changes in human activity and lifestyles.

As more than 120 countries and regions have set the goal of becoming carbon neutral by 2050 and are promoting various initiatives, the awarding of the Nobel Prize in Physics to Dr. Manabe Syukuro, a leading researcher on global warming, has become a major topic of discussion.

The Nobel Prize selection committee cited Dr. Manabe's research being "fundamental to the modern study of climate" as the reason for his award. What exactly was his research? Put very simply, "his research revealed that an increase in carbon dioxide increases Earth's temperature, leading to global warming."

Global climate change is a very complex phenomenon to begin with. That is because changes occur one after another as heat and water vapor are exchanged between the atmosphere, oceans, and land.

Dr. Manabe developed the world's first method of reproducing the Earth's climate using a mainframe computer by converting this complex relationship into a mathematical formula. Doing so made it possible to show numerically that the temperature of the Earth's surface rises in line with increasing levels of carbon dioxide in the atmosphere. This achievement became the foundation on which research on global warming and climate change has progressed.

Tokyo Moves Toward Zero Emissions

Until now, the Nobel Prize in Physics has been awarded only in the fields of astronomy, astrophysics, atomic physics, and molecular physics, making this the first time that the field of meteorology and climate research has been selected. A great deal of people will surely take an increased interest in climate change and global warming as a result of Dr. Manabe's award.

Everyone is participating in the fight against global warming. In January 2021, the Tokyo Metropolitan Government announced its intent to reduce greenhouse gas emissions in the city by 50% by 2030 (compared to 2000 levels) and to increase the proportion of electricity generated by renewable sources to around 50%.

To achieve this, the socio-economic structure of all sectors must be restructured and redesigned, shifting to a decarbonized model. In addition to the energy-saving and renewable energy expansion measures it has been implementing, the Tokyo Metropolitan Government has also been promoting initiatives across all areas that can be attributed to urban activity, such as measures against food loss and the use of plastics.

Aiming to realize a "Zero Emission Tokyo" that will contribute to the global net zero carbon-dioxide emission goal by 2050, the Tokyo Metropolitan Government will be comprehensive and proactive in developing mitigation measures to stop global warming and adaptation measures to brace for the effects of global warming that have already begun to occur.