### Environment Expansion of uninhabitable zones - Survival crisis at the beginning of the 21st century

### Environment Expansion of uninhabitable zones - Survival crisis at the beginning of the 21st century

In the early 21st century, researchers warn that billions of people may be locked out of the comfortable climatic conditions on which human civilization was built. The human-friendly environment with an average temperature of 13 to 25 degrees Celsius is shrinking, and a future in which one-third of the earth's population will live in areas with an average temperature exceeding 29 degrees Celsius without migration, and extreme heat in the Sahara Desert will become a daily occurrence, is becoming a reality. This prediction is not only a hypothesis, but is backed up by accumulating scientific findings and shared as a serious crisis that directly affects the survival of the human race.

The Kyoto Protocol, adopted in 1997, set a goal of limiting the rise in temperature within two degrees Celsius, but reductions have not progressed due to the withdrawal of the United States and the expansion of emissions by emerging countries, and it remains difficult to control the rise in temperature. In reality, heat waves have repeatedly occurred in India and Pakistan, and in the Middle East, extreme heat exceeding 40°C has become the norm day and night. Furthermore, in the Sahel region of Africa, droughts and food shortages are becoming more severe, and the mass exodus of refugees is strengthening the character of the situation as an international problem. These phenomena are not future predictions, but rather crises that have already begun to shake the world.

Population growth and urbanization are also exacerbating the situation. Hundreds of millions of people in South Asian and African cities with inadequate cooling systems and power grids are exposed to extreme heat, and heat stroke and water shortages have become serious social problems. Although efforts are being made to develop heat-resistant crops, introduce energy-efficient building materials, and disseminate high-efficiency cooling technology, economic disparities are hindering their spread, limiting the areas that can benefit from them. As a result, "emigration" has emerged as a practical solution, and high-latitude regions such as Canada and Northern Europe are attracting attention as new places to live. Thus, a new international issue of "climate refugees" has emerged in the post-Cold War order, and the expansion of uninhabitable zones is being described as a "survival crisis" confronting humanity.