### Shifts in Global Perceptions of Climate Change—From 2007 to the 2020s

### Shifts in Global Perceptions of Climate Change—From 2007 to the 2020s **The Turning Point of 2007** In 2007, the IPCC (Intergovernmental Panel on Climate Change) released its Fourth Assessment Report, concluding that global warming was progressing rapidly and that it was primarily caused by human activities. At that time, atmospheric CO₂ concentrations had reached 380 ppm, a level far exceeding those of past climate cycles (approximately 200–300 ppm). This warming was believed to have the potential to trigger global environmental changes, such as the melting of the Arctic and Greenland ice sheets, the degradation of coral reefs, and the frequent occurrence of extreme weather events. Incidents such as the damage caused by Hurricane Katrina, which struck the southern United States (1,800 deaths, total damage of approximately $125 billion), and the 70,000 deaths resulting from the 2003 European heatwave impressed upon the world the gravity of climate change. Additionally, the Stern Review was published in the United Kingdom, revealing the economic impact of measures to combat global warming. It was estimated that 1% of GDP (approximately 6.7 trillion to 9.8 trillion yen) would need to be allocated to climate change measures, and that if left unaddressed, losses could reach 5% to 20% of GDP. In response to these reports, the UK proposed the concept of “climate security” and advocated for the international community, including the US, to cooperate in addressing climate change. **Progress in Corporate Climate Change Initiatives** Japanese companies followed this trend and actively participated in the Clean Development Mechanism (CDM). Mitsubishi Corporation promoted a project in Pakistan to install denitrification equipment, aiming to reduce emissions by approximately 1 million tons of CO2 equivalent annually, while Tokyo Electric Power Company (TEPCO) recovered methane gas from a pig farm in Chile, projecting a reduction of approximately 2 million tons of CO2 equivalent. In South Korea, Ineo Chemical recovered and destroyed HFC-23 (a CFC substitute), securing approximately 9.8 million tons of CO2 emission credits. Since HFC-23 has a global warming potential 11,700 times that of CO2, this reduction was considered extremely significant. **Current Status and Further Progress in the 2020s** As we entered the 2020s, the impacts of climate change have become even more apparent. In 2023, torrential rains in southern China caused dam breaches and urban flooding, resulting in severe damage. These extreme weather events are attributed to increased atmospheric water vapor, clearly demonstrating the effects of global warming. Meanwhile, progress is being made on climate change countermeasures, with a particular focus on the adoption of renewable energy and the reduction of greenhouse gas emissions. In the U.S. solar panel market, the Israeli company Lument has developed new manufacturing technologies, and South Korea’s Hanwha Group Q Cells is currently building a supply chain in the U.S. state of Georgia. Additionally, the International Energy Agency (IEA) has suggested that the use of AI technology could potentially reduce energy consumption in buildings by 15–25%. Furthermore, there is a growing trend toward linking executive compensation to climate-related goals. By 2023, 54% of S&P 500 companies had incorporated climate-related metrics into CEO compensation, making a company’s ability to implement climate change measures a key evaluation criterion. Through these initiatives, efforts to reconcile climate change measures with economic activity are advancing further, and there is an increasing need for coordination across the entire international community.