1.1 Impacts of climate change are increasing and will accelerate with further warming The effects of human-induced climate change are already being felt today Since the beginning of industrialization, about 2,300 billion tonnes (gigatonnes or Gt) of anthropogenic CO2 have been released into the atmosphere,2 with over 900 GtCO2 (approximately 40% of that total) added within the last three decades.3 This pushed the CO2 concentration beyond 427 parts per million in the summer of 20244 — a level not previously seen in at least 3 million years5 (see Figure 1). As a result, average global temperatures have already increased approximately 1.2°C versus pre-industrial levels6 (see Figure 2). Meanwhile, according to the World Meteorological Organization, the frequency of natural disasters such as extreme heat, floods, droughts, storms and wildfires has increased five-fold over the past 50 years.7 While it is difficult to attribute any one individual disaster to climate change, there is very high certainty that the increasing frequency has been strongly influenced by man-made emissions.8 For example, the European 2019 heatwave, which caused approximately 2,500 excess deaths across the continent, was made 10 to 100 times more likely by human-induced climate change.9 Extreme rainfall in Brazil (Rio Grande do Sul) in April and May 2024 led to catastrophic flooding, displacing over 580,000 people. Human-induced climate change made this event twice as likely and increased its intensity by 6% to 9%.10 As global temperatures continue to rise, so will the rate and severity of extreme weather events As long as humanity continues to add greenhouse gases to the atmosphere, global temperatures will continue to increase. This will not only increase the frequency but also the intensity of extreme weather events. Warmer temperatures shift historical weather patterns, resulting in increasing evaporation, lower soil moisture, worsening drought conditions and a greater risk of devastating wildfires. Warmer oceans provide more energy for storms, intensifying both their frequency and strength. Warmer air can hold more moisture, increasing rainfall amounts and flooding risks. The world will also experience more frequent extreme heat events, with higher peak temperatures (see Figure 3). These events already cost lives, increase damage to infrastructure and threaten global food systems (see Table 1). They also make our societies more unstable by disrupting livelihoods, displacing populations and straining resources. The likely resulting political instability would make global climate-related challenges even more difficult to solve. Carbon dioxide concentrations in summer 2024 hit a level not previously seen in at least 3 million years. The Cost of Inaction: A CEO Guide to Navigating Climate Risk 9

The Cost of Inaction 2024