2023 was a landmark year for climate extremes. Mean land and sea surface temperatures overshot previous records each by up to 0.2 degrees Celsius resulting in what scientists believe could be the warmest year in possibly the past 100,000 years.⁽¹⁾ Record ‘average’ heat masks temperature extremes at a localized level that are difficult to comprehend. Phoenix, Arizona, for example, recorded 31 consecutive days of highs at or above 110 F last summer. In a grim reflection of climate realities, Maricopa county, home to Phoenix, now publishes regular Heat Reports⁽²⁾ which detailed 579 confirmed cases of heat-associated deaths in 2023, up 50% year on year.

The NOAA National Center for Environmental Information (NCEI) confirmed 2023 as a historic year in the number of tropical storms, hurricanes and climate extreme events. There were 28 weather and climate disasters, climate events that resulted in over $1billion in damages in 2023, surpassing the previous record of 22 in 2020⁽³⁾. Such events consequently bring with them an untold human impact which is far more significant to reflect upon when recounting the costs of climate change.

The scale of the problem that the global community has to address in anthropogenic warming over the decades to come will be determined by the speed at which we can mitigate future rises in CO₂ in the atmosphere. Climate mitigation spending is broadly defined as capital deployed to transition industry away from carbon intensive processes, for example the shift to electric power trains in transportation and renewable generation in the power generation stack. The reality is, however, that for the next approximately 20 years, the die is cast in effect. Any dollar spent today on mitigation will likely not assist in curbing carbon dioxide levels in the atmosphere for, at minimum, 20 years.