The McKinsey Global Institute published a report assessing climate adaptation needs, which indicated that heat is likely to affect more people and account for a larger share of adaptation costs than flooding. The report also found that past discussions on climate adaptation have primarily centered on the impacts of severe flooding.

The analysis for the report incorporated geospatial data for four hazards: heat, drought, wildfires, and flooding, and evaluated 20 distinct adaptation measures. Currently, global adaptation spending is estimated at approximately $190 billion per year, which provides protection for about 1.2 billion people. The report estimates that approximately three billion people globally have limited protection from various climate hazards.

Extending protection to all 4.1 billion people currently exposed to heat, drought, wildfires, and flooding would require an annual investment of $540 billion, which is roughly three times the current spending. The report states that only 18% of individuals in places currently experiencing heat stress have access to air conditioning.

The report projects that, based on current emissions trajectories, the world will reach 2°C of warming above preindustrial levels by approximately 2050. At this level of warming, an additional 2.2 billion people may be exposed to heat stress, a projected increase greater than those for drought or flooding. To protect against all hazards at 2°C warming, an estimated $1.2 trillion would be needed annually, with heat adaptation measures accounting for almost three-fifths of this total. The analysis suggests that private entities would be responsible for more than half of the total adaptation cost at 2°C warming.