Threats from the unexpected.  Now it is air conditioning and refrigeration. World-wide the demand for air conditioning is expected to rise by 33 times by the end of the century.  By 2050 the world population will use more electricity for cooling than for heating. This will make the planet hotter, because cooling requires the burning of fossil fuels.  Coolness is required in homes, for the longer life of food in supermarkets, for medicines and vaccines, and data centres. As demand for cooling goes up the amount of CO2  emissions will increase by 25% by the middle of the century, cancelling out any hoped-for improvements elsewhere (if they seriously materialize)!.