Significant reduction of unequal population exposure to climate extremes
by achieving the carbon neutrality
Abstract
Climate extremes, such as hot temperature and heavy precipitation
events, have devastating effects on human societies. As the planet gets
warmer, they have become more intense and more frequent. To avoid
irreversible damages from climate extremes, many countries have
committed to achieving net-zero anthropogenic carbon emissions, or
carbon neutrality, by the 2050s. Here, we quantify the impact of carbon
neutrality on population exposure to climate extremes using multi-model
projections from the Coupled Model Intercomparison Project Phase 6
(CMIP6) Shared Socioeconomic Pathway (SSP)1-1.9 and SSP3-7.0 scenarios.
It is found that the increasing population exposure to hot-temperature
and heavy-precipitation extremes under SSP3-7.0 scenario can be
substantially reduced by 87–98% in the late 21st century by achieving
the carbon neutrality based on SSP1-1.9 scenario. The benefits of carbon
neutrality are particularly pronounced in Africa and Asia. The potential
benefits of carbon neutrality are also significant in North America,
Europe, and Oceania, where a reduction in climate extremes is more than
twice as important as population decline in reducing population exposure
to climate extremes. These results provide important scientific support
for ongoing efforts to achieve net-zero carbon emissions by the 2050s to
reduce potential climate risk and its inequity across continents.