Limiting global warming to 1.5°C is much more beneficial than to 2°C, a new study led by the University of East Anglia has found.
The international Paris Climate Accords, signed in 2016 by 195 nations, sought to limit global warming to "well below" 2 degrees Celsius above pre-industrial levels while aspiring to ideally keep warming at 1.5°C.
Using risk-related metrics of human exposure to harmful effects of global warming, the study examined the effects of global warming on the Earth, if global warming was limited to 1.5°C above pre-industrial levels by the end of the century.
These effects include droughts, declines in crop yield, exposure to malaria, coastal flooding, heat stress and water scarcity.
The research team calculated the risk factors in three scenarios: One in which warming is constrained to 1.5°C, another to 2°C and for comparison, one where global warming is allowed to reach 3.66°C.
The researchers found large global benefits to limiting warming by 2100 to 1.5°C, citing significantly reduces exposure to droughts, flooding, heat stress, diseases and more, compared to both a 2°C global warming world and a 3.66°C global warming world.
The study projected that it is up to 85% more beneficial to limit warming to 1.5°C globally.
The researchers also noted that, while water scarcity globally decreases in all scenarios, that should not be seen as a benefit of global warming. That is because the increase and decrease of available drinking water will be regional and because where there is reduced water scarcity, "there is often an associated increase in runoff and consequently flood risk."
Hotspots at risk from global warming
The study also found that by limiting global warming to 1.5°C, South America, Indonesia and some "isolated patches of Russia" will be the few regions that would not benefit from the warming drop.
Overall, Africa, India and the Middle East were identified as "hotspots" for increased exposure to drought, with numbers also expected to increase in South America, Europe and East Asia.
The risk of flooding is mostly evident in West Africa, India and parts of central East Asia, the study found, adding to previous studies which concluded that vulnerable populations in Africa and southern Asia will be disproportionately impacted by global warming.