Megacities of the world could face stronger and more frequent heat waves and see thousands of related deaths even if global warming is halted at levels agreed in the Paris climate deal, a new study has warned.
Countries supporting the Paris Agreement penned in 2015 have pledged to keep global warming below 2 degrees Celsius above pre-industrial levels by cutting carbon emissions, but even if the said limit is approached, extreme heat events could still be expected to occur, researchers said.
Heat Waves In Megacities
"As the climate warms, the number and intensity of heat waves increases … Our research is the latest to show that we can expect even larger increases as the climate continues to warm," lead researcher and UK climatologist Tom Matthews said in a statement.
The team conducted an analysis of 44 out of the 101 most highly populated megacities worldwide, investigating the impact of global warming on heat stress in humans. They used climate models and delved on how global temperature rise could change heat stress estimates in the largest cities on Earth.
They found that the number of cities suffering heat stress doubled with 1.5 degrees Celsius (2.7 degrees Fahrenheit) of warming. If the trend continues, over 350 million more people will be likely exposed to heat stress by 2050.
It is likely that risk heat stress will strike in more land surface area, and those already experiencing it will suffer longer, more frequent heat waves.
In heat waves back in 2015, over 2,000 in India and around 1,200 in Pakistan died. The factors making this possibly may not be unique to these nations, as heat waves are particularly threatening to populous large cities that feature plenty of heat-absorbing concrete and asphalt.
A lot of U.S. cities, for instance, have not established response plans and programs to mitigate heat waves and their effects, said Dr. Georges Benjamin, the American Public Health Association’s executive director, highlighting the “unacceptable” rate of heat wave-related premature deaths today.
For Matthews, the United States won’t be immune to more frequent, intense heat waves as the climate continues to warm. Expect more fatalities, he warned.
The U.S. National Weather Service revealed that in 2015 alone, 45 Americans perished from extreme heat. In general, more than 9,000 were killed by heat-related factors since 1979, based on data from the Environmental Protection Agency.
“Dangerous” heat is defined as having a 105 degree Fahrenheit heat index.
According to the researchers, precautions to fight these deadly heat waves will involve changes and upgrades in infrastructure and community assistance. Building design, for instance, should be reviewed for increased energy efficiency and reduced internal temperatures.
Adaptation, on the other hand, includes upgrading the electrical grid to make sure it can withstand peak demand during potent and prolonged episodes of heat. Cities could also establish so-called “cooling centers” for people to flee to during the warmest days.
On the international scale, the researchers added, global warming needs to be tackled head-on, and the limits set by the Paris agreement may not be a safe amount anymore.
The findings were discussed in the journal PNAS.
Recently, a team of Oslo scientists proposed a “carbon law” policy to slash by half the world’s carbon dioxide emissions every decade from 2020 to fight climate change. Similar to the carbon tax, the policy seeks to impose penalties on emitters to better speed up the total shift to renewably energy.
This instrument can be used by nations in implementing the Paris deal, where some 200 governments worldwide pledged to move away from fossil fuels in the next 50 years.