Guest blog Climate talks can solve another global crisis: Air pollution
Originally published in THE HILL on the 10th of November (during COP26) - now a guest blog here by Jason West, Ph.D., is a professor of environmental sciences and engineering at the University of North Carolina at Chapel Hill. His research connects air pollution, climate change, energy and health, through computer modeling of the global atmosphere. His lab’s studies have demonstrated the global health benefits of methane emission reductions to control ozone air pollution, as well as the global air quality and health co-benefits of aggressive GHG reductions.
The UN COP26 meeting in Glasgow has so far brought successes in emission reduction pledges, but those successes are very likely insufficient to keep global warming from exceeding 1.5 or 2 degrees Celsius above preindustrial levels. But at stake is not only climate change. In Glasgow, world leaders also have a historic opportunity to end another global crisis — the plague of fossil-fueled air pollution.
Globally, air pollution
kills about 6.7 million people annually — as many as all transportation
accidents, diabetes, tuberculosis, HIV, malaria, breast cancer and prostate
cancer combined. About one of every 8.5
deaths occurs prematurely because of exposure to air pollution, from heart
attack, stroke, respiratory diseases and lung cancer. We now understand well that air pollution is
the most important environmental risk factor for global health, and that it
impacted health in industrial regions through the 20th century, even if its full
toll has not been calculated. While the
U.S. and Western Europe have already improved their air quality through
regulations, India, Southeast Asia, Africa and other regions continue to
worsen.
Climate change and air
pollution are closely linked through fossil fuel combustion, the source of 89
percent of human CO 2 emissions and about 71 percent of global exposure to fine
particles (PM2.5). Consequently, most actions to reduce greenhouse gas (GHG)
emissions also reduce air pollutants. The monetized benefits of improved air
quality and health are comparable to the costs of GHG reductions, or even
exceed them, even without other benefits of slowing climate change. In other words, the health benefits of
cleaner air alone can justify many actions now being considered to address
climate change.
Further, because air
pollution benefits are realized quickly and mainly locally — whereas the
benefits of slowing climate change are distributed globally and spread over
decades — they can motivate countries to take action.
While climate action is
expected to reduce air pollution, the opposite is not necessarily true. Regions that successfully decreased air
pollution — the U.S. and Western Europe since about 1980 — have done so while
GHG emissions have remained roughly flat. China in the past decade decreased
air pollution while GHGs grew.
These regions decoupled
air pollution from GHGs through their actions to achieve cleaner air —
smokestack controls on power plants and large industries and tailpipe controls
on motor vehicles — actions which do not decrease fossil energy use and so have
little effect on GHGs.
So, while the actions to address climate change — improving energy efficiency and switching to cleaner fuels including renewables — can markedly decrease air pollution, the actions taken historically to address air pollution do not slow climate change.
But this picture is
changing rapidly — mostly because of the falling costs of renewable energy. In
the U.S. and elsewhere, old inefficient coal plants have recently closed,
replaced by cheaper and cleaner natural gas or renewables — mainly because of
economic drivers. With costs falling and new electricity storage technologies,
intermittent renewables can feasibly provide most electricity generation and
power electric vehicles. This change in cost structure is among the biggest
disruptions to the energy industry of the past century.
One success of Glasgow
has been the Global Methane Pledge, which will effectively slow the rate of
climate change — seen as essential to keep warming from exceeding 1.5 or 2
degrees Celsius – in addition to improving air quality. But missed in the Glasgow negotiations is the
opportunity to reduce other short-lived climate pollutants including ozone
precursors, and black carbon — actions that will also be important in cleaning
our air and saving lives.
At COP26, the world is at
a crossroads. We can improve air quality through more aggressive smokestack and
tailpipe controls while continuing to burn fossil fuels. Or we can finally end
our fossil fuel dependence and enact a sustainable future driven by renewable
energy, achieving both clean air and a stable climate.
The world’s past inaction
on climate now requires dramatic reductions in GHGs to stabilize warming at 1.5
or 2 degrees. Meanwhile, new World
Health Organization air quality guidelines affirm that even lower
concentrations impact health, and over 90 percent of the world’s population —
rich and poor alike — breathes air that exceeds the guidelines. As for climate, bold action is also needed to
meet these guidelines — smokestack controls alone will likely not be enough in
many cities.
Both air pollution and
climate change are pointing to the same solution: rapidly moving away from
fossil fuels through a wave of investment in renewable energy. Doing so would
end the 20th century plague of fossil-fueled air pollution through 21st-century
actions to stabilize climate. More
aggressive action in the last days of the Glasgow meeting can achieve this.
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