September 16th is World Ozone Day, a celebration of the world’s ozone layer and measures taken to protect it. The day provides an opportunity to consider the successes so far in protecting the ozone layer and the challenges that remain.
Ozone layer
Far above us, in the stratosphere, the world’s ozone layer protects people and natural systems from the Sun’s harmful ultraviolet rays. Much of the life on Earth has adapted to live under this protection.
Human life has disrupted the natural balance. In the twentieth century, as society developed new technologies, especially refrigeration and cooling, we released chemicals that travelled to the stratosphere and depleted some of this stratospheric ozone, creating expanding “holes” through which protection did not occur.
Scientists began sounding the alarm in the 1970s. They were eventually joined by governments and then selected industries to develop replacement chemicals and establish a legal framework for protecting the ozone layer.
Montreal Protocol
Most countries in the world have since joined the international treaties that protect the ozone layer: the Vienna Convention and the Montreal Protocol. Today on World Ozone Day we celebrate the ozone layer and the world’s efforts to protect it.
The Montreal Protocol was arguably the most successful environmental protection effort in human history, under which the ozone layer recovered. A large part of this success was due to adherence to robust, independent science and democratic mechanisms that provide equitable influence for countries around the world.
This includes the Multilateral Fund, which funds technical experts in developing countries and their efforts to phase out artificial substances that deplete the ozone layer.
New threats to the ozone layer
The ozone layer faces new threats from human-caused pollution. Climate change has induced wildfires that create atmospheric dynamics that push soot into the stratosphere.
In addition, rocket traffic is leaving aerosol pollution in its wake. Satellites at the end of life disintegrate and leave metallic particulates in the upper atmosphere. This space pollution is minor today, but a growing threat for the future
Critical gaps in observations of the stratosphere
Since the 1990s scientific monitoring of the stratosphere has gradually declined. There are only four research aircraft in the world that fly in the stratosphere for sampling sparse substances, all owned by NASA.
Balloons offer advantages as relatively inexpensive platforms for monitoring the stratosphere. Balloons that can observe the stratosphere include those that can carry heavy payloads, fly long periods at altitude and return to their launch site, generally costing hundreds of thousands of dollars, limiting their use. Inexpensive commercial balloons pop when they reach high altitudes and can thus carry only cheaper, disposable instruments.
This means that while threats to the ozone layer are growing, observing capabilities for measuring them are scarce and not accessible to researchers in most of the world.
HOPE: Expanding and democratizing stratospheric observations
In August, in an effort led by lighter-than-air platform specialists Sarah Schubert and Dan Bowen, SilverLining launched a navigable, high-altitude, long-duration balloon with instruments for stratospheric observations: High-altitude Observing Platform Explorer (HOPE).
The first HOPE flight reached 58 thousand feet and flying at altitude for 10 hours. It carried a particle measurement instrument that detected aerosols from wildfires in California, as well as weather instruments.
HOPE is one of a number of science and innovation programs within SilverLining’s Safe Climate Research Initiative. It is a step forward in advancing a roadmap of research and innovation to provide information and capabilities, and equitable and responsible governance of them, to ensure a safe climate within a decade. This should help to redress the balance with monitoring the ozone layer.
