• The layer absorbs the Ultraviolet radiations from the sun.
• It has high ozone concentration in the stratosphere, 20 to 30 kilometres above the Earth’s surface.
Image: Gilbert Koech
Kenya is on course in phasing out dangerous chemicals responsible for the depletion of the ozone layer.
The layer absorbs the Ultraviolet radiations from the sun. It has high ozone concentration in the stratosphere, 20 to 30 kilometres above the Earth’s surface. It acts as an invisible shield and protects living things from harmful ultraviolet (UV) radiation from the sun.
So dangerous are the radiations that they damage the immune system, and increase exposure to skin cancer and eye cataracts. Long-term exposure to high levels of UV-B can severely ruin most animals, plants and microbes.
Speaking during International Ozone Day celebrations, experts said even though most of the dangerous chemicals have been phased out, a lot still needs to be done.
Environment PS Beatrice Maina represented CS Keriako Tobiko in marking the day at the Kenya Meteorological Department.
UN Secretary-General Antonio Guterres said, “Another year of record heatwaves, superstorms and climate disruption tells us we have no choice but to act now before it is too late.”
Guterres said parties to the Montreal Protocol have for 32 years done a lot to slash the use of ozone-depleting chemicals, used largely by the cooling industry.
“As a result, the ozone layer that shields us from the sun’s harmful ultraviolet radiation is healing,” he said in a speech read by Unep ozone layer secretariat communication officer Stephanie Haysmith.
The UN boss said as energies are shifted to tackling climate change, countries must be careful not to neglect the ozone layer and stay alert to the threat posed by the illegal use of ozone-depleting gases.
KMD senior metrologist Annette Nyagah said they carry out ozone measurements that include the vertical profile on a weekly basis because of cost implications.
“We use an electrochemical cell, which has a cathode, and an anode that is fed with potassium iodide solution because it readily reacts with ozone,” she said.
Nyagah said once the cell moves up, they are able to receive information as well as five weather parameters — pressure, temperature, wind speed, wind direction and relative humidity.
“To send the cell up, we use a balloon filled with hydrogen gas that is prepared within KMD. Hydrogen gas is used because it is lighter than air,” she said.
When the balloon is released, the cell has a small tube that sucks in air. The sucked air moves into the cathode and the anode and lead to a chemical reaction, which generates a current that is directly proportional to the amount of ozone present in the atmosphere and its height.
The flight takes between two and three hours. Within the troposphere, there is bad ozone.
At 27 kilometres, there is the highest concentration of ozone of about 13.04 parts per million observed from 2012 to date.
After the flight is terminated, the balloon bursts and comes down. It cannot be recycled as the cell cannot be used twice. For one release of a balloon, it cost about Sh250,000.
PS Maina said the responsibility of saving the earth belongs to all. “Protocols and agreements are commitments of shared responsibility,” she said in reference to the Montreal Protocol.
The protocol regulates production and consumption of nearly 100 man-made chemicals referred to as ozone-depleting substances.
It phases down the consumption and production of the different ozone-depleting substances in a step-wise manner, with different timetables for developed and developing countries.
Under the treaty, all parties have specific responsibilities related to the phase-out of different groups of ozone-depleting substances, control of substance trade, annual reporting of data, national licensing systems to control substance imports and exports, and other matters.
In the 1920s, coolants and fridges were discovered to be very toxic, causing severe health complications to humans.
Chlorofluorocarbons came handy as the solution to the problem, but decades later, they were found to be the root cause of a hole in the stratosphere — commonly referred to as the ozone hole.
Damage to the layer prompted governments to moot an environmental agreement to govern the production and use of harmful substances that damage the ozone.
The protocol was agreed on September 16, 1987. It came into force on January 1, 1989.
Already, there is a new deal that includes specific targets and timetables. It seeks to replace hydrofluorocarbons with more planet-friendly alternatives.
(Edited by F'Orieny)