Ozone layer

Ozone layer to recover in 4 decades, but aerosol injection may undo gains: UNEP.

The successful phasing out of banned substances, as envisioned by the Montreal Protocol, has set the stage for a complete recovery of the ozone layer by the 2060s.
While this is an achievement, the scientists warned of the detrimental effects of geoengineering technologies such as stratospheric aerosol injection on the ozone layer.

About
- Firstly, it is a high-ozone layer in the stratosphere of the Earth.
- This layer protects the Earth from the damaging UV radiation emitted by the Sun.
- It absorbs 97-99% of UV light from the sun.
- If the ozone layer did not exist, millions of people would be impacted by skin disorders, including cancer.
- UV radiation would also harm the ecosystem, resulting in decreased productivity.
- Depletion of the ozone layer also severely impacts Earth’s biodiversity.

On humans
- Non-melanoma skin cancer.
- Plays a significant role in malignant melanoma development.
- Furthermore, UVB has been linked to the development of cataracts, a clouding of the eye’s lens.
On Plants
- Firstly, the changes in plant form.
- Affects the timing of developmental phases and secondary.
- Affects flowering and photosynthesis in plants.
- Lower quality crops.
- In addition, the decline in plant productivity would, in turn, affect soil erosion and the carbon cycle.

According to the Scientific Assessment Panel, the success of the Montreal Protocol inspires confidence in the scientific community and governments striving to limit greenhouse gas emissions that cause climate change.
The scientists underlined that the effectiveness of the ODS ban could aid in implementing the Kigali Amendment to the Montreal Protocol, which calls for the phase-out of specific hydrofluorocarbons (HFC).
Reducing HFC concentrations can help prevent global warming of 0.3-0.5°C over pre-industrial levels by the end of the century.
Furthermore, the action on ozone sets a precedent for climate action.
The accomplishment of eradicating ozone-depleting chemicals shows what can and must be done promptly to transition away from fossil fuels, cut greenhouse gas emissions, and limit temperature rise.

About
- The Montreal Protocol was established to minimise the production and consumption of ozone-depleting compounds and to protect the earth’s weak ozone layer.
- The treaty was opened for signature on September 16, 1987, and it entered into force on January 1, 1989, following a first meeting in Helsinki in May 1989.
- The protocol required a ban on using and commerce of 100 ozone-depleting chemicals (ODS), and 99 per cent of these have been phased out successfully.
- The most recent addition, the Kigali Amendment, called for eliminating hydrofluorocarbons (HFCs) in 2016.
- These HFCs replaced a batch of ozone-depleting compounds phased out under the original Montreal Protocol.

The ozone layer is a thin layer of the Earth’s atmosphere that absorbs almost all of the sun’s harmful UV radiation.
The ozone layer, which shields life on Earth from harmful solar radiation, is on track to regenerate within decades.
Still, disputed geoengineering proposals to address global warming threaten to reverse that progress.

Pic Courtesy: Down to Earth

Content Source: Down to Earth