World Ozone Day – Electric Vehicles Making an Impact
Suchitra Subramaniyan , September 14, 2023
The ozone layer is a delicate gas shield that safeguards Earth from the sun’s harmful rays. It plays a crucial role in preserving life on our planet.
The International Day for preservation of the Ozone Layer, or simply, “World Ozone Day”, commemorates the ratification of the Montreal Protocol, an international environmental treaty, signed on September 16, 1987. Its primary objective was to protect the Earth’s ozone layer by phasing out the production and consumption of substances known as ozone-depleting substances (ODS). It has been highly effective in achieving its objectives and has had positive environmental and health impacts at a global scale.
The Ozone layer, known for acting as a protective barrier for the earth from the sun’s ultraviolet (UV-B) radiation, is mainly present in the stratosphere (also known as stratospheric ozone). This makes up for 90% of the ozone layer and begins 6 miles above the Earth’s surface, extending up to 31 miles. The remaining 10 percent of atmospheric ozone is located in the troposphere, which extends from the surface of the Earth to the stratosphere. This is considered harmful for its lethal effects on people and the environment, unlike stratospheric ozone, and its formation is contributed by presence of NOx and VOCs. Although ozone at ground level is less concentrated, it has high global warming potential.
This year the theme of World Ozone Day is “Fixing the ozone layer and reducing climate change”. The latest update from the Scientific Assessment Panel to the Montreal Protocol confirmed that ozone layer recovery is on track and ozone levels are expected to return to 1980 levels by around 2066 over the Antarctic. (source). The verdict is clear – for nearly 4 decades, the Montreal Protocol has been instrumental – and will continue to be instrumental – in protecting human health, nature and the climate.
Road transport and ground-level ozone – fossil fuel powered ICE vs Electric vehicles
According to a study conducted in the UK, if only tailpipe emissions are considered, diesel has the highest “per kilometre ground level ozone impact, with gasoline and LPG following in second and third position (44-88% impact of diesel) source. In comparison, electric vehicles with their zero tailpipe emissions, do not emit pollutant such as particulates (PM 2.5 and above), hydrocarbons, ground level ozone, various oxides of nitrogen and other volatile organic compounds (VOCs).
Electric Vehicles with their zero tailpipe emissions have no impact due to zero PM 2.5 and NOx emissions unlike its other counterparts.
However, when both tailpipe emissions and fuel production are accounted for, the environmental impact shifts to the site of generation plants and depends upon how the EVs are being powered (thermal/gas powered stations vs renewable power plants). Thus the impact on ground level ozone now depends on “long tailpipe of electric vehicles” (i.e. combination of tailpipe emission and source of power generation).
Despite this, the ozone impact of fossil fuel powered EVs would still be less than its conventional counterparts due to a lower emissions per unit power in a large power plant as compared to that for a fossil fuel powered ICE.
The message, thus, is clear; EVs powered by renewable sources would not only make the EV lifecycle greener, but will also further lower their impact on surface-level ozone and contribute to reducing global warming.
With India’s plan to add 50GW renewable energy capacity for the next five years to achieve the target of 500 GW renewable power by 2030, the “long tailpipe emissions” of electric vehicles are sure to become cleaner!