Air Quality related illnesses account for an estimated 4.2 million premature deaths globally and even more are left with lifelong health conditions [1]. With the current pandemic spreading quickly around the world forcing an economic shutdown, it seems like a good time to put things in perspective. Now more than ever we can easily see how interconnected we are on planet earth. This novel coronavirus attacks the lungs leading to respiratory failure. In our attempts to flatten the curve and not overwhelm hospitals we have shut down travel at all levels. The side effect is that for the first time in decades air pollution has drastically decreased as about 80% of all travel has stopped. Now imagine a future after COVID-19 where air quality levels remain the same as they are right now even with complete economic development and growth.

You don’t have to imagine because we can use the data from current events to calculate the percentage of electric vehicles required to maintain this air quality. The World Health Organization, WHO, maintains a detailed understanding of air quality-related diseases. "The research concludes that pollutants with the strongest evidence for public health concern include particulate matter (PM), carbon dioxide (CO2), ozone (O3), nitrogen dioxide (NO2) and sulfur dioxide (SO2)" [1]. All these chemicals are released from internal combustion vehicles every minute they are operating. Electric vehicles have no tailpipe emissions but do contribute to pollution during manufacturing and power generation to charge them. Research shows that full battery electric vehicles produce significantly less emission than internal combustion vehicles even, accounting for pollution from power generated. Three independent studies have found an average 70% reduction in pollution for the entire lifespan of a fully electric vehicle [3] .

Reducing air pollution offers a “win-win” strategy for both health and climate. Lower levels of air pollution result in the better cardiovascular and respiratory health of populations in both the long- and short-term. Considering that coronavirus is a respiratory disease that causes lung or heart failure, and some studies have linked poor air quality to higher rates of death, accelerating the transition to electric transportation to save more lives is a no brainer. [4]

Transportation makes up 14% of that pollution in the US and 23% worldwide. [5] Unlike many industry pollutants, the concentration and exposure to transportation pollution is higher because the majority of the public comes into direct contact with tailpipe emissions. Walking on busy roadways, sitting in traffic, riding your bike on the side of a busy road, or just living in urban areas increase the concentration of your exposure. These harmful chemicals and particles damage lung tissue. "About 65 million people suffer from the chronic obstructive pulmonary disease (COPD) and 3 million die from it each year, making it the third leading cause of death worldwide" [2]. At the time of writing this, 1.9 Million people have tested positive for COVID-19 and 120K have died from it. While this is tragic, we can learn from this pandemic and find ways to save more lives every year by changing how our transportation network is powered. We can continue to grow our economy while lowering our pollution simply by converting  a percentage of vehicles fully eclectic.

The shelter in place order in California has affected 11 million residents for the last 3 weeks and the environment is reacting to our absence.  By comparing the last 3 weeks worth of data with last year’s air quality trends and last year’s Air Quality Index (AQI) data, I found the AQI dropped 43% during COVID-19’s Bay Area quarantine. This same idea has been done with satellite images in many other cities around the world, including Wuhan China where COVID-19 originated and the lockdown lasted 3 months. [6]

By knowing how much the AQI improved during quarantine in the Bay Area, we need to calculate the impacts an EV and internal combustion engine vehicle have on the AQI. This calculation is rather complex because it requires a few assumptions that affect the amount of pollution each vehicle generates, such as mpg, age, fuel type, and miles driven per day. These assumptions make our calculated error ±20%. A Plug-in Prius, Camry, BMW 3 Series, or Model 3 vary greatly in how much they pollute. A typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year. We assume the average gasoline vehicle on the road today has a fuel economy of about 22.0 miles per gallon and drives around 11,500 miles per year. Every gallon of gasoline burned creates about 8,887 grams of CO2. In addition to carbon dioxide (CO2), automobiles produce methane (CH4) and nitrous oxide (N2O) [7]. These gases contribute to a higher concentration of 2.5micron particles (PM2.5) that are small enough to damage lung alveoli; the smallest tissue in your lungs that transfers oxygen into the bloodstream and CO2 out. To connect AQI to CO2 and NO2 emission we have to break down the AQI equation.

The Environmental Protection Agency created the AQI to help people quickly understand the health risk of air quality. They extrapolate from NO2, CO2 and PMx to calculate an index value for the last 12 hours. I’ve calculated a 39.8% reduction in AQI measurements from vehicles emissions. It’s clear transportation has a direct impact on air quality. Based on data from CalTrans, 10 million vehicles operated in normal conditions this time last year on Bay Area roads. Due to shelter in place, 70% of vehicles are no longer operating daily. That 70% has a 30% impact on AQI, where the last 9.8% comes from industry. To maintain current air quality, a total of 73% of vehicles need to convert to electric.

Maps from Descartes Labs, a data analytics company, use satellite data to track the steep changes in air quality. In March and the first week of April, NO2 pollution fell around 19% in Seattle compared to the same period last year. In New York, it fell 22%; in Denver, 15%; in Los Angeles, 33%. As the virus spreads around other parts of the world, some cities are seeing even steeper declines. In India, where 1.3 billion people are now under lockdown, the capital of New Delhi has seen 70% drops in both nitrogen dioxide pollution and PM 2.5. Seeing such a drastic drop in places like New Dehli, that have no vehicle air quality requirements, shows that this concept applies globally, with varying levels of impact based on regulated vehicle efficiencies.

Regardless of whether you take on climate change, or internal combustion vs electric vehicles, it makes sense to have a large majority of the transportation network operating on electricity. The goal is to get to 100% electric vehicle transportation and reduce emissions as much as possible as our world population continues to increase. COVID-19 has given us a glimpse of what is possible by converting a small part of our fleet to electric vehicles. With clear skies, sheltered at home means we don’t get to enjoy them. As life slowly returns to normal over the next few months, please consider switching to an electric vehicle to help save more lives, just like you staying home during these times is saving lives now.

Sources

  1. https://www.who.int/airpollution/ambient/health-impacts/en/
  2. https://www.who.int/gard/publications/The_Global_Impact_of_Respiratory_Disease.pdf
  3. https://www.carbonbrief.org/factcheck-how-electric-vehicles-help-to-tackle-climate-change
  4. https://www.nytimes.com/2020/04/07/climate/air-pollution-coronavirus-covid.html
  5. https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data
  6. https://www.fastcompany.com/90489321/these-8-maps-show-the-massive-drop-in-smog-caused-by-the-coronavirus
  7. https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle