Changes Made by Public Transportation

What Your Mobility Choice Really Means for the Planet

Green Signal – Episode 11

✏️ Column by Baek Changhee | ⏱️ Reading Time: 8 minutes

“Should I drive today or take the subway?”

It sounds like a simple everyday question. But the impact of that choice on our planet is far greater than we think. For a 25km trip in Seoul, a private car emits about 5.25kg of CO₂, while a bus emits 0.69kg, and the subway only 0.038kg. A car produces 138 times more CO₂ than the subway for the same distance.

As of 2025, the transport sector accounts for about 13.5% of Korea’s total greenhouse gas emissions. The government has set a target to cut emissions from transport by 37.8% by 2030. The key to this goal is clear: a large-scale shift from private cars to public transportation. Even replacing one car trip a week with a bus ride can reduce about 252kg of CO₂ a year. If you switch your daily commute to public transport, you can easily cut more than a ton of CO₂ annually.

🚆 Carbon Footprint by Mode of Transport

CO₂ Emissions per 1km by Transport Mode (2025)
• Private car: 198g
• Bus: 57g (about one-third of a car)
• Subway: 26g (about one-eighth of a car)
• Bicycle / Walking: 0g (zero-emission!)

Let’s assume a one-way commute distance of 10km and an annual travel distance of about 5,000km for commuting alone. The yearly CO₂ emissions look like this:

• Private car: approx. 990kg CO₂ (requires 142 pine trees to absorb it)
• Bus: approx. 285kg CO₂ (equivalent to 41 pine trees)
• Subway: approx. 130kg CO₂ (equivalent to 19 pine trees)
• Bicycle: 0kg CO₂ (no trees needed!)

Simply switching from a car to the subway for your commute can reduce around 860kg of CO₂ per year. That’s similar to planting about 123 pine trees. A single change in how you move can create this scale of environmental impact.

💚 The Hidden Advantages of Public Transport

1. Economic Benefits
Let’s compare commuting 20km a day (round trip) by car vs. by public transport:
• Car: about $170/month for fuel + $85/month for parking + insurance and maintenance costs → over $300 per month
• Public transport: about $50/month with a commuter pass (Seoul standard)
• Net saving: around $250/month, or nearly $3,000 per year

2. Freedom to Use Your Time
When you drive, your hands and eyes are completely occupied. On public transport, your time becomes free.
• Read books, study, watch lectures or films
• Check work emails, catch up on news
• Meditate, rest, or take a quick nap
• A 2-hour round-trip commute can give you around 500 hours of “free time” per year

3. Health Benefits
Public transport usually comes with walking built in.
• Walking to and from stations can add 2,000–3,000 extra steps a day
• This can cover 20–30% of the WHO’s recommended 10,000 steps daily
• Less driving stress + reduced exposure to roadside pollution over time

4. Less Congestion, Better Cities
The road space taken up by 100 cars can be replaced by just 2 buses.
• Reduced traffic jams
• Eased parking shortages
• More room for parks, bike lanes, and people-friendly streets

🌍 E – Environment

Decarbonizing Transport
Around 94% of emissions from the transport sector in Korea come from road vehicles. If one million car commuters switch to the subway, the total annual reduction could reach about 1.25 million tons of CO₂.

Increasing the share of public transportation is essential to achieving the 37.8% emission reduction target for 2030. Individual choices add up to national progress.

🤝 S – Social

Mobility as a Social Right
Public transport guarantees mobility for people who cannot own cars – including youth, seniors, and low-income households. It is a basic social infrastructure that keeps cities inclusive.

Germany’s “9-Euro Ticket” is a well-known example. Over three months, public transport use increased by around 25%, and CO₂ emissions dropped by 1.8 million tons. Affordable, accessible public transport is a foundation of a fairer society.

⚖️ G – Governance

Policy, Incentives, and Citizen Participation
Korea offers various incentives such as the Car Carbon Point System and “Eco-mileage” schemes. Joining these programs can provide benefits worth $170–$850 a year, depending on how much you cut your driving.

Citizen feedback also shapes public transport policies: route expansion, transfer discounts, and fare systems. Speaking up for “the public transport we want to use” is itself an ESG action.

🚴 Bicycles and Walking: Perfect Zero-Emission Mobility

The “Triple Effect” of Cycling
1. Environment: 0g of CO₂ emissions
2. Health: Riding 1 hour at 15km/h burns around 500kcal (supports weight control and cardio health)
3. Economy: No fuel costs, minimal maintenance, almost free commuting

Seoul’s public bike system “Ttareungi” surpassed 30 million cumulative rides in 2024. If you commute 10km round-trip by bike:
• CO₂ reduction: about 990kg/year (compared to driving)
• Calories burned: around 130,000kcal/year (equivalent to burning about 18kg of body fat)
• Transport cost savings: roughly $600/year

The Power of Walking
For distances under 2km, walking can be the best choice.
• 15–20 minutes of walking burns around 100kcal
• A daily goal of 10,000 steps significantly lowers the risk of chronic diseases
• Walking also supports local businesses – people on foot are more likely to stop by small shops than drivers

🚀 3-Step Action Guide

Step 1: Start With One Day a Week (★☆☆)

• Goal: Make Monday your personal “No Car Day”
• How: Use public transport only on Mondays instead of driving
• Impact: Approx. 200kg less CO₂ and around $430 saved per year
• Tip: Leave home 30 minutes earlier on Mondays and turn your subway time into a reading or reflection routine

Step 2: Use Public Transport at Least 3 Days a Week (★★☆)

• Goal: Commute by public transport on Monday, Wednesday, and Friday
• How: Use a monthly public transport pass and plan routes in advance
• Impact: Around 600kg less CO₂ and about $1,700 saved annually
• Tip: Enroll in the Car Carbon Point System to earn extra financial rewards for reduced driving

Step 3: Full Transition (★★★)

• Goal: Move your entire commute to public transport, cycling, and walking
• How: Use car-sharing services only when truly needed, and combine subway + bike for daily travel
• Impact: Around 1,000kg less CO₂ and more than $3,400 saved per year
• Tip: Link your transport cards with eco-mileage systems and point-earning programs to maximize rewards

✨ Stories That Prove Change Is Possible

Case: “P” (35, IT professional, living in Seoul)
• Before: Daily commute by car (15km one way)
• After: Switched to subway + public bike (“Ttareungi”)
• Period: 1 year
• Results:
– CO₂ reduction: approx. 1,485kg (equivalent to 212 pine trees)
– Cost savings: about $3,600/year (fuel, parking, insurance, maintenance)
– Weight loss: 8kg (thanks to daily cycling)
– Reading: 24 books finished in one year during commute time
• Reflection: “At first it felt inconvenient. Now, driving actually feels more tiring. My time on the subway has become the most relaxing part of my day.”

If just 10% of Seoul’s 10 million residents switched from driving to public transport, the city could cut about 990,000 tons of CO₂ a year. That’s like removing around 210,000 cars from the road.

🎁 Incentives You Should Know: Save Money While Going Green

1. Car Carbon Point System (Korea)
• Operated by: Korea Environmental Industry & Technology Institute
• Eligible: Non-commercial passenger vehicles (up to 12 seats)
• Benefits: Depending on reduced mileage, participants can receive benefits worth about $170–$850 a year
• How to join: Register online → Submit odometer photos → Receive rewards after a 6-month evaluation period

2. “Thrifty Transport Card” (Walking + Public Transport Mileage)
• Operated by: Local governments across Korea
• Benefits: Earn up to 20% of your transport fare back as mileage based on walking and cycling distance to and from stations
• Use: Accumulated mileage is deducted from next month’s transport fees
• Plus: Can be linked with eco-friendly credit cards to earn additional eco-points

3. Local Cycling & Walking Challenges
• Daegu’s “Bike-to-Work Challenge”: Points based on commute distance verified through an app
• Seoul’s “Ttareungi Mileage”: Discounts and perks for frequent users
• Many municipalities run similar programs – it’s worth checking your local government website

⚠️ Important Things to Keep in Mind

1. Check Weather and Health Conditions
On days with heavy fine dust, yellow dust, heat waves, or extreme cold, it may be safer to choose indoor public transport rather than cycling. Always prioritize your physical condition and safety.

2. Follow Cycling Safety Rules
Helmets are essential. Use lights at night, stay on bike lanes, and never cycle after drinking alcohol – it is treated as drunk driving under Korean traffic law.

3. Avoid “All or Nothing” Thinking
You don’t have to be perfect from day one. Even shifting 70% of your trips to greener modes makes a big difference. ESG is not about overnight perfection – it’s about steady, sustainable change.

💬 Join Our ESG Mobility Community

Join the KakaoTalk Open Chat
Share your public transport commutes, log your reduced emissions, and encourage others.
Monthly “Public Transport Challenge” participants may receive public transport gift cards as rewards. 🎁

“The moment you put down your car key, you quietly become a small hero for the planet.”

Tomorrow morning, a single transport ticket can be the first step toward cutting one ton of CO₂ in a year.

ESG