Reduce SourcesTransportationShift to Alternatives
CO2 Equivalent
Reduced / Sequestered
Billion $US
Net First Cost
(To Implement Solution)
Trillion $US
Lifetime Net
Operational Savings
When people share common origins, destinations, or stops en route, they can ride together. Carpooling uses seats and fuel more efficiently, cutting emissions.

Solution Summary*

In 2015, the Oxford English Dictionary added ride-share to its pages. Ridesharing is the act of filling empty seats by pairing drivers and riders who share common origins, destinations, or stops en route. When trips are pooled, people split costs, ease traffic, and lighten the load on infrastructure, while curtailing emissions per person.

A wave of technologies has accelerated ridesharing’s popularity:

  • Smartphones allow people to share real-time information about where they are and where they are going.
  • The algorithms that match them with others and map the best routes are improving daily.
  • Social networks are buoying trust, so individuals are more likely to hop in with someone they have not met.

Getting people to double or triple up in their cars is not always easy. When fuel is cheap, carpooling declines. An abundance of free or cheap parking also steers people to journey solo. So does the desire for autonomy, privacy, and expedience.

For many, cars have seemed indispensable to day-to-day life. But, increasingly, mobility is seen as a service to access. When cars are used collaboratively, you can catch a glimpse of the future—one with fewer cars overall.

* excerpted from the book, Drawdown

Our projection for carpooling focuses on approaches to increase global urban car occupancy, the number of passengers in each car trip. We assume that urban car occupancy can rise from 1.57 in 2018 to 1.75 or 2.0 by 2050, assuming 3 passengers per carpool trip. Carpooling has no implementation costs and can reduce emissions by 4.2-7.7 gigatons of carbon dioxide while saving $2.8-$5.2 trillion in operating costs.