Overview
- See how your vehicle performs with this vehicle emissions calculator https://vehicle-emissions-calculator.vercel.app/
- Washtenaw County residents are driving more overall, and that matters for holiday emissions. The Washtenaw Area Transportation Study (WATS) reports that Vehicle Miles Traveled (VMT) in the county rose 5% in 2023, reaching 3.81 billion miles (WATS 2023 Crash Report & Trends). This growth occurs even as Ann Arbor and Washtenaw County pursue aggressive climate goals. The U.S. Environmental Protection Agency identifies transportation as the largest source of U.S. greenhouse-gas emissions at 28% in 2022 (EPA Transportation Emissions). Reducing unnecessary holiday driving—by trip-chaining, consolidating family visits, or choosing nearer destinations—directly supports these local emission-reduction targets.
- Residents can meaningfully reduce emissions by increasing vehicle occupancy and using transit where it exists. The Center for Sustainable Systems (CSS) at the University of Michigan reports that vehicle occupancy has fallen from 1.87 passengers per mile in 1977 to 1.5 in 2019, increasing per-person emissions (CSS Personal Transportation Factsheet). Meanwhile, WATS finds that 63.3% of Washtenaw County residents live within 0.5 miles of a fixed-route transit stop, and 70% of jobs are similarly close to transit (WATS Performance Measures). Carpooling to holiday gatherings, sharing rides with family, or using TheRide for local errands align directly with emissions-reduction strategies in Ann Arbor’s A2ZERO plan and the county’s Resilient Washtenaw framework.
- Air travel carries a significant carbon footprint, and many Washtenaw County residents rely on flights to reach distant relatives. The CSS Carbon Footprint Factsheet states that commercial aircraft emitted 130.8 million metric tons of CO₂-equivalent in 2022, and that an average domestic flight produces about 0.41 pounds of CO₂-equivalent per passenger-mile (CSS Carbon Footprint Factsheet). Since many local travelers fly through Detroit Metropolitan Airport or other regional hubs, choosing nonstop flights where possible reduces the number of takeoff/landing cycles—typically the most fuel-intensive parts of any flight—and lowers total trip emissions in a documented, measurable way.
- Train and bus alternatives, where available, often outperform flights on a per-passenger-mile basis—and may help Washtenaw travelers reduce holiday impacts. Global mode-comparison data from Our World in Data show that rail and coach travel emit significantly less CO₂-equivalent per passenger-kilometer than short-haul flights (Our World in Data – Travel Carbon Footprint). For Washtenaw County residents traveling to cities connected by rail or intercity buses—Detroit, Chicago, Toledo, Grand Rapids, and others—choosing these modes can provide meaningful emission reductions. When feasible, avoiding short-hop flights aligns with both the A2ZERO and Resilient Washtenaw transportation-reduction goals.
- Cleaner vehicle choices and efficient driving habits offer immediate emission reductions for Washtenaw drivers. Lifecycle analysis from CSS shows that small SUVs emit 429 g CO₂-equivalent per mile in gasoline models, compared with 312 g for plug-in hybrids, 258 g for hybrids, and 267 g for battery-electric vehicles (CSS Personal Transportation Factsheet). The same factsheet notes that aggressive driving and high speeds can reduce fuel economy by 10–40%, increasing emissions. For Washtenaw County households making annual winter trips—within Michigan or across the Midwest—choosing a more efficient vehicle and driving at moderate speeds directly reduces holiday-travel emissions and supports local climate targets.
Transcription
David Fair: This is 89.1 WEMU, and we're just a week away from Christmas Eve now. And for the fortunate among those who celebrate, it's a time for family and friends and long-awaited get-togethers. I'm David Fair, and welcome to 89.1 WEMU's Issues of the Environment. Now, you might ask. What do the holidays have to do with the environment? Well, some will be traveling to be with loved ones. Others will have family travel here to be with you. Travel has a huge impact on the health of our environment, and that's what we're going to discuss today. Our expert guest is Greg Keoleian. He serves as co-director of the University of Michigan Center for Sustainable Systems. And a happy holiday season to you, Greg! I appreciate your time!
Greg Keoleian: You have a nice holiday too, David, and look forward to talking to you!
David Fair: Well, with all of the gatherings we're going to have locally throughout the state, country, and world for that matter, what kind of impact does this heavy kind of travel have on our environment?
Greg Keoleian: Well, transportation accounts for 30% of the energy consumption in the United States and 28% of the greenhouse gas emissions. That is travel including moving people, personal transportation, as well as moving stuff or goods. The light duty vehicles, in terms of transportation, this is over half of those impacts in terms of energy and emissions. But then, of course for holidays, there's a lot of travel by air for long distance.
David Fair: Can we distill those impacts down to what happens right here in Washtenaw County?
Greg Keoleian: So, we actually did a study of the greenhouse gas impacts of gas-powered vehicles and compared them with hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles, and looked at the full life cycle in terms of the emissions with producing the vehicle, using the vehicle, and retiring the vehicle. And we found that, national average, there's a 75% reduction if you compare a battery electric vehicle with a comparable, bivehicle-type, gas-powered vehicle. So, that's a tremendous improvement, in terms of environmental impact.
David Fair: We consistently hear how we are approaching or might even be at an environmental climate tipping point. Can we continue to travel the way that we do without pushing ourselves over the edge?
Greg Keoleian: No. We need to make some fundamental changes, because, as you know, we need to reduce our emissions down to zero by 2050. And 2030, we should be half of our emissions, and we're not on track with that right now. We actually did a study looking at if we had 50% sales of battery electric vehicles in 2030, would we be on that trajectory to hit to zero by 2050? And we're pretty close, but we're not on track with 50% sales of new vehicles being battery electric. So, there's a lot we need to do. And I think the recent actions in Washington are not helping that, in terms of taking away the EV tax credit and some other policies that may be setting us back. But that really shifts it to us individuals, in terms of what actions we could take, and there's a lot we can do.
David Fair: This is 89.1 WEMU and our Issues of the Environment conversation with Greg Keoleian continues. He serves as co-director of the University of Michigan Center for Sustainable Systems. And before we talk about how we can do things on an individual basis, I want to talk economics for a moment. There's a cost to implementing sustainability measures and advancing our technologies to try and better adapt to our environmental realities. While we slowly work toward that end, do we have a handle on what it will cost us longer-term by not moving more quickly?
Greg Keoleian: Yes. The National Oceanic and Atmospheric Administration has been tracking the cost and damages from billion-dollar weather and climate disasters. They've been doing this for the last 40 years. The impacts are increasing in intensity and frequency from climate pollution. And that includes flooding, wildfires, droughts, heat stress. And just last year alone, it was $183 billion of damage. And I think us in Michigan, one thing that we observed was the wildfire smoke or experience, which was really awful. Those events are going to continue to increase in frequency and intensity. And that's why we need to take action to limit our emissions from transportation.
David Fair: As we explore the economics of future transportation and mobility, many people are already being priced out of air travel. The cost of new vehicles is becoming prohibitive for many, and they've already been priced out of much of the market. It has implications on a multitude of levels. What is going to be required of the transportation industry itself to keep people on the road and in the air while also protecting jobs and adequately stewarding a program of environmental responsibility?
Greg Keoleian: Well, one thing is public transit is generally more affordable than ownership. And when it comes to vehicle ownership, we have done research on the total cost of ownership of vehicles, so that's the purchase, the fuel, the insurance, the maintenance. And we're finding that, with electrified vehicles, they're coming close in parity to gas-powered vehicles, and that's because there's tremendous savings in the operation of the vehicles. And new vehicles are very difficult, particularly for low-income families. 70% of vehicle purchases are used, and we're just finishing up a study now on used vehicles and finding that the total cost of ownership is very favorable compared to new vehicles. They're depreciating a little bit more. And so, we're finding that buying a a used electrified vehicle three to five years old can really help lower costs. Now, of course, one needs to look at charging and is there the ability to have access to charging infrastructure. And ideally, you would have home charging because public charging is at least twice the cost of home charging.
David Fair: Our Issues of the Environment conversation with U of M Center for Sustainable Systems. co-director Greg Keoleian continues on 89.1 WEMU. So, let's talk further about responsibility, and you pointed out we each have a role in this. As we approach this particular holiday travel season, what are some of the things we can do to reduce our personal carbon footprint when we go to visit family and friends and then carry that on through the rest of the year?
Greg Keoleian: Sure. I mean, one of the biggest things we could do is reduce the travel distance, so that's your vehicle miles traveled. And that, obviously, if you're visiting family, unless you're going do it virtually, which is not something you're necessarily going want to share your holiday dinner with virtually, that doesn't work, or bringing gifts that doesn't work. But, yeah, just in general we're reducing distance, but one can reduce impact by carpooling, bundling trips if you're visiting. Instead of doing individual trips, you bundle trips. The other is choosing the right vehicle if you're going to be driving a car and you have different vehicles in your household. So, that's, in general, something you want to do is match the vehicle with the trips. Commuting to work, you don't do that in a big SUV, you would do that in a sedan. Individually is purchase a battery electric vehicle, as I mentioned, there's dramatic reductions in emissions and also cost of fueling.
David Fair: You know, America's built on many things, and one of the underdiscussed characteristics is our unquenched desire for more and more convenience. Changing our mobility and our environmental future is going to require behavioral, attitudinal, and political changes, and I'm not sure that climate adaptation and cleaner air and water are sufficient impetus to get us there. What do you think it's going to take to finally move the needle to where it needs to be?
Greg Keoleian: Well, I think I agree with you that climate may not be on a top priority on people's decision-making about purchasing vehicles or how they travel. But I will say that these events--these extreme events--are becoming more and more frequent, and I think climate pollution is becoming more visible. And so, I think that is going to motivate people. But I think the other is there is a shift in transformation, in terms of how we're moving. Many younger people, for example, aren't owning cars. They're living closer to where they're work in urban centers. The transition, with regard to electric vehicles--now it's stalled a bit because of what's happened in Washington. But the performance of electrified vehicles is actually, I think, going to help accelerate that transition because they're quieter, they have good acceleration, there's no tailpipe pollution, and the costs are going to be really better than gas-powered vehicles because battery costs are coming down dramatically. And, again, the charging with electricity is less than filling up your tank with gasoline. So, I think just the technology is improving. That's also going to help us. But then, again, we need to look at taking advantage of other modes. Like, getting to the airport from Ann Arbor, there's a bus that we could take. If I want to get to Tiger Stadium, I could take a a bus from Ann Arbor directly to Detroit and just walk a couple of blocks, and I'm at the stadium. So, really take advantage of some of these opportunities. It's really recommended.
David Fair: Well, I'm glad I got to take advantage of your time and have the conversation today! I appreciate it! And a happy holiday season to you and yours!
Greg Keoleian: You too! I really enjoy talking with you, David! And you have a great program! We really appreciate it!
David Fair: Well, thank you very kindly! That is Greg Keoleian. He is director of the U of M's Center for Sustainable Systems. He's been our guest on Issues of the Environment. For more information and more about sustainable travel, stop by our website at WEMU.org. Issues of the Environment is produced in partnership with the office of the Washtenaw County Water Resources Commissioner, and you hear it every Wednesday. I'm David Fair, and this is your community NPR station 89.1 WEMU-FM Ypsilanti.
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