Greenhouse Gas Emissions: Data Shows Transportation is Key

Post updated April 19th 2023 to include new METRO proposals

Greenhouse Gas Reductions Require Public Transit

According to research presented in the October 2020 Driving Down Emissions report from Smart Growth America1, transportation accounts for the largest share of carbon emissions in the U.S., and those emissions are rising—even as emissions have decreased in other sectors. To reverse that trend, the SGA states, “Modeling consistently shows that rapid emissions reductions depend on taking fewer, shorter car trips and shifting trips from cars to transit, walking, and biking.”

The report notes that increased fuel efficiency standards for automobiles and shifting to electric vehicles are worthwhile and important steps, but will not do enough. According to the SGA report, “Even as the [USA personal automobile] fleet overall got far more efficient, emissions still rose 22 percent over the same time period” (1990-2017). “Why? A 50 percent increase in driving overwhelmed all of those improvements in fuel efficiency. This increase in driving was not just due to population growth—vehicle miles traveled (VMT) per capita grew by 15 percent over that period.”

What’s Holding Us Back?

If the data is clear that we need to increase public transportation use in order to bring greenhouse gas emissions down, why isn’t there more focus on creating affordable, reliable public transportation in the USA and here in Santa Cruz County? The SGA found that, while the connection between transportation and climate is better understood, 

there has been a sense by policymakers and environmentalists that the amount people drive is outside of anyone’s control. As if the increase in driving is inexorable—a force of nature or, at least, economics, that is impossible to contain. Rarely do we look at the things governments are doing, at all levels, to make driving the easier choice, if not the only choice.

The report points out that a primary cause of our continually increasing driving rates in the USA is actually government action:

Policies and funding at all levels of government encourage more and wider highways and sprawling development. [This causes] people [to] live farther away from the things they need and the places they go, causing most people to drive more every year and generate more emissions to accomplish daily needs. Emissions have risen despite increases in fuel economy standards and the beginning of electric vehicle deployment.

Locally we see this kind of government action in the form of a highway widening project that is proceeding apace, even though it is projected to increase greenhouse gas emissions, while support for increasing our public transportation system was stalled by a tied vote at our Regional Transportation Commission. 


Making the Switch


What would effective greenhouse gas reductions look like here in Santa Cruz County? With 60% of our local emissions coming from transportation, reducing Vehicle Miles Traveled (aka reducing the amount of trips we take in personal vehicles) is a key local solution. Many local trips are less than a few miles away.  Making it possible and enjoyable to take those trips via other means is necessary to change local habits. This means we need to invest heavily in our local transportation infrastructure, including in expanding METRO service, expanding our protected bicycle networks, vastly improving pedestrian infrastructure and implementing Vision Zero policies and of course, building the Rail Trail and implementing Electric Passenger Rail Service.   

With the new additional service frequency proposed by Santa Cruz METRO and the addition of rail service this expanded transportation network would be a fast, reliable, and affordable public transportation system which will give Santa Cruz County residents a true alternative to driving. Having the trail and safe streets in combination with expanded bus and rail service will allow residents currently stuck in traffic to ride bikes, walk or bus to the train, take bikes on board, and then ride, walk, or bus from the train station to their final destinations. A single ticket system and timed connections will make transfers smooth and reliable.

Can We Just Switch to Electric Cars? 


While electrifying our vehicle fleet is an essential part of reducing carbon emissions, the SGA report warns that turning over the fleet will take decades, if not longer.  “California has found that even if the state meets its ambitious target of 15 percent zero emissions vehicles on the road by 2030—ten times the current adoption rate—every person in the state would still need to drive less. [Otherwise] we will need ever more pavement for ever more cars, whether they are gas or electric” and emissions will not go down enough to address the climate emergency.  

As Farhad Manjoo in a New York Times editorial in March 2020 pointed out, “the problem isn’t just gas-fueled cars but car-fueled lives. … Liberation from car culture requires a more fundamental reimagining of how we get around, with investments in walkable and bike-able roadways, smarter zoning that lets people live closer to where they work, and a much greater emphasis on public transportation.” 

This is what we’re advocating for with the Coast Connect vision. 



1) Smart Growth America is a 501(c)(3) committed to helping states and local governments use a smart growth approach to address environmental and economic issues. 


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