字幕列表 影片播放 列印英文字幕 Our ability to get to faraway places fast is a marvel. Transportation allows us to share ideas, see loved ones, seek out all the cool cat cafes and glacier museums, even swap our best inventions. So let’s say I’m on an expedition to my favorite glacier in Iceland, and I forget my favorite jacket. In just a few days, I can have it shipped to me, and I’ll finally feel complete again. But for as magical as that is, transportation is also one of the most visible and personal ways we’re transforming the Earth’s climate. Cars, ships, and planes release heat-trapping greenhouse gases into the atmosphere every day. Which means that, to decarbonize transportation, we’ll have to take to the road, the air, and the sea. Hi hi! I'm M Jackson and this is Crash Course Climate and Energy. [INTRO] When it comes to climate change, it’s easy to point fingers at transportation. If you have a car, say your beat-up Camry, hotrod, or a hotrod Camry it’s probably the most visible source of emissions in your life. And transportation is an important piece of the emissions puzzle. Planes, cars, cruise ships — the whole industry — transportation spews 8.2 billion tons of greenhouse gases into the atmosphere every year. That’s 16% of the around 51 billion tons we release annually — and the fourth-largest fossil fuel emitting industry. And that’s just the fuel required to power vehicles. That’s not even including the fossil fuel emissions required to refine the oil before it gets to the pump, or to produce the steel the cars are made of in the first place. So, it’s not an insignificant slice of the gassy pie! Which, gross, by the way. Who wrote this? Almost half of the emissions from transportation comes from personal vehicles: the cars, vans, motorcycles, and SUVs we drive in our daily lives. The other half comes from all the other vehicles: cargo ships, semi-trucks, planes, buses, and more, transporting lots of stuff or people. Decarbonizing both realms will mean fewer greenhouse emissions and less pollution for the entire planet. But decarbonizing transportation also has a second major benefit: Beyond helping slow the global effects of climate change, it could also be a step towards correcting environmental inequities — things like air, water, and noise pollution that disproportionately affect some more than others. For example, many highways in the U.S. have intentionally been built right through low-income communities. That means the people who live there — often, people of color — have had to bear the brunt of transportation’s air and water pollution, and experience unjust physical and mental health outcomes as a result. So, decarbonizing the vehicles that drive by every day would have dual benefits. It would lower carbon levels globally, but could also be one step towards improving specific living environments that, in many cases, the residents didn’t ask for. Wherever you live, there is good news! The first step to tackling decarbonization is clear and underway. To decarbonize our rides, we must first electrify them. And what we can’t electrify, we’ll have to make as efficient as possible and supply with alternative fuels. When it comes to personal transportation, you’ve probably seen electric vehicles in the wild by this point. Instead of having to fuel up at a gas station, they can plug in at homes or grocery stores, or cat cafes, and zoom from point A to point B on rechargeable batteries. Because they run on electricity, these vehicles release fewer emissions and air pollutants than gas-powered cars, no matter where they’re driven. But: an electric car is only as sustainable as the electricity it’s plugged into. That means a car charged on renewable electricity comes closer to zero emissions than one driven off of a coal-burning power plant. This is why carbon-free electricity is such a big deal: It’s involved in decarbonizing all of our other industries, including how we get places. But carbon-free electricity isn’t the main barrier to electric vehicles. There are bunches of reasons they’re still not everywhere. One is charging station access. Most electric cars can be plugged in at home, with similar outlets in the garage to what your power tools use. But if you drive long distances without a predictable place to plug in, that’s a problem. Globally, more charging stations are being built every year, especially in large cities. But for electric vehicles to really take off, there’s a need for more charging infrastructure in more places — especially rural areas. Governments and private entities have a role to play in promoting this, by offering incentives, even updating building codes on places like parking garages so that more spaces have electricity access. Another challenge, though, is the pesky specter of the Green Premium: the cost difference between low-carbon tech and the conventional, carbon-emitting choice. For instance, people in Europe and China have been quicker to adopt electric vehicles than people in the U.S. In parts of Europe, sky-high gas prices already match the cost of electric cars, which means the Green Premium there is lower. But in the U.S., this hasn’t always been the case. In 2021, almost two-thirds of Americans thought electric cars were better for the environment… but more expensive. And only 40% said they would consider buying one. But, the cost to build electric cars has dropped, as government subsidies and cheaper batteries drive prices down. And the closer an electric car’s upfront cost gets to its gas-powered equivalent, the easier it should be to afford plugging in over gassing up. That said, manufacturers have tended to focus on making luxury electric vehicles instead of affordable ones. And the metals in batteries aren’t always easy to come by — not to mention the environmental impacts of mining those rare Earth metals. So, although electrifying our rides is the end goal, the journey there is probably not going to be one seamless electric slide into the sunset. I mean, we hope it would be. We’d love for that to be a big part of the choreography, if not at least the grand finale. But we’ll probably need to learn some other dance moves along the way. And one potential dance partner is… government policy. Trust me, they’ve got some moves. Even if they step on your toes sometimes. Some countries are banning the sale of petroleum-powered vehicles. France plans to ban them by 2040, and the UK by 2030. And some countries offer cash rebates or tax incentives to electric car buyers. But as we transition away from gas-powered cars, we’ll likely still be sharing the road with them. So another policy move is adjusting fuel economy standards — basically, requiring manufacturers to build more efficient cars, which emit less carbon. There’s also congestion pricing, or charging drivers a fee on high-trafficked roads. The old “discourage driving, reduce emissions” trick. But congestion pricing is most equitable when people have alternative ways of getting where they need to go. If we want to encourage people to drive less — and reduce the half of transportation emissions that come from personal vehicles — we also have to design cities friendly to that, with sidewalks, bike lanes, and robust public transit systems. Some surveys suggest that having good public transport and ride-sharing services can lead to as much as a 35% drop in car ownership — and the emissions that come with it. But designing cities that are truly friendly for everyone means leveraging the most powerful tool we’ve got: people themselves. Let’s head to the Thought Bubble. Tulsa, Oklahoma is a sprawling area of suburbs, rural fringes, and an urban core. And it can be tough to get around without a car. But it helps if you’ve got a 12-meter bus. That’s what the Indian Nations Council of Governments enlisted when tasked with bettering Tulsa’s public transportation. Also known as INCOG, they’re a mix of tribal and local governments. And instead of holding your traditional city meeting to try and improve public transport, they took to the streets, and turned a bus into a mobile outreach center. Outfitted with interactive screens and displays, the bus spent four months driving all over the city. And anyone on-board could talk to transportation planners, learn about public transit possibilities, and weigh in on what should happen next. No one had to come downtown for a formal meeting on a busy weeknight: The conversation came to them. By the end of the tour, the bus had reached 2,000 citizens, most of whom had never had a voice in transportation planning before. And as a result, INCOG was able to identify 16 places in Tulsa where bus routes were most needed. And a couple years later, a separate project also had locals identify places that weren’t inviting on foot, like busy roads without sidewalks. When citizens get left out of these conversations, you can end up with public transportation that… doesn’t serve the whole public. Or a city full of people in their personal vehicles. By taking to the streets, INCOG helped Tulsa more than just reduce future carbon emissions: They helped the city make a plan that will create a cleaner, more equitable community. Thanks, Thought Bubble. Designing more walkable cities with more public transit would help reduce the way transportation affects us and the planet, especially while we work on decarbonizing personal vehicles. It’s a win for both environmental justice and global carbon levels. But then, there’s the other half of transportation’s emissions — the cogs in the rest of the global machine. There’s the bus I take to buy mac and cheese, yes. But there’s also the fleet of semi-trucks carrying mac and cheese around the country, and the recycling truck hauling the box away when I’m done. Then, there’s also the heavyweights. The ships and airplanes that carry the powdered cheese, and the noodles, and the cardboard. And me once I’m properly fueled with mac and cheese when I’m off to Antarctica to check out a glacier. The heavier the vehicle, the harder it is to replace liquid fuels with electricity. Liquid petroleum packs a lot of energy into not much space, to the point where the average lithium-ion battery carries anywhere from 50 to 100 times less energy than an equivalent amount of gasoline. And even the best batteries still have 35 times less energy per unit of weight. What that actually tells us is to supply an already very heavy vehicle with enough power to drive a long time on a single charge… you sacrifice cargo space. And not a little space. For example, a diesel-fueled truck can go over 1,600 kilometers on a single tank. But for an electric truck to go the same distance on a single charge, that truck would have to be mostly batteries, with barely any room in the back for mac and cheese. And a plane wouldn’t even be able to get in the air The good news is, batteries can still work for the lighter of these big vehicles, like buses and garbage trucks that make short trips and have a consistent spot to charge every night. Now, if you’re interested in becoming a scientist or an engineer, there are all kinds of opportunities to work on the next generation of batteries — tech that could help extend the range of electric vehicles, lower the Green Premiums on them, and help more consumers go electric. Or, you could explore working on even newer technologies to help the biggest vehicles! For instance, instead of diesel, cargo ships could be fueled with ammonia — yeah, the stuff in cat pee — a colorless, renewable fuel that packs ten times more energy than the best batteries. And for planes, lithium-air batteries — which carry double the energy in the same amount of space – could make some electric-powered flights possible. But for any of these technologies to get transportation off the ground, we’re gonna need a lot more research funding. So, another route is to invest in research that lowers the Green Premium of drop-in fuels. Like we mentioned in Episode 5, these lower-carbon alternatives can be substituted – or “dropped in” – to our current engines. For example, second-generation biofuels can be made from non-edible farming byproducts, such as cornstalks. And electrofuels can be made by mixing hydrogen with carbon dioxide captured from industrial plants, in a process powered by carbon-free electricity. Right now, a big barrier is the cost difference between these newer drop-in fuels and the fossil fuels most vehicles were built to run on. But investing in these substitutes is a good step in the lower-emission direction. We wouldn’t need to modify heavy engines or build entirely new vehicles. Plus, these fuels can be moved using tanks and pipelines we already have. So — decarbonizing transportation is complicated! If it wasn’t, it likely would have already been done. After all, it’s one thing to change how you move around. It’s another thing to change how lots of people or lots of stuff moves around. So, our best step is to electrify as many vehicles as possible. And where that isn’t possible, we need to explore alternatives to the energy-dense fuels currently powering them. It’ll also be important to capture the carbon they emit, to offset those emissions we can’t yet avoid. We’ll dive more into those solutions in our next episode. Special thanks to Kyle and Amanda Fredrickson, the dance choreographers for this episode. Thanks for keeping our moves funky and fresh — and teaching us that nobody says “funky and fresh” anymore — and thanks for supporting us on Patreon. Crash Course Climate and Energy is produced by Complexly with support provided by Breakthrough Energy and Gates Ventures. This episode was filmed at Castle Geraghty Studio and was made with the help of all these nice people. If you want to help keep Crash Course free for everyone, forever, you can join our community on Patreon.
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