The greening of planes, trains and automobiles
飞机、火车和汽车的绿色化
Moving goods and people around the world is responsible for a large part of global CO2, emissions. As the world races to decarbonize everything, it faces particular problems with transportation-which accounts for about a quarter of our energy-related greenhouse gas emissions. Here's the breakdown of the emissions in 2018 for different modes of transport.
在全球范围内运输货物和人员是全球二氧化碳排放的主要来源。随着世界各国竞相实现脱碳，交通运输面临着特殊的问题，交通运输约占我们能源相关温室气体排放的四分之一。以下是2018年不同交通方式的排放明细。
ROAD VEHICLES
公路运输
ROAD (PASSENGER) 45.1%
公路（乘客） 45.1%
ROAD(GOODS) 29.4%
公路（货物） 29.4%
AIRPLANES 11.6%
航空 11.6%
SHIPPING 10.6%
水运 10.6%
RAIL 1%
铁路 1%
OTHER 2.2%
其他 2.2%
The fuels for transport need to be not just green, cheap and powerful, but also lightweight and safe enough to be carried around. Each mode of transport has its specific fuel needs. Much is still to be settled, but here are some of the solutions to get us going green.
运输燃料不仅需要绿色、廉价和强大，还需要足够轻便和安全，可以随身携带。每种运输方式都有其特定的燃料需求。许多问题仍有待解决，但以下是一些让我们走向绿色的解决方案。
FUTURE FUELS
未来燃料
PLANES-Synthetic hydrocarbons
飞机——合成碳氢化合物
The hardest sector to decarbonize is aviation. One long-term option for sustainable fuel for planes is to make hydrocarbons from recycled air.
最难脱碳的行业是航空业。飞机可持续燃料的一个长期选择是从回收的空气中制造碳氢化合物。
CARS-Batteries
汽车——电池
Batteries are energy-efficient and electric cars can plug into existing systems and services. New solid-state batteries will take a car farther on a single charge.
电池是节能的，电动汽车可以接入现有的系统和服务。新的固态电池一次充电就能让汽车走得很远。
TRAINS-Electricity
火车——电力
Some trains are already electrified through rails or wires: others can be made electric in pretty simple ways.
一些火车已经通过轨道或电线实现了电气化：其他火车可以通过非常简单的方式实现电气化。
TRUCKS-Hydrogen fuel cells
卡车——氢燃料电池
Hydrogen fuel cells are a lighter choice than batteries for trucks, but making green hydrogen is expensive.
氢燃料电池是比卡车电池更轻的选择，但制造绿色氢气的成本很高。
SHIPS-Liquid ammonia
轮船——液氨
Liquid ammonia is easy to keep and transport, but it is hard to ignite and requires an engine redesign.
液氨易于保存和运输，但很难点燃，需要重新设计发动机。
This energy transition is global, and the amount of renewable energy the world will need is “'a little bit mind-blowing,” says mechanical engineer Keith Wipke at the National Renewable Energy Laboratory. It's estimated that the global demand for electricity could more than double by 2050. Fortunately, analyses suggest that renewables are up to the task. “We need to speed up the development of green energy, and it will all get used,” says Wipke.
国家可再生能源实验室的机械工程师Keith Wipke表示，这种能源转型是全球性的，世界所需的可再生能源数量“有点令人震惊”。据估计，到2050年，全球电力需求可能会翻一番以上。幸运的是，分析表明可再生能源能够胜任这项任务。Wipke说：“我们需要加快绿色能源的开发，所有这些能源都会得到利用”。
