The greening of planes, trains and automobiles
Moving goods and people around the world is responsible for a large part of global CO2emissions (排放). 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.
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.
This energy transition (变革) 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.