In the race to be the world's leader in green technology, China is speeding ahead of its global competition.
Nowhere is that more apparent than in the cockpit of one of China's high-speed bullet trains, where you can see trains screaming toward you at speeds up to 230 miles per hour. Next year, the Chinese plan to test a train that could top 300 miles per hour.
Watch "World News with Diane Sawyer" for more from China tonight.
We joined the crush of passengers in Beijing boarding a high-speed train to Tianjin, a nearly 80-mile trip that takes just 30 minutes. Traveling the same distance on America's fastest train line would take nearly an hour and a half.
On top of the speed, the Chinese say their rail technology is better for the environment.
"It is energy efficient, which is quite significant when it comes to our growing dependence on oil," the train's conductor told me.
The trains are just one example of China's green wave, which moves as quickly as the view out the window.
China spends a staggering $12 million every hour on green energy, according to the Center for American Progress.
On the ground in China, you can see the effect of that spending nearly everywhere. The landscape is lined with the largest number of wind-powered turbines in the world. In rural farming towns, solar-powered street lights are evidence that the green infrastructure reaches far from the big cities.
Even the escalators are different. Instead of moving non-stop all day long, they remain frozen until they sense that a passenger is about to get on. Then, they use just enough energy to carry the passenger before automatically shutting off again.
There's a reason for this focus on green technology, but it's not global warming. For China, it's all about the math.
"China does not have a choice," said Cheng Li, director of the National Committee on U.S.-China Relations at the Brookings Institution. "As a country, it's dealing with serious resources scarcity. China needs to find a better way to survive."
Right now, China is devouring oil and coal. Electricity use has doubled in the last decade, and 6 million new cars were added to the roads in just the last year.
China already has the world's largest population, and as it continues to grow, it's being forced to change.
"China is rapidly changing from the factory of the world to the clean tech laboratory of the world," said Peggy Liu, chair of the Joint U.S.-China Collaboration on Energy. "The thing they are really beating the U.S. on is not the manufacturing of these parts, but the mentality of how we're tackling this issue."
It's believed that China spends 10 times what the U.S. does on green energy, but the spending is fueling something else -- huge profits.
South of Beijing, we visited Yingli Solar, which has harnessed China's green enthusiasm and exported it to the U.S. The company manufactures solar panels that end up on homes and schools in places like California.
Inside the factory, we saw robots examining each panel.
But on Capitol Hill, there are now serious questions about whether all of this is fair.