A tractor uses a leaf blower to gather the fallen leaves on the North Lawn as the sun rises over the White House on Nov. 18, 2017. Alex Brandon/AP hide caption

Signs warn drivers of icy road conditions on Interstate 66 in Fairfax County, Va., in March 2014. The state's Department of Transportation recently added rush hour tolls to the road, using dynamic pricing, which continuously adjusts the cost based on congestion. Karen Bleier/AFP/Getty Images hide caption

Melt ponds dot a stretch of sea ice in the Arctic Ocean, north of Greenland. This year was the Arctic's second-warmest in at least 1,500 years, after 2016. Nathan Kurtz/NASA hide caption

An illustration comparing the giant penguin to an average person. Kumimanu biceae weighed about 220 pounds and was a bit shorter than 6 feet in height. It swam around off the coast of New Zealand between 55 and 60 million years ago. Gerald Mayr hide caption

Kam Franklin (left) is lead singer of The Suffers, a band from Houston that started touring three years ago. Amber Daniel is lead singer and bassist of Blame the Youth from North Carolina. They're preparing for their first tour. Courtesy of Jay Bee Zay and Allison Slade hide caption

Younger workers today expect the power dynamic at work to be more egalitarian, with less top-down management. And that is changing the dynamic for all workers. andresr/Getty Images hide caption