Here again, some changes have been positive, others not. Material possessions are available that a person living a century ago could not have imagined. But economic expansion has also brought pollution, deforestation, depletion of the ozone layer, and other ills.The pace of world political evolution began to speed up even more by the beginning of the 1900s. Democracy was rapidly eroding the legitimacy of monarchs. In 1900, there were still czars and Kaisers ; they would be gone in less than two decades. Nationalism increasingly undermined the foundations of multiethnic empires.