The 21st (twenty-first) century is the current century of the Anno Domini era or Common Era, in accordance with the Gregorian calendar. It began on January 1, 2001, and will end on December 31, 2100. It is the first century of the 3rd millennium.
The beginning of the 21st century has been marked by the rise of a global economy and Third World consumerism, deepening global concern over terrorism and an increase in private enterprise. Effects of global warming and rising sea levels continued, with eight islands disappearing between 2007 and 2014. The Arab Spring of the early 2010s led to mixed outcomes in the Arab world, resulting in several civil wars and governments overthrown. The United States remains the only global superpower. Most member states of the European Union introduced a common currency, the Euro, and the United Kingdom withdrew from the European Union. In 2020, the COVID-19 pandemic spread around the world, causing severe global economic disruption, including the largest global recession since the Great Depression.
The Third Industrial Revolution which began around the 1950s continued into the late 20th century, and started to transition into Industry 4.0 and the Fourth Industrial Revolution in the beginning of the 21st century.
Due to the proliferation of mobile devices, more than half of the world's population have access to the internet (2018 estimate), allowing humans to be more interconnected than ever before. DNA sequencing costs continued to fall: the first human genome cost three billion dollars; in 2018, sequencing one human genome cost about $1000.