The 21st (twenty-first) century (or the XXIst century) is the current century in the Anno Domini era or Common Era, under the Gregorian calendar. It began on January 1, 2001 (MMI) and will end on December 31, 2100 (MMC).
Marking the beginning of the 21st century was the rise of a global economy and Third World consumerism, deepening global concern over terrorism after September 11, 2001, terrorist attacks and increased private enterprise. The NATO interventions in Afghanistan and Iraq of the early 2000s and overthrowing several regimes during the Arab Spring of the early 2010s led to mixed outcomes in the Arab world, resulting in several civil wars and political instability. The United States has remained the global superpower, while China is now considered an emerging global superpower.
In 2017, about half (49.3%) of the world's population lived in "some form of democracy", though only 4.5 percent lived in "full democracies".
The European Union was greatly expanded in the 21st century, adding 13 member states, but the United Kingdom withdrew. Most European Union member states introduced a common currency, the Euro.
Effects of global warming and rising sea levels exacerbated the ecological crises, with eight islands disappearing between 2007 and 2014.
In early 2020, the COVID-19 pandemic began to rapidly spread worldwide, causing severe global economic disruption, including the largest global recession since the Great Depression.
With the proliferation of mobile devices, more than half of the world's population obtained access to the internet (2018 estimate). After the success of the Human Genome Project, DNA sequencing services became available and affordable.