Homo sapiens first arose on the Earth between 400 and 250 thousand years ago during the Palaeolithic period. This occurred after a long period of evolution. Ancestors of humans, such as Homo erectus, had been using simple tools for many millennia, but as time progressed, tools became far more refined and complex. At some point, humans had begun using fire for heat and for cooking. Humans also developed language in the Palaeolithic, as well as a conceptual repertoire that included systematic burial of the dead and adornment of the living. During this period, all humans lived as hunter-gatherers, who were generally nomadic.

Modern humans spread rapidly from Africa and the frost-free zones of Europe and Asia. The rapid expansion of humankind to North America and Oceania took place at the climax of the most recent Ice Age, when temperate regions of today were extremely inhospitable. Yet, humans had colonised nearly all the ice-free parts of the globe by the end of the Ice Age, some 12,000 years ago.

The Agricultural Revolution, beginning about 10,000 BCE, saw the development of agriculture. Farming permitted far denser populations, which in time organised into states. Agriculture also created food surpluses that could support people not directly engaged in food production. The development of agriculture permitted the creation of the first cities. These were centres of trade, manufacture and political power with nearly no agricultural production of their own. Cities established a symbiosis with their surrounding countrysides, absorbing agricultural products and providing, in return, manufactures and varying degrees of military control and protection.[30][31][32] [1][2]Cuneiform script, the earliest known writing systemThe development of cities equated, both etymologically and in fact, with the rise of civilization itself 40,000 BC People begin living in man-made shelter huts in northern Punjab and central Asia (Bactria) 7,000 BC Evidence of people growing barley in this area and raising sheep, goats. People begin living in mud-brick dwellings in villages; some of which are still in existence : first Sumerian civilization, in lower Mesopotamia (3500 BCE),[33][34] followed by Egyptian civilization along the Nile (3300 BCE)[12] and Harappan civilization in the Indus Valley (3300 BCE).[35][36] Elaborate cities grew up, with high levels of social and economic complexity. Each of these civilizations was so different from the others that they almost certainly originated independently. It was at this time, and due to the needs of cities, that writing and extensive trade were introduced.

This period also saw the origins of complex religion.[37][38][39] Religious belief in this period commonly consisted in the worship of a Mother Goddess, a Sky Father, and of the Sun and Moon as deities.[40] (See also: Sun worship.) Shrines developed, which over time evolved into temple establishments, complete with a complex hierarchy of priests and priestesses and other functionaries. Typical of the Neolithic was a tendency to worship anthropomorphic deities. Some of the earliest surviving written religious scriptures are the Pyramid Texts, produced by the Egyptians, the oldest of which date to between 2400 and 2300 BCE.[41] Some archeologists suggest, based on ongoing excavations of a temple complex at Göbekli Tepe ("Potbelly Hill") in southern Turkey, dating from ca. 11,500 years ago, that religion predated the Agricultural Revolution rather than following in its wake, as had generally been assumed.[42]

[edit] Ancient historyEdit

Main article: Ancient history===[edit] Origin of civilization=== Main article: Bronze Age[3][4]Ancient Egyptians built the Great Pyramids of Giza.The Bronze Age forms part of a three-age system. In this system, in some areas of the world, the Bronze Age follows the Stone Age. During this era the most fertile areas of the world saw city states and the first civilizations develop. These were concentrated on four fertile river valleys: The Tigris and Euphrates in Mesopotamia, the Nile in Egypt, the Indus in South Asia, and the Yangtze and Yellow River in China.

Mesopotamia saw the rise of the Sumerian city states. It was in these cities that the earliest known form of writing, cuneiform script, appeared ca. 3000 BCE. Cuneiform writing began as a system of pictographs. Over time, the pictorial representations became simplified and more abstract. Cuneiforms were written on clay tablets, on which symbols were drawn with a blunt reed for a stylus. Writing made the administration of a large state far easier. This era also saw new military technologies, such as chariots, that allowed armies to move faster.

These developments lead to the development of empires. The first empire, controlling a large territory and many cities, developed in Egypt that formed with the unification of Lower and Upper Egypt c. 3100 BCE . Over the next millennia the other river valleys would also see monarchical empires rise to power. In the 24th century BCE, the Akkadian Empire arose in Mesopotamia.[43] and in China the Xia Dynasty arose c. 2200 BCE.

Over the next millennia civilizations would develop across the world. Trade would increasingly become a source of power as states with access to important resources or controlling important trade routes would rise to dominance. In c.2,500 BCE the Kingdom of Kerma developed in Sudan south of Egypt. In modern Turkey the Hittites controlled a large empire and by 1600 BCE, Mycenaean Greece began to develop.[44][45] In India this era was the Vedic period, which laid the foundations of Hinduism and other cultural aspects of early Indian society, and ended in the 500s BCE. From around 550 BCE, many independent kingdoms and republics known as the Mahajanapadas were established across the country. In the Americas, civilizations such as the Maya, Zapotec, Moche, and Nazca emerged in Mesoamerica and Peru at the end of the 1st millennium BCE.

[edit] Ancient empiresEdit

C. 4300 BC

Rajanaka Bhumi Chand founded the Katoch Dynasty C. 3000 BC

The Rajas of Kangra fought against the Hindu deity lord

[edit] Religion and philosophyEdit

Main article: Axial ageMain articles: History of philosophy, Timeline of religion, and History of religion[5][6]Angkor Wat temple, Cambodia, early 12th centuryBeginning in the sixth century BCE a set of transformative religious and philosophical ideas developed. During this century Chinese Confucianism, Indian Buddhism and Jainism, Persian Zoroastrianism, Ancient Egyptian Monotheism, and Jewish Monotheism all developed. In the fifth century Socrates and Plato would lay the foundations of Ancient Greek philosophy.

In the east, three schools of thought were to dominate Chinese thinking until the modern day. These were Taoism,[46] Legalism[47] and Confucianism.[48] The Confucian tradition, which would attain dominance, looked for political morality not to the force of law but to the power and example of tradition. Confucianism would later spread into the Korean peninsula and toward Japan.

In the west, the Greek philosophical tradition, represented by Socrates,[49] Plato,[50] and Aristotle,[51][52] was diffused throughout Europe and the Middle East in the 4th century BCE by the conquests of Alexander III of Macedon, more commonly known as Alexander the Great.[53][54][55]

[edit] Regional empiresEdit

Main articles: Civilization and Global empire[7][8]The Parthenon epitomizes the sophisticated culture of the ancient Greeks.The millennia from 500 BCE to 500 CE saw a series of empires of unprecedented size develop. Well-trained professional armies, unifying ideologies, and advanced bureaucracies allowed a single emperor to rule over tens of millions of subjects.

This period in the history of the world was marked by slow but steady technological advances, with important developments such as the stirrup and moldboard plow arriving every few centuries. There were, however, in some regions, periods of rapid technological progress. Most important, perhaps, was the Mediterranean area during the Hellenistic period, when hundreds of technologies were invented.[56][57][58] Such periods were followed by periods of technological decay, as during the Roman Empire's decline and fall and the ensuing early medieval period.

The great empires depended on military annexation of territory and on the formation of defended settlements to become agricultural centres.[59] The relative peace that the empires brought encouraged international trade, most notably the massive trade routes in the Mediterranean that had been developed by the time of the Hellenistic Age, and the Silk Road. [9][10]Ptolemy's world map, reconstituted from his Geographia (ca. 150)The empires faced common problems associated with maintaining huge armies and supporting a central bureaucracy. These costs fell most heavily on the peasantry, while land-owning magnates were increasingly able to evade centralised control and its costs. The pressure of barbarians on the frontiers hastened the process of internal dissolution. China's Han Empire fell into civil war in 220 CE, while its Roman counterpart became increasingly decentralised and divided about the same time.

In the west, the Greeks established a civilization that is the foundational culture of modern western civilization. Some centuries later, in the 3rd century BCE, the Romans began expanding their territory through conquest and colonization. By the reign of Emperor Augustus (late 1st century BCE), Rome controlled all the lands surrounding the Mediterranean. By the reign of Emperor Trajan (early 2nd century CE), Rome controlled much of the land from England to Mesopotamia.

In the third century BCE, most of South Asia was united into the Maurya Empire by Chandragupta Maurya and flourished under Ashoka the Great. From the third century CE, the Gupta dynasty oversaw the period referred to as ancient India's Golden Age. Empires in Southern India included those of the Chalukyas,the Rashtrakutas, the Hoysalas, the Cholas and the Vijayanagara Empire. Science, engineering, art, literature, astronomy, and philosophy flourished under the patronage of these kings.

[edit] Declines and fallsEdit

The great empires of Eurasia were all located on the temperate coastal plains. From the Central Asian steppe horse based nomads dominated a large part of the continent. The development of the stirrup and the breeding of horses strong enough to carry a fully armed archer made the nomads a constant threat to the more settled civilizations.

The gradual break-up of the Roman Empire,[60][61] spanning several centuries after the 2nd century CE, coincided with the spread of Christianity westward from the Middle East. The western Roman Empire fell[62] under the domination of Germanic tribes in the 5th century, and these polities gradually developed into a number of warring states, all associated in one way or another with the Roman Catholic Church. The remaining part of the Roman Empire, in the eastern Mediterranean, would henceforth be the Byzantine Empire.[63] Centuries later, a limited unity would be restored to western Europe through the establishment of the Holy Roman Empire[64] in 962, which comprised a number of states in what is now Germany, Switzerland, Belgium, Italy, and France.

In China, dynasties would similarly rise and fall.[65][66] After the fall of the Eastern Han Dynasty[67] and the demise of the Three Kingdoms, Nomadic tribes from the north began to invade in the 4th century CE, eventually conquering areas of Northern China and setting up many small kingdoms. The Sui Dynasty reunified China in 581, and under the succeeding Tang Dynasty (618-907) China entered a second golden age. The Tang Dynasty also splintered, however, and after half a century of turmoil the Northern Song Dynasty reunified China in 982. Yet pressure from nomadic empires to the north became increasingly urgent. North China was lost to the Jurchens in 1141, and the Mongol Empire[68][69] conquered all of China in 1279, as well as almost all of Eurasia's landmass, missing only central and western Europe, and most of Southeast Asia and Japan.

In these times, northern India was ruled by the Guptas. In southern India, three prominent Dravidian kingdoms emerged: Cheras, Cholas and Pandyas. The ensuing stability contributed to heralding in the golden age of Hindu culture in the 4th and 5th centuries CE. [11][12]Machu Picchu, "the Lost City of the Incas"—the most recognizable symbol of Inca civilizationAlso at this time in Central America,[70] vast societies began to be built, the most notable being the Maya and Aztecs of Mesoamerica. As the mother culture of the Olmecs[71] gradually declined, the great Mayan city-states slowly rose in number and prominence, and Maya culture spread throughout Yucatán and surrounding areas. The later empire of the Aztecs was built on neighboring cultures and was influenced by conquered peoples such as the Toltecs.

In South America, the 14th and 15th centuries saw the rise of the Inca. The Inca Empire of Tawantinsuyu, with its capital at Cusco, spanned the entire Andes Mountain Range.[72][73] The Inca were prosperous and advanced, known for an excellent road system and unrivaled masonry.

[edit] Middle AgesEdit

Main article: Middle AgesThe Middle Ages are commonly dated from the fall of the Western Roman Empire in the 5th century.

The period corresponds to the Islamic conquests[74], subsequent Islamic golden age[75][76], and commencement and expansion of the Islamic/Arab Slave Trade followed by the Mongol invasions in the Middle East and Central Asia. South Asia saw a series of middle kingdoms of India followed by the establishment of Islamic empires in India. The Chinese Empire saw the succession of the Sui, Tang, Liao, Yuan and Ming Dynasties.

The Black Death was one of the deadliest pandemics in human history. Starting in Asia, the disease reached Mediterranean and western Europe during the late 1340s,[77] and killed tens of millions of Europeans in six years; between a third and a half of the total population.[78]

The Middle Ages[79] witnessed the first sustained urbanization of northern and western Europe. Many modern European states owe their origins to events unfolding in the Middle Ages; present European political boundaries are, in many regards, the result of the military and dynastic achievements during this tumultuous period.[80]

The Middle Ages lasted until the beginning of the Early Modern Period[22] in the 16th century, marked by the rise of nation-states, the division of Western Christianity in the Reformation,[81] the rise of humanism in the Italian Renaissance,[82] and the beginnings of European overseas expansion which allowed for the Columbian Exchange.[83]

[edit] Modern historyEdit

Main article: Modern historyModern history (the "modern period," the "modern era," "modern times") is history of the period following the Middle Ages. "Contemporary history" encompasses historic events that are immediately relevant to the present time; its intentionally loose ambit includes major events such as World War II, but not those whose immediate effects have dissipated.

[edit] Early Modern periodEdit

Main article: Early Modern period"Early modern period"[84] is a term used by historians to refer to the period in Western Europe and its first colonies that spans the centuries between the Middle Ages and the Industrial Revolution. The early modern period is characterized by the rise to importance of science and by increasingly rapid technological progress, secularized civic politics, and the nation-state. Capitalist economies began their rise, initially in northern Italian republics such as Genoa. The early modern period also saw the rise and dominance of the mercantilist economic theory. As such, the early modern period represents the decline and eventual disappearance, in much of the European sphere, of feudalism, serfdom and the power of the Catholic Church. The period includes the Protestant Reformation, the disastrous Thirty Years' War, the European colonization of the Americas, and the peak of European witch-hunting.

[edit] Rise of EuropeEdit

Further information: History of Europe[13][14]The movable-type printing press arose in the mid-15th century. Less than 50 years later, nine million books were in print.Nearly all the agricultural civilizations have been heavily constrained by their environments. Productivity remained low, and climatic changes easily instigated boom and bust cycles that brought about civilizations' rise and fall. By about 1500, however, there was a qualitative change in world history. Technological advance and the wealth generated by trade gradually brought about a widening of possibilities.[85][86][87][88][89][90][91][92][93][94][95]

Outwardly, Europe's Renaissance, beginning in the 14th century,[96] consisted in the rediscovery of the classical world's scientific contributions, and in the economic and social rise of Europe. But the Renaissance also engendered a culture of inquisitiveness which ultimately led to Humanism,[97] the Scientific Revolution,[98] and finally the great transformation of the Industrial Revolution. The Scientific Revolution in the 17th century, however, had no immediate impact on technology; only in the second half of the 18th century did scientific advances begin to be applied to practical invention.

The advantages that Europe had developed by the mid-18th century were two: an entrepreneurial culture,[citation needed] and the wealth generated by the Atlantic trade (including the African slave trade). By the late 16th century, American silver accounted for one-fifth of Spain's total budget.[citation needed] The profits of the slave trade and of West Indian plantations amounted to 5% of the British economy at the time of the Industrial Revolution.[99] While some historians conclude that, in 1750, labour productivity in the most developed regions of China was still on a par with that of Europe's Atlantic economy (see the NBER Publications by Carol H. Shiue and Wolfgang Keller[100]), other historians like Angus Maddison hold that the per-capita productivity of western Europe had by the late Middle Ages surpassed that of all other regions.[101]

A number of explanations are proffered as to why, from the late Middle Ages on, Europe rose to surpass other civilizations, become the home of the Industrial Revolution,[102] and dominate the world. Max Weber argued that it was due to a Protestant work ethic that encouraged Europeans to work harder and longer than others. Another socioeconomic explanation looks to demographics: Europe, with its celibate clergy, colonial emigration, high-mortality urban centers, periodic famines and outbreaks of the Black Death, continual warfare, and late age of marriage had far more restrained population growth, compared to Asian cultures. A relative shortage of labour meant that surpluses could be invested in labour-saving technological advances such as water-wheels and mills, spinners and looms, steam engines and shipping, rather than fueling population growth.

Many have also argued that Europe's institutions were superior,[103][104] that property rights and free-market economics were stronger than elsewhere due to an ideal of freedom peculiar to Europe. In recent years, however, scholars such as Kenneth Pomeranz have challenged this view, although the revisionist approach to world history has also met with criticism for systematically "downplaying" European achievements.[105] [15][16]Vasco da Gama reached India by sea in 1498.Europe's geography may also have played an important role. The Middle East, India and China are all ringed by mountains but, once past these outer barriers, are relatively flat. By contrast, the Pyrenees, Alps, Apennines, Carpathians and other mountain ranges run through Europe, and the continent is also divided by several seas. This gave Europe some degree of protection from the peril of Central Asian invaders. Before the era of firearms, these nomads were militarily superior to the agricultural states on the periphery of the Eurasian continent and, if they broke out into the plains of northern India or the valleys of China, were all but unstoppable. These invasions were often devastating. The Golden Age of Islam[106] was ended by the Mongol sack of Baghdad in 1258. India and China were subject to periodic invasions, and Russia spent a couple of centuries under the Mongol-Tatar Yoke. Central and western Europe, logistically more distant from the Central Asian heartland, proved less vulnerable to these threats.

Geography also contributed to important geopolitical differences. For most of their histories, China, India and the Middle East were each unified under a single dominant power that expanded until it reached the surrounding mountains and deserts. In 1600 the Ottoman Empire[107] controlled almost all the Middle East, the Ming Dynasty ruled China,[108][109] and the Mughal Empire held sway over India. By contrast, Europe was almost always divided into a number of warring states. Pan-European empires, with the notable exception of the Roman Empire, tended to collapse soon after they arose. Another doubtless important geographic factor in the rise of Europe was the Mediterranean Sea, which, for millennia, had functioned as a maritime superhighway fostering the exchange of goods, people, ideas and inventions.

[edit] Age of DiscoveryEdit

Main article: Age of Discovery[17][18]Columbus sought India aboard the Santa Maria in 1492.In the fourteenth century, the Renaissance began in Europe.[110][111] Some modern scholars[who?] have questioned whether this flowering of art and Humanism was a benefit to science. The era did see an important fusion of Arab and European knowledge.[112][113] One of the most important developments was the caravel, which combined the Mediterranean lateen sail with European square rigging to create the first vessels that could safely sail the Atlantic Ocean.[114] Along with important developments in navigation, this technology allowed the Italian Christopher Columbus in 1492 to journey across the Atlantic Ocean and bridge the gap between Afro-Eurasia and the Americas.

This had dramatic effects on both continents. The Europeans brought with them viral diseases that American natives had never encountered,[115] and uncertain numbers of natives died in a series of devastating epidemics. The Europeans also had the technological advantage of horses, steel and guns that helped them overpower the Aztec and Incan empires as well as North American cultures.[116]

Gold and resources from the Americas began to be stripped from the land and people and shipped to Europe, while at the same time large numbers of European colonists began to emigrate to the Americas.[117][118] To meet the great demand for labor in the new colonies, the mass import of Africans as slaves began.[119] Soon much of the Americas had a large racial underclass of slaves. In West Africa, a series of thriving states developed along the coast, becoming prosperous from the exploitation of suffering interior African peoples.

Europe's maritime expansion unsurprisingly — given that continent's geography — was largely the work of its Atlantic states: Portugal, Spain, England, France, and the Netherlands. The Portuguese and Spanish Empires were the predominant conquerors and source of influence, and their union resulted in the Iberian Union,[120] the first global empire, on which the "sun never set". Soon the more northern English, French and Dutch began to dominate the Atlantic. In a series of wars fought in the 17th and 18th centuries, culminating with the Napoleonic Wars, Britain emerged as the new world power.

Meanwhile the voyages of Admiral Zheng He were halted by China's Ming Dynasty (1368–1644), established after the expulsion of the Mongols. A Chinese commercial revolution, sometimes described as "incipient capitalism", was also abortive. The Ming Dynasty would eventually fall to the Manchus, whose Qing Dynasty at first oversaw a period of calm and prosperity but would increasingly fall prey to Western encroachment.

[edit] 19th centuryEdit

Main article: 19th centuryAfter Europeans had achieved dominance over the Americas, their imperial appetites turned to the countries of Asia. In the 19th century the European states had a distinct technological advantage over Asian states and peoples. Britain gained control of the Indian subcontinent, Egypt and the Malay Peninsula; the French took Indochina; while the Dutch cemented their control over the Dutch East Indies. In addition, Russia colonised large pre-agricultural areas of Siberia. The British also colonised places inhabited by Neolithic peoples, including Australia, New Zealand and South Africa. large numbers of British colonists emigrated to these colonies. In the late 19th century, the European powers divided the remaining areas of Africa. Within Europe, economic and military challenges created a system of nation states, and ethno-linguistic groupings began to identify themselves as distinctive nations with aspirations for cultural and political autonomy. This nationalism would become important to peoples across the world in the twentieth century.

This era in European culture saw the Age of Reason lead to the Scientific Revolution. The Scientific Revolution changed humanity's understanding of the world and happened simultaneously with the Industrial Revolution, a major transformation of the world's economies. The Industrial Revolution began in Great Britain and used new modes of production — the factory, mass production, and mechanisation — to manufacture a wide array of goods faster and using less labour than previously.

The Age of Reason also led to the beginnings of modern democracy in the late-18th century American and French Revolutions. Democracy would grow to have a profound effect on world events and on quality of life.[dubiousdiscuss][neutrality is disputed]

During the Industrial Revolution, the world economy became reliant on coal as a fuel, as new methods of transport, such as railways and steamships, effectively shrank the world. Meanwhile, industrial pollution and environmental damage, present since the discovery of fire and the beginning of civilization, accelerated drastically.

[edit] 20th century to presentEdit

Main articles: 20th century and 21st century====[edit] Early 20th century==== [19][20]World War I, fought by the Allies (green) and Central Powers (orange), ended the German, Austro-Hungarian, Russian and Ottoman Empires.The 20th century[121][122][123] opened with Europe at an apex of wealth and power, and with much of the world under its direct colonial control or its indirect domination.[124] Much of the rest of the world was influenced by heavily Europeanized nations: the United States and Japan.[125] As the century unfolded, however, the global system dominated by rival powers was subjected to severe strains, and ultimately yielded to a more fluid structure of independent nations organized on Western models.

This transformation was catalysed by wars of unparalleled scope and devastation. World War I[126] destroyed many of Europe's empires and monarchies, and weakened Britain and France.[127] In its aftermath, powerful ideologies arose. The Russian Revolution[128][129][130] of 1917 created the first communist state, while the 1920s and 1930s saw militaristic fascist dictatorships gain control in Italy, Germany, Spain and elsewhere.[131]

Ongoing national rivalries, exacerbated by the economic turmoil of the Great Depression, helped precipitate World War II.[132][133] The militaristic dictatorships of Europe and Japan pursued an ultimately doomed course of imperialist expansionism. Their defeat opened the way for the advance of communism into Central Europe, Yugoslavia, Bulgaria, Romania, Albania, China, North Vietnam and North Korea. [21][22]Nuclear bombs, dropped on Japan in 1945, ended World War II and opened the Cold War.Following World War II, in 1945, the United Nations was founded in the hope of allaying conflicts among nations and preventing future wars.[134][135] The war had, however, left two nations, the United States[136] and the Soviet Union, with principal power to guide international affairs.[137] Each was suspicious of the other and feared a global spread of the other's political-economic model. This led to the Cold War, a forty-year stand-off between the United States, the Soviet Union, and their respective allies. With the development of nuclear weapons[138] and the subsequent arms race, all of humanity were put at risk of nuclear war between the two superpowers.[139] Such war being viewed as impractical, proxy wars were instead waged, at the expense of non-nuclear-armed Third World countries.

[edit] Late 20th centuryEdit

The Cold War lasted through to the ninth decade of the twentieth century, when the Soviet Union's communist system began to collapse, unable to compete economically with the United States and western Europe; the Soviets' Central European "satellites" reasserted their national sovereignty, and in 1991 the Soviet Union itself disintegrated.[140][141][142] The United States for the time being was left as the "sole remaining superpower".[143][144][145]

In the early postwar decades, the African and Asian colonies of the Belgian, British, Dutch, French and other west European empires won their formal independence.[146][147] These nations faced challenges in the form of neocolonialism, poverty, illiteracy and endemic tropical diseases.[148][149] Many of the Western and Central European nations gradually formed a political and economic community, the European Union, which subsequently expanded eastward to include former Soviet satellites.[150][151][152][153] [23][24]Last Moon landing — Apollo 17 (1972)The twentieth century saw exponential progress in science and technology, and increased life expectancy and standard of living for much of humanity. As the developed world shifted from a coal-based to a petroleum-based economy, new transport technologies, along with the dawn of the Information Age,[154] led to increased globalization.[155][156][157] Space exploration reached throughout the solar system. The structure of DNA, the very template of life, was discovered,[158][159][160] and the human genome was sequenced, a major milestone in the understanding of human biology and the treatment of disease.[161][162][163][164][165] Global literacy rates continued to rise, and the percentage of the world's labor pool needed to produce humankind's food supply continued to drop.

The technologies of sound recordings, motion pictures, and radio and television broadcasting produced a focus on popular culture and entertainment. Television spots sold both commercial products and political candidates. Some worried that the young generation was losing basic literacy skills. Then, in the last decade of this century, a rapid increase took place in the use of personal computers. A global communication network emerged in the Internet. Mass entertainment gave way to individual communication in what has been called a shift from the fourth to a fifth civilization.[166]

The century saw the development of new global threats, such as nuclear proliferation, worldwide epidemics of diseases, global climate change,[167][168] massive deforestation, overpopulation, and the dwindling of global resources (particularly fossil fuels).[169]

21st centuryEdit

Main article: Contemporary historyAs the 20th century yielded to the 21st, worldwide demand and competition for resources rose due to growing populations and industrialization, mainly in India, China, and Brazil. This demand is resulting in increased levels of environmental degradation and greater threats of global warming.[170] This led to development of alternate sources of energy such as solar and other renewable energy varieties, to proposals for cleaner fossil-fuel technologies, and to consideration of expanded use of nuclear energy.[171][172][173]