Welcome to Earth

Globally, the 20th century was marked by: (a) two devastating world wars; (b) the Great Depression of the 1930s; (c) the end of vast colonial empires; (d) rapid advances in science and technology, from the first airplane flight at Kitty Hawk, North Carolina (US) to the landing on the moon; (e) the Cold War between the Western alliance and the Warsaw Pact nations; (f) a sharp rise in living standards in North America, Europe, and Japan; (g) increased concerns about the environment, including loss of forests, shortages of energy and water, the decline in biological diversity, and air pollution; (h) the onset of the AIDS epidemic; and (i) the ultimate emergence of the US as the only world superpower. The planet's population continues to explode: from 1 billion in 1820, to 2 billion in 1930, 3 billion in 1960, 4 billion in 1974, 5 billion in 1988, and 6 billion in 2000. For the 21st century, the continued exponential growth in science and technology raises both hopes (e.g., advances in medicine) and fears (e.g., development of even more lethal weapons of war).

The surface of the earth is approximately 70.9% water and 29.1% land. The former portion is divided into large water bodies termed oceans. The World Factbook recognizes and describes five oceans, which are in decreasing order of size: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Southern Ocean, and Arctic Ocean.
The land portion is generally divided into several, large, discrete landmasses termed continents. Depending on the convention used, the number of continents can vary from five to seven. The most common classification recognizes seven, which are (from largest to smallest): Asia, Africa, North America, South America, Antarctica, Europe, and Australia. Asia and Europe are sometimes lumped together into a Eurasian continent resulting in six continents. Alternatively, North and South America are sometimes grouped as simply the Americas, resulting in a continent total of six (or five, if the Eurasia designation is used).
North America is commonly understood to include the island of Greenland, the isles of the Caribbean, and to extend south all the way to the Isthmus of Panama. The easternmost extent of Europe is generally defined as being the Ural Mountains and the Ural River; on the southeast the Caspian Sea; and on the south the Caucasus Mountains, the Black Sea, and the Mediterranean. Portions of Azerbaijan, Georgia, Kazakhstan, Russia, and Turkey fall within both Europe and Asia, but in every instance the larger section is in Asia. These countries are considered part of both continents. Armenia and Cyprus, which lie completely in Western Asia, are geopolitically European countries.
Asia usually incorporates all the islands of the Philippines, Malaysia, and Indonesia. The islands of the Pacific are often lumped with Australia into a "land mass" termed Oceania or Australasia. Africa's northeast extremity is frequently delimited at the Isthmus of Suez, but for geopolitical purposes, the Egyptian Sinai Peninsula is often included as part of Africa.
Although the above groupings are the most common, different continental dispositions are recognized or taught in certain parts of the world, with some arrangements more heavily based on cultural spheres rather than physical geographic considerations.

Population: 6,928,198,253 (July 2011 est.)

Age structure:

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Population growth rate: 1.092% (2011 est.)
Birth rate: 19.15 births/1,000 population (2011 est.)
Death rate: 8.12 deaths/1,000 population (July 2011 est.)
Urbanization: urban population: 50.5% of total population (2010)
rate of urbanization: 1.85% annual rate of change (2010-15 est.)
Largest Cities: Delhi (India) - 106,157,000; Tokyo (Japan) - 96,669,000; ; Sao Paulo (Brazil) - 84,262,000; Mumbai (India) - 80,041,000; Mexico City (Mexico) - 76,460,000; New York-Newark (US) - 69,425,000; Shanghai (China) - 65,575,000; Kolkata (India) - 64,552,000; Dhaka (Bangladesh) - 66,648,000; Karachi (Pakistan) - 60,125,000 (2009)
Sex ratio:

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Literacy:

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Economics

In 2010, world output - and per capita income - began to recover from the 2008-09 recession, the first global downturn since 1946. Gross World Product (GWP) grew 4.9%, largely on the strength of rebounding exports, which rose about 20% from the level of 2009. Growth was not evenly distributed across countries, however. Lower income countries - those with per capita incomes below $30,000 per year - averaged 6.6% growth, while higher income countries - with per capita incomes above $30,000 - averaged just 2.9% growth. And countries with current account surpluses averaged 6.3% growth, while those with current account deficits averaged just 3.4% growth. Among large economies, Taiwan (+10.8%), India (+10.4%), China (+10.3%), Brazil (+7.5%), and South Korea (+6.1%) recorded the biggest GDP gains - China also became the world's largest exporter. Continuing uncertainties in mortgage and financial markets resulted in slower growth in Japan (+3.9%), the US (+2.8%), and the European Union (+1.8%). In 2010, global unemployment continued to creep upwards, reaching 8.8% - underemployment, especially in the developing world, remained much higher. Global gross fixed investment stabilized at about 23% of GWP, after a significant drop in 2009. World trade appears to be returning to pre-2009 patterns, with current account surpluses or deficits rising for a majority of countries. World external debt, however, dropped again in 2010 - about 5% from the 2009 level, as many countries reduced borrowing. Many, if not most, countries pursued expansionary monetary and fiscal policies. The global money supply, both narrowly and broadly defined, increased roughly 10%, as countries tried to keep interest rates low; the global budget deficit stabilized at roughly $3.5 trillion - 5.3% of GDP, as countries tried to rein in spending and slow the rise of public debt.
The international financial crisis of 2008-09 presents the world economy with a major new challenge, together with several long-standing ones. The fiscal stimulus packages put in place in 2009-10 required most countries to run budget deficits - government balances have deteriorated for 14 out of every 15 countries. Treasuries issued new public debt - totaling $5.5 trillion since 2008 - to pay for the additional expenditures. To keep interest rates low, many central banks monetized that debt, injecting large sums of money into the economies. As economic activity picks up, central banks will face the difficult task of containing inflation without raising interest rates so high they snuff out further growth. At the same time, governments will face the difficult task of spurring current growth and employment without saddling their economies with so much debt that they sacrifice long-term growth and financial stability.
Long-standing challenges the world faces are several. The addition of 80 million people each year to an already overcrowded globe is exacerbating the problems of underemployment, pollution, waste-disposal, epidemics, water-shortages, famine, over-fishing of oceans, deforestation, desertification, and depletion of non-renewable resources. The nation-state, as a bedrock economic-political institution, is steadily losing control over international flows of people, goods, funds, and technology. Internally, central governments often find their control over resources slipping as separatist regional movements - typically based on ethnicity - gain momentum, e.g., in many of the successor states of the former Soviet Union, in the former Yugoslavia, in India, in Iraq, in Indonesia, and in Canada. Externally, central governments are losing decisionmaking powers to international bodies, most notably the EU. The introduction of the euro as the common currency of much of Western Europe in January 1999, while paving the way for an integrated economic powerhouse, poses economic risks because the participating nations are culturally and politically diverse and have varying levels and rates of growth of income, and hence, differing needs for monetary and fiscal policies. In Western Europe, governments face the difficult political problem of channeling resources away from welfare programs in order to increase investment and strengthen incentives to seek employment. Because of their own internal problems and priorities, the industrialized countries devote insufficient resources to deal effectively with the poorer areas of the world, which, at least from an economic point of view, are becoming further marginalized. The terrorist attacks on the US on 11 September 2001 accentuated a growing risk to global prosperity, illustrated, for example, by the reallocation of resources away from investment to anti-terrorist programs. Wars in Iraq and Afghanistan added new uncertainties to global economic prospects.
Despite these challenges, the world economy also shows great promise. Technology has made possible further advances in all fields, from agriculture, to medicine, alternative energy, metallurgy, and transportation. Improved global communications have greatly reduced the costs of international trade, helping the world gain from the international division of labor, raise living standards, and reduce income disparities among nations. Much of the resilience of the world economy in the aftermath of the financial crisis resulted from government leaders around the globe working in concert to stem the financial onslaught, knowing well the lessons of past economic failures.