Europe is a peninsula that makes up the western fifth of the Eurasian landmass. Its maritime borders are made up of the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean, Black, and Caspian Seas to the south
Land relief in Europe shows great variation within relatively small areas. The southern regions are more mountainous, while moving north the terrain descends from the high Alps, Pyrenees, and Carpathians, through hilly uplands, into broad, low northern plains, which are vast in the east. This extended lowland is known as the Great European Plain, and at its heart lies the North German Plain. An arc of uplands also exists along the north-western seaboard, which begins in the western parts of the islands of Britain and Ireland, and then continues along the mountainous, fjord-cut spine of Norway.
This description is simplified. Sub-regions such as the Iberian Peninsula and the Italian Peninsula contain their own complex features, as does mainland Central Europe itself, where the relief contains many plateaus, river valleys and basins that complicate the general trend. Sub-regions like Iceland, Britain, and Ireland are special cases. The former is a land unto itself in the northern ocean which is counted as part of Europe, while the latter are upland areas that were once joined to the mainland until rising sea levels cut them off.
[[File:Vegetation Europe.png|frame|Biomes of Europe and surrounding regions:
The climate is milder in comparison to other areas of the same latitude around the globe due to the influence of the Gulf Stream. The Gulf Stream is nicknamed "Europe's central heating", because it makes Europe's climate warmer and wetter than it would otherwise be. The Gulf Stream not only carries warm water to Europe's coast but also warms up the prevailing westerly winds that blow across the continent from the Atlantic Ocean.
Therefore the average temperature throughout the year of Naples is 16 °C (60.8 °F), while it is only 12 °C (53.6 °F) in New York City which is almost on the same latitude. Berlin, Germany; Calgary, Canada; and Irkutsk, in the Asian part of Russia, lie on around the same latitude; January temperatures in Berlin average around 8 °C (15 °F) higher than those in Calgary, and they are almost 22 °C (40 °F) higher than average temperatures in Irkutsk.
Europe's most significant feature is the dichotomy between highland and mountainous Southern Europe and a vast, partially underwater, northern plain ranging from Ireland in the west to the Ural Mountains in the east. These two halves are separated by the mountain chains of the Pyrenees and Alps/Carpathians. The northern plains are delimited in the west by the Scandinavian Mountains and the mountainous parts of the British Isles. Major shallow water bodies submerging parts of the northern plains are the Celtic Sea, the North Sea, the Baltic Sea complex and Barents Sea.
The northern plain contains the old geological continent of Baltica, and so may be regarded geologically as the "main continent", while peripheral highlands and mountainous regions in the south and west constitute fragments from various other geological continents. Most of the older geology of western Europe existed as part of the ancient microcontinent Avalonia.
The geological history of Europe traces back to the formation of the Baltic Shield (Fennoscandia) and the Sarmatian craton, both around 2.25 billion years ago, followed by the Volgo-Uralia shield, the three together leading to the East European craton (≈ Baltica) which became a part of the supercontinent Columbia. Around 1.1 billion years ago, Baltica and Arctica (as part of the Laurentia block) became joined to Rodinia, later resplitting around 550 million years ago to reform as Baltica. Around 440 million years ago Euramerica was formed from Baltica and Laurentia; a further joining with Gondwana then leading to the formation of Pangea. Around 190 million years ago, Gondwana and Laurasia split apart due to the widening of the Atlantic Ocean. Finally, and very soon afterwards, Laurasia itself split up again, into Laurentia (North America) and the Eurasian continent. The land connection between the two persisted for a considerable time, via Greenland, leading to interchange of animal species. From around 50 million years ago, rising and falling sea levels have determined the actual shape of Europe, and its connections with continents such as Asia. Europe's present shape dates to the late Tertiary period about five million years ago.
Having lived side-by-side with agricultural peoples for millennia, Europe's animals and plants have been profoundly affected by the presence and activities of man. With the exception of Fennoscandia and northern Russia, few areas of untouched wilderness are currently found in Europe, except for various national parks.
The main natural vegetation cover in Europe is mixed forest. The conditions for growth are very favourable. In the north, the Gulf Stream and North Atlantic Drift warm the continent. Southern Europe could be described as having a warm, but mild climate. There are frequent summer droughts in this region. Mountain ridges also affect the conditions. Some of these (Alps, Pyrenees) are oriented east-west and allow the wind to carry large masses of water from the ocean in the interior. Others are oriented south-north (Scandinavian Mountains, Dinarides, Carpathians, Apennines) and because the rain falls primarily on the side of mountains that is oriented towards the sea, forests grow well on this side, while on the other side, the conditions are much less favourable. Few corners of mainland Europe have not been grazed by livestock at some point in time, and the cutting down of the pre-agricultural forest habitat caused disruption to the original plant and animal ecosystems.
Probably 80 to 90 per cent of Europe was once covered by forest. It stretched from the Mediterranean Sea to the Arctic Ocean. Though over half of Europe's original forests disappeared through the centuries of deforestation, Europe still has over one quarter of its land area as forest, such as the taiga of Scandinavia and Russia, mixed rainforests of the Caucasus and the Cork oak forests in the western Mediterranean. During recent times, deforestation has been slowed and many trees have been planted. However, in many cases monoculture plantations of conifers have replaced the original mixed natural forest, because these grow quicker. The plantations now cover vast areas of land, but offer poorer habitats for many European forest dwelling species which require a mixture of tree species and diverse forest structure. The amount of natural forest in Western Europe is just 2–3% or less, in European Russia 5–10%. The country with the smallest percentage of forested area is Iceland (1%), while the most forested country is Finland (77%).
In temperate Europe, mixed forest with both broadleaf and coniferous trees dominate. The most important species in central and western Europe are beech and oak. In the north, the taiga is a mixed spruce–pine–birch forest; further north within Russia and extreme northern Scandinavia, the taiga gives way to tundra as the Arctic is approached. In the Mediterranean, many olive trees have been planted, which are very well adapted to its arid climate; Mediterranean Cypress is also widely planted in southern Europe. The semi-arid Mediterranean region hosts much scrub forest. A narrow east-west tongue of Eurasian grassland (the steppe) extends eastwards from Ukraine and southern Russia and ends in Hungary and traverses into taiga to the north.
Glaciation during the most recent ice age and the presence of man affected the distribution of European fauna. As for the animals, in many parts of Europe most large animals and top predator species have been hunted to extinction. The woolly mammoth was extinct before the end of the Neolithic period. Today wolves (carnivores) and bears (omnivores) are endangered. Once they were found in most parts of Europe. However, deforestation and hunting caused these animals to withdraw further and further. By the Middle Ages the bears' habitats were limited to more or less inaccessible mountains with sufficient forest cover. Today, the brown bear lives primarily in the Balkan peninsula, Scandinavia, and Russia; a small number also persist in other countries across Europe (Austria, Pyrenees etc.), but in these areas brown bear populations are fragmented and marginalised because of the destruction of their habitat. In addition, polar bears may be found on Svalbard, a Norwegian archipelago far north of Scandinavia. The wolf, the second largest predator in Europe after the brown bear, can be found primarily in Eastern Europe and in the Balkans, with a handful of packs in pockets of Western Europe (Scandinavia, Spain, etc.).
European wild cat, foxes (especially the red fox), jackal and different species of martens, hedgehogs, different species of reptiles (like snakes such as vipers and grass snakes) and amphibians, different birds (owls, hawks and other birds of prey).
Important European herbivores are snails, larvae, fish, different birds, and mammals, like rodents, deer and roe deer, boars, and living in the mountains, marmots, steinbocks, chamois among others. A number of insects, such as the small tortoiseshell butterfly, add to the biodiversity.
Sea creatures are also an important part of European flora and fauna. The sea flora is mainly phytoplankton. Important animals that live in European seas are zooplankton, molluscs, echinoderms, different crustaceans, squids and octopuses, fish, dolphins, and whales.