🗺️World Geography Unit 4 – North America: Geography, Climate & Ecosystems

Overview of North America

• North America is the third-largest continent by land area, covering approximately 9.54 million square miles (24.71 million square kilometers)
• Consists of 23 sovereign states and several dependent territories, with the United States, Canada, and Mexico being the largest countries by land area and population
• Bordered by the Arctic Ocean to the north, the Atlantic Ocean to the east, the Caribbean Sea and the Pacific Ocean to the southeast and south, and the Pacific Ocean to the west
• Home to diverse landscapes, including vast plains, towering mountain ranges (Rocky Mountains, Appalachian Mountains), dense forests, and sprawling deserts (Sonoran Desert, Chihuahuan Desert)
• Boasts an array of climatic regions, from the frigid Arctic tundra to the tropical rainforests of Central America
• Inhabited by a wide variety of plant and animal species, many of which are unique to the continent (bald eagle, American bison, monarch butterfly)
• Rich in natural resources, such as oil, natural gas, coal, precious metals, and freshwater
• Shaped by a complex history of indigenous cultures, European colonization, and modern nation-building

Physical Geography

• North America's topography is characterized by a central plain flanked by mountain ranges along the eastern and western coasts
• The Rocky Mountains, extending from Alaska to New Mexico, form the continent's backbone and serve as a continental divide, separating rivers that flow to the Pacific Ocean from those that flow to the Atlantic Ocean or Gulf of Mexico
  • The highest peak in the Rockies is Mount Elbert in Colorado, standing at 14,440 feet (4,401 meters) above sea level
• The Appalachian Mountains, located in the eastern part of the continent, are older and more eroded than the Rockies, with the highest peak being Mount Mitchell in North Carolina at 6,684 feet (2,037 meters)
• The Mississippi River, the longest river in North America, flows from Minnesota to the Gulf of Mexico, draining a vast basin that covers much of the central United States
  • The river and its tributaries (Missouri River, Ohio River) form a crucial transportation network and support diverse ecosystems
• The Great Lakes (Superior, Michigan, Huron, Erie, Ontario) form the largest freshwater system in the world by surface area, holding about 21% of the world's surface fresh water
• The Gulf of Mexico, an inlet of the Atlantic Ocean, is bordered by the United States, Mexico, and Cuba, and is known for its warm waters, hurricanes, and oil reserves
• The Baja California Peninsula, a long, narrow peninsula in northwestern Mexico, separates the Pacific Ocean from the Gulf of California, also known as the Sea of Cortez

Climate Zones

• North America spans several climate zones due to its vast size and varied topography
• The Arctic region, including northern Alaska and Canada, experiences a polar climate with long, cold winters and short, cool summers
  • Temperatures can drop below -40°F (-40°C) in winter, and permafrost (permanently frozen ground) is common
• The subarctic climate, found in central and southern Alaska and much of Canada, features long, cold winters and short, mild summers
  • Boreal forests (taiga) dominate the landscape, consisting mainly of coniferous trees (spruce, fir, pine)
• The temperate climate, prevalent in much of the United States and southern Canada, is characterized by distinct seasons with warm to hot summers and cool to cold winters
  • This climate zone supports diverse ecosystems, including deciduous forests, grasslands (prairies), and temperate rainforests (Pacific Northwest)
• The subtropical climate, found in the southern United States (Florida, Gulf Coast) and parts of Mexico, features hot, humid summers and mild winters
  • This climate is conducive to the growth of citrus fruits (oranges, lemons), sugarcane, and cotton
• The tropical climate, present in southern Mexico, Central America, and the Caribbean, is characterized by high temperatures and rainfall throughout the year
  • Tropical rainforests, known for their biodiversity, thrive in this climate
• Arid and semi-arid climates are found in the southwestern United States and northern Mexico, with low precipitation and extreme temperature variations between day and night
  • Deserts (Sonoran, Mojave) and grasslands (Chihuahuan) are adapted to these dry conditions

Major Ecosystems

• North America is home to a diverse array of ecosystems, each with its unique flora and fauna
• Tundra ecosystems, found in the Arctic regions of Alaska and Canada, are characterized by low-growing vegetation (mosses, lichens, sedges) and permafrost
  • Iconic species include the polar bear, Arctic fox, and caribou (reindeer)
• Boreal forests (taiga) stretch across much of Canada and parts of Alaska, featuring coniferous trees (spruce, fir, pine) adapted to cold temperatures and short growing seasons
  • Animals such as the moose, lynx, and snowshoe hare inhabit these forests
• Temperate deciduous forests, found in the eastern United States and southeastern Canada, are known for their vibrant fall foliage as trees (oak, maple, hickory) shed their leaves in autumn
  • White-tailed deer, black bears, and a variety of songbirds are common in these forests
• Temperate grasslands (prairies) once covered vast areas of the central United States and Canada but have largely been converted to agricultural land
  • Remaining grasslands support species like the pronghorn, bison, and prairie dog
• Temperate rainforests, found along the Pacific coast from Alaska to northern California, are characterized by high rainfall, cool temperatures, and towering conifers (redwoods, Douglas firs)
  • These forests are home to the Roosevelt elk, marbled murrelet, and banana slug
• Deserts, such as the Sonoran, Mojave, and Chihuahuan, are found in the southwestern United States and northern Mexico, with adaptations to hot, dry conditions
  • Iconic desert species include the saguaro cactus, roadrunner, and Gila monster
• Tropical rainforests, located in southern Mexico and Central America, are known for their high biodiversity and complex canopy structure
  • Jaguars, howler monkeys, and toucans are among the many species found in these forests
• Wetlands, including the Florida Everglades and the Mississippi River Delta, provide critical habitat for waterfowl, fish, and other aquatic species
  • American alligators, roseate spoonbills, and cypress trees are emblematic of these ecosystems

Natural Resources

• North America is rich in natural resources, which have played a significant role in the continent's economic development
• Fossil fuels, including oil, natural gas, and coal, are abundant in many parts of the continent
  • The United States is the world's largest producer of oil and natural gas, with major reserves in Texas, Alaska, and offshore in the Gulf of Mexico
  • Canada's oil sands in Alberta hold the third-largest proven oil reserves globally
  • Coal is mined extensively in the Appalachian region and the Powder River Basin of Wyoming and Montana
• Precious metals, such as gold and silver, have been mined in North America since the early days of European colonization
  • Major gold deposits are found in Alaska, California, and Nevada in the United States, and in the Yukon and British Columbia in Canada
  • Mexico is the world's largest producer of silver, with significant mines in Zacatecas and Durango states
• Copper, a crucial metal for electrical wiring and construction, is mined in the western United States (Arizona, Utah, New Mexico), Canada (Ontario, British Columbia), and Mexico (Sonora, Zacatecas)
• Uranium, used for nuclear power and weapons, is mined in the western United States (Wyoming, Utah) and Canada (Saskatchewan, Ontario)
• Freshwater is an essential resource, with the Great Lakes and major river systems (Mississippi, Missouri, Colorado) providing water for drinking, irrigation, and hydroelectric power
• Forests, particularly in Canada and the northwestern United States, supply timber for construction, paper production, and other wood products
• Arable land, concentrated in the central United States, southern Canada, and parts of Mexico, supports large-scale agriculture (corn, wheat, soybeans)
• Fisheries, both coastal and inland, provide food and livelihoods for many communities
  • Major fishing regions include the Grand Banks off the coast of Newfoundland, the Gulf of Mexico, and the Pacific coast from Alaska to California

Human Impact on the Environment

• Human activities have significantly altered North America's natural landscapes and ecosystems
• Deforestation, particularly in the temperate and tropical regions, has led to habitat loss and fragmentation
  • Logging, urban expansion, and conversion to agricultural land are the main drivers of deforestation
• Agriculture has transformed vast areas of grasslands and forests into cropland and pastures
  • The use of pesticides and fertilizers has led to water pollution and soil degradation
  • Irrigation has depleted groundwater resources in some regions (Ogallala Aquifer)
• Urbanization has led to the loss of natural habitats, increased air and water pollution, and the creation of urban heat islands
  • Sprawling cities (Los Angeles, Houston) have encroached on surrounding ecosystems and increased the demand for resources
• Industrial activities, such as mining, oil and gas extraction, and manufacturing, have caused air, water, and soil pollution
  • The release of toxic chemicals (mercury, lead) has contaminated ecosystems and posed health risks to humans and wildlife
• The construction of dams and water diversion projects has altered river systems and affected aquatic ecosystems
  • The Hoover Dam on the Colorado River has changed downstream habitats and reduced sediment flow to the delta
  • The Everglades in Florida have been drained and diverted for agriculture and urban development, affecting the region's unique wetland ecosystem
• Overfishing has depleted fish stocks in many coastal and inland waters
  • The collapse of the Atlantic cod fishery off the coast of Newfoundland in the 1990s is a notable example
• Climate change, driven by greenhouse gas emissions from human activities, is affecting North America's ecosystems and communities
  • Rising temperatures, changing precipitation patterns, and more frequent extreme weather events (hurricanes, droughts) are altering habitats and species distributions
  • Melting Arctic sea ice threatens the survival of polar bears and other ice-dependent species
• Invasive species, introduced intentionally or accidentally by humans, have disrupted native ecosystems
  • The emerald ash borer, a beetle native to Asia, has killed millions of ash trees in the eastern United States and Canada
  • Kudzu, a fast-growing vine from Japan, has overtaken native vegetation in the southeastern United States

Key Geographic Features

• North America is characterized by a diverse array of geographic features that shape its landscapes and influence its climate and ecosystems
• The Rocky Mountains, a major mountain range stretching from Alaska to New Mexico, form the continental divide and create distinct climate zones on their eastern and western slopes
  • The highest peak in the Rockies is Mount Elbert in Colorado, at 14,440 feet (4,401 meters) above sea level
  • The range is known for its rugged peaks, deep canyons (Grand Canyon), and diverse wildlife (grizzly bears, bighorn sheep)
• The Appalachian Mountains, an older and more eroded range in the eastern United States and Canada, are home to diverse forests and unique plant and animal species
  • The range includes notable subranges, such as the Blue Ridge Mountains and the Great Smoky Mountains
  • The Appalachian Trail, a 2,200-mile (3,500-kilometer) hiking route, traverses the length of the range
• The Great Plains, a vast expanse of flat to gently rolling grasslands, stretch from the Rocky Mountains to the Mississippi River
  • This region, known as the "breadbasket" of North America, is a major agricultural area (wheat, corn, soybeans)
  • The plains are also home to iconic wildlife, such as the American bison and the pronghorn
• The Mississippi River, the largest river system in North America, drains a vast basin that covers much of the central United States
  • The river and its tributaries (Missouri, Ohio) form a crucial transportation network and support diverse aquatic ecosystems
  • The Mississippi River Delta, a vast wetland at the river's mouth, is a critical habitat for migratory birds and fish
• The Great Lakes (Superior, Michigan, Huron, Erie, Ontario) form the largest freshwater system in the world by surface area
  • The lakes are important for transportation, recreation, and water supply for the surrounding region
  • Niagara Falls, a series of waterfalls on the Niagara River between Lake Erie and Lake Ontario, is a major tourist attraction
• The Gulf of Mexico, a large inlet of the Atlantic Ocean, is bordered by the United States, Mexico, and Cuba
  • The gulf is known for its warm waters, abundant oil reserves, and frequent hurricanes
  • The Gulf Coast is home to important port cities (New Orleans, Houston) and popular beach destinations (Cancun, Florida Keys)
• The Yucatan Peninsula, a limestone platform in southeastern Mexico, is known for its flat terrain, tropical climate, and Mayan ruins (Chichen Itza, Tulum)
  • The peninsula is also home to unique geological features, such as cenotes (sinkholes) and underground rivers
• The Baja California Peninsula, a long, narrow peninsula in northwestern Mexico, separates the Pacific Ocean from the Gulf of California
  • The peninsula is known for its rugged desert landscapes, stunning beaches, and rich marine life (gray whales, whale sharks)
  • The Gulf of California, also known as the Sea of Cortez, is a unique marine ecosystem with high levels of endemism (species found nowhere else)

Regional Challenges and Conservation Efforts

• North America faces a range of environmental challenges that threaten its natural resources, ecosystems, and human well-being
• Climate change is a major concern, with rising temperatures, changing precipitation patterns, and more frequent extreme weather events affecting the continent
  • Efforts to mitigate climate change include reducing greenhouse gas emissions through renewable energy (wind, solar), energy efficiency, and carbon pricing
  • Adaptation strategies, such as coastal protection and water conservation, are being implemented to build resilience to climate impacts
• Habitat loss and fragmentation, caused by human activities like urbanization, agriculture, and resource extraction, are major threats to biodiversity
  • Conservation efforts include establishing protected areas (national parks, wildlife refuges), restoring degraded habitats, and promoting sustainable land-use practices
  • The Yellowstone to Yukon Conservation Initiative (Y2Y) is an example of a large-scale effort to connect and protect habitats across the Rocky Mountains
• Water scarcity and pollution are growing challenges, particularly in arid regions and areas with intensive agriculture and industry
  • Efforts to address water issues include improving water efficiency, protecting wetlands and watersheds, and implementing pollution control measures
  • The Colorado River Compact, an agreement among seven U.S. states and Mexico, aims to manage and allocate the river's water resources
• Invasive species, introduced by human activities, can disrupt native ecosystems and cause economic damage
  • Prevention efforts include monitoring and regulating the movement of potentially invasive species, such as through ballast water management in ships
  • Control and eradication programs, such as the use of biological control agents or targeted removal, are used to manage established invasive populations
• Overfishing and unsustainable fishing practices have depleted many fish stocks and damaged marine ecosystems
  • Fisheries management strategies, such as setting catch limits, implementing no-take zones, and promoting sustainable aquaculture, aim to restore and maintain fish populations
  • The Marine Stewardship Council (MSC) certifies sustainably managed fisheries and promotes consumer awareness of sustainable seafood choices
• Pollution from industrial activities, agriculture, and urban runoff affects air, water, and soil quality
  • Pollution control measures include implementing stricter emissions standards, promoting clean technologies, and improving waste management practices
  • The Great Lakes Water Quality Agreement between the United States and Canada aims to restore and protect the Great Lakes ecosystem
• Environmental justice is a growing concern, as low-income and minority communities often bear a disproportionate burden of environmental hazards
  • Efforts to address environmental justice include involving affected communities in decision-making, ensuring equal access to environmental benefits, and prioritizing cleanup and restoration in disadvantaged areas
• Conservation efforts in North America involve a range of actors, including governments, non-governmental organizations (NGOs), indigenous communities, and private landowners
  • The United States and Canada have extensive systems of protected areas, including national parks (Yellowstone, Banff), wildlife refuges, and marine protected areas
  • NGOs, such as The Nature Conservancy and the World Wildlife Fund, work to