GEOGRAPHY 1000 Introduction to Physical Geography Lithosphere Hydrosphere Atmosphere Biosphere Understanding the Earth’s natural environment from local to global scales Your course instructor Dr. Matthew G. Letts [email protected] WE2052, 403-317-2842 Ph.D. M.Sc. B.Sc. B.A. Geography Geography Geography Biology University of London (King’s) McGill University Queen’s University Queen’s University 2003 1998 1995 1994 Interests: Plant ecology, microclimatology, hydrology and soils Where? Canada, Colombia and France Where are you from ? Where are you from? What is the landscape like? What kind of weather do you get? What kind of plants grow there? How do people use natural resources? WHY? Are there environmental problems? What are the solutions? The Earth’s Four Spheres Lithosphere Hydrosphere Atmosphere Biosphere Who discovered the spherical Earth? Not Cristóbal, Colón ! Eratosthenes even knew the circumference in 247 BC. Knowledge of a spherical Earth Ancient Greece Pythagoras (2506 - 2581 BP) Aristotle proved Earth to be spherical in (2395 - 2333 BP) Ancient Egypt Eratosthenes calculated the polar circumference (2258 BP) Incan astronomers Accurately calculated the precession of the equinoxes England: Newton predicted that Earth bulges slightly at equator (324 BP) Today: Geodesy - Earth’s shape and size characterized by surveys and mathematical calculations – Geoid How do we display the Earth in two dimensions? How did you do? Latitude Longitude GEOGRAPHY Geo (“Earth”) + Graphein (“to write”) Geography is the study of synergistic interactions among natural systems, geographic areas, society, and cultural activities over space Spatial analysis is the key to geography •The nature and character of physical space •Human-environment interactions and the spatial & temporal distribution of human behaviour and Earth system processes What is Physical Geography ? “The spatial analysis of all the physical elements and processes that make up the environment: energy, air, water, weather, climate, landforms, soils, animals, vegetation and Earth itself.” Physical Geography is an Earth Systems Science. As a science, it employs the scientific method The main concept of Earth Systems science is That “interacting physical, chemical and biological systems produce the conditions of the whole Earth.” Understand Environmental Problems The scientific method A small scale system Global Carbon Balance: large system Open Systems • • • • Permeable to energy and mass* Energy can be supplied by the surrounding environment Inputs and outputs can cross back and forth between the system and the surrounding environment The Earth is an open system in terms of energy but is nearly closed in terms of matter Closed Systems • • • • Self-contained from the surrounding environment Not permeable to energy and mass* Truly closed systems do not exist, using the natural science definition Theoretical construct: energy can never increase, entropy can never decrease N.B.: Physicists may refer to a closed system as one in which there is exchange of energy but not matter Positive feedback •Further production in the system leads to growth in the system Example: 1.Greenhouse gas emissions cause warming 2. Warming causes melting of polar ice 3. Reduced reflectivity causes more warming 4. Warming causes more release of greenhouse gases from oceans and landmasses •Aspects of systems may reach critical thresholds causing instability Negative feedback The higher the temperature of a body, the more infrared radiation is emitted Over certain time scales, Earth temperatures have been in a state of dynamic equilibrium, but there is concern that there may be thresholds or tipping points that could destabilize the system. Global monthly average surface air temperature since 1979 (Source: Hadley CRUT). What is your passion? Outdoor adventure? Undergraduate Field Trips Apply what you learn in class and in the lab Summer Research GIS: Solve problems from indoors too!