ES110 Lecture 1 Anthropocene: - Period when human activity replaced natural processes as the dominant force shaping the earth Global human population: - Each year we add more than 2 Canadas worth of people to the globe For each person who dies, 3 babies are born Consumption: - People consume more resources than the earch can replenish naturally “overshoot day” = the day each year we go into deficit In Canada, we go into deficit on March 11 Lecture 2 Key terms we will need for this course: - Environment Change Natural capital, ecosystem goods and services Ecological footprint Sustainab Environment: - Environment = almost everything, everywhere on earth Environmentalism: - Term refers to social movements with aim of improving/protecting aspects of the environment Environmental studies/science: - We use scienctific and social science methods to generate a continually improving understanding of earth, its systems, and human role within them Challenges in environmental studies: - Complexity of the systems o Complicated map Time scales o Nothing is static in earth systems, they are always changing o Environmental change occurs naturally, and operated at multiple time scales o Daily change (day/night) seasonal change; annual change; decadal change, longer time periods… o Glacial/interglacial occur over thousands of years; wildfires last for days/weeks - - o E.g. the fire in Australia Spatial scales o Human activity causes environmental changes at local, regional, and global scales o Changes across the scales may be interconnected across scales and/or accumulate o Some system are inherently global The oceans, the atmosphere are global systems When human activity affects one part of the system, the impacts are felt globally o The friendly floatees: 29000 rubber ducks and stuff lost as sea in 1992 have o Example of local and regional changes include: biodiversity loss, deforestation, desertification, etc… o Bias, our own ignorance: o Genuine lack of knowledge: e.g. DDT was widely used in the 1950s to control insects, until its harmful ecological effects were discovered, its use is now controlled o Deliberate ignorance and bias: people often ignore facts when (1) the facts challenge their preconceived beliefs or ideologies. (2) they profit from ignoring the facts, or (3) they aren’t personally affected Natural capital: - - Natural resources o Air o Water o Soil o Energy o Minerals o Forests o Can be renewable or non-renewable Ecosystem services o Ability of environment to break down waste o Nutrient cycling o Water purification o Natural controls on pests, diseases. Carrying capacity: - The max number of individual of a given species that can be sustained indefinitely in a given space How many humans can our planet sustain? Depends on how we use our natural capital Ecological footprint: - How much productive land/water are needed to support your lifestyle Sustainability and sustainable development: - Idea arose in 1970s Gained broad acceptance with 1987’s out common future Definition of sustainable development: development that meets the needs of the present without comparing the ability of future generations to meet their own needs Means we need to keep our ecological footprint to less than one Sustainable development: - How do you develop a sustainable society? Key elements: o Intergenerational equity o Intergenerational equity Next generation should have the same land, resources as you do right now ImPAcT model: - - I = P x A* x T Where I = impact on environment P=population A=Affluence* o Affluence can cause our environmental impact to grow T=technology o Some tech are environmentally harmful o As affluence goes up, we have *or C = Consumption This model suggests: - A small, affluent, and technologically advanced populations will have a greater impact Summing Lecture 3 Biodiversity loss Bison Population decline: - Estimated Indigenous bison hunts: European bison hunting: - For skins To open grazing land for cattle Some say to hasten extermination of indigenous people on the plains Limiting factors for bison population before European contact: - Human predation Climate, weather Disease European predation Anthropogenic habitat change: European want to change the habit Canadian conservation efforts to save the plains bison: - By 1888 there were only 8 plains bison left in Canada In 1907, the Canadian government bought 400 bison from Montana ranchers and released them at Elk island national park Western Canadian bison herds became infected with cattle diseases, further Why are plains bison not listed as protected or endangered species in Canada? - Because we eat them Biodiversity loss: - Decline of the bison just one example of tens of thousands of species in steep decline or extinct in last century Many scientists believe we are in the midst of a mass extinction event caused of human activity Scale of the global biodiversity crisis: - One third of all known land vertebrate species are declining in numbers “background” extinction Key causes of biodiversity decline and species extinction: - Destruction or damage to habitat caused by Why is biodiversity importent: - - For some people, it’s life and death, for indigenous people, their primary food sources might be species Economic importance o Costanza estimated the dollar value of ecological goods and services bigger value of human economy Food systems Cultural, spiritual, intrinsic value What is biodiversity? - Biodiversity is short for “biological diversity” Refers to o - At local scales, the variety of species in a given location or habitat and their relative abundance o At larger scales, the genetic diversity of species o At still larger scales, the diversity of habitats in ecosystems o At still larger scales, the diversity of ecosystems Species diversity: - Boreal forest Structural diversity within habitats o How many niches are there? Habitat integrity Key stone species: - A species that, when it is missing, causes habitat or ecosystem to change When the keystone species is removed, other species may either grow or fall A brief segue into population dynamics: - - Species numbers are always changing o The number of organisms within an ecosystem from any given species is not static o Tends to fluctuate along with environmental conditions Carrying capacity: describes the upper limit to the number of organisms that an ecosystem can support over the long term Environmental resistance Biotic potential o The ability for a species to increase in number under optimum conditions o We use letter r to represent the theoretically fastest rate We can classify wildlife species by their potential to increase in number - A fruit fly is r specie Fruit fly can go from egg to reproductive adult in a matter of days Fruit fly growth experiment: - Add fruit flies to jar with some food and water, allow air to get in but flies can’t get out It is a J curve r-selected species = opportunities - Characteristics: o Reproduce at an early age o Have many offspring k-selected species are the opposite: - Characteristics: o Reproduce later in life When other species encounter humans… - K-selected have trouble competing with humans Some r-selected species actually thrive alongside humans, for example, fruit flies Predator-prey relationships: - A basic principle of biology is that populations of predators and prey fluctuate, but tend to stabilize over the long term Critical number: - The minimum number of organisms required to ensure that the population will not go extinct Without human intervention, a species below the critical number disappears American chestnut: - The native chestnut was once a common tree in eastern US, south-western Ontario (<25% of all trees) Billions of the trees were killed Ashe trees are now dying in large numbers (another common tree in Invasive species: - Imported to north America from Asia in 1990s Is spreading across Ontario Ash population are not below critical number yet Our native ash trees Extinct bird: passenger pigeons - Once widespread across eastern North America Early Europeans describe enormous flocks of millions of birds Causes of extinction: human predation, habitat loss Extinct bird: Great auk: - Flightless shorebird once common in Atlantic Canada, Iceland, British Isles Behavior similar to penguins Causes of extinction = human predation, habitat loss Last onces died in mid 1800s Human population growth = an underlying driver of biodiversity loss - As human population expan Consume more resources Alter land and aquatic systems Out compete other species Deliberately or inadvertently cause other species to disappear How big a number is 7 billion? - People have trouble distinguishing the difference in scale between millions, billions, trillions, etc…
