ENVR101 Global Environmental Challenges

Focus: Big picture, setting the scene for global environmental crises.
Subsequent lectures will cover biodiversity, nutrient cycles, and a New Zealand-specific perspective.
Emphasis on how everyday actions contribute to global crises.

Refers to the massive increase in global economic activity, especially post-World War II.
Driven by technological advances in medicine, water quality, and energy harvesting, leading to improved living standards.
Consequences include ecosystem degradation, biodiversity loss, and climate change.
Observed through increased population, foreign investment, car ownership, telephone usage, and McDonald's restaurants.
Correlates with increased atmospheric $CO_2$ , greenhouse gases, ozone depletion, surface temperature, deforestation, and flood frequency.

Climate change: Human-induced rises in greenhouse gases (carbon dioxide, methane, and nitrous oxide) from sources like fossil fuels, agriculture, and deforestation, leading to temperature increases, extreme weather events, loss of sea ice, altered ecosystems, sea-level rise, and ocean acidification with potential impacts on coastal areas, agriculture, water resources, habitat loss, glaciers, tourism, and health.
Loss of biodiversity: Changes in land and sea use, direct exploitation of organisms, climate change, pollution, and invasive species leading to significant environmental, economic, and social consequences, including anthropocene defaunation, with trends less severe in areas managed by indigenous peoples and local communities; a third of the world's land and three-quarters of freshwater used for crop or livestock production; and limited diversity in the food chain.
Overuse of natural resources: Accelerating resource use since the 1950s, rapidly increasing since the 1980s, leading to degradation and loss of habitats, production of waste and pollution, changes in biogeochemical cycles, and increased conflict over resources.
Impacts on human health and well-being: Resulting from pollution, climate change and biodiversity loss, and including weather-related mortality, infectious diseases, respiratory illnesses, and decreased access to water, food, and medicine.

Human-induced rises in greenhouse gases: carbon dioxide, methane, and nitrous oxide.
Sources: Fossil fuels, agriculture, and deforestation.
New Zealand's challenge: Methane from animals and nitrous oxide from fertilizer and animal urine.
Changes: Temperature increases, extreme weather events, loss of sea ice, altered ecosystems, sea-level rise, and ocean acidification.
Potential effects: Impacts on coastal areas, agriculture, water resources, habitat loss, glaciers, tourism, and health (weather-related mortality, infectious diseases, respiratory illnesses).

Encompasses variety of species, genetic spread, ecosystems, and ecosystem processes (energy flow, nutrient cycling).
Changes include land and sea use, direct exploitation of organisms, climate change, pollution, and invasive species.
Significant environmental, economic, and social consequences.
Anthropocene defaunation: Loss of fauna in our time.
More species threatened than ever before; human mass exceeds wild mammal mass.
Trends less severe in areas managed by indigenous peoples and local communities.
A third of world's land and three-quarters of freshwater used for crop or livestock production.
Limited diversity in food chain (rice, corn, maize, wheat).

Particularly impacted, especially in Latin America (Amazon Basin for cattle ranching and sugar production) and Southeast Asia (for palm oil).

Quantifying benefits humans get from intact ecosystems:

Provisioning: Food and water production.
Regulating: Climate and disease control.
Supporting: Nutrient cycles and crop pollination.
Cultural: Spiritual and recreational benefits.
Loss impacts human well-being: Access to water, food, medicine, spread of disease.

Natural assets used for economic production or consumption.
Mineral and energy, soil, water, and biological resources.
Renewable (sunlight, wind, water, biomass) and non-renewable (mineral resources, fossil fuels).
Resource use accelerating since the 1950s, rapidly increasing since the 1980s.

Introduction of substances or energy into the environment, causing harm.
Energy contaminants: Light, heat, sound.
Chemical pollutants: Nitrogen from farms, heavy metals from roads, microplastics.
Increased material use leads to increased waste and emissions.

Rapid growth in population alongside rapid consumption of resources is a key driver of the global environmental challenges.
The triple planetary crisis – pollution, climate change and biodiversity – are interlinked and impacting on human well-being.