L32 - Anthropogenic Global Issues Lecture

Exponential Population Growth

Historical rapid growth of human population, now increasing rapidly. Every hour, the human population grows by more than 9,000 people.

How many times higher is the current extinction rate that the typical background extinction rate?

The current extinction rate is 100 to 1,000 times the "background" extinction rate

Anthropocene epoch

humans have such a powerful impact in terms of planetary change

Exinction rates

The current extinction rate is 100 to 1,000 times the "background" extinction rate • Human activities threaten Earth' s biodiversity at all levels

Human mass vs mammal mass

mass of humans is higher than wild mammals combined

Biodiversity Crisis

Current high rate of extinction caused by human activities threatening Earth's biodiversity.

The Impact of Humanity on the Biosphere

Human activity contributed to the Quaternary Megafauna Extinction
Intense whaling and exploitation of other marine mammals have resulted in an approximately fivefold decrease in marine mammal global biomass.

Quaternary Megafauna Extinction

Loss of many species with large body sizes across multiple continents

the Great Acceleration

a unique event in the 4.5-billion-year history of our planet - with exploding human population and economic growth driving change through the increased demand for energy, land and water

IMPACT ON FRESHWATER

1 in 3 freshwater species are threatened with extinction

IMPACT ON INSECTS, SOIL, FOOD

500k insec species are threatened with extinction. Insects help to pollinate plants that provide food for people and wildlife - 3 out of 4 food crops depend, at least in part, on them.
Soil is a critical component of the natural environment and soil biodiversity plays a vital role in the ecosystem services on which we depend

how many plants are threatened with extinction?

1 in 5.
The current rate of plant extinction is twice that of mammals, birds and amphibians combined

impact on marine species

66% of the marine environment has been significantly altered by human actions
40% of amphibian species, almost 33% of reef-forming corals and more than a third of all marine mammals are threatened

impact on domestic breeds

680 vertebrate species have been driven to extinction since the 16th century and more than 9% of all domesticated breeds of mammals used for food and agriculture had become extinct by 2016, with at least 1,000 more breeds still threatened.

What are some top threats to species?

Habitat loss, degradation, overfishing, and overhunting

How do human activities impact species?

Human activities like habitat loss, degradation, overfishing, and overhunting directly threaten species