Ecology is about how the world works, the interdependence between people and the natural world, as well the consequences of human activity on the environment The Intergovernmental Science Policy Platform on Biodiversity Ecosystem Services (an independent intergovernmental body, with 130 member states) Its 2019 report shows human actions have now significantly altered nature across the globe :

Animal agriculture creates 64 of man made ammonia emissions This contributes to acid rain/acidification of ecosystems (UN Food Agriculture Organisation 2006) Acid rain effects aquatic environments by increasing aluminium absorption from soil The water becomes toxic to some aquatic animals and others in the food chain Soil is robbed of essential nutrients which makes it hard for trees to absorb water Humans can experience asthma and eye irritation as a result of acid rain in inhaled fog.

52% of the world’s wildlife species disappeared in just e.g. whaling has devasted populations Source: World Wildlife Fund (1970-2010)

There have been 4 or 5 major extinctions (defined as the loss of at least 75 of species within a geologically short time period) in the Earth’s history most caused by CO 2 increase, 1 by an asteroid Many scientists consider we are now in the 6th mass extinction of life to occur in the Earth’s 4 5 billion year history caused by the climate crisis, destruction of wild habitat for animal farming, logging and development

“We produce enough calories to feed 10-11 billion people worldwide but, the majority of this food goes to feed livestock, not hungry people” (One green planet 2017).

Excessive conversion of forests - that are rich in diverse species - to pastureland for grazing that does not support diverse ecosystems significantly reduces the biodiversity (number of species) - on which the planet depends