World Environment Day (5 June) is a day to acknowledge humanity's impacts on nature, and to lift ambition to end its destruction, according to Sustainable Population Australia (SPA).
The theme of this year's World Environment Day reflects the United Nations' Sustainable Development Goal 15, namely, to protect, restore and promote sustainable use of terrestrial ecosystems, to sustainably manage forests, to combat desertification, to halt and reverse land degradation and to end biodiversity loss.
The United Nations says that more than 2 billion hectares of the world's land is degraded, affecting 3.2 billion people driving species to extinction and intensifying climate change. Vital ecosystems and countless species are under threat.
Sustainable Population Australia's national president Peter Strachan says human management, or mismanagement, of the land is the major factor.
"Part of the mismanagement is allowing an imbalance between the resources that the land provides and the number of people that depend on them," says Mr Strachan.
"In too many places, human populations have outgrown the land's ability to sustain them. Degradation, sometimes to the point of desertification, has followed.
"For instance, a 2021 paper found that in Ethiopia, the second most populous country in Sub-Saharan Africa, rapid population growth leads to soil erosion and soil fertility loss. Population pressure leads to water courses drying up, and to depletion and pollution of aquifers.
"Where population growth rates are high and people are poor and dependent on the land, they will tend to overcrop and overgraze the land, rather than leave the land fallow to recover its fertility after cropping," says Mr Strachan.
"Where ever more mouths have to be fed, trees are cut down for fuel and to provide more land for cropping or pasture. In high rainfall areas, as in Brazil, this leads to erosion."
"If there were fewer people," said Mr Strachan, "there would be less need to convert so much land to agriculture."
Ibrahim Thiaw, Executive Secretary of the UN Convention to Combat Desertification said in 2022: 'Modern agriculture has altered the face of the planet more than any other human activity. We need to urgently rethink our global food systems, which are responsible for 80% of deforestation, 70% of freshwater use, and the single greatest cause of terrestrial biodiversity loss.'
"Ending population growth would mean less need to convert so much land to agriculture," says Mr Strachan. "We have to end population growth everywhere , use natural resources with respect and frugality, and place the interests of future generations above those of short-term profits."