The actions of mankind could lead to the extinction of half of African birds and mammals by the end of 2100, a UN-backed study has said.
The report conducted by 550 experts from around the world said reduced biodiversity could affect people's quality of life.
It also found 42% of land-based animal and plant species in Europe and Central Asia have declined in the last decade.
The findings come after the death of the last male northern white rhino.
Despite the bleak findings, the study also pointed to some successes in reversing declines in wildlife.
The study by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) showed forest cover in China and other parts of north-east Asia had risen by more than 20% between 1990 and 2015.
It also found that animals, such as the amur leopard, which were once on the verge of the extinction had grown in population.
Speaking at the 2018 Biodiversity Summit in Colombia, leading British scientist Sir Robert Watson said: "We must act to halt and reverse the unsustainable use of nature or risk the future we want and have.
"Fortunately, the evidence also shows that we know how to protect and partially restore our vital natural assets."
Academic volunteers looked through some 10,000 scientific publications for what is said to be the most extensive biodiversity survey since 2005.
Among the list of the biggest threats to food and water security were pollution, climate change, and deforestation.
Scientists say governments, businesses, and individuals must consider the impact on biodiversity when taking decisions on farming, fishing, forestry, mining, or infrastructure development.