Biodiversity loss

**Global Biodiversity Loss:**
– The current rate of global biodiversity loss is 100 to 1000 times higher than the background extinction rate.
– In 2021, 28% of assessed species are listed as threatened with extinction.
– A 2022 study estimated that roughly 30% of species have been globally threatened or extinct since 1500.
– Research in 2023 found that 48% of species face decreasing populations due to human activities.

**Methods to Quantify Biodiversity Loss:**
– Biodiversity is defined as genes, species, and ecosystems of a region.
– Scientists measure biodiversity loss rates by recording species richness and variation over time.
– Local abundance and relative species abundance are key indicators.
– Various biodiversity indexes explore different scales and time spans.
– Biodiversity includes phylogenetic, species, genetic, and nucleotide diversity.

**Wildlife Population Decline:**
– Wildlife populations declined by an average of 69% since 1970.
– Swiss Re analysis in 2020 showed one-fifth of countries are at risk of ecosystem collapse.
– The World Wildlife Fund reported a 68% decline in 4,400 animal species between 1970 and 2016.
– Insects, comprising up to 90% of all animal species, have shown a 5.2% annual decline in flying insect biomass.
– Declines in insect populations are attributed to habitat destruction, pesticides, introduced species, and climate change.

**Causes of Biodiversity Loss:**
– Habitat loss, fragmentation, degradation, and land use intensification contribute to biodiversity loss.
– Nutrient pollution, pollution, overexploitation, and invasive species are key factors.
– Climate change poses risks to biodiversity.
– Jared Diamond’s Evil Quartet and Edward O. Wilson’s HIPPO model highlight major causes.
– Human actions like habitat destruction and over-harvesting drive biodiversity loss.

**Impact of Human Activities on Biodiversity:**
– Overexploitation can lead to resource destruction and inability to replenish.
– Human population growth and overconsumption contribute significantly to biodiversity loss.
– Invasive species threaten biological diversity and are increasing due to tourism and globalization.
– Pollution from fossil fuel extraction impacts biodiversity through land conversion and pollution.
– Industrial agriculture is a leading cause of biodiversity collapse.