What needs to be done to protect biodiversity? A study in Nature (Maxwell et al. 2016) sets out to answer this question, as the issue of climate change continues to dominate both the media and policy discussions in addressing biodiversity loss mitigation efforts. The authors of the study examine the number of species affected by various threats such as pollution and urban development, and have found that issues of overexploitation and agricultural activity pose the biggest danger to species worldwide. By focusing on climate change (which comes 7th on the list of “big killers”) and not on these more pressing issues, the authors warn that we may fail to act to truly protect the flora and fauna that remain on the Earth today.
The study draws on the IUCN Red List of Threatened Species to make its calculations, including a total sample size of 82,845 species and their population projections across three generations (or a ten-year period, whichever is longer). Of this list, 6,241 species are affected by overexploitation, an umbrella term encompassing human logging, hunting, fishing and plant gathering activities. To put these numbers into context, 72% of these overexploited species are already of threatened or near-threatened status including the Sumatran rhinoceros, Western gorilla and Chinese pangolin. Similarly, 5,407 species are threatened by the agricultural expansion and intensification of crops, livestock, timber and aquaculture, and 62% of these species are listed as threatened or near-threatened including the Africa’s cheetah, hairy-nosed otters, and huemul deer.
Comparatively, the effects of climate change such as flooding, habitat modification and droughts currently place 1,688 species under threat. While this figure must not be taken lightly, 19% of the species in this number is classified as threatened or near-threatened — a considerably lower statistic than that due to overexploitation and agriculture.
Although the paper acknowledges limitations to the way these threats have been treated as discrete, to taxonomic records, and to population projections, it emphasizes that the results do not change drastically; no matter how they are viewed, and, as a result, we must act swiftly and decisively against the most dangerous threats to biodiversity: mitigating overexploitation of species and agricultural expansion must take precedence over climate change action if we are to save the Earth’s species, and we must not let newer problems overshadow massive and long-standing ones. Therefore, the paper makes recommendations for policy makers to develop sustainable harvest regimes, curb the use of pesticides and fertilizers, establish key biodiversity areas and enforce regulations to protect these areas.
SOURCE STUDY: Maxwell, S.L., Fuller, R.A., Brooks, T.M., Watson, J.E.M. 2016. Biodiversity: The ravages of guns, nets and bulldozers. Nature, 536, 143-145.
*Note: The source article uses a really beautiful and succinct infographic to communicate its message. You might want to check it out!