From the advent of global warming theory in 1896 to the declaration of the black rhino as extinct in 2011, human impact on Earth has long made headlines. At the time of writing, more than 1 million people have ‘checked in’ to Standing Rock Indian Reservation to fight a pipeline that could potentially contaminate water sources for thousands of downstream inhabitants. Paris agreements have just last week come into play, marking the beginning of a pledge to keep the increase in global average temperature to below 2 degrees above pre-industrial levels. Now, just in time for Attenborough’s highly anticipated Planet Earth 2, comes the news that global wildlife populations have fallen by 58% between 1970 and 2012.
According to WWF’s ‘The Living Planet Report’, a two-yearly publication assessing global wildlife, the trend could continue to decline, seeing two-thirds of vertebrates gone by 2020. Monitoring 14,200 populations over 3,700 species of mammals, fish, birds, reptiles and amphibians, the study covered roughly 6% of the world’s vertebrate species. It compared the findings with similar results from 1970, with weighting against geographical areas in which there was a surplus of data to counterbalance any skew towards already well-documented decline. Freshwater animals have been the most dramatically affected, with an 81% decline compared to 38% of terrestrial and 36% of marine life. Moreover, the 2014 Living Planet Report had found biodiversity, a measure of the range of species on Earth, was also found to have dropped by 52%.
Destruction of wild areas for farming and logging is the largest known factor in the report. Widespread deforestation means just 15% of the Earth’s land area is protected for nature, leaving animals vulnerable to predators, unable to nest or find adequate food sources.
Unsustainable hunting practices also play a significant role in the decline; 301 species are currently thought to be being ‘eaten to extinction’ by the bushmeat trade. An estimate from the centre for International Forestry Research estimates that 6 million tonnes of animals are trafficked annually in this industry alone.
Industrial pollutants have been shown to be destroying marine life, with the UK’s last pod of killer whales ‘doomed to extinction’ by high levels of toxic PCB found in their blubber. Amphibian trade is causing a fatal epidemic of fungal disease, and vultures in South-East Asia have suffered a serious loss from eating the meat of cows treated with anti-inflammatory agents.
Despite the significant findings, some sources have cast aspersions on the report. Most notably, Professor Stuart Pimm from Duke University has stated that looking at wildlife as a whole is inefficient, and that looking at particular groups, such as birds, is much more precise. He also says “some of the numbers are very, very sketchy”, pointing out that there is little-to-no data from South America or tropical Africa. The study is skewed massively towards Western Europe, making the figures less relevant globally. However, Dr. Freeman, head of ZSL’s Indicators and Assessments Unit, says he is confident his team have used the best method to present an overall estimate of population decline. He adds that data is missing because it didn’t exist or was very difficult to monitor, and therefore flaws in his method would be more likely to underestimate the damage, rather than overestimate.
Dr. Freeman remained positive in light of the results, saying that the decline was linked to decreasing numbers of prevalent animals, rather than extinctions, allowing us a window of opportunity to allay the damage. Tiger numbers are thought to be increasing, and giant pandas and the manatee have been removed from the list of endangered species. Influence has even spread to politics, with a recent global wildlife summit introducing new protection for some the world’s most trafficked wild products, including rosewoods and pangolins.
So, how can we aid the immediate action required to halt, or at least slow, the decline of wildlife globally? It all boils down to how society consumes resources; eating less meat can be an effective tactic, as the livestock are likely to be grazing on deforested land. Businesses should also be held more accountable, says the WWF director of science, Mike Barrett. Their supply chains should be shown to be sustainable, especially with regards to the meat trade and timber supply. Politicians, he adds, should also be under pressure to push environmental law to the forefront of the agenda, ensuring all of their policies, not just environmental ones, are sustainable.