Major study shows biodiversity losses can be reversed

Humanity’s use of land for agricultural production has come at a cost, according to a major collaborative research project.

A global network of contributors has submitted data from every continent, providing the most complete picture yet of the effects of land-use by humans. The team of scientists assessed changes in biodiversity from year 1500 until the present day. Over 280 publications have been consulted, with 26,593 species considered by researchers.

The study, published this week on 2 April in the scientific journal Nature, revealed that by 2005 land-use change had caused a decrease of 14 per cent in the average number of species found in local ecosystems, compared to the pre-industrial era. Most of the loss has come in the last 100 years.

In brief:
» Human-driven land use has caused an estimated fall of 13.6% worldwide in average local species-richness
» Most of these losses occurred in the last century
» Future reductions are not inevitable: scenario analysis suggests that the last 50 years of losses could be reversed by 2100, if strong carbon markets are used to mitigate against climate change
» Our analysis included over 1.1 million records for nearly 27,000 species at over 11,500 sites

… if society takes concerted action, and reduces climate change by valuing forests properly, then by the end of the century we can undo the last 50 years of damage to biodiversity on land

Andy Purvis, London’s Natural History Museum »

The team concluded that, if human impacts continue to grow as they have been, future losses in biodiversity will be concentrated in biodiverse but economically poor countries.

Achim Steiner, UN Under-Secretary-General and Executive Director of the UN Environment Programme (UNEP) said:
“As our understanding of the human impact on ecosystems and the escalating loss of species grows so must our willingness to change course. The adoption of robust policy frameworks that support the emergence of effective carbon markets and land-use practices for the preservation of natural habitats are but one example of the opportunities we must seize.”

Lead author of the study, Tim Newbold of UNEP’s World Conservation Monitoring Centre, said:
“The worst-case scenario we have mapped would have a severe impact upon most regions of the planet. Our models predict that rapid agricultural expansion, particularly in poorer countries, will cause rapid further losses of biodiversity. However, other scenarios give a much more positive outcome for biodiversity, especially for poorer countries.”

Researchers found that the worst-​affected areas had lost one in three of their species, enough to sub­stan­tially impact the func­tion­ing of those environments.

Lead scientist, Andy Purvis of London’s Natural History Museum, said:
“These findings are a significant milestone in understanding our impact on the planet. They show that what happens next is completely down to us. If we carry on as we are, numbers of species will fall by nearly 3.5 per cent on average by 2100. But if society takes concerted action, and reduces climate change by valuing forests properly, then by the end of the century we can undo the last 50 years of damage to biodiversity on land.”

The publication in Nature is the first global analysis produced within the project PREDICTS. This project of Projecting Responses of Ecological Diversity In Changing Terrestrial Systems is a collaborative effort aiming to use a meta-analytic approach to investigate how local biodiversity typically responds to human pressures such as land-use change, pollution, invasive species and infrastructure, and ultimately improve our ability to predict future biodiversity changes.

(Source: Natural History Museum press release, 01.04.2015; PREDICTS website)