John C. Briggs Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97333. USA. Present address: 2320 Guerneville Rd., Santa Rosa, CA 95403, USA. Telephone: 760-289-3193 Environmental Skeptics and Critics ISSN 2224-4263 http://www.iaees.org/publications/journals/environsc/online-version.asp 2016 5 2 20 27 International Academy of Ecology and Environmental Sciences Hong Kong 7 April 2016 20 April 2016 1 June 2016 biodiversity loss biodiversity gain terrestrial marine islands continents For the past 50 years, the public has been made to feel guilty about the tragedy of human-caused biodiversity loss due to the extinction of hundreds or thousands of species every year. Numerous articles and books from the scientific and popular press and publicity on the internet have contributed to a propaganda wave about our grievous loss and the beginning of a sixth mass extinction. However, within the past few years, questions have arisen about the validity of the data which led to the doom scenario. Here I show that, for the past 500 years, terrestrial animals (insects and vertebrates) have been losing less than two species per year due to human causes. The majority of the extinctions have occurred on oceanic islands with little effect on continental ecology. In the marine environment, losses have also been very low. At the same time, speciation has continued to occur and biodiversity gain by this means may have equaled or even surpassed the losses. While species loss is not, so far, a global conservation problem, ongoing population declines within thousands of species that are at risk on land and in the sea constitute an extinction debt that will be paid unless those species can be rescued. DOI 10.0000/issn-2224-4263-environsc-2016-v5-0003 http://www.iaees.org/publications/journals/environsc/articles/2016-5(2)/global-biodiversity-loss-exaggerated-versus-realistic-estimates.pdf