Humanity is now the cause of the Earth's sixth mass extinction event due to our widespread destruction of the natural environments that house other species1,2,3,4. Since 1970 we have devastated freshwater habitats, causing a disastrous 83% reduction in population sizes3. We are presiding over "the worst loss of life on Earth since the demise of the dinosaurs"5. This is a problem that requires strong international co-ordination to fix, and yet, this decade, the spirit of international collaboration has been damaged by the rise of popularism6. Although 196 countries have done, the world's biggest consumer, the USA, has never signed the UN's Convention on Biological Diversity, and unfortunately, many of those that have signed up are not taking the issue seriously. It is of utmost importance that no matter what, we as a species stop our destruction of the natural world, primarily by ceasing the conversation of land for farming and housing.
There may be 100 million unique species on Earth at the moment. But this is only one tenth of the total number of species that have ever existed - 9/10ths are now extinct1,2. We are causing entire species to go extinct at 100 to 10,000 times the natural rate4. Scientists and environmentalists say the prime cause of this is the degradation of the environment by humanity1 and this constitutes the latest mass extinction event - the previous 5 being the result of natural phenomenon.
Between 1970 and 2014, we decimated wildlife populations by 60% globally3. The rate is increasing, alongside our population; just four years ago, it was only 52%.
“The majority of species that have ever lived are extinct. [...] Five episodes of 'mass extinction' during the history of life are known and in the greatest of them, at the end of the Permian Era about 248 million years ago, it has been estimated that as many as 95% of animal species then living became extinct. [...] The cause for concern today is not the fact of extinction, but rather the rate at which it is now occurring, which appears to be far from normal. As E. O. Wilson has put it '... virtually all students of the extinction process agree that biological diversity is in the midst of its sixth great crisis, this time precipitated entirely by man'.”
At the moment, 12% of all species are endangered, with the highest rates being in highly developed countries and in small islands where local environments have the least redundancy to cope with the changes we effect7. Our effect on the environment is by far the greatest cause of the loss of species. Between 1990 and 2008 alone we removed 1.2% of the world's forested areas and at that rate we are losing 12% per decade, which gives us only two generations to either severely reduce the deforestation rate before recovery becomes meaningless7. In Africa several countries have lost around a third of all their forests between 1990 and 2008 - Comoros, Togo and Nigeria have lost 68%, 52% and 43% respectively7. The forests house a massive range of species and every survey reveals many more, but the media only normally "focus on a few totemic species, such as lions, chimpanzees and pandas, rather than the collapsing ecosystems on which we depend"5.
"Scientists and environmentalists fret that an increasing number of species may become extinct because of the degradation of the environment by humanity"1. We have damaged freshwater habitats the most, with populations decreasing by 83% since 1970; animals such as crocodiles are both directly hunted, in addition to losing the places where they can live and feed3. The worst region is south and central America3. We are destroying the balances between different species and destabilizing ecosystems, resulting in effects that will continue for a very long time3. The WWF reports that "the main drivers of biodiversity decline continue to be the overexploitation of species, agriculture and land conversion"8.
In the last 40 years, we have destroyed 20% of the Amazon; this rainforest is the largest on Earth, so rich in life that 1/3 of all species live there9. But huge swathes of land have been cleared and sold to cattle farmers and plantation owners9 - especially soya-bean producers as a result of a surge in demand since the 1990s5,9. Before this period, it took us 450 years to clear the same amount of rainforest9. One third of all species on Earth only live in the Amazon9, and we have directly caused the extinction of thousands of them.
It is not just the wholesale destruction of habitats that is having a negative effect: Human constructions such as long roads, fences, walls and other obstacles result in habitat fragmentation10. Whilst it is hard for many of us to see this as a problem, it is a "major issue" and has "severe consequences for many species"10. Species that suffer can end up with serious population crashes and eventual local extinction.3
Habitat connectivity allows species to migrate to favourable conditions on a year-by-year basis, and, perhaps permanently if their home habitats become too degraded or altered. The greater the speed of change, and the greater the extent of change, the greater the need for suitable pathways in which species can migrate. Some solutions are simple; for example animal crossings can be constructed that pass beneath roads. But even simple solutions are rare: We as a species are simply very poor at being careful with our effects on natural habitats.
Birds are very well studied, and serve as a great indicator of overall wildlife health12. The IUCN Red List divides populations (not just birds) into categories depending on the species' risk of going extinct. The rate of bird extinctions is "far higher than the natural background rate" and the causes are "agricultural expansion, logging, overexploitation, urbanisation, pollution"13. The chart to the right, based on Birdlife International data, shows what extinction vectors are affecting the 1469 bird species currently at the highest risk.
“Analysis of the IUCN Red List shows that there has been a steady and continuing deterioration in the status of the world´s birds since the first comprehensive assessment in 1988. Highly threatened species continue to go extinct, while formerly common and widespread species are in sharp decline. At least 40% of bird species worldwide (3,967) have declining populations, compared with 44% that are stable (4,393) [also 7% are increasing and 8% lack data]. [...] As of , 1,469 bird species (13% of the total, or one in eight) are globally threatened with extinction.”
|Convention on Biological Diversity|
|Pos.||Later is worse|
|195||Andorra||2015 May 05|
|194||Palestine||2015 Apr 02|
|193||Somalia||2009 Dec 10|
|192||Iraq||2009 Oct 26|
|191||Brunei||2008 Jul 27|
|190||Timor-Leste (E. Timor)||2007 Jan 08|
|189||Montenegro||2006 Jun 03|
|188||Thailand||2004 Jan 29|
|187||Tuvalu||2003 Mar 20|
|186||Afghanistan||2002 Dec 18|
|185||Bosnia & Herzegovina||2002 Nov 24|
|184||Kuwait||2002 Oct 31|
|183||Serbia||2002 May 30|
|182||Saudi Arabia||2002 Jan 01|
|181||Libya||2001 Oct 10|
|180||Malta||2001 Mar 29|
|179||Liberia||2001 Feb 06|
|178||Azerbaijan||2000 Nov 01|
The Convention on Biological Diversity (CBD) was originally sparked from United Nations activity in the 1980s as a result of rising scientific alarm over the impact of human activity on natural habitats, including a rising awareness of extinctions and shifts in ecosystems that occasionally cause widespread disruption that is difficult (or impossible) to reverse.
After a long period of international consultation involving hundreds of scientists and environmental ministers, the Convention was finalized and launched at the Rio Earth Summit in 1992, and received 168 signatures over the subsequent year.
Part of the first wave of signees were a large number of small island nations, who are uniquely susceptible to over-exploitation by rich companies and countries, but simultaneously, are (as a group) the least responsible for driving global extinctions.
Data on when each country ratified the CBD forms part of the formula of the Social and Moral Development Index, with countries losing points for reticence (taking into account the foundation dates of newly independent countries). The USA stands alone in not ratifying it, but is the world's greatest driver for activities that cause biodiversity loss.
“While thousands of scientific studies have been published and then translated into policy reports, many experts have concluded that we have no made sufficient progress in stemming the losses of ecosystems and species. We are stymied by a range of obstacles, from lack of political will to unchanging human habits. For many environmentalists there is a growing realization that a broader sense of vision and values is missing. [...] Dire facts about environmental problems, as overwhelming as they may be, have not altered the kinds of human behaviour that are rapaciously exploiting nature [nor changed] habits of addictive consumption [and] policy experts are realizing that legislative or managerial approaches to nature are proving insufficient. [...] Values and ethics, religion and spirituality, are important factors.”
“Mike Barrett, executive director of science and conservation at WWF, said the starting point should be a recognition that the international response until now has been a failure. [We need to] consider trade and investment because it is no use wealthy countries donating a few hundred million dollars for conservation programmes in Africa, Asia and Latin America if they continue to promote trillion-dollar trades in commodities that accelerate the loss of habitats. As an example, he said the contributes money to efforts to protect the Cerrado savannah in Brazil yet at the same time imports vast quantities of the soya beans that are the biggest cause of deforestation in that region.”
"Habitat loss threatens all our futures, world leaders warned" in The Guardian (2018 Nov 17)5