| TIMELINE of HUMAN POPULATION GROWTH VS SPECIES LOSS | |||
| or HUMAN IMPACT UPON BIODIVERSITY | |||
| World | |||
| YEARS AGO | REASON | Human Pop. | EXTINCTIONS |
| (millions) | |||
| 40,000 - 25,000 | Ice age; hunting by humans | 95% of megafauna in Australia and New Guinea | |
| 40,000 - 13,000 | Hunting by humans | 30 - 50% of megafauna ( large animals, birds, reptiles) in Europe, North Asia | |
| 20, 000 - 10,000 | Hunting by humans | 75% or 30 types of large mammals in North & South America | |
| 13,000 | Agriculture | 10 | Wild gazelles in Fertile Crescent Area of Middle East |
| 7,000 - 3,000 | Hunting by humans | 20 | Giant ground sloths, monkeys and tortoises in Caribbean Is. |
| 5,000 | Hunting & agriculture | Dwarf megafauna including elephants in the Mediterranean Is. | |
| 3,500 | Hunting | 50 | Mammoths in Siberian Arctic |
| 1,500 - 200 | Hunting | 300 | Moas and other large flightless birds in New Zealand. |
| 1,000 - 200 | Hunting | 1000 | Large birds, tortoises, lemurs small hippopotami in Madagascar |
| 500 - 35 | Spread of European colonisation | Decline of many species of fish, birds & mammals | |
| 35 - future | Overpopulation, globalisation | 6000 | 3,000 species declined 40% from 1970 to 2000. . |
| Species are going extinct at 1,000 times the natural or . | |||
| backround rates typical of the Earth's past. | |||
| Estimates 2 million to 10 million species of plants, | |||
| animals and microorganisms are in the world today. | |||
| The background rate of extinction has been one species every . | |||
| 4 years on average. | |||
| Half of all species could become extinct in next 100 years; | |||
| 20% by 2022 | |||
| 50% of all current species gone in 100 years. Probably | |||
| 10 million to 100 million species in the world.Could say 50 million | |||
| Human-caused | |||
| extinction now may be 120,000 times the background level. | |||
| [this equates to 30,000 species per year]. | |||
| Norman Myers estimates 600 species are becoming extinct | |||
| each week. Some say 1,000 - but no certainty.Myers thinks | |||
| 10 million species in the world, of which 600,000 lost since 1950. | |||
| If tree felling continues at the rate of about 2% p.a., the | |||
| world will lose 25% of all species by 2000 and another 33% | |||
| in next 100 years. | |||
| Number of species doubles with every ten-fold increase in area. | |||
| Thus reverse can be applied | |||
| Over one million species will be threatened with extinction by | |||
| 2050. Forecast range: minimum 18%, medium 24%, high 35%. | |||
| Global diversity assessment of 1995: 13 million species, of which | |||
| only 13% scientifically described. In coral reefs alone, 200,000 | |||
| species will die out in 40 years. |
