Scientific estimates based on several types of data suggest that the pace of extinction may quicken in the future.

Based on current understanding approximately 1,100 bird species are likely to become extinct in the next few decades this is10 times more than the number that are thought to have died out in the last century. 1,100 is approximately 10 percent of the total bird population. If 10 percent of all species were to die off in the next century, we would lose at least 10,000 species per year, or 30 species per day.

However because the loss of one species can directly bring about the demise of others this estimation may be very low.

An alternative way of estimating species loss is to consider the effect that habitat damage/destruction has on wildlife. This is known as the "species-area relationship and indicates how many species are likely to survive in an area of a certain size.

Scientists have found that if a wilderness area is cut in half, about 15 percent of species in the original area will die out. If the remaining area is halved again, another 15 percent of the species will be lost.

Using this and other supporting methods scientists have predicted that we may lose as much as one-half of the world's species during the next 100 years unless human activities change dramatically.

Rates of loss

These estimates of species loss might seem extreme and must be considered against the natural levels of extinction. However the United Nations Global Biodiversity Assessment has recently reviewed the methods used to calculate natural extinction rates and have compared these figures with currently estimated rates. The results, which are intentionally conservative, indicate that current extinction rates are at least 50 to 100 times larger than the expected natural background. Taking habitat destruction into account further raises this to a level that would approach and possibly surpass the mass extinction's of the geological past e.g. when dinosaurs and other life forms disappeared, approximately 65 million years ago.