The polar bear and hippopotamus join the ranks of animal and vegetal species threatened with extinction, according to the latest "red list" published by the World Conservation Union (IUCN).

Since 1948, the IUCN has listed 16,119 species whose existence is being severely jeopardised as a result of human activities. The IUCN "2006 Red List" adds 530 species to the 2004 record, illustrating what it describes as a clear trend: "biodiversity loss is increasing, not slowing down." IUCN assessments are widely recognised as the most authoritative source of the global status of plants and animals.

Among other endangered species, polar bears are set to become one of the most notable casualties, because of the strong damages caused by global warming in the Arctic area. Their population is expected to decrease by 50% to 100% over the next 50 to 100 years, according to IUCN projections.

The hippopotamus is another mammal now deemed "vulnerable" by the international organisation. Its decline in the Democratic Republic of Congo (by about 95% in a decade) is attributed to political instability in the region, which has allowed for unregulated hunting for meat and for the ivory in their teeth.

Neither far-removed deserts nor oceans escape this dramatic trend. Many species of Saharan gazelles have suffered unregulated hunting and habitat degradation, and about 20% of shark and ray species are threatened with extinction as fisheries extend into ever deeper waters.

The IUCN points at the far-reaching "implications of this trend for the productivity and resilience of ecosystems and livelihoods of billions of people who depend on them (…)." While previous conservation campaigns are said to have delivered, the 2006 Red List aims to act as "a weak-up call" to the international community for a better protection of biodiversity via a sharp reduction in greenhouse gases' emissions and stricter regulation of hunting and fishing activities. Biodiversity will be the main theme of this year's annual Green Week event organised by the Commission from 30 May to 2 June.