Polar bears will not be the only ones to disappear because of global warming. Many other – less visible or less symbolic – species will also be threatened. For them, global warming will be the last straw as man is already putting the environment under a lot of pressure: the destruction of habitats, environmental fragmentation, pollution etc. If the temperature increases by 2 or 3°C, about a third of all species will face higher risks of extinction.
It all depends on rhythm. The living world is constantly evolving and it has adapted to many environmental changes. But global warming causes very rapid changes in ecosystems. These will probably happen too fast for many living organisms to keep adapting.
Icy conditions and coral reefs have the most vulnerable ecosystems. Just one more degree Celsius can destroy the symbiosis between coral and microscopic algae it needs to survive: this makes it whiten and die. Savannahs and deserts have the least vulnerable ecosystems. Even “virgin” areas where man is not (very) present – like the heart of the Amazon forest or tundra regions – could be affected because the climate’s evolution affects the whole Earth.
Today, the Earth is facing its sixth mass extinction. After each of these extinctions, biodiversity undergoes new phases of diversification and expansion. But today, only one species – Homo sapiens – is directly responsible. And we could also become the victims. Even if the extinction of the polar bear seems mostly symbolic, the disappearance of coral would be disastrous: it is home to a quarter of marine species! Insects pollinate plants and recycle our waste. Mangrove swamps act as buffers against storms, floods, soil erosion…to name but a few examples.