PRESSURE: what birds tell us about problems

BirdLife Human colonisation increases the threat from fire Zoom In

People cause the immediate pressures on biodiversity. Habitat destruction, driven especially by agriculture and unsustainable forestry, is the worst threat at present, but climate change will have major impacts in future. Threats are intensifying and often interlinked. They are rooted in difficult human problems – including a consistent undervaluation of biodiversity.

The immediate threats to species, sites and habitats are nearly always caused by people. Very often, these threats are interconnected and reinforce each other. Habitat destruction – with the degradation and fragmentation that go with it – is by far the biggest immediate problem, impacting 86% of Globally Threatened Birds. In particular, unsustainable forestry and expanding and intensifying agriculture are the paramount threats.

Many other factors are also significant, including our ever-spreading infrastructure. When poorly planned and managed, this destroys natural habitat and brings with it damaging human activities, including logging, agriculture and fire. Environmental pollution of air, land and water often has a direct impact on birds – an indication of the wider, costly problems it creates for biodiversity and society.

Seabirds continue to be drowned on the hooks of long-line fishing boats, causing devastating population declines and disrupting ocean ecology. Unsustainable hunting and trapping remain a critical issue for many species. Global travel and trade and changing climate encourage the spread of invasive species of animals, plants and microbes, including new diseases. Invasives are a particular threat on islands, but increasingly a problem on continents too.

Climate change is taking place because of human activities, especially the burning of fossil fuels. We can already see many impacts on biodiversity, and more severe effects – including bird extinctions – are predicted. Whether we lose a few species or very many will depend critically on the degree of warming.

The immediate threats to birds and other biodiversity are rooted in some of humanity's most serious problems. These include continuing strong growth in human population and material consumption, widespread poverty, inequitable access to resources, and an unfair global trade regime. Ignoring or undervaluing biodiversity in our economics undermines sustainability. So long as our accounting is inadequate, we will continue to destroy the resources on which we depend, and short-term gains will be massively outweighed by long-term losses.