Conservation parks are growing, so why are species still declining?

Nearly 15% of Earth’s land surface is protected in parks and reserves. By 2020, we should reach the agreed global target of 17%. This is good news for species diversity, right? Biodiversity loss continues apace despite these global agreements and conservation actions, and is unlikely to stop any time soon.
We explored this apparent paradox with the help of a simple model that simulates the current relative proportions globally of the area of remaining tropical forest, and the area that has been cleared for agricultural development. We used the model to look at what happens to these proportions when networks of conservation reserves expand.
Our research led to two insights: both the area of forest protection and the area of clearing for development can expand at the same time; and the governance regimes responsible for protected areas can actually be weakened by protected area expansion. This is because pressure for the creation of new protected areas comes largely from public discourse.
In the real world we are doing the opposite; investing heavily in the force that drives tropical forest clearing. The leaders of the G20 nations recently gave a huge boost to the power of development regimes, by pledging to invest up to US$70 trillion on new infrastructure projects by the year 2030. This is precisely the kind of driving force that will harm wildlife conservation, and which the growth of protected areas will fail to counter.
It seems counter-intuitive, but our research suggests that increasing the area of the world’s conservation reserves can also reduce the perception of the risk of ongoing biodiversity loss, primarily because the focus on the 17% protection targets takes our eye off the critical issue of halting habitat loss.
As a result, the global distribution of protected areas is currently “high and far”, skewed toward mountainous areas and places far from development frontiers. If achieving 17% leads the public to conclude that biodiversity is now safe, it can lower the main feedback currently giving power to the protect force – public pressure for political action.