The current global network of protected areas is quite extensive, covering 17 million square kilometers of land and 2 million square kilometers of oceans. But the more than 100,000 areas appear to be insufficient to halt global biodiversity loss, according to an assessment published in the journal Marine Ecology Progress Series.
A widely advocated minimum target for effective biodiversity conservation is turning 30% of the world’s ecosystems into protected areas. At current rates it will take 185 years for land and 80 years in the case of oceans to reach a global area of that extent. A pace that is far too slow to compete with the rapid growth of threats like habitat loss, resource exploitation and climate change.
The authors based the assessment on global data and existing literature on biodiversity loss and human generated threats. They found a clear correlation between growing world population, natural resources consumption and biodiversity loss and concluded that biodiversity loss will probably not be stemmed without decreasing the ecological footprint of humanity. Under conservative scenarios of human population growth and present conditions of human consumption, we will need up to 27 earths by 2050 to produce the cumulative need for natural resources.
A number of technical and practical shortcomings were identified in the process of implementation of protected areas that impede relying on them as a global solution to prevent biodiversity loss. The five main shortcomings are a too slow growth of protected area, protected areas are too small and inadequately connected, they often only amend human threats, expenditure is a fourth of what it should be and it is unlikely that trade-off will be found between human development and sustaining biodiversity that will be in favour of the latter.
Protected areas have helped preserve species at local scales and are as such very useful conservation tools. We still need more of them, but they cannot be the sole solution to our biodiversity problems. According to lead author Camilo Mora of University of Hawaii at Manoa, we have to get serious about addressing the growth in size and consumption rate of our global population if we are to curtail biodiversity loss.
© Jorn van Dooren | www.bitsofscience.org