Biodiversity Loss Report 2011
by Tom Zeller
Although there has been substantial growth in the amount of land and sea designated as protected habitat over the last four decades, a new study has established that the diversity of species across the world continues to fall drastically. Over 100,000 so-called protected areas-- 7 million square miles of land and nearly 1 million square miles of ocean—have been established since the 1960's. Yet according to the Living Planet Index, widely cited to track planetary biodiversity, the wealth of terrestrial and marine species has seen steady decline over roughly the same period. Simply protecting swaths of land and sea -- a common conservation strategy worldwide -- is not preventing a steady, on-going loss of species.
This problem is bigger than one we can realistically solve with protected areas -- even if they work under the best conditions. The protected area approach is expensive and requires a lot of political and human capital. Our suggestion is that we should redirect some of those resources to deal with ultimate solutions.
Camilo Mora, University of Hawaii
The steady loss of biodiversity -- the rich variety of living things -- will have profound implications for human civilization, which relies on healthy, variegated ecosystems to provide a host of ecological services from water filtration and oxygen generation to food, medicine, clothing and fuel. The precise value of such services is difficult to quantify, but one economic analysis estimated they were worth some $33 trillion globally.
Protected areas can only protect from over-exploitation, and from habitat destruction due to exploitation and other direct human actions within their borders. They are a tool for regulating human access and extraction," says the study's co-author Peter Sale, assistant director of the United Nations University Institute for Water, Environment and Health. "Biodiversity loss is also caused by pollution, arrival of invasive species, decisions to convert habitat to other uses -- farms, villages, cities -- and by various components of climate change. None of these are mitigated by the creation of protected areas except, possibly, the removal of habitat to other uses." In other words, the implementation of habitat protection cannot keep pace with other stressors that contribute to overall species loss.
This is partly due to lack of enforcement. Only about 5.8 percent of terrestrial protected areas and 0.08 percent of marine sanctuaries see reliable and consistent enforcement. Research suggests that between 10% and 30% of the world's ecosystems need to be protected to preserve optimal biodiversity. But the increase in protected lands is much too slow to achieve those targets anytime soon.
The study notes that demand on marine fisheries is projected to increase 43% by 2030 to supply ongoing food demands, while projected CO2 emissions by 2050 are expected to severely impact over 80% of the world's coral reefs and affect marine fish communities globally, causing local extinctions and invasions with changes in species composition of up to 60%. On land, the growing human population and demand for housing, food and energy are expected to substantially increase the intensity of stressors associated with the conversion of land cover to agriculture and urbanization. The extent of protected areas is still limited, and growing at a slower rate than that at which biodiversity threats are developing. Global human population is expected to pass 7 billion this year according to the United Nations: an increase of 1 billion people in about a dozen years.
Reversing biodiversity losses will require a wholesale rethinking of conservation strategy -- one that redirects limited resources toward more holistic solutions. These would include efforts to reduce human population growth -- and its attending consumption patterns -- as well as the deployment of technologies to increase the productivity of agriculture and aquaculture to meet human needs. Peter Sale concludes that we need a fundamental restructuring of world views to bring them in line with a world of finite resources:
In the final analysis, we have to recognize that we are pushing up against limits set by the way the biosphere functions. Biodiversity loss is one sign of this.