This is the ninth in a series of weekly blog posts covering conservation topics with a focus on protected areas and the laws and institutions that support them (or don’t).

What will it take to achieve long-term, sustainable conservation? Think big. One visionary initiative answers this question with a catchy phrase: Nature Needs Half. What does this mean exactly? The vision set forth is to protect 50% of the surface of the planet in order for nature (and subsequently, people) to thrive. Given the realities of accelerating population growth, development, consumption, and a lack of political focus on the environment, this may seem like an impractical goal. However, a vision to protect half of the planet is admittedly powerful. This narrative inspires a “think big” approach which could serve to motivate conservationists and all people as we plan for the future. Protecting half of the planet, especially large wilderness areas like boreal forests and the Amazon, would help store carbon, regulate the climatic and hydrological systems, and preserve species, among other benefits.

Before we accept the Nature Needs Half mantra, let’s consider some of the technicalities involved. First of all, how much of the planet is currently protected? According to the most widely used protected area ledger (the World Database of Protected Areas), globally about 15% of the land and 3% of the oceans are protected. There is a long way to go until we cover half of the planet with protected areas. However, especially for terrestrial jurisdictions, we are not far from reaching Aichi Target 11 of the Convention on Biological Diversity. This target directs signatory nations to protect 17% of their terrestrial and 10% of their marine areas by 2020. These targets are obviously more short term and achievable than a target of 50% coverage. This begs the question: what is the right target to set? 17%? 25%? What about 100%? Of course, international targets are likely to be driven by political, rather than ecological, considerations. There is no “right” answer here.

Even if the Aichi targets are met – how will it ever be possible for half of the planet to be officially protected? There is one approach that may make this goal more achievable. Let’s expand upon what we mean by “protected.” To date, to be officially classified as a protected area and entered into the World Database of Protected Areas, the location must fit the following definition:

“A clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long term conservation of nature with associated ecosystem services and cultural values.” (IUCN Definition 2008)

However, these officially designated lands and waters are not the only places on the planet that are viable for conservation. In fact, many other management and ownership schemes exist which focus on biodiversity conservation – sometimes solely and sometimes in conjunction with other goals – that are not accounted for in official ledgers. Here are just a few examples of these interventions:

1. Conservation easements are privately protected lands, usually held by a land trust. Similarly to nationally protected areas, conservation easements restrict certain types of land use such as extractive activities or development and preserve the area for its scenic, ecological, and/or cultural values.

2. Community Based Natural Resource Management (CBNRM) relies on a bottom-up approach. Within CBNRM schemes, local communities organize to make decisions about resource management and also share benefits.

3. Military training areas may include large swaths of undeveloped, fenced-in land that provide habitat for biodiversity. Military training areas cover as low as 1% but likely up to 6% of the planet and have the potential to deliver great conservation benefits, especially given the large budget of the military itself (Zentelis and Lindenmayer 2014).

Beyond these three, there are many other types of conservation schemes that go “outside the box” of traditional protected areas. After first acknowledging the existence of these diverse interventions, an obvious question arises: are these other conservation schemes as effective as the “gold-standard” protected areas? Although we don’t have a comprehensive picture of the performance of all of these interventions yet, we do have some evidence about the success of “non-traditional” protection strategies.

1. In Costa Rica, Payments for Ecosystem Services schemes increased forest cover. Evidence has shown that Payments for Ecosystem Services (PES) programs – programs that pay landowners to refrain from deforesting their land – worked to increase forest cover in Costa Rica (Arriagada et al. 2012). Costa Rica is indeed famous for its conservation ethic, so it is not possible to generalize these results globally for all PES programs. However, this offers some hope about the potential for nontraditional protected approaches to be effective.

2. Indigenous reserves were just as (if not more) effective than protected areas in Brazil. In one study, deforestation and fire occurred about equally frequently in protected areas and indigenous reserves (Nepstad et al. 2006). However, the protected reserves tended to be located in more remote areas, which suggests that deforestation or fire would naturally occur less often in these areas. In contrast, indigenous areas were created “in response to frontier expansion, and many prevented deforestation completely despite high rates of deforestation along their boundaries” (Nepstad et al. 2006). This suggests that Brazilian indigenous reserves provide extremely strong levels of protection, likely due to stringent enforcement.

3. Sacred sites can be important places for conservation. For example, traditional communities that live in the Zambezi valley of Zimbabwe consider the local dry forests to be sacred. Researchers found that the sacred forests experienced far less conversion than other localities. Notably, the research also revealed that forest loss was higher in locations where traditional leaders felt disempowered as compared to areas where leaders retained power (Byers et al. 2001). This is another piece of evidence that the engagement and empowerment of local communities is critical for effective conservation.

Although we have some evidence, much more research should be done to document and evaluate the performance of these diverse conservation interventions to understand the true reach of conservation action. It would be interesting to compare the ecological performance over time of a locality that has undergone dynamic changes to its governance in the form of different conservation interventions. It would also be interesting to compare the socioeconomic enabling conditions and ecological performances of these various interventions – in other words, what works, where, and why? Evidence of the viability of these interventions could help justify their accounting in official protected area ledgers. Eventually, this could even help us achieve the vision of protecting 50% of the planet and giving Nature the half that she needs.