How effective are advocacy campaigns at driving permanent policy changes that lead to forest conservation results? We suspected this might be a difficult question to answer scientifically, but nevertheless we gamely set out to see what researchers had discovered when they attempted to do so as part of a special Mongabay series on “Conservation Effectiveness.”We ultimately reviewed 34 studies and papers, and found that the scientific evidence is fairly weak for any claims about the effectiveness of advocacy campaigns. So we also spoke with several experts in forest conservation and advocacy campaigns to supplement our understanding of some of the broader trends and to fill in some of the gaps in our knowledge.We found no evidence that advocacy campaigns on their own drive long-term forest conservation, though they do appear to be valuable in terms of raising awareness of environmental issues and driving people to take action. But it’s important to note that, of all the conservation interventions we examined for the Conservation Effectiveness series, advocacy campaigns appear to have the weakest evidence base in scientific literature. When a final agreement to protect the Great Bear Rainforest was announced in February 2016, it was hailed as a major victory for First Nations and environmental activists. More than 85 percent of the vast temperate rainforest on the Pacific coast of British Columbia, Canada, was made off-limits to industrial logging, and the rights of First Nations as decision-makers on their traditional lands were codified into law.The impacts of the Great Bear deal will likely be felt far beyond British Columbia. “They really set a global precedent for large-scale conservation,” Nicole Rycroft, executive director of the Vancouver-based environmental group Canopy, told Mongabay at the time. “The fact that it’s human well-being alongside large landscape conservation means it can be applied to places like [the] Leuser [Ecosystem in Indonesia] where millions of people live on the land and depend on it.”At 3.6 million hectares (13,900 square miles), the Great Bear Rainforest represents roughly one-quarter of all intact temperate rainforest left in the world. By the mid-1990s, it had become the scene of a fierce struggle between activists concerned about the destruction of old-growth forests and the forestry industry that was clear-cutting British Columbia’s forests. Newspapers dubbed this struggle “the War in the Woods.” More than 900 people were arrested in 1993 alone for taking direct action to stop the logging.But while protests and blockades were halting loggers’ work in one valley, the next valley over might be razed to the ground — and this fragmentation of the forest was jeopardizing the health of the ecosystem as a whole.So in 1997 Greenpeace, Rainforest Action Network, the Sierra Club, and other environmental non-governmental organizations (NGOs) launched a new environmental advocacy campaign that aimed to deliver a long-term solution by forcing fundamental changes to how the forestry industry operated in British Columbia.Such campaigns are now quite common and seen as increasingly influential. Through them, NGOs seek to pressure a target — usually a corporation, a government, or a governmental body — to adopt some policy or course of action intended to increase forest conservation. These campaigns employ a variety of tactics and make different demands of their target.In the case of Great Bear, the NGOs took a market-based approach, attempting to persuade the main customers for products from the rainforest to spend their money elsewhere. “The environmental groups took their message to the marketplace—the international buyers of wood and paper products from coastal British Columbia. ForestEthics, Greenpeace, Rainforest Action Network and other groups contacted corporations such as Home Depot, Staples, Ikea, the Fortune 500 companies and the German pulp and paper industry and showed them the destruction associated with their purchases,” Merran Smith of ForestEthics (now called Stand.earth) and Art Sterritt of Coastal First Nations, an alliance of B.C. First Nations, write in an account of the campaign.A bear climbs over a fallen tree in the Great Bear Rainforest in British Columbia, Canada. The Kermode or Spirit bear, a subspecies of black bear that sometimes has a white coat, is the namesake of the Great Bear Rainforest. Photo © Andrew Wright / www.cold-coast.com.Some customers immediately cancelled contracts with forest products companies operating in B.C., but many remained unmoved. The NGOs responded by organizing high-profile actions like rallies at stores, boycotts of recalcitrant companies, and shareholder resolutions, as well as placing ads in prominent media outlets and inflicting what’s known as “brand damage” on the laggards.“For the forest companies, what had been a public relations problem had transformed itself into a customer-relations debacle,” Smith and Sterritt write. “Whether it was a blockade at a remote logging site, a demonstration at a corporation’s headquarters in Europe or an article in the New York Times, the message was taking root: ‘The world’s old-growth forests are disappearing. It’s time to protect what’s left.’”In 2000, the B.C. forestry industry at last came to the negotiating table with the First Nations groups and NGOs that stood in opposition to their operations, and a truce was called. The activists would halt their campaign targeting the logging companies’ customers and the companies would stop cutting forests in 100 intact areas. The truce held, and in 2004 the B.C. government and 24 First Nations began formal government-to-government negotiations, which ultimately resulted in the initial Great Bear Rainforest Agreements in 2006 and the strong final agreement announced in 2016.The campaign to save British Columbia’s forests led to long-term, durable policy changes that appear to make a real difference on the ground, but that is certainly not true of every forest advocacy campaign launched by an NGO. Zero Deforestation Commitments have become a common demand of environmental campaigners when targeting producers of agricultural commodities like palm oil, soy, and cattle, for instance, but research has consistently shown that companies are still doing far too little to actually implement those policies and that the companies are thus unlikely to meet their own deforestation targets.So how effective are advocacy campaigns at driving permanent policy changes that lead to forest conservation results?How we investigated effectiveness of advocacy campaignsWe suspected this might be a difficult question to answer scientifically, but nevertheless we gamely set out to see what researchers had discovered when they attempted to do so.Because “environmental advocacy campaigns” is a large and varied topic, we looked for evidence on the effectiveness of campaigns that specifically aimed to conserve globally important forests. We focused on campaigns targeting the environmental impacts of six “forest-risk” commodities: beef and cattle, biofuels, oil palm, pulp and paper, soy, and timber.While we were able to find enough studies through a systematic search of the scientific literature for the other articles in Mongabay’s Conservation Effectiveness series, we used a more opportunistic approach to finding literature evaluating the effectiveness of environmental advocacy campaigns at protecting forests because our systematic search didn’t deliver many articles that focused on outcomes related to one of those six forest-risk commodities.We searched on Google Scholar for relevant studies, we used the references from the studies we found, and used recommendations from researchers that we interviewed to get the final set of 34 studies that we reviewed for this article (you can see a full list of the literature we reviewed here).Though we did examine one literature review assessing the effectiveness of grassroots campaigns related to tree plantations (Gerber 2011), we deliberately did not search for research examining the effectiveness of grassroots campaigns in conserving global forests. Our analysis is limited to national and international campaigns.We found no studies that rigorously or experimentally measured the impact of environmental campaigns. Much of the literature we reviewed used perception-based measurements (such as asking people if they thought the campaigns were effective), did not consider counterfactual scenarios (what would have happened if the campaign hadn’t occurred), and were based on case reports that did not use controls or take into account confounding variables.The research we examined that did use more rigorous methodologies (e.g. case-control studies that compare outcomes in areas that were subject to a campaign with areas that were not; see here for an explanation of the various evidence types we examined for the Conservation Effectiveness series) was mostly related to Zero Deforestation Commitments as opposed to directly measuring the impacts of any specific campaign (e.g. Gibbs et al. 2015, Azevedo et al. 2015).Many of these Zero Deforestation Commitments resulted, at least in part, from advocacy campaigns. Because most of the research on environmental advocacy outcomes that we examined didn’t measure impacts on the ground (e.g. forest cover) but were based on perceptions or specific outcomes (e.g. stopping a project), we included literature on Zero Deforestation Commitments in our analysis as a means of exploring whether or not there were some indirect impacts of advocacy on forest cover.