In a nutshell: From a lights-out gesture to a global movement

Earth Hour is the world’s largest environmental grassroots movement and engages millions of people across 180 countries and territories every year.

Held on the last Saturday of March annually, it is known for its symbolic ‘lights out’ call, which encourages individuals, businesses and cities to turn off non-essential lights for one hour to demonstrate their commitment to the planet.

Launched in Sydney in 2007, Earth Hour was conceived in response to growing concerns about climate change and the perceived lack of public engagement on the issue. In 2006, Australia experienced record-high temperatures and severe drought, which prompted discussions about sustainability and climate mitigation.

At the time, WWF-Australia wanted to create an initiative that visibly showcased public support for environmental action. This led to the idea of asking the public to turn off electric lights as a symbolic gesture of support.

The campaign quickly gained traction. Approximately 2.2 million people and over 2,000 businesses got involved in its first year, and by 2008, it had expanded to 35 countries and territories.

In 2025, Earth Hour participants from 118 countries and territories contributed nearly 3 million hours to environmental actions. The hours given were used to reconnect with nature, participate in restoration projects, learn about the planet or inspire others. The campaign also trended in 31 countries and more than 19,000 media mentions in more than 125 countries and territories from 1 Mar to 25 Mar. Some coverage highlights include AP, AFP, CBS, DW, DPA, Sky News Breakfast, Euronews Spanish, Euronews French, Globo, Times of India, and ZDF. The top locations include Germany, Spain, the US, Vietnam, and Egypt.

Today, at a time when our world is increasingly divided and facing mounting crises - from record-breaking temperatures to alarming biodiversity loss - Earth Hour stands as a beacon of hope. It is a reminder that even in the face of daunting challenges, collective action has the power to create change. As an open-source platform, it empowers local organizations, businesses, governments, and communities around the world to localise the movement and drive bigger impacts - proving that when we act together, we can create real change. More than ever, we need Earth Hour to support us in achieving our Roadmap 2030 goals and ensuring a sustainable future for all.

The campaign employs storytelling and powerful visuals to shift public perceptions, making conservation a shared value rather than a niche concern.

Scaling out and deep: Campaigning as a scaling tool

Scaling conservation impact can be achieved through three interconnected strategies: scaling out, scaling up and scaling deep.

Scaling out involves expanding a successful conservation solution to new, different locations and adapting it to the novel contexts. Scaling up drives systemic change by influencing policies, governance and institutional frameworks to create the conditions necessary for conservation success. Scaling deep ensures a lasting impact by shifting cultural norms, values and behaviours within communities.

While scaling out increases the reach of conservation efforts, scaling up and scaling deep creates the enabling conditions that amplify and sustain impact. Together, these three strategies help conservation efforts achieve widespread, long-lasting and transformative effects.

The design of the Earth Hour initiative exemplifies both scaling out through its worldwide replication efforts and scaling deep by embedding environmental values into everyday life. Earth Hour aims to raise awareness of climate change and nature loss, reframe cultural narratives, mobilize collective action, and encourage shifts in public perceptions of sustainability. By combining the processes of scaling out with that of scaling deep, Earth Hour broadens its reach and ensures that participation leads to lasting conservation impact.

Impact achieved: From lighting up iconic landmarks to shaping policy

While the campaign is known for its symbolic lights-off event, supported by iconic landmarks such as the Eiffel Tower (Paris) and the Empire State Building (New York), as a global show of solidarity, its true impact lies in its potential to influence public attitudes and actions. Earth Hour exemplifies how scaling deep can help shape norms, values and behaviour.

The campaign’s decentralized, open-source model enables widespread participation without the need for formal approval. By making climate action accessible, unifying and empowering, Earth Hour fosters personal responsibility and encourages long-term engagement beyond the annual event.

Earth Hour has led to tangible conservation outcomes, such as the establishment of Uganda’s Earth Hour Forest and Argentina’s largest marine protected area in 2013.

Some corporations have integrated Earth Hour’s messaging into their marketing strategies. Others started a new corporate journey by incorporating sustainability commitments into their operations. In 2024, Seiko Epson Corporation (Epson) became Earth Hour’s first-ever international corporate partner. Epson used the campaign to promote energy-saving actions and highlight its commitment to using 100% renewable electricity at all its sites.

Earth Hour has also helped to ensure policy changes. An example is Ecuador’s resolution in 2014 to ban plastic bags in the Galapagos Islands in order to promote environmental responsibility.

Moving to scale: Scaling from a national to a global campaign

The overwhelming participation in the first event in Sydney in 2007 showcased the campaign’s potential to mobilize people on a large scale. This prompted WWF-Australia and campaign organizers to shift their vision from a national initiative to establishing an international movement. The international campaign was run by the Earth Hour campaign team in WWF-Australia from 2006 - 2011.

To expand the campaign more internationally, Earth Hour Global was established in Singapore as a separate legal entity with funding from WWF International, WWF-Singapore and Singapore Economic Development Board (EDB). The co-funding model helped facilitate its growth from 2012 to 2015. During this period, Earth Hour grew from 156 countries and territories to over 180 countries and territories and became the world’s largest environmental grassroots movement. It is also one of the few open-source not-for-profit movements on this global scale.

However, upon completion of the Singapore EDB grant, Earth Hour Global was dissolved, and its governance was reintegrated into WWF International from 2016 onwards.

Scaling success factors: Open-source, collaborative and low-cost model and has a clear call to action

An open-source and collaborative model: Earth Hour uses an open-source model, allowing growth beyond WWF’s direct control, while keeping the global message consistent. The organization provides free branding and toolkits to help individuals, organizations and governments adapt Earth Hour to suit their local environmental objectives. Earth Hour’s flexible and decentralized model can be adapted to suit different cultures, economies and political situations.
A positive and inclusive approach: Earth Hour emphasizes optimism and teamwork, in contrast to crisis or loss, which many other conservation efforts focus on. This approach attracts a broader audience, including people who often feel disconnected from environmental activism.
Stakeholder buy-in: The campaign has established partnerships to broaden its reach, boost participation, and sustain momentum. By securing buy-in from a diverse network of stakeholders, including governments, corporate partners, schools, local NGOs and individuals, Earth Hour has successfully scaled both in reach and impact.
Low implementation costs: Access to Earth Hour branding and campaign materials is free for anyone who wants to organise their own event. The actual implementation costs are borne by the participating entity, making Earth Hour cost-effective for WWF and as inexpensive—or as elaborate—as each local organiser chooses.
‘Doers’ and ‘payers’ considered: Scaling literature highlights the importance of both ‘doers’ and ‘payers,’ as successful scale depends on implementation capacity and sustained funding beyond the originating organisation. The Earth Hour campaign was intentionally designed with both in mind, recognising that its success would rely on a wide network of actors to deliver and support the movement. The ‘doers’ include organisers who drive local events and ensure continued growth, as well as catalysts who create toolkits and build networks to support them. The ‘payers’ are those who fund the catalyst teams within WWF, along with local funders (WWF National Offices, local NGOs, schools, businesses etc) who support Earth Hour events around the world. By structuring the campaign around external doers and payers, WWF enables Earth Hour to scale far beyond its own resources and direct control.
A clear and consistent call to action: The campaign’s simple yet powerful call to ‘switch off and give an hour for Earth’ has remained consistent and helps ensure a sense of collective purpose. Earth Hour’s simple, clear identity makes it easy to distinguish, thereby building trust and ensuring lasting impact.

Scaling challenges: Funding constraints and tricky impact measurement

Despite its success, Earth Hour has faced challenges in sustaining and expanding its impact.

Funding constraints and sustainability: The campaign operates with a lean annual budget that depends heavily on the limited capacity of the WWF International communications teams to create minimal campaign materials and basic digital infrastructure. Ensuring its long-term sustainability is an ongoing concern. One of the strengths of the open-source model is that it encourages global participation without demanding substantial financial commitments from stakeholders. Unfortunately, this approach also restricts structured revenue generation. As such, striking a balance between monetizing partnerships and maintaining campaign accessibility poses a delicate challenge.
Difficulty measuring impact: Earth Hour is mainly focused on raising awareness and changing cultural norms. This makes it hard to measure the effects of this initiative compared to that of direct conservation efforts. Consequently, explaining its impact to stakeholders and supporters can be challenging. Earth Hour’s latest 7-year campaign focused on collecting ‘hours for Earth’ is an attempt to measure its global impact and actions.
Ensuring ongoing engagement: Earth Hour is now an annual tradition. However, keeping people excited and involved in this campaign can be challenging, especially in locations, organizations and WWF offices where people have participated for many years. WWF must regularly update messages, activities, and online strategies to keep everyone engaged.

Next steps

Leveraging its anniversary for support renewal: Earth Hour’s 20th anniversary in 2026 will help showcase its importance in the global environmental movement.
Securing sustainable funding: As a communications-driven initiative, Earth Hour has faced challenges in securing consistent funding. Without sustained funding for Earth Hour, it is extremely difficult to put in place a long-term strategy for Earth Hour. To tackle this issue, WWF should explore new fundraising methods and partnerships as well as extend fundraising capacity to the Earth Hour global team.
Expanding engagement: Efforts are also underway to improve Earth Hour’s digital engagement and encourage year-round participation in the campaign to sustain momentum. Strategies to strengthen online advocacy, provide accessible educational content, and leverage digital storytelling will be employed to keep environmental issues at the forefront and encourage ongoing involvement from individuals, communities, and organizations.