2040 is an Australian documentary film directed by and starring Damon Gameau. The film looks at the effects of climate change over the next 20 years and what technologies that exist today can reverse the effects.

2040 follows Gameau's imagining of a future for his four-year-old daughter Velvet, where climate change has been solved. Described as “an exercise in fact-based dreaming” the film is structured as a letter to his daughter whereby Gameau travels around the world investigating numerous solutions that can contribute towards climate mitigation and imagining what a future would be like where they have been implemented at scale. In choosing what to feature in the film, Gameau restricted it to solutions that are either already available or have a realistic potential to greatly contribute to reversing climate change by the year 2040. The film features interviews with numerous academics, ecological experts and entrepreneurs and covers five broad areas.

It examines how renewable energy, like rooftop solar, have enabled micro-grids to form in Bangladesh enabling communities to produce, own and trade their own energy. The film addresses mobility and how a move away from car-ownership through self-driving cars and ride-sharing can enable the redesign of urban areas by promoting green spaces and more livable cities.

It also examines the role of agriculture and how a shift towards regenerative agricultural practices can not only reduce greenhouse gas emissions but also contribute to carbon sequestration while enabling greater resilience, such as through increased water retention. The climate benefits of adopting plant-rich diets are also discussed.

The film also looks at the many uses of seaweeds and how bringing seaweed ecosystems to the open ocean through Marine Permaculture can enable the sustainable harvest of seaweeds and fish to help guarantee food security while regenerating marine life and sequestering carbon.

Finally, Gameau considers the cascading societal benefits of the empowerment of women and girls, notably through education, as it enables women to have greater control over their life-decisions thereby providing a non-coercive, human-rights based means to reduce population growth.