It considers population growth as a major contributor to environmental degradation, biodiversity loss, resource depletion and climate change.

The charity promotes positive, voluntary measures to achieve a sustainable human population size that enables everyone to have a decent quality of life while safeguarding our natural environment.

The United Nations projects that global population size will reach 9.7 billion in the year 2050 and 10.9 in 2100,[6] which illustrates the urgency of the matter, according to the organisation.

[13][14][15] Over the years, the organisation has run various campaigns, including supporting Caroline Lucas' Bill to make Personal, Social, Health and Economic education (PSHE) a statutory requirement in state-funded schools.

[21] Finally, the charity undertakes and commissions research to examine some issues in depth, for example, publishing a report on the rise of coercive pronatalism,[22] or exploring the feasibility of lower future population scenarios.

Population Matters' patrons are prominent public figures who are concerned about the impacts of human population growth, including Sir David Attenborough,[28] Chris Packham,[29] Dr. Jane Goodall,[30] Leilani Münter,[31] Jonathon Porritt, Sir Partha Dasgupta, Professor Paul Ehrlich, and Professor John Guillebaud.