A new global initiative aimed at supporting locally led solutions to the health impacts of climate change has been launched during London Climate Action Week.

The initiative, called Nexa, was announced by Grand Challenges Canada (GCC) and the Science for Africa Foundation (SFA Foundation).

Nexa will support innovations designed to address climate-related health challenges in low- and middle-income countries, where communities are increasingly exposed to rising temperatures, changing disease patterns and extreme weather events.

The programme is being led by Grand Challenges Canada, in partnership with the Government of Canada and the Science for Africa Foundation, alongside a network of international partners.

These include the Novo Nordisk Foundation, Sanofi Foundation, the Fund for Innovation in Development, and members of the Global Grand Challenges Network in Botswana, Brazil, Malawi, Rwanda, Senegal and South Africa.

Partners say they aim to mobilise more than US$50m in investments to expand climate and health innovations in vulnerable countries. The first funding call opened on 22 June and targets innovations in Africa and the Americas.

Climate change has been described by the medical journal The Lancet as the greatest global health threat of the 21st Century. An estimated 3.6 billion people worldwide currently live in regions considered vulnerable to climate change.

Nexa is intended to respond to growing concerns that intensifying climate pressures are creating new and worsening health risks while placing additional strain on already overstretched health systems in many developing countries.

"Communities around the world are facing rapidly growing threats to their health and livelihoods while global climate commitments are weakening," said Dr Karlee Silver, Chief Executive Officer of Grand Challenges Canada.

Dr Silver said the initiative would support locally led innovations aimed at helping people protect their health in the face of climate change.

The programme has been informed by findings from what partners describe as the largest climate and health survey conducted so far. The survey involved 6,400 respondents across 107 low- and middle-income countries.

In 2025, Grand Challenges Canada, the Science for Africa Foundation, the Global Grand Challenges Network and the Geneva Learning Foundation gathered insights from health workers, scientists, innovators, policymakers and humanitarian workers affected by climate-related health threats. The findings are being prepared for publication in an academic journal.

Chief Executive Officer of the Science for Africa Foundation, Dr Tom Kariuki, said addressing the links between climate change and health would require new forms of partnership and investment.

"Those closest to these challenges are often closest to the solutions," he said.

He added that the initiative demonstrates what can be achieved when African priorities, local innovation and global collaboration are brought together.

According to partners, vulnerable groups, including pregnant women, children, people living with chronic illnesses and communities with limited access to healthcare, are among those most affected by climate-related health risks.

Nexa will prioritise innovations that address three major drivers of climate-related health threats including changing patterns of disease-carrying insects responsible for illnesses such as malaria and dengue fever, extreme heat, and poor air quality.

Canada's Secretary of State for International Development, Randeep Sarai, said investments in locally led climate and health innovations could help vulnerable communities respond to the health impacts of climate change.

The initiative will provide funding for both early-stage and more established projects. Early-stage projects will be eligible for up to US$200,000 over 18 to 24 months, while proven innovations could receive between US$250,000 and US$2m, depending on their level of development.

They said innovations could include products, services, processes or delivery models that improve existing approaches and can be expanded to reach more people.

Applications for projects in Africa and the Americas will remain open from 22 June to 22 July 2026. Future funding rounds will focus on climate and health innovations in Asia, while the first investments are expected to be made in early 2027.