This report by Adaptation Without Borders rings the alarm bell on transboundary climate risks. It is the first collection of evidence on risks that undermine effective responses to climate change, yet that remain largely unrecognized: a “blind spot” in both climate policies and solutions. It brings together the best available knowledge, drawing on a wealth of case studies.

Key messages

  • Transboundary climate risks, which are triggered by a climate hazard in one country, cross borders, continents and oceans to affect communities on the other side of the world. So do the consequences of some adaptation actions.
  • In a world that is increasingly interconnected, these risks are transmitted through shared natural resources and ecosystems, trade links, finance and human mobility.
  • Transboundary climate risks are expected to increase as global warming accelerates to threaten entire societies and economies.
    No country is immune: transboundary climate risks can affect any country, at any time, regardless of its level of development. They combine with non-climate drivers such as poverty and conflict to undermine our collective wellbeing.
  • Transboundary climate risks have the greatest impact on the poorest and most vulnerable people, exacerbat-ing inequities and the root causes of their vulnerability.
  • Evidence shows that transboundary climate risks are a global concern, yet the international, regional and local mechanisms to adapt to climate change are not yet equipped to meet this common challenge.
  • The authors argue that a global response to transboundary climate risks is necessary to build collective resilience to climate change.
People struggle along a narrow footpath in Venice, up to mid calf in moving water, the morning after the 2019 187cm flood disaster.

Photo credit: Adam Sébire / Climate Visuals