Ascension Climate

CRACAB Project

Funded by the Darwin Initiative

Understanding global change at a local scale

There is now incontrovertible evidence that the Earth’s climate is warming as a result of anthropogenic greenhouse gas emissions, threatening to destabilise ecosystem functioning on a global scale. However, while the global implications of climate change are increasingly well understood, at a local scale, the nature of the threat is often diffuse and ill-defined. This lack of quantifiable local impacts, can act as a barrier to adopting the proactive, forward-thinking policies and management practices that are needed to adapt to climate change and build more resilient ecosystems.

The ‘CRACAB’ project (Climate Resilience and Conservation of Ascension’s Biodiversity) was developed specifically to address a shortage of information on how a changing climate might affect the biodiversity of Ascension Island and uncertainty over the most appropriate local responses.



0.25 mm/year

Current rate of sea level rise at Ascension Island



1.5 °C

Predicted increase in mean temperature at Ascension Island by 2100 under intermediate emissions scenario (IPCC; RCP4.5)

What will be affected?

Climate change has the potential to impact all aspects of Ascension Island’s biodiversity, from the mountain cloud forest and its unique collection of endemic plants to the surrounding open ocean, recently designated as one of the world’s largest marine protected areas.

To reflect the breadth of the threat, the CRACAB project will adopt a “whole island” approach that assesses impact of climate change across a range of indicator species and habitats in the terrestrial and marine biomes.

On land, new techniques will be used to assess how critically-endangered endemic plants inhabiting the Island’s arid, volcanic plains might be affected by changes in rainfall and drought; as well as quantifying the impacts of rising temperatures and sea levels for the Island’s iconic green turtle nesting population.

In the ocean, state-of-the-art global circulation models will be used to assess how changes in regional oceanography might impact Ascension’s marine ecosystem, including its globally-important seabird nesting populations whose productivity and survival is inextricably linked to the availability of pelagic prey within reach of the island.

Building resilience

Although actions taken on Ascension Island cannot alter the course of climate change, decisions taken locally may help to mitigate some of its worst impacts. Throughout the CRACAB project, there is an emphasis on finding sustainable solutions to the challenges posed by a changing climate, as well as contributing to the global dialogue on the nature and severity of the threat. For example, the project team will be:

Trialling irrigation options to boost the survival of drought-stressed plants

Exploring how artificial nest-shading and natural migration of nesting beaches enabled through proactive coastal land use planning might mitigate climate change impacts for sea turtles

Seeking to understand how the implementation of the Ascension Island MPA can contribute to climate resilience in the marine environment.