How meeting the 2C goal cuts the climate risks for 25,000 marine species

Climate change is rewiring marine ecosystems at an alarming rate. Warming waters are causing the distribution of marine life to shift, with species such as bluefin tuna showing up in the Arctic while others are moving out of the tropics.

By CarbonBrief

These – and many other – changes will only continue to increase, reshuffling food webs and impacting virtually all life in the ocean from bacteria to whales.

However, the complexity of these impacts – to which species have different tolerance levels – makes it incredibly difficult to understand the net risks to individual marine species and ecosystems.

Our new study, published in Nature Climate Change, outlines a new index – the Climate Risk Index for Biodiversity (CRIB) – that assesses the climate risk for nearly 25,000 marine species and their ecosystems.

The findings show that, under very high emissions, almost 90% of these species are put at high or critical risk, with species at risk across 85% of their native areas, on average. However, in an emissions mitigation scenario consistent with the 2C global warming limit in the Paris Agreement, the risk is reduced for virtually all marine species and ecosystems.

Our climate risk assessment can help prioritise vulnerable species and ecosystems and lays the groundwork for supporting climate-smart approaches to conservation.

Climate report card

The “risk” in the CRIB framework is measured as the likelihood that a species will no longer be able to persist in a location where it is currently found.

Using a statistical approach, we essentially created a climate report card for each species and ecosystem that tells us which will be winners or losers under climate change.

Just as a report card grades students on subjects such as maths and science, we used a data-driven approach to score individual species on 12 specific climate risk factors in all parts of the ocean where they live.

The framework is based on an analysis of how the innate characteristics of a species – such as body size and temperature tolerance – interact with past, present, and future climate conditions. You can see these characteristics in section b of the graphic below.

Read the full story with infographics at CarbonBrief here.

Photo by NOAA on Unsplash