Project Overview

On completion of the GAA1, the ASG established its Red List Authority in 2009 to maintain the amphibian data on the IUCN Red List. With time, it became increasingly difficult to keep up to date with the formidable description rate of amphibian species and the generation of new information.

In response, the ARLA initiated the second Global Amphibian Assessment (GAA2) in 2015. Building on reassessment efforts during 2012-2014, it updated the 6,260 species from the GAA1 and its 2006 and 2008 minor updates, and added 2,000+ first-time assessments for newly described species.


The last of the assessments for the GAA2 were completed in June 2022. The tabular and spatial data of the 8,011 amphibian assessments will soon be available for download. The Red List assessments for all species will be available on the IUCN Red List in December 2023.

The key findings of the GAA2 including calculation of the Red List Index to measure trends in extinction risk were published in Nature: Ongoing declines for the world’s amphibians in the face of emerging threats (Luedtke et al. 2023).

Key results

  • With 41% of assessed species in the Critically Endangered, Endangered, or Vulnerable Red List categories, amphibians continue to be more threatened than birds (13%), mammals (27%), or reptiles (21%).
  • Agriculture is the most common cause of habitat loss and degradation threatening amphibians.
  • Salamanders are the most threatened of the three amphibian orders, with 60% of species in the three threatened Red List categories.
  • The Neotropics, home to almost half of the world’s amphibians, is also the most threatened realm, with 48% of its species in threatened categories.
  • The leading cause of increases in extinction risk in amphibians shifted from disease (chytridiomycosis) during the 1980–2004 period to climate change effects during 2004–2022.
  • Amphibian species are showing signs of recovery in some areas where critical habitat has been protected, but scaled-up investment is urgently needed to reverse current trends.

The State of the World’s Amphibians: The Second Global Amphibian Assessment is a comprehensive synthesis of the current global status of our planet’s amphibians. Following on from the analysis of GAA1 data in the book Threatened Amphibians of the World, this report presents an in-depth of the GAA2 data and details the threats amphibians are currently facing.

Importantly, the report highlights the urgency at which we must now act in order to halt the current extinction crisis. It also identifies opportunities around which coalitions of governments, organizations, and individuals can come together to conserve these amazing creatures and their habitats at scale.