Statement of World Aquatic Scientific Societies on the Need to Take Urgent Action against Human-Caused Climate Change, Based on Scientific Evidence

The Institute joins with over 100 world societies to call on world leaders at COP26 to take urgent action to protect aquatic systems from human induced climate change

Water is the most important natural resource on Earth as it is vital for life. Aquatic ecosystems, fresh- water or marine, provide multiple benefits to human society, such as provisioning of oxygen, food, drinking water, and genetic resources; regulation of atmospheric composition and climate; water pu- rification; storm buffering; mitigation of floods/droughts; recreation areas; and other purposes. Our existence and well-being depend on the health and well-functioning of aquatic ecosystems. People naturally distribute around water—approximately 40% of the world’s population lives within 100 km (62 mi) of a coast.

The world’s aquatic resources are now under their greatest threat in human history. Human-caused climate change is accelerating the degradation of aquatic ecosystems and the services they provide. Aquat- ic ecosystems are among the most affected worldwide (e.g., in case of freshwater ecosystems, one measure of biodiversity, the freshwater living planet index for species populations, declined 83% from 1970 to 2014, while up to 90% of coral reefs will disappear by mid-century if the current trends continue).

We, the world’s aquatic scientists, spend our lives studying these systems. We see exceptional and disturbing changes in the world’s aquatic ecosystems due to climate change and believe that we must continue to share peer-reviewed scientific findings with the public and policymakers to emphasize the seriousness of this threat and the need for immediate action. For the first time, the assessment of global risks conducted by the World Economic Forum ranked the impact of “climate action failure,” “biodiversity loss,” and “water crisis” among the top five risks over the next decade.3 In recent years, migration has increased and geopolitical tensions have been exacerbated: between 2008 and 2016, more than 20 million people per year have been forced to move due to extreme weather events, while according to the United Nations, in 2017, water was a major conflict factor in 45 countries.3 These negative effects are expected to increase under current climatic trends. For example, in the United States, the climate-related economic damage is estimated to reach 10% of the gross domestic product by the end of the century.3 In Europe, the minimum cost of not adapting to climate change is estimat- ed at €100 billion per year in 2020 and €250 billion in 2050.4

Experts in environmental, social, and economic fields collectively point towards a severe envi- ronmental and humanitarian crisis, with repercussions at a global level, unless worldwide concerted climate actions are implemented urgently.

This document summarizes key scientific findings highlighting the effect of climate changes on aquatic ecosystems. These findings provide evidence of what effects are currently happening and why world policymakers and all of humankind need to act jointly and launch concerted actions now if they wish to mitigate these impacts.

Read the full statement below