Introducing the Ecosystem Integrity Index (EII) by Single.Earth

Scientists agree  — we are now facing the dual crises of biodiversity loss and climate change driven by the unsustainable use of planetary resources. Nature, with all its biodiversity, is an incredibly positive force in our lives. It provides fresh air, clean water, habitat for wildlife, regulation of natural processes, and all the essentials for a healthy living environment (often referred to as ecosystem services). 

“We’re finally acknowledging that nature loss poses direct and immediate risks to the global economy and financial system while also magnifying climate risks,” says Tony Goldner, the Executive Director of the Taskforce on Nature-related Financial Disclosures (TNFD). In response to this growing awareness, a complex landscape of metrics, tools, and frameworks is being developed to assess and monitor biodiversity. Furthermore, a value needs to be assigned to ecosystems and the services they provide to humans.

By developing and introducing a novel methodology for assessing the health of forests — the Ecosystem Integrity Index (EII) — Single.Earth makes a strong contribution to tackling both biodiversity loss and climate change. The approach allows landowners and local communities to pursue a sustainable relationship with nature. In this article, you can find more about the relevance, importance, and concept of EII by Single.Earth. 

Biodiversity loss and climate change: two sides of the same coin

Climate change and biodiversity loss are two of the most pressing environmental issues of our time. Their impacts are far-reaching and interrelated. Warmer temperatures, caused by increasing greenhouse gasses, threaten species’ habitats and reduce the availability of essential resources such as food and water. As habitats are destroyed, species become more vulnerable to disease and extreme weather events, leading to further biodiversity loss. Climate change can also increase the spread of invasive species, which can outcompete native species and further reduce biodiversity.

Although the climate and biodiversity crises are fundamentally connected, they have primarily been addressed independently. Fortunately, there is an increasing recognition that a more integrated global approach is essential. 

“We must look at climate, biodiversity, and also land degradation as one crisis. We can’t look at them separately because the solutions are also connected,”

emphasized Elizabeth Mrema, Executive Secretary of the United Nations Convention on Biological Diversity (CBD) and co-chair of TNFD, at last year’s COP26 climate summit.

Moreover, everything in nature is connected. Analysis shows that passing one tipping point would unfold cascading events, destabilizing everything with a rapid, irreversible, and dangerous domino effect. The world is on the brink of five tipping points with extremely critical states in the loss of biosphere integrity (biodiversity loss and extinctions), biochemical flows, climate change, and land degradation. The latest study on tipping points by Armstrong et al. states that even global warming of 1°C, a threshold that we already have passed, places humankind at daily risk. No one knows precisely when and what will push us over the edge. 

Importance of preserving natural ecosystems and biodiversity

Biodiversity (aka biological diversity) is the variety and variability of life on Earth. We must protect biodiversity as it is essential for our health, well-being, and economy. If an ecosystem is diverse and large enough, it’s more likely to adapt and cope better with threats like pollution, climate change, or human activities. A variety of animals, plants, fungi, and microorganisms make up our natural world. All of these species and organisms work together in various natural ecosystems such as aquatic, terrestrial, tropical, tundra, desert, shrubland, and others. A healthy ecosystem works as an intricate web to maintain balance and support life. 

The health of Earth’s ecosystems is decreasing drastically. According to the Living Planet Report 2022, several species have sharply declined (up to 69%) their populations since 1970 due to threats like habitat loss, barriers to migration routes, pollution, rising temperatures, food production, and more. The abundance of mammals, birds, fish, amphibians, and reptiles is falling fast, as populations of sea lions, sharks, frogs, salmon, and many more species might collapse entirely.

Read more: The biodiversity crisis in numbers – a visual guide by The Guardian

Forests are a key component of natural ecosystems. They host high levels of biodiversity and perform vital ecological functions, including carbon sequestration. Every year, we lose forests about the size of Portugal — that’s a lot. Besides global warming and habitat loss, deforestation also puts food security and the livelihoods of millions of people at risk.

Unfortunately, the world failed to meet any of the Aichi Biodiversity Targets. Set in 2010 by the United Nations, the plan consisted of 20 targets to slow down and eventually stop the decline of species and ecosystems by 2020. Not reaching these targets also threatens progress toward Sustainable Development Goals.

In December 2022, Parties to the UN Convention on Biological Diversity will meet again in Montreal, Canada, to determine the Post-2020 Global Biodiversity Framework. The biodiversity conference, called COP15, is seen as the Paris Agreement equivalent for biodiversity. The stakes are high: will there be an agreement on the requirement for the world to become nature positive by 2030 and reach full recovery of nature by 2050?

Read more: Biodiversity in focus at COP15: halt and reverse nature loss by 2030

Ecosystem integrity — explained by Single.Earth’s science team

Species biodiversity requires ecosystem diversity. Without suitable habitats, species are unable to survive. Thus, measuring biodiversity using a single metric (for example, species richness) will not ensure continued biodiversity and won’t capture the detrimental impacts associated with increases in non-native species. 

According to the Below the Canopy study by WWF, it is important to note that changes in tree cover do not always reflect changes in the populations of animals below the canopy, and that forest area is therefore a poor proxy for assessing global forest biodiversity. A focus on forest area alone neglects the many important factors that determine whether standing forests retain their wildlife or whether newly planted or regenerated forests become rich in biodiversity — restoring trees is important, but alone it is not enough. It is, therefore, essential that the monitoring of forest biodiversity is improved. 

For these reasons, we focus on ecosystem integrity (EI) which is defined by Hansen et al. as “a measure of ecosystem structure, function, and composition relative to the reference state of these components being predominantly determined by the extant climatic–geophysical environment”. 

The approach quantifies ecosystem properties influenced by human pressure and recognizes that ecosystems have a characteristic range of behavior governed by natural disturbance regimes, climate variation, and geodiversity. This is important because this “natural range of variation” (measured with reference to a baseline) is used as a reference state to evaluate whether the EI is declining, increasing, or stable, which is a desirable characteristic for any long-term monitoring.

How do we measure ecosystem structure, function, and composition? That is the focus of our Ecosystem Integrity Index, or EII.

Evaluating forest health with the Ecosystem Integrity Index (EII)

Land use change is one of the main drivers that magnify the climate and biodiversity crises, predominantly affecting forests. This is why Single.Earth starts with forest ecosystems and, most importantly, focuses on the multiple co-benefits provided by nature to people instead of carbon removal only. The EII approach aims to assess the health status of forest ecosystems and monitor changes in forest conditions. In other words, the EII helps to quantify the ecosystem’s health, completeness, and resiliency to natural and human-induced disturbances.

We base our method on the ecosystem integrity concept, which has been proposed in the Post-2020 Global Biodiversity Framework by the Convention on Biological Diversity (CBD) to support global biodiversity monitoring. By combining peer-reviewed models with satellite data, we develop a comprehensive approach that captures ecosystem integrity.  

How does this relate to the MERIT token? The first generation of nature-backed MERIT tokens has been based on the CO₂ flux assessment of a specific land plot. 1 MERIT equals 100 kg of CO₂ removed from the atmosphere. With this new robust estimation of ecosystem integrity (EI), the next-generation MERIT tokens will also represent how healthy an ecosystem is. The implementation timeline is yet to be revealed.

Read more: Single.Earth’s Ecosystem Integrity Approach (PDF)

The Ecosystem Integrity Index, a methodology by Single.Earth has been submitted for publishing in 2023 in Frontiers in Forests and Global Change.  

Key takeaways

Nature provides much more than raw materials and should be valued for biodiversity and vital ecosystem services supporting all life on Earth. Climate change and ecological breakdown (e.g., biodiversity loss, overshooting of ecosystem services, etc.) are significant existential threats placing ecosystems and humankind at daily risk of “tipping over”. 

To achieve global climate and biodiversity goals by 2030, we must assess and value nature as an interlinked ecosystem. Single.Earth’s approach to quantifying ecosystem integrity provides a simple and scalable solution to measure and monitor the conditions of forest ecosystem health from local to global perspectives. 

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