Biosphere integrity: it underpins our survival

know your planetary boundaries: biosphere integrity 1/10

Do you know the boundaries of the planet we call “home”?

In the mid-2000s, a team of scientists united behind a single goal: define Earth’s boundaries for a “safe operating space for humanity”. They identified nine key Earth system processes that keep the atmosphere, oceans, and ecosystems in balance. One of these processes is the integrity of the Earth’s biosphere, which underpins our ability to thrive. The integrity of the biosphere rests on the functional integrity of ecosystems and the genetic diversity within and between the species living in them.

In this post, which is the second in the series “Know your planetary boundaries”, we’ll discuss what the biosphere integrity planetary boundary transgression means for the living biosphere and if and how we can return to a safe state. But before we go there, know there is much more to this topic; check out our previous posts for a short overview of all planetary boundaries, the previous one on climate change, and more information on climate tipping points & feedback loops and the human climate niche.

The loss of biosphere integrity

Since the late 19th century, the Earth’s biosphere has experienced a rapid loss of integrity due to the expansion of agriculture into ecosystems, our direct exploitation of organisms, the introduction of non-native species in the environment, and anthropogenic climate change and pollution. But these issues are just the symptoms of the underlying problem: people’s disconnect with nature and the insufficient recognition of its importance.

And now, after decades of human-driven environmental degradation and careless disregard for the environment, Earth’s biosphere can no longer meet our demands. Scientists now fear that the ongoing degradation of ecosystems and the rapid loss of biodiversity could disrupt the functions and services we all depend on.

The functions provided are vital for the survival of all living species on Earth. While all species contribute and depend on the functionalities provided by ecosystems, these functionalities are often referred to as Nature’s Contributions to People (NCP).

Resilient ecosystems reduce the impacts of natural disasters and regulate the climate, nutrients, and air and freshwater quality. They provide and maintain habitats, pollination and seed distribution, manage diseases and various biological functions, and maintain the overall balance. Nature underpins all dimensions of human and planetary health, generates ecosystem services, such as food, fibre and medicine, and contributes to non-material aspects of quality of life.

What is functional integrity and genetic diversity?

Functional integrity refers to the ability of an ecosystem to maintain species interactions that support ecosystem functions necessary for generating ecosystem services. Human activities significantly disrupt ecosystems through agriculture, grazing and forestry, limiting the available natural carbon for consumption by other organisms.

Studies suggest that we can only safely harvest, alter or eliminate 10% of the annually generated carbon, also known as the biosphere’s net primary production (NPP). With an annual NPP loss of 30%, we consume much more resources than Earth’s ecosystems can replenish, placing us far beyond the safe operating space.

The ability of ecosystems to persist under and adapt to change is primarily determined by their genetic diversity. But, with the growing pressure on ecosystems to continuously supply us with food, water, land and energy, the genetic diversity within and between species and ecosystems is rapidly declining, resulting in biodiversity loss and increased species extinction.

The current rate of 100 extinctions per million species per year (E/MSY) is much higher than the rate at which new species evolve. While the safe boundary is set at 10 E/MSY, the current rate is expected to increase tenfold by the end of this century. This is precisely why scientists argue that we are in the midst of a 6th mass extinction – and this one is human-driven.

Restoration is key

Biodiversity is one of the pillars supporting the biosphere, and by transgressing the boundaries, we directly threaten our own survival. Insects play a vital role in recycling nutrients, maintaining healthy soils, and pollinating crops, which are essential for the global food system. However, the expansion of intensive monoculture agriculture, excessive use of pesticides, and ecosystem fragmentation have led to a significant decline in insect populations. Essentially, the way we produce food is wiping out the very thing our food production relies on.

But not all is lost. By restoring 15% of the converted lands – or 30% of all degraded lands – we can conserve at least 80% of species, avoid 60% of expected species extinction, sequester 30% of the total CO2 increase since the Industrial Revolution, and move us back towards the safe operating space.

Studies suggest that 40% of the world’s ice-free land area has insufficient functional integrity and shows symptoms of resilience loss, reducing the ability to cope with natural disasters and pollution. Because most functions are provided or supported by insects with limited mobility, it is suggested that at least 20-25% per km2 of human-dominated land – this includes cities – needs to be covered by natural area. Doing so would significantly improve microclimate, water management, air quality, and health.

Getting us back into the safe operating space

Our global food system is the primary driver of the transgression of the biosphere boundaries. Studies suggest that it’s possible to feed a population of 10 billion people and stay within the planetary boundaries, but this will require us to halt the expansion of animal agriculture, protect and quickly restore land, treat agricultural lands as agroecosystems, work towards land management systems that work with nature instead of against it, reduce food waste throughout the production and supply chain, and a transition to plant-based food sources.

Such a transition would not only reverse the damage to ecosystems and halt biodiversity loss but also get the biosphere, climate, land, freshwater, and nutrients back towards the safe operating space.

We could discuss much more, but this is all we could fit into a single Instagram carousel. Have you seen it already? Scroll through our slider below, and let us know what you think through one of our social channels – we like to hear from you!

Next up is the planetary boundary land-system change!

Elise & Joy

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