How many years to restore the planet’s ecosystems?

3.9K

Summary

How many years will it take to restore the planet’s ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More? To restore the planet’s ecosystems, we need to rebuild wildlife populations. This is discussed extensively in this blog. This story gives an overview. There are several factors to consider. The first is the rate at which we are currently destroying ecosystems. The second is the rate wildlife can recover. The third is the rate at which stabilisation occurs, which is in the order of thousands of years. The final one is recovery from extinction. But if we reach this point, we probably won’t be around to worry about it.

• We are facing ecosystem collapse within 30 years.
• We can restore important ecosystem processes within 3-20 years.
• We may need 100 years to fully rebuild wildlife populations.
• We may need a further 10,000 years to fully restabilise ecosystems.
• We may need 10 million years if we allow 30% of animals to go extinct.

This is our first deadline:

• DEADLINE #1: We have about 30 years to be making considerable progress.
• The decisions we make in the next decade will be critical!

How long does it take to restore ecosystems?

Think in terms of the following three recovery factors that operate at different scales. As you move down the list, the time to recreate a habitable Earth increases from decades to millions of years:

1. 🐅 Species recovery (decades): The rate at which a non-extinct species can breed to recover its population. This is based around simpler biology and habitat availability.
2. 🌳 Ecosystem recovery (tens of thousands of years): The rate at which connectivity of species with the environment can be developed. This delivers human life support and requires behavioural and cultural selection, on top of genetic traits.
3. ❌ Extinction recovery (millions of years): The rate at which species can be recreated by nature through natural selectionDarwin’s theory how species are formed, where those that stand in closest competition with those undergoing beneficial modification and improvement, will go extinct faster. Natural selection is by survival of the likeliest, not survival of the fittest. The fittest are only likely to survive because they happen to be most suited to the environment into which they are born. The More.

🐅 Species recovery

This is the time it takes for an animal to reach original numbers based on their biology and dispersal. It is constrained by the amount of available habitat and how fragmented that has become. Animals can breed very fast and recover in relatively unspoilt habitat, because they already have the cultural connection. It’s like moving into a fully-furnished housing estate.

We know animals can recover their populations quite fast if we remove the threats that are causing their decline. Whaling of Humpback Whales off Australia stopped in 1963. They may have just reached pre-whaling numbers now, after about 60 years. Poisoning had relegated UK Red Kites to a few remote valleys in Wales by the 1990s. After reintroduction into satellite sites in Britain, the species numbers increased and spread. The graph below shows the data up to 2004 but there are probably 1,800 pairs now.

Recovery of land-based species will never be back to pre-industrial levels, because of permanent loss of habitat. We’ve converted most precious living space (particularly in the northern hemisphere) into cities, forestry and farmland. Humpback Whales were a victim of hunting. Though, apart from climate and fishing pressures, the ocean environment has remained relatively intact during their recovery.

Recreating habitat means literally rebuilding and furnishing the housing estate. It’s not enough just to have one animal, you have to have all the infrastructure. This means every animal from microbes to insects, birds and mammals, all need to be operating together.

Isabella Tree in Wilding talks about the years it has taken to rebuild Turtle Dove numbers, after revegetation. Recently it’s taken eight years to double numbers. I reckon it can take twice as long if the habitat needs restoring as well. If the UK commits to rewilding Britain as a whole, 120 years might be needed to get this species back to pre-war levels.

• DEADLINE #2: It will take at least 100 years to recover wildlife populations, if we placed an immediate ban on direct killing, protected all remaining existing habitat and restored damaged habitat.

🌳 Ecosystem recovery

We’ve lost 83% of all mammals on Earth (68% of all animals) in the last 50 years. By that I mean individual creatures, not species. The processes these animals drive are infinitely complex and it’s that ecosystem structure that takes longer to restabilise.

Animals aren’t just there to look pretty. They are a mechanism for everything from food security, to climate, fresh water and fisheries. What we should be doing, is prioritising the rapid re-expansion of the commonest species while rebuilding capacity for the rarest. At the moment, we do the opposite, we try to retain and rebuild the rarest while allowing the commonest to slip further towards extinction.

I just wrote this response to a piece on Reddit about de-extinction of the Passenger Pigeon in the US. Scientists are talking about genetically engineering the species and breeding it back into existence. The problem I can see, is they haven’t considered that genetics is only a tiny fraction of the process needed for a species to form a connection to the environment:

The Passenger Pigeon De-extinction Project

A plan for restoring flocks of Passenger Pigeons and stimulating cycles of regeneration to make forests more productive and diverse. /r/megafaunarewilding

A. It’s exciting but perhaps I am a little cynical. I reckon it takes 10,000-25,000 years for wild animal populations to fully develop cultural connection to ecosystems. EntropyThe degree of disorder or chaos in a system, most often used to describe thermodynamic energy but also used the behaviour of information. All else being equal, physics determines that all matter and energy moves towards chaos, therefore biological systems are in a continual state of battling against entropic forces in order to remain stable. The most stable ecosystem is More processes are both barriers and enablers of ecosystem function(Of an ecosystem). A subset of ecosystem processes and structures, where the ecosystem does something that provides an ecosystem service of value to people. More and animals are inherently tied to those systems. So introducing a new species (any species) will result in an uncertain outcome due to hysteresis principles. I think it’s more likely, if this is successful, that they’ll end up with another species that has no more or less chance of survival than any other existing endangered species and will develop a new ecology of its own, which is entirely unpredictable due to the complex nature of ecosystems. Which does rather beg the question, if it’s better to focus on recovery of extant and declining species that already retain some cultural normality. The ecosystem science aspects of these proposals always seem to be omitted in favour of genetics which only really encode for basic function but not biodiversityWhat is the definition of biodiversity? When we ask, what is the definition of biodiversity? It depends on what we want to do with it. The term is widely and commonly misused, leading to significant misinterpretation of the importance of how animals function on Earth and why they matter a great deal, to human survival. Here I will try to More outcomes - they are driven by thermodynamicsThermodynamics are at the heart of our understanding of ecosystems and not an altogether difficult concept to grasp but one that isn't widely taught to ecologists. Basically, all life on Earth, is derived from the Sun's heat. This renewable energy source constantly bombards ecosystems with energy but they would overheat, if it wasn't for the absorptive capacity of food webs. More and natural selection and cannot be engineered.  SM.

The cultural component to restore ecosystems

When Aboriginal Australians settled the continent of Sahul, we know they altered the landscape from heavily forested and megafauna-dominated to grassy woodland. It dried the continent and most megafaunaThe largest animals that represent the top of the trophic pyramid. These are the final building blocks in ecosystem structures for maximum entropy production. Megafauna can be measured at any spatial scale. The largest animal that ever lived on Earth is the Blue Whale. In a grassland, spiders could be considered megafauna The term is generally reserved for animals larger More went extinct after about 25,000 years. That’s evidence that it could take 25,000 years to recreate habitable ecosystems after you’ve completely altered them.

This is because animals have to settle into patterns, cultures and routines … it’s a very complex system and it depends on natural selection, not simply of the single species’ genetics but also the extensions of behaviour and the inter-related genetics of all the plants and other animals that cooperate in the system, to stabilise it. Each animal has to rebuild the environment to suit itself and it doesn’t reach a steady state until everything has settled into place.

When Aboriginal Australians did this, wildlife was abundant world-wide. Unfortunately, we have little excess resilienceReferring to an ecosystem’s ability to maintain a steady stable-state. The need to build resilience is entirely anthropocentric and symptomatic of ecosystems that are damaged or declining, leading to loss of ecosystem services on which humans depend. More or redundancy left in the biosphere to absorb the consequences of further change. We’ve killed most of the world’s animals, so habitat change is global, and there is no Planet 2.0 to take up the strain. This is why eco-engineering projects are questionable. Each time we do that, we reset the animal impactWhat is Animal Impact? Without wildlife, Earth would not be habitable for humans, because it's animals that stabilise ecosystems. It’s a fundamental law of nature that animals (and humans) exist because we are the most likely lifeforms to minimise environmental chaos. Animal impact, therefore, is a measure of how much all wildlife is collectively responsible for creating a habitable Earth. The More and this puts the biosphere under greater duress.

Also read: Will regreening deserts work to address climate change and famine?

• CONCLUSION It will take 10,000 years to recover ecosystems to a state where we can stop investing in cooperative management of ecosystems. In other words, for the foreseeable future of all civilisation, we are going to have to be carefully and precisely protecting wildlife.

❌ Extinction recovery

This is the slowest of all. It can only be replaced via evolution (creation through natural selection of new genetic traits).

Based on current extinction rates, we are heading for a mass extinctionAnimal life hasn't existed for very long on planet Earth. In the last 500 million years, there have been five mass extinctions, defined as events that wiped out at least 75% of animal life. The Devonian mass extinction is considered to have been caused by the rise of plants on land, which polluted the oceans in the absence of animals. More within 240 – 500 years. To put that into context, the next fastest mass extinction took 60,000 years. The magic number of years for ecosystems to become resaturated by animals is about 30 million. But let’s say we manage to avoid the worst catastrophe.

A quarter of the world’s animals are already threatened with extinction. In a scenario where 30% go extinct, to restabilise a habitable world might take 10 million years or more.

Of course we can argue the accuracy of all these figures. But because we’re talking several orders of magnitude change in the risk profile at each step, it hardly makes any difference.

• CONCLUSION It could take 10 million years to recover, if we delay reversing global wildlife extinctions to the point that a third of all animals go extinct.

What are our prospects of restoring ecosystems?

How many years will it take to restore the planet’s ecosystems? The answer is, an increasing amount of time, the longer we leave it. The good news is that we are changing the narrative quite quickly. Reframing the story to be about why conservationWhy is animal conservation important? Animal conservation is important, because animals are the only mechanism to create biodiversity, which is the mechanism that creates a habitable planet for humans. Without animals, the energy from today’s plants (algae, trees, flowers etc) will eventually reach the atmosphere and ocean, much of it as carbon. The quantity of this plant-based waste is so More is essential to human survival is the only one that makes sense. We need a change in human values. This is why it’s essential every voice is heard, because it’s all our futures that depend on building a world rich with an abundance of wildlife.

Spotlight

They also say that extinction is strongly ‘shaped’ by climate change. This is true but scientists rarely mention that climate change has never been the cause of mass extinctions. Climate change is a symptom of biodiversity loss and accelerates the process of extinction. It’s still loss of animals today that is driving destabilization, leading to risk of recovery taking millions of years. Unless this gets mentioned, we risk continuing to think we can solve climate problems by minimizing carbon whereas loss of animal impact is the greater problem. Image thumbnail  European Space Agency, CC BY-SA

---