Wylder Earth

Brace yourself because this makes for some tough reading. Key earth systems are at risk of collapse – they’re close to tipping point. We’re reliant on these systems: without them, the stability of our societies is threatened. Conversely, there are some encouraging positive tipping points which are moving things swiftly in the right direction in some areas. This post is based on the Global Tipping Points report.

So what is a tipping point?

A tipping point is typically the abrupt change of a system from one state of stability to another state of stability. A key factor is that the change in the system becomes self-perpetuating – it passes beyond a threshold which makes that change inevitable.

I used to be a teacher. So imagine this. Billy is bored. He starts rocking back on his chair. Now, Tilly next to him is sitting still. All four legs of her chair are on the floor. Her chair is in a stable state. Billy’s chair is getting less and less stable by the second. He’s rocking back and forth. Only two chair legs on the ground. Now only one as he pushes right back and makes his chair spin a little. Billy seems to have forgotten that he’s sitting on his chair. He’s dependent on it for his own stability and safety. And no matter how many times I tell him, he could fall and hurt himself, he won’t listen. He’s scratching his nose with his middle finger and laughing to himself.

Bang! Billy’s but hits the floor. His head follows. Thwack!

His chair has abruptly moved from one steady state to another – tipped over on the floor. There was a point at which this change became self-perpetuating.

And Billy – who depended on his chair for safety – is now sprawled on the floor, rubbing his head and looking a bit shocked, confused and – most of all – embarrassed.

Tilly looks down at him and offers him her hand. ‘You all right there, Billy?’

‘Yeah, I’m fine,’ he replies. ‘Why wouldn’t I be?’

So just like Billy, we rely on a set of systems (chair legs) for our safety and stability. We rely on planetary systems to provide water, a stable climate, oxygen, conditions to grow crops, to live safely and to enjoy our lives with our families. The above figure illustrates which parts of the earth’s systems are most at risk: coral reefs; parts of the cryosphere – the frozen landscapes of world (Greenland, West Antarctic and the permafrost which wraps around the North of the planet); and the subpolar gyre (SPG), the circulation of ocean currents in the North Atlantic. Other key parts of the system are also at risk: the Amazon rainforest, mangroves, seagrass meadows, fisheries.

So why does this matter?

The key point with tipping points is this: the change is abrupt and/ or irreversible. Billy was totally confident in his capacity to maintain his chair’s state of equilibrium – until he found himself on the floor rubbing his head and nursing his ego. But Billy can get up, pick his chair up and set it back to its former stable state – all four legs on the floor. We can’t do that. Once the permafrost has gone, we can’t refreeze it. Once the complex, biodiverse system of the Amazon rainforest has gone, it can’t be replaced – at least not in our lifetime.

Many of us are detached from nature. We may live in cities and only ever visit the coast or countryside a couple of weeks of the year to go on holiday. Many people will never have visited a farm. So it’s easy to be complacent and think – coral reefs are pretty but we can live without them; the Amazon rainforest is a great primary school project – but do we really need it?

But collectively these natural systems underpin our lives – our health, our culture, our economies, our food production. Their loss – or even disruption -will have severe impacts for us all. Coral reefs are incredibly productive areas of the ocean and support fisheries which 500 million people depend on for their livelihoods. They also provide protection against storm surges for coastal communities. Amazon dieback will have significant implications for the regional and global climate, and could cost between US$1-3.5 trillion in economic damages. Antarctic ice sheet instability may lead to a sea level rise of two metres by 2100 exposing 480 million people to annual coastal flooding events. An AMOC (Atlantic Meridional Overturning Circulation) collapse could trigger something like the transition to the ‘little ice age’ in Europe and could substantially reduce crop productivity across large areas of the world, with profound implications for food security. Similarly, disrupting monsoon systems will have severe implications on agriculture in Asia. Just like Billy’s chair – these systems keep us stable. They are our life-support systems.

Positive Tipping Points

The good news is there are also positive tipping points. These are places we can intervene in the system to fast track behavioural change. This is where we need to focus our energy to avert catastrophic impacts.

Positive tipping points don’t just happen, they need strategic, co-ordinated intervention to take place. This might be technological innovation, policy intervention or financial investment. Together these factors create enabling conditions which create momentum, driving change in the right direction – towards a safe and just world. For example, market forces mean that new, more sustainable products and technologies become cheaper as more people adopt them. There is also ‘social contagion’ – when you see someone else adopt a new technology or behaviour, you are more likely to adopt it yourself. Positive tipping points are starting to occur in energy systems and in the electric vehicle markets, but they are yet to occur at scale in the food system.

The move towards a positive tipping point typically passes through three phases: enabling, accelerating and stabilising. There are three key ways to intervene in the system to change it: create enabling conditions; increase reinforcing feedbacks (or reduce the dampening feedbacks); attempt to trigger the positive tipping point. Once you cross that tipping point, the system accelerates towards a positive, desirable outcome, before restabilising in a qualitatively different state. The primary characteristic of a tipping point is a shift in the balance of feedbacks, so that a different mode of operating becomes preferable. The old paradigm no longer makes sense.

Global Tipping Points is led by Professor Tim Lenton from the University of Exeter’s Global Systems Institute with the support of more than 200 researchers from over 90 organisations in 26 countries. You can listen to Tim explaining tipping points in more detail here: On the edge: Why everyone needs to talk about planetary tipping points | The Straits Times