As the climate crisis is accelerating, and the effects of greenhouse gases are becoming more visible, you might have come across the term tipping points.
The term tipping point is by no means exclusive to sustainability. It’s a phenomenon known in many fields, said to have originated in the field of epidemiology when an infectious disease reaches a point beyond any local ability to control it from spreading more widely.
In fact, “Tipping Point” is also a British gameshow, as well as an experimental jazz band. But for our jargon buster, we’ll leave infectuous disesase, the tv-show and jazz band aside and stick with tipping points in the climate and in society.
The idea behind tipping points is that drastic change happens at one particular point. It’s a threshold, a critical moment when a seemingly minor change makes all the difference.
It can be hard to wrap our brain around this, because it’s not intuitive, and we think that change happens slowly and in a linear way. And to an extent, it does. But we’ve all experienced tipping points in our life. If not, try this little experiment at home: get yourself some strawberries (almost in season!) and whip up some fresh cream.
Put liquid cream in the mixer, and the air will shake the molecules around and stiffens it into whipped cream. If you look away for a moment and turns a bit too thick for your liking, just pour in some more liquid and you should be able to fix it. But, look away for too long, and you’ll end up with butter. Yep.
Without getting too sciency (you can do that here if you’re curious) the same action (whipping) caused a shift in the structure of the system (the molecules). You’ve passed a tipping point. And no matter what you do – you can’t turn butter back into cream.
Tipping Points in the Climate
At the moment, we mostly experience the impact of global warming as gradual changes.
A few extra hot days in summer, some Arctic sea ice melting and severe droughts that somehow, barely even make the news. These are all effects of global warming, but unfortunately, for many people, it doesn’t feel like a state of alarm.
But several parts of our Earth system are like the cream. (yeah, ok, that does sound a bit weird) These parts of the system have tipping points, and thus the potential to change abruptly in response to warming.
Three Groups of Tipping Points
There are roughly three main groups of tipping elements:
As we briefly mentioned in a previous Jargon Buster, white surfaces, like ice, reflect solar radiation back into the atmosphere. When the ice melts, the darker surface underneath is exposed, and more heat is absorbed which will then accelerate the melting of the remaining ice.
The melting of large ice sheets such as the Greenland and the West Antarctic lead to rising sea levels, by several meters over time.
Last but not least, about 25% of the northern hemisphere has a layer of permafrost, or frozen soil. In the arctic, the ground has been frozen for centuries or even millennia. Scientists estimate it stores hundreds of billions of tons of carbon and methane, which would be released if the soil starts to defrost.
The reason we have different weather patterns is because of circulation. This is caused by the rotation of the Earth and the amount of heat different parts of the Earth receive. This heat is transported around the world via wind and ocean in specific patterns.
As the oceans are warming up and are diluted with fresh melting water, these patterns change, leading to different general weather conditions as well as more and longer periods of extreme weather like heat waves, floods and droughts.
Forests as well as ocean life play a key role in keeping our planet healthy.
They absorb carbon dioxide, help stabilize Earth’s climate and of course they are the home of a great diversity of plants and animals. And rainforests for instance also help maintain the world’s water cycle.
The coniferous forests of the nordic regions represent 30% of the global forest area, and the Amazon accounts for more than half of the world’s rainforest cover. But deforestation and climate change are destabilizing them.
Losing these forests would not only mean a destruction of habitats for animals and plants, but also massive release of carbon dioxide. For the Amazon, one estimated tipping point is 40% deforestation, after which the shift from rainforest to savannah becomes unstoppable.
The Intergovernmental Panel on Climate Change (IPCC) introduced the idea of tipping points two decades ago. Back then, it was considered unlikely we would tip any scales until about 5 degrees of warming. But now, IPCC suggests this could happen even in the 1° – 2° warming scenario.
To put that a bit more into perspective, with the current pledges around reducing greenhouse gas emissions, the recent UNEP report “Making Peace with Nature’ suggests we’ll probably hit 1.5° by 2040, and 3° by 2100.
And where researchers previously considered the tipping points to be independent, a growing concern is the cascade, or domino effect where one element reaching a tipping point will accelerate others as well.
So if we keep looking away for too long, well, let’s say it won’t be butter.
Tipping Points for good?
So is it all doom and gloom? Fortunately not! Research from the University of Exeter identified positive tipping points that could help cut carbon emissions rapidly, such as production cost and adoption of electric vehicles as well as around the decarbonization and shift to renewable energy in the power sector.
In light of that, another definition of a tipping point comes from Malcolm Gladwell:
“That magic moment when an idea, trend, or social behaviour crosses a threshold, tips, and spreads like wildfire.”Malcolm Gladwell
We’ll dive into that a bit more next week. In the meantime, what do you think?
When it comes to sustainability, how much longer is it going to take?
Or in other words…
Minou & Pamela