Latest news with #tippingpoints
The Guardian
a day ago
- Science
- The Guardian
‘Positive cascades could help accelerate change': social tipping points expert on fixing climate crisis
Timothy Lenton is a professor of climate change and Earth system science at the University of Exeter. He started working on tipping points in the 1990s, making him one of the first scientists in the world to study this form of planetary risk. In an upcoming book, Positive Tipping Points: How to Fix the Climate Crisis, he argues the Earth has entered an 'unstable period' but humanity can still prevail if we can trigger positive social and economic tipping points to reverse the damage that has already been done. On 30 June, he will host a global conference on tipping points. How do you define a tipping point?A tipping point is where change becomes self-propelling within a system, meaning it will shift from one state to another. That can happen because the balance of feedback in the system switches from damping feedback to amplifying feedback. The result can look very rapid and irreversible. How has our understanding of these risks changed?We first published a map of climate tipping elements in 2008, Since then, we have added much more than we have subtracted from that map. And, unfortunately, in the intervening 17 years, the evidence suggests we're much closer to some of these tipping points than we thought. Which tipping points might we have passed?Things are undoubtedly happening faster than anticipated. The tipping points of greatest concern include the West Antarctic ice sheet, where the loss of a significant chunk of the ice sheet is self-propelling, which could raise the world's sea levels by about 1.2 metres. There is also the Greenland ice sheet, which is losing mass at an accelerating rate. Then we have the permafrost, parts of which are already passing localised tipping points – and that's adding methane and carbon dioxide to the atmosphere. Then there's the unprecedented bleaching and dieback of coral reefs, which hundreds of millions of people depend on for their livelihoods. And which are close?There's a tipping point in the circulation of the north Atlantic Ocean, when deep water stops forming in the middle of the subpolar gyre south-west of Greenland. That system seems quite volatile, and a tipping point there is like a small version of a bigger tipping point of the Atlantic meridional overturning circulation (Amoc), which studies suggest is at much greater risk than we thought even a few years ago. That in turn could trigger monsoon tipping points in west Africa and India. I'd also note the risk of tipping Amazon rainforest dieback from a mixture of climate change and direct human disruption. Unfortunately, I could reel off quite a few more. How accurate are the predictions?If anything, we have underestimated the risks. When we did our first assessment in 2008, we thought Greenland was close to a big tipping point. We haven't changed that judgment, but we thought West Antarctica would need at least 3C of warming [above pre-industrial levels]. Unfortunately, everything that's been observed since suggests we were way too optimistic. As a rule, the more we learn, the closer we think the tipping points are – and meanwhile we've been warming the planet up. It's like running faster into a sea that is rising to drown us. Why has it taken so long for the world to talk about these catastrophic threats?In the climate science community, we have tended to concentrate on assessing what's the most likely thing to happen, but the more important question is: what's the worst thing that could happen? That's the difference between a scientific assessment and a risk assessment. I would argue we've not been treating climate change as a risk assessment. That is also because a lot of well-funded entities have been systematically undermining the knowledge consensus on climate change, which has forced the scientific community to defend what's in effect 19th-century physics. That hasn't put us in a great position to emphasise tipping point risks, which inherently have more uncertainty around them. Why do we need to talk about them now?Because tipping point risks are real and potentially existential. If we have a tipping point in the Atlantic Ocean – the so-called Amoc – we could lose more than half the area for growing staple crops worldwide. It would cause water security crises and severely disrupt the monsoons in west Africa and India, which would affect billions of people. We have to level up to those risks, better understand them and how close they are, and what things we can do in response. Even if we can't stop the events happening, we can do things that reduce the vulnerability of people exposed to the risks. That is why we are drawing attention to tipping points. This is not as a council of despair; on the contrary, it is more like a council of practicality. In terms of the upfront costs to decarbonise the global economy, it is a great investment for the return you get, which is lowering the risk of otherwise catastrophic outcomes. It would help if the IPCC [the United Nations Intergovernmental Panel on Climate Change] took a more in-depth look at tipping points. A large number of countries wanted to see an IPCC special report on tipping points in this assessment cycle, but the IPCC said no. Instead there's due to be a chapter in the next assessment report. Is there an alternative?Yes. I and more than 200 other researchers have published a global tipping points report, and we're writing another one for Cop30, [the UN climate change summit which takes place in Brazil, in November]. We felt the risk was important to communicate and this is a timely moment. So we are trying to fill in the assessment gap in an accessible way. People are crying out for that. I understand the global tipping points conference will also look at positive tipping points in technology, economics and politics?Yes. [There are some] more optimistic scenarios; the impacts of wind power and photovoltaic innovation, or the knock-on effects of campaigning by Greta Thunberg and others. There are also policy feedbacks that could create a change in the landscape in a good way, where you start a policy path towards the renewable energy revolution that's very hard to reverse. That is arguably what the architects of the German feed-in tariffs for renewables managed to do. They made it hard for the doubters to change course even after a change of government. Has renewable energy reached a positive tipping point?Yes, our analysis suggests that solar photovoltaic power is now in a phase of self-propelling global uptake with exponential growth of installed generating capacity, doubling every two years or less. Factoring in the cost of battery storage, solar is already the cheapest source of new power in most of the world, and for every doubling of installed capacity its price drops by nearly a quarter. This is rapidly making solar power the cheapest source of electricity ever, which brings many benefits, including access to electricity for the roughly 700 million people who don't currently have it. And electric vehicles?Yes, the price of batteries plummeted nearly tenfold in a decade as the range you can get from a given mass of battery increased by nearly a factor of three. This has brought China and several European markets to the tipping point where adoption of EVs is self-propelling: the more EVs that get bought, the better and the cheaper they get, encouraging further adoption. The US is lagging behind, but the global south is starting to reap the benefits of electrifying mobility, as it is much cheaper to run an electric rickshaw in India or an electric motorbike taxi in east Africa than their fossil-fuelled equivalents. Any other examples of potential positive tipping points?I'm working on regenerative nature. We already see cases where degraded ecosystems have been tipped back into a better state – for example, when wolves were reintroduced to Yellowstone National Park and started preying on elk, it triggered abrupt vegetation recovery, or when sea otters returned to north Pacific coastal ecosystems and started feasting on sea urchins it tipped the recovery of kelp forests. We also see social tipping points that are nature-positive, where community conservation initiatives, like locally managed marine protected areas, spread rapidly and widely among and across societies. Can you explain cascading feedbacks?In all complex systems – such as the climate and the economy – if you can tip one thing, it can have consequences for other bits of the system. If you tip one part of the system it can make tipping another part of the system more likely. For example, if you've suffered a medical shock it can have knock-on effects on other parts of the body. In the climate, these causal connections can be quite significant and strong. In Earth's history, when there were tipping points in the overturning circulation of the Atlantic Ocean, that tipped major shifts in the tropical monsoons of west Africa and India. In the economy, a cascade can be more positive. For example, an investment in renewable energy can bring forward a tipping point in other sectors. It basically means renewables are making electricity cheaper than it has ever been, and that incentivises electrifying mobility, like cars and trucks and buses, or electrifying heating in homes. At the same time, batteries get cheaper because of economies of scale, which then helps to balance renewable electricity supply and demand. So feedbacks between sectors of the economy can create tipping points that reinforce each other. We've recently mapped out a bunch of positive tipping cascades that could help accelerate change to zero greenhouse gas emissions. What should the world do at Cop30 in Belém to address tipping points?We need policymakers to implement policies that bring forward the positive tipping points we need to stop greenhouse gas emissions and prevent the bad climate tipping points. If the EU and China were to coordinate, it could be enough to shift the balance towards clean green alternatives. Even with Trump in the United States, the beauty of tipping points is you don't need everybody, you typically only need a fifth to tip to the new alternative and then you get to a situation where everybody else is compelled to follow. Tipping points – in the Amazon, Antarctic, coral reefs and more – could cause fundamental parts of the Earth system to change dramatically, irreversibly and with devastating effects. Here, we ask the experts about the latest science – and how it makes them feel. Read more
The Guardian
a day ago
- Science
- The Guardian
‘Positive cascades could help accelerate change': social tipping points expert on fixing climate crisis
Timothy Lenton is a professor of climate change and Earth system science at the University of Exeter. He started working on tipping points in the 1990s, making him one of the first scientists in the world to study this form of planetary risk. In an upcoming book, Positive Tipping Points: How to Fix the Climate Crisis, he argues the Earth has entered an 'unstable period' but humanity can still prevail if we can trigger positive social and economic tipping points to reverse the damage that has already been done. On 30 June, he will host a global conference on tipping points. How do you define a tipping point?A tipping point is where change becomes self-propelling within a system, meaning it will shift from one state to another. That can happen because the balance of feedback in the system switches from damping feedback to amplifying feedback. The result can look very rapid and irreversible. How has our understanding of these risks changed?We first published a map of climate tipping elements in 2008, Since then, we have added much more than we have subtracted from that map. And, unfortunately, in the intervening 17 years, the evidence suggests we're much closer to some of these tipping points than we thought. Which tipping points might we have passed?Things are undoubtedly happening faster than anticipated. The tipping points of greatest concern include the West Antarctic ice sheet, where the loss of a significant chunk of the ice sheet is self-propelling, which could raise the world's sea levels by about 1.2 metres. There is also the Greenland ice sheet, which is losing mass at an accelerating rate. Then we have the permafrost, parts of which are already passing localised tipping points – and that's adding methane and carbon dioxide to the atmosphere. Then there's the unprecedented bleaching and dieback of coral reefs, which hundreds of millions of people depend on for their livelihoods. And which are close?There's a tipping point in the circulation of the north Atlantic Ocean, when deep water stops forming in the middle of the subpolar gyre south-west of Greenland. That system seems quite volatile, and a tipping point there is like a small version of a bigger tipping point of the Atlantic meridional overturning circulation (Amoc), which studies suggest is at much greater risk than we thought even a few years ago. That in turn could trigger monsoon tipping points in west Africa and India. I'd also note the risk of tipping Amazon rainforest dieback from a mixture of climate change and direct human disruption. Unfortunately, I could reel off quite a few more. How accurate are the predictions?If anything, we have underestimated the risks. When we did our first assessment in 2008, we thought Greenland was close to a big tipping point. We haven't changed that judgment, but we thought West Antarctica would need at least 3C of warming [above pre-industrial levels]. Unfortunately, everything that's been observed since suggests we were way too optimistic. As a rule, the more we learn, the closer we think the tipping points are – and meanwhile we've been warming the planet up. It's like running faster into a sea that is rising to drown us. Why has it taken so long for the world to talk about these catastrophic threats?In the climate science community, we have tended to concentrate on assessing what's the most likely thing to happen, but the more important question is: what's the worst thing that could happen? That's the difference between a scientific assessment and a risk assessment. I would argue we've not been treating climate change as a risk assessment. That is also because a lot of well-funded entities have been systematically undermining the knowledge consensus on climate change, which has forced the scientific community to defend what's in effect 19th-century physics. That hasn't put us in a great position to emphasise tipping point risks, which inherently have more uncertainty around them. Why do we need to talk about them now?Because tipping point risks are real and potentially existential. If we have a tipping point in the Atlantic Ocean – the so-called Amoc – we could lose more than half the area for growing staple crops worldwide. It would cause water security crises and severely disrupt the monsoons in west Africa and India, which would affect billions of people. We have to level up to those risks, better understand them and how close they are, and what things we can do in response. Even if we can't stop the events happening, we can do things that reduce the vulnerability of people exposed to the risks. That is why we are drawing attention to tipping points. This is not as a council of despair; on the contrary, it is more like a council of practicality. In terms of the upfront costs to decarbonise the global economy, it is a great investment for the return you get, which is lowering the risk of otherwise catastrophic outcomes. It would help if the IPCC [the United Nations Intergovernmental Panel on Climate Change] took a more in-depth look at tipping points. A large number of countries wanted to see an IPCC special report on tipping points in this assessment cycle, but the IPCC said no. Instead there's due to be a chapter in the next assessment report. Is there an alternative?Yes. I and more than 200 other researchers have published a global tipping points report, and we're writing another one for Cop30, [the UN climate change summit which takes place in Brazil, in November]. We felt the risk was important to communicate and this is a timely moment. So we are trying to fill in the assessment gap in an accessible way. People are crying out for that. I understand the global tipping points conference will also look at positive tipping points in technology, economics and politics?Yes. [There are some] more optimistic scenarios; the impacts of wind power and photovoltaic innovation, or the knock-on effects of campaigning by Greta Thunberg and others. There are also policy feedbacks that could create a change in the landscape in a good way, where you start a policy path towards the renewable energy revolution that's very hard to reverse. That is arguably what the architects of the German feed-in tariffs for renewables managed to do. They made it hard for the doubters to change course even after a change of government. Has renewable energy reached a positive tipping point?Yes, our analysis suggests that solar photovoltaic power is now in a phase of self-propelling global uptake with exponential growth of installed generating capacity, doubling every two years or less. Factoring in the cost of battery storage, solar is already the cheapest source of new power in most of the world, and for every doubling of installed capacity its price drops by nearly a quarter. This is rapidly making solar power the cheapest source of electricity ever, which brings many benefits, including access to electricity for the roughly 700 million people who don't currently have it. And electric vehicles?Yes, the price of batteries plummeted nearly tenfold in a decade as the range you can get from a given mass of battery increased by nearly a factor of three. This has brought China and several European markets to the tipping point where adoption of EVs is self-propelling: the more EVs that get bought, the better and the cheaper they get, encouraging further adoption. The US is lagging behind, but the global south is starting to reap the benefits of electrifying mobility, as it is much cheaper to run an electric rickshaw in India or an electric motorbike taxi in east Africa than their fossil-fuelled equivalents. Any other examples of potential positive tipping points?I'm working on regenerative nature. We already see cases where degraded ecosystems have been tipped back into a better state – for example, when wolves were reintroduced to Yellowstone National Park and started preying on elk, it triggered abrupt vegetation recovery, or when sea otters returned to north Pacific coastal ecosystems and started feasting on sea urchins it tipped the recovery of kelp forests. We also see social tipping points that are nature-positive, where community conservation initiatives, like locally managed marine protected areas, spread rapidly and widely among and across societies. Can you explain cascading feedbacks?In all complex systems – such as the climate and the economy – if you can tip one thing, it can have consequences for other bits of the system. If you tip one part of the system it can make tipping another part of the system more likely. For example, if you've suffered a medical shock it can have knock-on effects on other parts of the body. In the climate, these causal connections can be quite significant and strong. In Earth's history, when there were tipping points in the overturning circulation of the Atlantic Ocean, that tipped major shifts in the tropical monsoons of west Africa and India. In the economy, a cascade can be more positive. For example, an investment in renewable energy can bring forward a tipping point in other sectors. It basically means renewables are making electricity cheaper than it has ever been, and that incentivises electrifying mobility, like cars and trucks and buses, or electrifying heating in homes. At the same time, batteries get cheaper because of economies of scale, which then helps to balance renewable electricity supply and demand. So feedbacks between sectors of the economy can create tipping points that reinforce each other. We've recently mapped out a bunch of positive tipping cascades that could help accelerate change to zero greenhouse gas emissions. What should the world do at Cop30 in Belém to address tipping points?We need policymakers to implement policies that bring forward the positive tipping points we need to stop greenhouse gas emissions and prevent the bad climate tipping points. If the EU and China were to coordinate, it could be enough to shift the balance towards clean green alternatives. Even with Trump in the United States, the beauty of tipping points is you don't need everybody, you typically only need a fifth to tip to the new alternative and then you get to a situation where everybody else is compelled to follow. Tipping points – in the Amazon, Antarctic, coral reefs and more – could cause fundamental parts of the Earth system to change dramatically, irreversibly and with devastating effects. Here, we ask the experts about the latest science – and how it makes them feel. Read more
The Guardian
5 days ago
- Science
- The Guardian
‘This is a fight for life': climate expert on tipping points, doomerism and using wealth as a shield
Climate breakdown can be observed across many continuous, incremental changes such as soaring carbon dioxide levels, rising seas and heating oceans. The numbers creep up year after year, fuelled by human-caused greenhouse gas emissions. But scientists have also identified at least 16 'tipping points' – thresholds where a tiny shift could cause fundamental parts of the Earth system to change dramatically, irreversibly and with potentially devastating effects. These shifts can interact with each other and create feedback loops that heat the planet further or disrupt weather patterns, with unknown but potentially catastrophic consequences for life on Earth. It is possible some tipping points may already have been passed. Dr Genevieve Guenther, an American climate communications specialist, is the founding director of End Climate Silence, which studies the representation of global heating in the media and public discourse. Last year, she published The Language of Climate Politics: Fossil Fuel Propaganda and How to Fight It, which was described by Bill McKibben as 'a gift to the world'. In the run-up to the Global Tipping Points conference in July, Guenther talks to the Guardian about the need to discuss catastrophic risks when communicating about the climate crisis. The climate crisis is pushing globally important ecosystems – ice sheets, coral reefs, ocean circulation and the Amazon rainforest – towards the point of no return. Why is it important to talk about tipping points? We need to correct a false narrative that the climate threat is under control. These enormous risks are potentially catastrophic. They would undo the connections between human and ecological systems that form the basis of all of our civilisation. How have attitudes changed towards these dangers? There was a constructive wave of global climate alarm in the wake of the Intergovernmental Panel on Climate Change (IPCC) report on 1.5C in 2018. That was the first time scientists made it clear that the difference between 1.5C and 2C would be catastrophic for millions of people and that in order to halt global heating at a relatively safe level, we would need to start zeroing out our emissions almost immediately. Until then, I don't think policymakers realised the timeline was that short. This prompted a flurry of activism – Greta Thunberg and Indigenous and youth activists – and a surge of media attention. All of this converged to make almost everybody feel that climate change was a terrifying and pressing problem. This prompted new pledges, new corporate sustainability targets, and new policies being passed by government. This led to a backlash by those in the climate movement who prefer to cultivate optimism. Their preferred solution was to drive capitalist investment into renewable technologies so fossil fuels could be beaten out of the marketplace. This group believed climate fear might drive away investors, so they started to argue it was counterproductive to talk about worst-case scenarios. Some commentators even argued we had averted the direst predictions and were now on a more reassuring trajectory of global warming of a little under 3C by 2100. But it is bananas to feel reassured by that because 3C would be a totally catastrophic outcome for humanity. Even at the current level of about 1.5C, the impacts of warming are emerging on the worst side of the range of possible outcomes and there is growing concern of tipping points for the main Atlantic Ocean circulation (Amoc), Antarctic sea ice, corals and rainforests. If the risk of a plane crashing was as high as the risk of the Amoc collapsing, none of us would ever fly because they would not let the plane take off. And the idea that our little spaceship, our planet, is under the risk of essentially crashing and we're still continuing business as usual is mindblowing. I think part of the problem is that people feel distant from the dangers and don't realise the children we have in our homes today are threatened with a chaotic, disastrous, unliveable future. Talking about the risks of catastrophe is a very useful way to overcome this kind of false distance. In your book, you write that it's appropriate to be scared and the more you know, the more likely you are to be worried, as is evident from the statements of scientists and the United Nations secretary general, António Guterres. Why? Some people at the centre of the media, policymaking and even research claim that climate change isn't going to be that bad for those who live in the wealthy developed world – the UK, Europe and the United States. When you hear these messages, you are lulled into a kind of complacency and it seems reasonable to think that we can continue to live as we do now without putting ourselves, our families, our communities under threat within decades. What my book is designed to do is wake people up and raise the salience and support for phasing out fossil fuels. [It] is written for people who are already concerned about the climate crisis and are willing to entertain a level of anxiety. But the discourse of catastrophe would not be something I would recommend for people who are disengaged from the climate problem. I think that talking about catastrophe with those people can actually backfire because it'll just either overwhelm them or make them entrench their positions. It can be too threatening. A recent Yale study found that a degree of climate anxiety was not necessarily bad because it could stir people to collective action. Do you agree? It depends. I talk about three different kinds of doomerism. One is the despair that arises from misunderstanding the science and thinking we're absolutely on the path to collapse within 20 or 30 years, no matter what we do. That is not true. Second, there's a kind of nihilistic position taken by people who suggest they are the only ones who can look at the harsh truth. I have disdain for that position. Finally, there's the doomerism that comes from political frustration, from believing that people who have power are just happy to burn the world down. And that to me is the most reasonable kind of doomerism. To address that kind of doomerism, you need to say: 'Yes, this is scary as hell. But we must have courage and turn our fear into action by talking about climate change with others, by calling our elected officials on a regular basis, by demanding our workplaces put their money where their mouth is.' You need to acknowledge people's feelings, meet them where they are and show how they can assuage their fear by cultivating their bravery and collective action. The most eye-opening part of your book was about the assumptions of the Nobel prize winner William Nordhaus that we'll probably only face a very low percentage of GDP loss by the end of the century. This surely depends on ignoring tipping points? The only way Nordhaus can get the result that he does is if he fails to price the risk of catastrophe and leaves out a goodly chunk of the costs of global heating. In his models, he does not account for climate damages to labour productivity, buildings, infrastructure, transportation, non-coastal real estate, insurance, communication, government services and other sectors. But the most shocking thing he leaves out of his models is the risk that global heating could set off catastrophes, whether they are physical tipping points or wars from societal responses. That is why the percentage of global damages that he estimates is so ridiculously lowballed. The idea that climate change will just take off only a small margin of economic growth is not founded on anything empirical. It's just a kind of quasi-religious faith in the power of capitalism to decouple itself from the planet on which it exists. That's absurd and it's unscientific. Some economists suggest wealth can provide almost unlimited protection from catastrophe because it is better to be in a steel and concrete building in a storm than it is to be in a wooden shack. How true is that? There's no evidence that these protections are unlimited, though there are economists who suggest we can always substitute technologies or human-made products for ecosystems or even other planets like Mars for Earth itself. This goes back to an economic growth theorist named Robert Solow, who claims technological innovation can increase human productivity indefinitely. He stressed that it was just a theory, but the economists advising Ronald Reagan and Margaret Thatcher in the 1980s took this as gospel and argued it was possible to ignore environmental externalities – the costs of our economic system, including our greenhouse gas pollution – because you could protect yourself as long as you kept increasing your wealth. Except when it comes to the climate crisis? Yes, the whole spectacle of our planet heating up this quickly should call all of those economic assumptions into question. But because climate change is affecting the poor first and worst, this is used as evidence that poverty is the problem. This is a misrepresentation of reality because the poor are not the only ones who are affected by the climate crisis. This is a slow-moving but accelerating crisis that will root and spread. And it could change for the worst quite dramatically as we hit tipping points. The difference between gradual warming and tipping points is similar to the difference between chronic, manageable ailments and acute, life-threatening diseases, isn't it? Yes. When people downplay the effects of climate change, they often represent the problem as a case of planetary diabetes – as if it were a kind of illness that you can bumble along with, but still have a relatively good quality of life as long as you use your technologies, your insulin, whatever, to sustain your health. But this is not how climate scientists represent climate change. Dr Joelle Gergis, one of the lead authors on the latest IPCC report, prefers to represent climate change as a cancer – a disease that takes hold and grows and metastasises until the day when it is no longer curable and becomes terminal. You could also think of that as a tipping point. This is a fight for life. And like all fights, you need a tremendous amount of bravery to take it on. Before I started working on climate change, I didn't think of myself as a fighter, but I became one because I felt I have a responsibility to preserve the world for my son and children everywhere. That kind of fierce protectiveness is part of the way that I love. We can draw on that to have more strength than our enemies because I don't think they're motivated by love. I believe love is an infinite resource and the power of it is greater than that of greed or hate. If it weren't, we wouldn't be here. Tipping points – in the Amazon, Antarctic, coral reefs and more – could cause fundamental parts of the Earth system to change dramatically, irreversibly and with devastating effects. In this series, we ask the experts about the latest science – and how it makes them feel. Tomorrow, David Obura talks about the collapse of coral reefs Read more
