Podcast: Digitalisation for people and the planet

15 January, 2023

Reading time: 29 minutes

Our podcast explores how pathways for digitalisation in energy and mobility could be directed towards reducing energy demand and enhancing social justice.

CREDS in conversation

This podcast explores how pathways for digitalisation in energy and mobility could be directed towards reducing energy demand and enhancing social justice. Digitalisation is one of the high-level trends that will significantly impact future energy demand and carbon emissions, whilst creating social challenges and opportunities.

In conversation, Dr Steffen Lange, Professor Tim Foxon and Professor Tim Schwanen, with Dr Sarah Higginson.


Sarah Higginson: [00:00:00] Hello everybody and welcome to this podcast on digitalisation for people and the planet. This podcast is part of an international series called CREDS in Conversation. CREDS is the Centre for Research into Energy Demand solutions, funded by the UKRI Research and Innovation Energy Programme.

In CREDS we’re interested in how, when, and why people use energy in all its forms and believe reducing demand is essential to us reaching our net-zero targets. It seems that everything is going digital these days, from our energy systems to our transport systems. One of the things we don’t talk about though, is how much this will impact future energy demand and carbon emissions. And we also hear less than we should about the social challenges and opportunities created by digitalisation.

Today’s podcast draws on a recent European report called Digital reset: Directing Technologies for the Deep Sustainability Transformation, as well as work within CREDS about the future digital pathways and energy use and in transport.

My name is Sarah Higginson. I’m the Research Knowledge Exchange [00:01:00] Manager at CREDS, and I will be moderating the conversation today. With me I have three speakers. Dr. Steffen Lange. Steffen is an economist at the Institute for Ecological Economy Research, affiliated with the Resource Economics Group at Humboldt University in Berlin, an associated researcher at the Department of Social Ecological Transformation at the Technical University of Berlin.

I also have Professor Tim Foxon. Tim is Professor of Sustainability Transitions at SPRU, the Science Policy Research Unit in Sussex. His research explores the co-evolution of technologies and institutions for sustainable net-zero transition, and relations and interdependencies between energy use and economic growth.

I also have Tim Schwanen with me. He’s a professor of Transport Geography and the Director of the Transport Studies Unit in the School of Geography and the Environment at the University of Oxford. He has held visiting professor positions at the University of Gothenberg and Ghent, and is a fellow of the UK Academy of Social Sciences.

His research is organised around four concerns: [00:02:00] transformations in urban mobility, social and spatial inequality, wellbeing, and philosophies of transport and mobility. Welcome to the three of you. Thanks so much for joining us in the conversation today.

We’ll start by some introducing basic ideas. Steffen, could you please explain what you mean by a digital reset and tell us why it’s important for people and the planet?

Steffen Lange: Yes, and Sarah, thank you for having me. Digital reset. We published the report and I think the main message is that we need to reset digital technologies. So, in the past they have gone in the wrong direction and we need to redirect them. And one important concept here is that of a deep transformation.

So we don’t just have to reset a little bit. We don’t have to redirect it a little bit, but we need to fundamentally make it different and make it part of a fast and very fundamental transformation of our economy and our society in order [00:03:00] to achieve sustainability goals.

Sarah Higginson: Tim Foxon, please, could you start by giving us an overview of digitalisation pathways and how they might influence energy demand?

Tim Foxon: Yes, thanks very much, Sarah. So, within the CREDS centre, we’ve been looking at the role of digital society and this question of on the one hand, digital tech can help us save energy through efficiency and substituting for material ways of provision, but can also lead to increases through rebound effects and which mean that digital technologies create the opportunity for new services such as Amazon delivery is one example.

And what we’re thinking about in terms of digitalisation pathways is what happens with digitalization, and the social and environmental impacts depend on the social, political and technological choices that we make.

These can be done in different ways and we want to look at how these can contribute to the transition to [00:04:00] net-zero carbon emissions, but also to wider sustainability growth.

Sarah Higginson: Thanks Tim. Now over to the other, Tim – I’m sorry, we have two Tims with us today, so it’s complicated. Please can you tell us your expectations for automated vehicles and any impacts they might have on energy demand?

Tim Schwanen: Well, thank you Sarah. I think the short answer to that is that I don’t really know what the impacts are going to be, and I’ll try to explain that. I think, first of all, we need to consider what we actually mean by vehicle automation because there’s a wide range of things that can be grouped under that.

People are typically thinking of completely self-driving vehicles, where you as a passenger sit and can do whatever you want. In technical terms, we call that level four or level five of vehicle automation and it’s still some way off. But there are other, lower level forms of automation as well, and we have quite a few of those in existing vehicles, think for instance about something like cruise control or support [00:05:00] with parking, those are those are also forms of partial automation.

So we need to think about what level automation is pitched at. But then there are also many different effects that vehicle automation has.

We have direct effects, where we need to think about existing forms of automation tends to make driving easier for people, which it would seem may lead to longer distances because driving is less tiresome, less exhausting. You can do other things, so it’s not waste of time.

People may be living further from their work. So, there is this potential of longer distances and more energy consumed .

If we’re talking about level four, level five, so full automation, that is actually really much easier if we have electric vehicles, which have of course, very significant implications for energy consumption as well.

But then we not only should be looking at [00:06:00] direct effects but also indirect effects, because one of the expectations is that automated vehicles, once they become popular and used widely, that they will trigger a shift away from walking, cycling, public transport, and shipping and rail when we’re talking about freight. So that would mean more energy consumption.

And then last of all, we also need to think about what we call embodied emissions and energy use. And that’s the energy use that is required to produce the vehicles, the infrastructure and so on. And if we add all of that up, it is, at this point in time, quite unclear what the effects of vehicle automation will be.

And the expectation that these are environmentally sustainable is really only one of the possibilities, and it’s quite possible that we’ll see more consumption of certain types of energy [00:07:00] with widespread vehicle automation.

Steffen Lange: I would like to add on that example, and connected to the idea that we, and Tim Schwanen has been part of, that we developed in this report, Digital reset.

So the example that he gave is that an indirect effect can be that actually people move away from cars towards public transport. And I would say yes, digital technologies have that potential, but only if it goes along with, not specifically digital regulation, and public policies. So, I would say only if subsidies forecast in general and for infrastructure are being lowered, and if subsidies and the development of infrastructure for trains, etc. are expanded, then this shift can be a really a fundamental shift that we need to see.

Sarah Higginson: I’m going to go back to you again, Steffen, if that’s okay, and just ask you about the direction and speed of [00:08:00] innovation in relation to digitalisation and sustainability. Why do you think this is important?

Steffen Lange: Yes. I think the direction of digital innovation is quite important for the sustainability transformation. And the one reason is that I would say obviously technological change is very important on the path to sustainability. So when you look at you know, renewable energy, when you look at shifts from, as we heard from cars to transport, when you look at industrial production, circular economy, everywhere, technology is important.

And I would say, the speed and direction of digital innovations is so important because it is, I would argue, the broadest and the most important type of, you know, it’s not one technology, but the most important types of technologies that take place there.

What I think is very important to keep in mind that I think we must not only talk about technological innovation here, but about the combination between, between technological [00:09:00] and social innovation.

So, wherever we see concepts for sustainability using some type of digital technologies, when it’s really about to achieve sustainability it also goes along with behavioral change. Just to give you one example, there’s a lot of hope and I would say justified hope, that digital tools and in particular the availability of information can help us repair and recycle a lot of goods.

But that also, you know, it’s not only the technical possibility that we bring about, let’s say smartphones that can be repaired, but you also need the knowledge of people and the willingness to repair them. Or you need new business models where you can bring your smartphone so that they are repaired. So, it’s botth technological and social innovations [that are] necessary here.

Sarah Higginson: Great. What do you think Tim Schwanen? [00:10:00]

Tim Schwanen: I completely agree with Steffen, and I think the point about innovation as being much more than simply technology is so important and so easily overlooked.

In my domain, or the domain that I know most about, transport, I tend to say to students and to policymakers and other non-academic audiences I interact with, that the technology is really the easy bit of the innovation process and the real tricky things lie in questions of cultural change, institutional change, and finding business models that work.

And actually mobility is a very good example of this. If we’re thinking about what we call platform mobility, so think about ride hailing, bike share, mobility as a service, it’s really difficult to find business models that work, for instance. And a lot of the hype around these platform [00:11:00] services, I think can really be questioned if you look carefully at the business aspects and questions of regulation and institutional change around them. And we find in our work that governance is really the key issue, governance and business models are probably the key issues that we really haven’t resolved.

Sarah Higginson: That’s a perfect segue to you, Tim Foxon, and I imagine that you have something to say about that.

Tim Foxon: Great. Yes. Thank you. I mean, I think one thing to maybe highlight is the link to the work that our colleagues in CREDS, John Barrett’s colleagues have done looking at low energy demand scenarios for meeting our net-zero target by 2050.

And I think that they’ve shown that this can be done in a way which enhances people’s wellbeing whilst significantly reducing energy demand [00:12:00] and digitalisation is an important driver of this through to some of the opportunities that we’ve been hearing about from Steffen and Tim, and with links to ideas of circular economy, designing products for repair and reuse, for example, but these don’t happen automatically. And we have a narrow system at the moment which encourages business models which are significantly based on capturing and monetising people’s data, and that leads innovation in a particular direction, which obviously brings benefits, but as we’ve seen, brings many social disbenefits, and also we argue brings potential increases in environmental impacts.

And so thinking about these questions around governance and around new business models is crucial in enabling the way [00:13:00] that digitalisation occurs to meet these social and environmental goals, and enhance wellbeing, whilst addressing social equity and making sure everyone has access to these services so that we don’t increase polarisation in society while at the same time they have the potential for reducing energy use and environmental impact.

Sarah Higginson: Thanks, Tim. I think we’ve really covered the unconstrained use of digital technologies and how those could lead to increases in energy demand. So, Tim, I’ll come back to you again if I could and ask if you could please explain the concept of digital sufficiency.

Tim Foxon: I mean, I think it’s the idea that digitalisation shouldn’t be seen as a good thing in itself, it’s about asking the question of what things are best and most appropriately delivered through [00:14:00] the use of digital technologies and what areas do we maybe not need to digitalise, and how can digital technologies be used to enhance other forms of services in caring settings for but not necessarily just assuming that everything can be done through digitalisation.

Steffen Lange: Yes. And if I can connect to that, I agree a hundred percent. And I think a helpful manner to think about digital sufficiency is that we need it both in the digital sector itself and in the rest of the economy or in other sectors.

So digital sufficiency includes, using your smartphone longer and using your laptop longer. And from a software perspective, developing software that actually enables people to use their devices longer so that they don’t become obsolete because the software is too demanding. So that’s in the [00:15:00] digital devices sector, let’s say, and the digital economy.

But digital sufficiency, as I would understand it, also thinks about how to use digital applications, digital devices to live sustainable sufficient lives, or to have net-zero oriented business models in the rest of the economy. So we can do video conferences instead of flying somewhere. We can use the know-how that we find online to repair stuff and so on. I think the idea got across.

Sarah Higginson: Can I just check my understanding of sufficiency comes from Kate Raworth’s work, which seems to be a little bit different from the type of sufficiency that you’re talking about here.

But, Steffen, perhaps you can comment on that. In her case, my understanding of her work is basic, but the idea is that you could be under-consuming as well as over-consuming, and so there might be this idea of limits at the bottom, limiting unfettered growth at the top, [00:16:00] whilst also encouraging more use for people that are not using enough, and we talk about this in energy demand all the time. Is that something similar in the digital world?

Steffen Lange: Yes, that’s similar in the digital world. And I must say when I give examples, the underlying assumption is that I talk about the global north and in this case, I talk about over consumption in the digital area.

So certainly, you know, there’s this interesting aspect of the word sufficiency as well, that it’s enough but it’s not too much and it’s not too little. And of course, digital sufficiency would not mean, you know, to not have digital devices at all, but to reduce the consumption in particular of people who have a lot of devices and use a lot of services, in order to stay within the planetary boundaries, because at the moment, we have too much.

Sarah Higginson: Okay. Great, thank you for that clarification. Tim Schwanen, and I’m going to come to you now to talk a bit about shared mobility, and if you could just explain what that is and explain why it might be a [00:17:00] solution that should be encouraged.

Tim Schwanen: Sure. Sarah, are you okay if I first say something in addition to what Steffen says, because I think there’s a useful link to be made with the CREDS work.

Sarah Higginson: Yes, of course Tim, go ahead.

Tim Schwanen: So I think in the digital reset report, when we talk about sufficiency, we’re actually more focused on what, within the CREDS work on transport and mobility, we call excess mobility, that is really the mobility at the top, the 10% or perhaps even the 1% of really over-consumption.

And when we’re looking at the work of Kate Raworth and not as, their understanding of sufficiency is based in ethical theories around justice, which are focused on the idea that there also needs to be a minimum level of consumption, that people can reasonably be understood to have a right to or to have access [00:18:00] to.

And that bottom, that sort of lower level, that minimum level, really is something that is not really addressed as much in the digital research. On the question of shared mobility. Shared mobility is a very broad category because we have different transport modes that we need to consider when we’re talking about, for instance, e-scooters or bikes, where we talk about cars or whether we talk about rides rather than vehicles. So that’s an important distinction. Some taxi services are about the exclusive use of a vehicle. Others are what we call the Uber pool model, which is essentially a shared taxi model where you have a much higher vehicle occupancy rate, and it’s that shared taxi model that in many ways, from an environmental point of view, is the most desirable.

Then we also need to think about what this shared mobility is for, because it can be [00:19:00] a form of mobility in its own right, particularly for shorter distances, but increasingly we also think of it in terms of a first- and last-mile solution. So shared mobility options are really good to get you to public transport stops or stations where you can then travel to your destination at a greater distance. And when we think about what needs to be done to encourage shared mobility, I think it is important to both adopt a user-centric perspective and to look at the system of shared mobility, and with the user centered perspective, I’m really thinking about the importance of thinking about what we call door-to-door journeys, because people don’t use a transport mode. People want to get from an origin to a destination and may use multiple stages, multiple forms of transport to get there.

And I think [00:20:00] too often we still think about modes in isolation from one another rather in than in these chains, which are so important for people. In terms of systems, I think we’ve touched on this before because shared mobility is not just the app or the online payment system, but is all the other issues around it. And just to give an example, there has been quite a bit of debate, especially in parts of Asia, about the safety of using taxi rights, particularly for women. And what we’ve seen in response to that is that platform providers are putting in place informal codes of conduct for how you should behave and conduct yourself, both as a driver and as customer of these services.

And I think these kinds of more informal rules and more subtle changes are also very important if we want to make shared [00:21:00] mobility a safe and acceptable solution for everyone.

Now, there are things we can do to make shared mobility in general more attractive, and that really requires proactive action from governments. So, I think perhaps the most important thing we can do is to make solo driving your vehicle less attractive and discourage ownership of individual vehicles, which you can do in a variety of ways. But if we’re talking about discouraging ownership, parking restrictions and taxation on vehicle ownership are sort of very sensible things that are known to have worked, and probably parking restrictions at destinations, so not so much in where people live, but where they travel to is a particularly effective way of reducing car use.

What is also [00:22:00] important is that we create trust and collaboration between mobility service providers, and I think this is really something where the UK system is quite different from many continental systems, for instance, in Germany or the Netherlands, where there’s much more a culture of cooperation.

And thinking in terms of multimodal chains of mobility, and just one example is that in Germany, in the Netherlands, car sharing is really seen as part of public transport and is incredibly important in providing first- and last-mile solutions in lower density areas. The situation in the UK is quite different, where many public transport operators would see car sharing really as a competitor rather than something to collaborate with. [00:23:00]

So proactive action of government is really important, but there is no general recipe that will work everywhere. You will always have to sort of tailor what you do to local situations and the needs, and issues, and concerns of the local population.

So that means that we really cannot only encourage shared mobility solutions through top-down, quite technocratic modes of policymaking, but that we really need to be serious about participation in all stages and aspects of policy and governance, and participation is also a really useful way of tailoring to local conditions.

Sarah Higginson: Thanks, Tim. I can see that we got you on your specialist subject! So I’m going to move on now. As you’ve started to talk about policy, I think it’s widely known that the small number of large tech companies control this space, and policy [00:24:00] tends to struggle to keep up.

So, I’d like to move the conversation onto the options that there might be to influence developments in the direction of sustainability and social equity. I’ll start with you, Steffen.

Steffen Lange: Yes. Thank you. So when you start off by referring to GAFAM (Google, Apple, Facebook, Amazon, Microsoft) or the big tech companies I will focus on that and I think there are basically two strategies how we can transform these business models or, and this part of the economy, I mean, it has become a substantial part of the economy by now.

And the one is to control the big business models and the big businesses themselves, and the European Union as well as the US to some degree have actually started doing so this year and the last year. So, the Digital Services Act, the Digital Markets Act, those are quite substantial regulations of what social media platforms, what sales platforms, etc. can do and what they have to follow when they conduct the [00:25:00] business.

The point here is that the focus has been mostly on economic and data and privacy aspects. And we actually have been, as part of this project where the digital reset report came out, we have been in quite frequent debates with policymakers in the European Commission, and we always said, well, come on, bring in sustainability, environmental sustainability into these big, big policy initiatives.

And basically, the answer was, we already have to deal with enough. We first have to deal with monopoly and privacy, etc. issues. And we cannot now say also, okay, we need to bring in sustainability here. So this would be a further step, and I would say  there are also debates on whether to cut them into pieces, let’s say these big companies, or to somehow make them public. Those are the debates that we need in the [00:26:00] future as well due to democratic, due to social, due to environmental reasonings. So that’s the one path.

And the other path would be to build up more common good oriented, alternative organisations, let’s say – it doesn’t have to be companies here – that can replace them or be an alternative here. And I think there’s a good case to be made for this, I mean, at first sight it might appear radical, but when you look at, for example, that on Twitter, on Facebook, etc. a big part of the public discussions, the public discourse on political issues, on social issues takes place, this is really a fundamental democratic service that takes place there.

And if it takes place under conditions which are geared towards profit maximising via a lot of commercials, that’s just not how you want to have this public debate being organised.

So, I think there’s a strong case here to say, okay, we build up – and by we, [00:27:00] I think it’s somehow civil society maybe, with the role of the state – we build up alternatives here, and to give you, concrete, a very recent example is what is happening at the moment, as far as I follow it, with Elon Musk’s takeover of Twitter, where a substantial part, I don’t know how many, how much percentage that is, but a substantial part of people actually leave Twitter and go onto other platforms that are, in this case, open source. So in this case, it’s not the state, but it’s open source alternatives. The most famous names I think are Mastodon and the Fediverse.

So, this is where people now go. And of course, I’m afraid it will not be enough at this point, but when then governmental action comes in there and the civil society would, would be stronger here, we could actually see a switch towards more common good and sustainability-oriented organisations and platforms.

Sarah Higginson: Thanks, Steffen. Tim Foxon, have you found any evidence of trying to make a [00:28:00] change or difference here in the work that you’ve done on digital pathways?

Tim Foxon: I think as Steffen says that there has been just in the last few years, particularly at the European Union level, but also in the UK, the recognition that some of the social harms created by digitalisation need to be regulated and there’s a bill going through the UK Parliament the moment well as EU legislations that Steffen mentioned. One of the issues here is the monopolisation by this small number of large companies whose business model is basically based around monetising people’s data, so that then that can be used for advertising purposes and I think there’s now a recognition that this is not necessarily the most socially beneficial type of business model.

But again I think policymakers are struggling to catch up in a way, because we’ve sort of let these business models grow and also there’s a sort of economic framing around, well, they’ve been successful so it’s not necessarily seen as a monopoly issue, whereas I think some of us will argue that the outcome is that it is a monopoly and they are able to use their political power to prevent incumbents entering the market and I think that is sort of dangerous from a societal perspective.

And so I think we need policymakers to catch up with these social environmental issues and we need just to enhance the democratic [00:30:00] debate about where some of these limits lie.

Sarah Higginson: Tim Schwanen, do you have anything to add there?

Tim Schwanen: I think Tim Foxon is making a really important point there about the importance of politics in this, and again, transport is a very good example, where we see across the political spectrum, but perhaps more so on the right a very strong belief in these big tech service providers as sort of really offering a glimpse of what a future better society will be and that there is almost an ideological reluctance to regulate them strongly.

But there is also evidence of regulation being very significant and very effective. And one example is where we see that in more European countries, Uber-type services are now seen as [00:31:00] employers. And that has real ramifications for the income that the drivers can earn from providing their labor, which has led to an increase of the overall price of these kinds of services with very significant implications for their competitiveness and the number of services that are available. And we see in some European cities that the pendulum is swinging back towards more conventional taxi service providers. Not everywhere, but we do see some of this.

And I think there’s also something that Steffen said that I think is really important. And that is that we really have to combine regulating large, big tech company service provision with cultivating [00:32:00] smaller or different types of service provision that is based on and configured around the common good. And we see some of these solutions in the mobility sphere as well, where there are service providers that are locally grounded, that really respond to specific social needs in certain communities, and that are really focused on reducing the environmental harms that transport is causing. We also see however, that these services struggle to compete against the big transnational corporations, and this is where I think the authorities, the public authorities, really have a role to play in providing a layer of protection around these more commoning oriented services and platforms.

And I think that is really the way to go forwards. So, regulation will have to be a central ingredient of how we [00:33:00] try to cultivate digital platform service provision.

Sarah Higginson: Thanks, Tim. I must say, I found this is not my area really and I found it really interesting because I’ve always assumed that there was nothing one could do about these big tech companies.

So, I’m going to ask how optimistic or pessimistic each of you feels that digitalisation can be repurposed for the benefit of people on the planet. Steffen, we’ll start with you.

Steffen Lange: Yes, thank you. That’s the big question. I think digitalisation can only become purposed for the people on the planet if it becomes part of a socioecological transformation.

And then the question is, of course, how optimistic am I that we have a sociological transformation and that it comes soon enough. And I have to say all that I read in the media regarding climate change and biodiversity loss, I think we come too late rather than early enough. And with that, I would say digitalisation can do some good, but whether it’s enough to achieve the sustainability goals that we [00:34:00] have, I’m probably more on the pessimistic side.

Tim Schwanen: Tim Foxon, what about you?

Tim Foxon: I think I agree with Steffen that digitalisation has a significant role to play, but as part of wider environmental and social transformation. And I think there are ideas which do give cause for hope. And you mentioned Kate Raworth’s economics model, which has been taken up in Amsterdam and other cities, and ideas around wellbeing economics, which the government of New Zealand and others are, are taking up.

And I think as part of that wider social and environment confirmation of the sustainability digitalisation can play an important role.

Sarah Higginson: Thanks, Tim. And over to you, Tim Schwanen.

Tim Schwanen: Yeah, I guess like Steffen and Tim, my view is that digitalisation on its own will not be enough to get us where we need to be, particularly when we’re looking at climate change.

But it can [00:35:00] accelerate processes and dynamics of change, and I think that’s what we need to focus on. And for that we really need to think about cultural change, about institutional change, about different business models, and about proactive regulation and governance. And if we get all that right, then I think digitalisation is a tool that we should not overlook and that we cannot afford to miss.

Sarah Higginson: I wonder if you can just give us one or two things that listeners of this podcast might be able to do to improve the situation. Steffen start with you.

Steffen Lange: It’s a very concrete thing you can do is actually buy less digital devices and use them longer. Just producing the digital devices makes up one third of all the energy used in the whole digital economy.

So, when you know, you buy your smartphone only every six or seven years and not every one or two years, that makes a big difference. And if you need a new device, there are quite some sustainable devices out on the market [00:36:00] by now.

Sarah Higginson: Practical, thanks very much. What about you, Tim Foxon?

Tim Foxon: I mean, I think as Steffen mentioned as well, that you know, supporting these alternative models, the more local common space, and, you know, and we do have examples like Wikipedia as well as more locally based alternatives, so I think maybe looking and supporting those rather than maybe defaulting to the big tech choice.

Sarah Higginson: Thanks Tim, and Tim, over to you for the final word.

Tim Schwanen: Avoid buying your own car is a very good thing that you can do in the mobility sphere because that will inevitably mean that you will be looking at public transport and shared mobility services of various kinds. And within that, I think everyone can try to support local, community-based, commons [00:37:00] oriented providers of mobility services.

Sarah Higginson: Great. Thank you. And I guess I’ll add to that just by saying that in general people can attend to their energy demand and how much energy they use. And specifically in relation to digital, we’ve done some work in CREDS that shows that you can reduce your energy demand on your website by using fewer pictures or less energy consuming pictures, by sending fewer emails or certainly emails that are smaller with smaller attachments or not sending attachments at all. So, there are a few things that people can get started on and at least raises awareness and some of the issues involved.

That’s all we have time for today. Thanks so much for joining us today to share your insights. I really found it fascinating and I hope our listeners will agree.

Thanks very much and goodbye.

Banner photo credit: FPVmat A on Unsplash