Dani Arribas-Bel

I’m just back from my first Human Planet Forum. In its own words:

The Human Planet Forum 2025 is a flagship event of the GEO Human Planet Initiative (GHP) which works to understand and map human presence on earth using open geospatial data.

In my own, it’s an (the?) opportunity to see in one room, at the same time, all the wonderful nerds behind some of the most interesting data products using earth observation (EO) to map the world’s population. As an understatement, I was excited.

The organisers kindly asked me to prepare a ten minute summary of the event that’d help conclude it. As my email inbox will attest, I “had to” pay attention to all presentations, and thus the opportunity cost of getting distracted was higher than usual. I’m glad I was given this constraint because it made me appreciate the event and what was presented there much more. Below is a write up of that summary. Heads up, this is not a detailed account of each presentation (for that, you’ll have to wait for the report the JRC will put out in time), more of an opinionated view of what the event represents and why it is valuable.

I structured my contribution along three key dimensions: domains discussed, perspectives used, and common threads. I then added two extra slides, one with themes that will keep this community busy for the foreseeable future, and one with my own perspectives to wrap up.

Start with the domains. There was an important chunk of time spent discussing new ways and products that characterise environments. A lot of this is the evolution from the earlier work defining the extent of human settlements (the HS in GHSL!), and it’s very welcome to see these attempts becoming more sophisticated, adding more depth and providing more detail than what it has already been shown possible. It was not surprising to see a lot of work also towards identifying, measuring and monitoring disasters, vulnerability and exposure. Underlying it all was the looming presence of climate change and the consequences it is increasingly having on human systems. And one of the key distinctions between this meeting and almost any other one I can think of is its ambition to combine these domains with socio-economic aspects. Of course, population estimates is by now a staple of this community, but we also heard from efforts to characterise the building stock, the degree of urbanisation, or poverty, to name a few.

I identified three key perspectives. One is presentations on advances in the field, technical or otherwise. What are the things we can now do we couldn’t a few years ago? The second is a focus on introducing foundational layers. The word foundation has lost much meaning in the past few years “thanks” to the AI hype around LLMs¹, but its use here referred to something more meaningful: data layers built to develop a lot of applications on top of them, to be used by a wide range of stakeholders in a variety of contexts, and relied upon for many years to come. This aspect of temporal continuity for me deserves special praise. While the Valley mentality of “disrupting”, using the latest and greatest to put out catchy data products has its (mostly demonstrational) value, to me it pales in comparison with the commitment to support a data product over time.

All of the above stems from a series of shared values, a common narrative, that permeated through pretty much everything that was said in the meeting. The first is the very clear ambition to develop and use data to inform real decisions. There was a very interesting debate across different sessions of how much this ambition should dictate the data we develop and how we go about this task. The appeal to tailor something as close as possible to what decision makers state they need is clear. Less clear to me until I heard it was the notion that maybe such stakeholders are not always aware of what is possible and hence, when they specify needs, miss opportunities. It is then up to us to grab such opportunities to show new ways in which data can influence policy. There was also a lot of discussion about the need for capacity building, for addressing that “last-mile delivery” challenge to make sure the data and insights we develop have real impact. I half joked that, in some cases, I’m not sure how long that mile is. Sometimes, it feels our outputs should inform decisions, but in reality there’s a broader gap between them and the evidence needed to make a difference. At any rate, that this conversation featured so prominently across sessions seems to me like like a very healthy pre-condition to figure out the best way forward. And, finally, the third common thread was the value of Open. Everyone here understands that, for this work to be relevant, it is imperative it be openly available through permissive licenses. This is in contrast to other academic fora where my sense is that openness is seen as a desirable though not critical feature of work. I think the Human Planet folks are “on the right side of history” here.

After touching on domains, perspectives and common threads, I reflected on themes that, in my view, will remain relevant in the coming years, despite all progress already made. The first was the tension between developing global products and aiming to influence local decisions. This is what I called the everything, everywhere, all the time goal of the data products we develop. This is not only an aspirational goal, it is one whose goalposts are constantly shifting (what was “high resolution” or “frequent” five years ago is no longer now), so the need to always push the envelope does not go away with technological advances. To me the real value of the goal is not achieving it per-se (it is always going to somehow elude us), but to help focus our minds about the direction of travel and the “itinerary”: what are the pieces we really cannot sacrifice and which ones we can give up in the name of actually existing datasets? The second point I raised was that notion of “last-mile” discussed above. Figuring this one out will keep us entertained for a while. And the third was the need to continue standardising and harmonising data and approaches to make the ecosystem more useful than the sum of its (data product) parts. As more datasets are created, this becomes more important, but also more onerous.

I closed with three thoughts this Human Planet Forum has stimulated. First is this notion I’ve been mulling over for a while of EO as a data source of first resort. For a long time, at least in social science, one would use satellites because the data one was really interested in wasn’t available (a census, a survey, a building cadaster….). I think the time is ripe for this to change. Data from satellites (and the techniques we now have to work with them) have advanced to a point where I think, in many cases, they make for the best option. This is not fully obvious to everyone (yet) and perhaps it needs a bit more of shouting from people like us to spread this gospel. The second is the value, not only of pushing the boundaries of what is possible with these data, but also to bring such boundaries to the masses. So much of science gets “locked” in niche communities because it is too complicated, obscure, or there is no effort to disseminate. We cannot afford this with advances in satellite data. In this context, I really take away the idea of the “last-mile” as a neat way to encapsulate much of this challenge (and, perhaps, part of its solution). The final reflection I made is that there’s a lot of opportunity in bringing in conversation work along these lines of the Global North with that of the Global South. A lot of the focus in this community has historically focused in less developed countries (see the point about data of last resort above). As technology gets better and becomes more relevant not as a substitute for another data, but as the main focus, I think there’s a great opportunity for all the lessons learned while working on the Global South to be shared and amplified elsewhere. Yet more avenues for cross-pollination and collaboration.

And that was it. As I mentioned at the start, these were three very intense but extremely productive days. Michele and team did a stellar job in putting a fantastic show together and I’d like to thank them again for letting me be part of it. I hope to see many of the participants again very soon in different venues!