A digital twin of the entire planet

What is the upper limit of digital twinning? Well, how about a digital twin of the entire planet. That is the premise of ‘Destination Earth’, a project from the European Commission which, by 2030, aims to produce an interactive computer simulation of the whole of planet Earth. One of the organisations involved in this herculean task is The European Centre for Medium-Range Weather Forecasts. Their director for Destination Earth is Irina Sandu...

Irina - As we saw over recent years and even more so over recent months, the climate urgency is amplifying. We are entering uncharted territory. The global mean temperature is rising constantly. We just experienced the first day where the global mean temperature was two degrees warmer than the pre-industrial period. So what inspired the project is really the digital twin concept, together with the recognition that the latest breakthroughs in digital technologies, in supercomputing, in science, and in artificial intelligence, have the potential to enable us to create a digital twin of our planet.

Will - Earlier on in the show, I was introduced to a digital twin of an engine, and I thought 'that sounds like a lot of data going into that.' And then I was introduced to a digital twin of a heart, and I thought, 'that sounds like a lot of data going into that.' The entire Earth sounds like more data than I could possibly comprehend. What data is being fed into this digital twin and where does it come from?

Irina - This is true. To make a digital twin of the earth, you need a lot of data, but a lot of computing power as well. So what we are doing in destination is we are harnessing the power of Europe's world-leading supercomputing facilities. We are harnessing the recent advances in digital technologies, observations and artificial intelligence. And we are really building on decades of European leadership in weather and climate prediction to create this digital twin of the Earth. There are in situ observations of temperature, winds, humidity, but there is also a lot of satellite information. There are millions of satellite observations streaming every single day. And this gives information indeed about the clouds, about the temperature, the humidity, about the different elements of the earth system. Also about the ocean surface, about sea ice. So indeed you need all these observations, but you also need the numerical models because we don't have observations everywhere. The observations are sparse in time and space, and you need a model to glue all this together and to fusion it, twist the observations to really reconstruct the replica of the Earth's system.

Will - I see. So it is important to have all the information, but it is far more important to have something that can pull it all together into something meaningful.

Irina - Exactly. And this is what we call the numerical prediction systems for weather and climate, which bring together observations. Basically, they allow us to describe how the atmosphere, the ocean, the sea, will evolve in time.

Will - All of the other people I've spoken to in this episode have said they're really excited about digital twins, but the main thing holding their areas of study back is the difficulty of integrating multiple systems. This sounds like so much data from so many natural and manmade variables. Just how accurate do you think this will end up being?

Irina - We know from decades of experience in numerical weather predictions that the models we have already and the combination of models and observations, it's really accurate. The weather predictions, for example, have really improved over past decades and weather forecasts today four days ahead are as accurate as weather forecasts two days ahead, were two decades ago now we are going to go even further by enhancing the resolution of the numerical models, but also by better using the observations, using more observations, we are hoping to go to even higher levels of accuracy.

Will - So if you do manage to get all of this data in and the model makes it <laugh> usable and you pull off this remarkable endeavour, what will it allow us to do?

Irina - It'll allow us to complement the existing capabilities to respond to extreme events and adapt to climate change. And to do that, ECMWF in the first phase is implementing two first high priority digital twins. One focuses on extreme weather events. It'll provide information on a timescale of two to four days ahead with spatial resolutions of a few kilometres, two to four kilometres globally, but also with zooms of only a few hundred metres. So we can really activate this weather twin when extreme events happen over Europe and zoom over them to give more detail of how the extreme events would affect population and the infrastructure. The second digital twin is a digital twin focusing on climate change adaptation, which will provide globally consistent climate information at scales where extreme events matter and are felt. And here we talk really about a descent in scales, which is impressive. Climate models today offer information for the few decades ahead with spatial scales of about a hundred kilometres. The digital twin that we are constructing the Destination Earth will give information on spatial scales between five and 10 kilometres. That's a much higher resolution. It'll allow in this way to tailor the high quality information to needs and purposes of users from sectors which are most impacted by extreme events and climate change such as agriculture, forestry, public health or energy. And what makes really a digital twin is the ability to explore 'what if' scenarios, allowing to answer questions, for example, like how a heat wave will look in a warming world, how it'll look in a two degrees or a four degrees warmer world and it'll offer real world benefits for renewable energy sectors or for future urban planning.