Models are crucial for the weather and climate sciences. Without the current models, reliable weather forecasts beyond tomorrow would be almost impossible, and we would have only a vague idea of what global warming has in store for us.
Models are crucial for the weather and climate sciences. Without the current models, reliable weather forecasts beyond tomorrow would be almost impossible, and we would have only a vague idea of what global warming has in store for us.
In the recently started EXCLAIM research project
1
, we want to build on this achievement and develop the next generation of weather and climate models. The new models will provide a much higher resolution of the key processes in the atmosphere and oceans. Working within the Center for Climate Systems Modeling (C2SM), the research team will create the model and data infrastructure that will allow us to simulate storms, thunderstorms, and clouds on a global scale. This will lead to more reliable weather forecasts and more precise climate projections.
Are we betting on the right horse?
Of course, this also raises questions. Don’t we know already enough about climate change? What’s the point of making the weather forecast just that little bit better? Is it worth the enormous effort?
Indeed, we know already with high certainty that humans are responsible for most of the warming we observe. We understand the relationship between CO
2
emissions and temperature relatively accurately, and we have recognized that we need to reduce CO
2
emissions to net zero within the next few decades to meet the Paris climate targets. Our understanding of these issues is already sufficient for deriving clear policy recommendations.
However, there are many other aspects of climate change that we don’t know well. For example, we have a poor understanding of how weather and storm systems will develop in the future, whether tropical cyclones will become more frequent, and how clouds and precipitation will change. These limitations have much to do with the fact that today’s climate models, to put it bluntly, are simply too fuzzy in many respects; they just don’t adequately resolve these phenomena and processes.
Shedding light on fundamental processes
Climate models place a grid over the Earth or ocean and calculate the state of the atmosphere for each cell; this helps us to understand and predict weather and climate better. The smaller the grid cell, the higher the resolution. Current global climate models typically have grid cells with a width of about 100 km (à link CMIP6).
2
As a result, these models don’t resolve key processes in the atmosphere or ocean, particularly processes that occur on a scale of just a few kilometres such as clouds and storms. This forces us to estimate the influence of these processes indirectly, using parameterisations. This leads to uncertainty in predictions, as clouds and storms determine not only our daily weather but are also crucial for climate.
In the recently started EXCLAIM research project
1
, we want to build on this achievement and develop the next generation of weather and climate models. The new models will provide a much higher resolution of the key processes in the atmosphere and oceans. Working within the Center for Climate Systems Modeling (C2SM), the research team will create the model and data infrastructure that will allow us to simulate storms, thunderstorms, and clouds on a global scale. This will lead to more reliable weather forecasts and more precise climate projections (see ETH News report à).
Are we betting on the right horse?
Of course, this also raises questions. Don’t we know already enough about climate change? What’s the point of making the weather forecast just that little bit better? Is it worth the enormous effort?
Indeed, we know already with high certainty that humans are responsible for most of the warming we observe. We understand the relationship between CO
2
emissions and temperature relatively accurately, and we have recognized that we need to reduce CO
2
emissions to net zero within the next few decades to meet the Paris climate targets. Our understanding of these issues is already sufficient for deriving clear policy recommendations.
However, there are many other aspects of climate change that we don’t know well. For example, we have a poor understanding of how weather and storm systems will develop in the future, whether tropical cyclones will become more frequent, and how clouds and precipitation will change. These limitations have much to do with the fact that today’s climate models, to put it bluntly, are simply too fuzzy in many respects; they just don’t adequately resolve these phenomena and processes.
Shedding light on fundamental processes
Climate models place a grid over the Earth or ocean and calculate the state of the atmosphere for each cell; this helps us to understand and predict weather and climate better. The smaller the grid cell, the higher the resolution. Current global climate models typically have grid cells with a width of about 100 km (à link CMIP6).
2
As a result, these models don’t resolve key processes in the atmosphere or ocean, particularly processes that occur on a scale of just a few kilometres such as clouds and storms. This forces us to estimate the influence of these processes indirectly, using parameterisations. This leads to uncertainty in predictions, as clouds and storms determine not only our daily weather but are also crucial for climate.
