Université du Québec à Montréal
Taming climate complexity at the regional level
The Earth is warming – that much we know. Global temperatures have risen an average of 0.8°C since 1880. But what is in store over the next 100 years? And what will climate change’s effects be where you live? The answer is “it depends.”
“No one really knows how much humans will continue to emit greenhouse gases,” says Université du Québec à Montréal climate modeller René Laprise. “It depends on political and public will, and on technological developments. So we need to model optimistic, pessimistic and intermediate emission scenarios.”
Laprise’s specialty is modelling at the regional level hugely complex systems involving interactions between the atmosphere and the Earth’s land and water. These interactions are in turn influenced by factors such as Earth’s rotation rate, gases in the atmosphere, the depth of the oceans, land use patterns, mountains’ heights, and the intensity of the sun.
Predicting the effects of so many competing influences for a specific region requires sophisticated software that uses the laws of physics to calculate changes over time for precipitation, temperature, ocean salinity, sea ice, snow cover and other outcomes.
It also requires powerful research computing. That’s because every point in a 3D grid simulating land, water and atmosphere is intimately connected: “Each point ‘talks’ to its neighbours and affects them, and is affected by them,” says Laprise.
Of course, running such complex simulations can’t be done without a lot of storage space – on the order of several terabytes. “We have to interrogate huge amounts of stored data to get statistical information for projecting climate several decades ahead,” says Laprise.