Climate change and rapid urbanisation will result in increasing water management problems in urban areas through this century. Urban areas are particularly vulnerable to the expected increase in extreme weather conditions induced by climate change due their high population densities and high concentration industrial and infrastructural assets. The most important challenge is to obtain reliable data about rainfall, wind and temperatures at the urban scale, which is currently unavailable.
The interaction between fine dust particles in the air, the formation of clouds and the effect of clouds on climate change may be easily explained, but is notoriously hard to capture in scientific models. Clouds keep out sunlight, cooling down the earth. But they also act as ‘blankets’ keeping the earth warm. A lot of particulates (condensation nuclei) in the air, means smaller droplets in clouds, meaning that it will take longer for a cloud to ‘rain out’. Global warming might cause more water to evaporate, but might also mean that the atmosphere can contain more water vapor. What does this all mean for cloud formation, their life cycles and the consequent effect on climate change? Clouds so far make up the largest unknown factor in climate models.
Scientists within the TU Delft Climate Institute are both monitoring clouds, using radar, lidar and special airplanes, as well as model their behavior, using supercomputers and advanced 3D visualization techniques.
Ice & Sea Level Change
How does the ice mass of Greenland, Antarctica or of glaciers change over time? What will be the effect on the sea level? Predicting phenomena like these is complicated. Regional differences in the Earth’s gravity field have to be taken into account, together with postglacial rebound (the ‘rebounding’ of the land when ice masses disappear), tectonic movements and potential changes in the Earth’s rotation. The interplay of such forces make 'sea level rise' a very regional phenomenon.
Satellite observations are essential in the understanding, modelling, and prediction of these processes. Researchers Of TU Delft Climate Institute work on the control and propulsion of satellites, the sensors on board, but also on the processing of the huge amounts of data generated by them. By combining all this with other datasets and geophysical models, we are working towards a better understanding of the workings of these global processes and their regional impact.
What is the impact of climate change on the water cycle and, conversely, how does the water cycle effect climate change? Observations are crucial: a recent publication has shown that the number of weather stations is in decline in many regions of the world, while the need to understand precipitation patterns are higher than ever, in view of climate change, catchment modification and population growth. Precipitation, run-off through cities or rivers, condensation and cloud formation even sedimentation are all element of the water cycle of which we don’t know enough in relation to climate change. With TU Delft as leading expert in the field of hydrology, this is an essential part of the research of TU Delft Climate Institute.
The two main topics within geo-engineering that TU Delft Climate Institute will focus on the capture and use of CO2, and Stratospheric geoengineering, more specifically, Solar Radiation Management (SRM).
We would especially like to draw more attention to recent developments in process technology which look promising. But if the response of society to counteract rising global temperatures is not implemented fast or effective enough, an intervention might be necessary to temporarily halt temperature increase. Solar Radiation Management offers such a temporary solution. A possible implementation of SRM is the injection of aerosols in the stratosphere, producing stratospheric clouds which reﬂect part of the incoming sunlight. This thin, high, long-lasting haze reflects a little sunlight, keeping us cool. Check this news article for more information: TU Delft students design new aircraft for last resort option of geoengineering.
We can’t stress enough that we have to be very reluctant in applying techniques like these, as we don’t know their influence on the earth system, we haven’t considered legal en ethical aspects enough, and we may even increase the problem by temporarily masking temperature rise. But there may come a time when we will actually be needing techniques like these, like it or not. The sooner we start investigating practicalities, potential pitfalls and consequences, the better prepared we will be.