Here we provide the first results on the evolution of the Ayeyarwady delta, the last unstudied megadelta of Asia. In addition to its intrinsic value as a founding study on the Holocene development of this region, we advance new ideas on the climate control of monsoonal deltas as well as describe for the first time a feedback mechanism between tectonics and tidal hydrodynamics that can explain the peculiarities of the Ayeyarwady delta.

This article is a contribution to a special issue on "Two centuries of modelling across scales". It describes the historical observations, evolving hypotheses, and early calculations that led to the development of the field of glacial isostatic sdjustment (GIA) modelling, which seeks to understand feedbacks between ice-sheet change, sea-level change, and solid Earth deformation. Recent and future advances are discussed. Future progress will likely involve an interdisciplinary approach.

The role of mountain uplift and associated silicate weathering in the global climate over geological times is controversial. Previous soil column models suggest that weathering falls at a high denudation rate. We present the results of a 3-D model that couples erosion and weathering, a CO₂ consumer during mountain uplift. Our model suggests that the weathering of temporarily stocked colluvium may contribute significantly to the mountain weathering outflux at high denudation rates.

Sediments produced by glaciers are transported by rivers and wind toward the ocean. During their journey, these sediments are weathered, and we know that this has an impact on climate. One key factor is time, but the duration of this journey is largely unknown. We were able to measure the average time that sediment spends only in the glacial area. This time is 100–200 kyr, which is long and allows a lot of processes to act on sediments during their journey.

The layer known as the critical zone extends from the tree tops to the groundwater. This zone varies globally as a function of land use, climate, and geology. Energy and materials input from the land surface downward impact the subsurface landscape of water, gas, weathered material, and biota – at the same time that differences at depth also impact the superficial landscape. Scientists are designing observatories to understand the critical zone and how it will evolve in the future.