Large blooms of single celled phytoplankton which make their shells out of silica, the diatoms, are responsible for transporting the majority of carbon from the surface ocean to the deep ocean. Changes in the productivity of diatoms therefore control how much carbon dioxide resides in the atmosphere and how much is conveyed and stored in the deep ocean. The aim of this proposal is to investigate the role of diatoms in driving changing climate on long and short timescales using a characteristic and novel signature of diatom productivity, namely the d30Si. Our intention is to find out whether major changes in diatom productivity which would have enhanced the draw-down of carbon dioxide from the atmosphere to the deep ocean, during the last ~ 50 Myrs could have contributed to Earth's transition from a greenhouse world with no or little ice, to the modern ice house world with the current bipolar ice sheets. Further, we aim to build on some preliminary evidence that diatoms are flourishing with global warming and find out whether diatom productivity could act as a negative feedback on anthropogenic emissions of carbon dioxide. As glaciers retreat around Antarctica and the meltwater flux increases into this highly productive coastal zone, there is the potential for increased input of nutrients and also enhanced stability of the water column, each of which can lead to enhanced diatom productivity. We shall construct a record of diatom productivity, again using d30Si, over the last 500 years in rapidly accumulating sediments of the Antarctic Peninsula. By targeting the last 500 years, our analyses will capture the last glacial advance and recovery from the Little Ice Age period (ending 1850) of the Holocene and allow us to test whether diatoms consistently increase productivity as glaciers retreat, and assess whether the diatom response to the anthropogenically forced glacial retreat is unprecedented on this timescale.

There is growing evidence that our increasing consumption of fossil fuels is leading to a change in climate. Such predictions have brought new urgency to the development of clean, renewable sources of energy that will permit the current level of world economic growth to continue without damage to our ecosystem. Photovoltaic cells based on organic or organic/inorganic hybrid materials have shown rapid improvements over the past decade, comparing favourably with existing inorganic semiconductor technology on energy, scalability and cost associated with manufacture. The most promising materials for organic or hybrid photovoltaics are based on blends of two components at whose interface light-generated excitations dissociate into charges contributing to a photocurrent. Blend morphology on the meso-scale plays a crucial role in these systems, with efficient photovoltaic operation requiring both large interfacial area and existence of carrier percolation paths to the electrodes. The proposed work will establish how both aims can be achieved, using a powerful new combination of non-contact femtosecond time-resolved techniques to examine a range of novel mesoscopic blends. This methodology will allow the simultaneous examination of exciton diffusion and dissociation, charge-carrier generation, recombination and conductivity, providing direct clues to the optimisation of materials for photovoltaics. Collaborations with researchers working on making photovoltaic devices will ensure that knowledge gained from these non-contact material probes will directly feed into enhancing device performance. This combined approach will allow the UK's exceptionally high expertise in the area of organic electronics to contribute effectively to its current goal of reducing harmful greenhouse gas emission.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

We propose a new seagoing research campaign in the Mid Pacific and the Emperor's Seamount Chain regions. Specifically, we are interested in the architecture and geometries of reefs situated atop of ancient volcanoes. In mid-ocean setting, corals and other carbonate producers tend to form significant reefs whenever a shallow substrate is available. As postulated by Darwin in the late 1800's, when the volcanic island sinks into the Earth mantle (a process called subsidence) the reefs keep growing and producing sediments, often forming a carbonate island known as an atoll. Sometimes, atolls can have a lagoon in the middle, where the volcano formerly stood. Interestingly, atolls can live for millions of years, but can also die and drown below the surface of the ocean. Drowned atolls are referred to as "guyots". A series of guyots in the mid Pacific piqued our interest. There the production of reefs extends from the Early Cretaceous (about 110 million years ago) to the Oligocene (about 30 million years ago) and to the present. Interestingly, the chemistry of the ocean has changed dramatically during this period: in the Early Cretaceous, the ocean was known as a 'calcitic sea', where the mineral calcite was preferentially precipitated. Somewhere between 50-30 million years ago, the chemistry of the oceans changed and we are now in an 'aragonitic sea', where most of the carbonate production is dominated by the mineral aragonite. Exactly why the chemistry of the ocean has changed remains only partially known, but a probable cause is that global climate had fundamentally changed from the Early Cretaceous warm, ice-free, high CO2 concentration world to the cold, punctuated glaciations and low CO2 concentration world of the recent past. There are two main things we wish to understand with this campaign. The first being the nature of carbonate production across this calcite to aragonite transition, and how the architecture of the carbonate atolls might have adapted in response to this chemical change. Understanding how past carbonates adapted to a different chemistry of the ocean is crucial for predicting how modern climate change will impact corals and other carbonate producers. For instance, will the change in chemistry force carbonate producers such as corals deeper/shallower in the water column? This would impact the geometry of the atoll. Our second objective is to understand by how much global sea-level might have change across the time interval of interest. Current global warming results in the melting of ice sheets at high-latitude, and dramatic sea-level rise. Looking at past example of sea-level changes allows us to calibrate by how much sea-level rises during global warming events. Quantifying the rate of sea-level change can be achieved in carbonates because the reef is growing very close to sea-level, so if we can track the position of the reef and how it changes through time, we can reconstruct global sea-level. For the Cretaceous to Eocene (our window of interest), this is poorly understood. To achieve our two main objectives, we need to collect data on 6 different drowned atolls (guyots); this ensures that we cover the entire geological period of interest, as each atoll is of a slightly different age. The primary data we will use in this research is known as seismic reflection: we send small seismic waves towards the bottom of the sea, and by reconstructing the time of arrival of the reflected seismic waves we can reconstruct the architecture of the atoll. In the future, we plan to select a few 'best' targets based on our data to go back to these atolls and sample the rocks using deep-sea scientific drilling.

This proposal falls under the Agriculture theme. Our research entails two projects that examine the impact of rural land rights on the decisions and outcomes of farmers in China. In the first project, we are interested in how giving farmers the legal right to lease their land may affect their ability to improve their outcomes. There are two particular ways through which we think that individuals' decisions may be changed by the introduction of leasing rights in a context where farmers previously only had use rights and could not legally engage in any market land transaction such as selling or renting. First, leasing rights may allow farmers to adjust and optimize the size of their land-holdings by renting in or renting out land. Second, the ability to lease out land may allow farmers to leverage the value of their property without working the land themselves. In this way, land leasing rights may alleviate constraints on labor mobility and allow some farmers to migrate to urban areas to pursue different labor market opportunities. We combine economic theory and detailed micro-level data to analyze this question. This research agenda can have potentially important implications for agricultural productivity and the flow of labor towards new economic opportunities both in China and in many other developing countries where institutions that enable private property rights are underdeveloped. In the second project, we are interested in thinking about the determinants of the types and the terms of the contracts that farmers sign when allowing other farmers or agricultural firms to use their land. After understanding the choices made by farmers regarding land contracts, we will analyze the impact of these contract choices on agricultural investment and productivity. This research agenda builds on economic theories that suggest that some types of contracts may lead to lower investment and lower levels of productivity. For example, farmers may enter into contracts that reduce their incentives to make profitable investments in the land in order to obtain insurance against negative shocks. This analysis makes use of a land reform that occurred in some areas of rural China where farmers were allowed to use their land as capital investment to enter into profit-sharing contracts with large-scale agricultural firms. Because our research project has a novel focus on contracts with both agricultural firms and with other individuals, we will collect a new data set that includes detailed information from both farmers and agricultural firms on their agricultural investments and outputs as well as on the contracts between these parties. This research will provide valuable insight into how land market interactions among farmers and between farmers and agricultural firms affect rural economic growth. In addition, the results of this project can also provide policy-relevant implications for process of economic transition associated with the rise of large-scale agricultural farming.