Details of Award
NERC Reference : NE/T007109/1
Past methane from lakes in Alaska: integrating proxy records and models
Grant Award
- Principal Investigator:
- Dr M van Hardenbroek, Newcastle University, Sch of Geog, Politics and Sociology
- Co-Investigator:
- Dr J Whiteside, University of Southampton, Sch of Ocean and Earth Science
- Co-Investigator:
- Professor M Edwards, University of Southampton, Sch of Geography & Environmental Sci
- Grant held at:
- Newcastle University, Sch of Geog, Politics and Sociology
- Science Area:
- Atmospheric
- Freshwater
- Terrestrial
- Overall Classification:
- Panel A
- ENRIs:
- Global Change
- Science Topics:
- Palaeoenvironments
- Climate change
- Lake sediments
- Palaeo proxies
- Palaeoecology
- Sediment/Sedimentary Processes
- Methanogenesis
- Biogeochemical Cycles
- Carbon cycling
- Isotopic analysis
- Lake sediments
- Microbial communities
- Wetlands
- Abstract:
- Increasing concentrations of greenhouse gases in the atmosphere trap heat and cause global warming. Methane is key, as it is 28 times more potent than carbon dioxide in trapping heat. Unfortunately, there is great uncertainty in how the amount of methane in the atmosphere will change under future conditions, so we urgently need more accurate numbers for future methane emissions as the Earth continues to warm. This proposal will make a radical new contribution by providing much better constrained estimates of methane contributions from lakes in Alaska, as an example of a high-latitude region susceptible to global warming. The high northern latitudes are particularly important to climate change effects because climatic warming is accentuated toward the poles, which will accelerate biological processing of carbon, including the production of methane. The uncertainty in future atmospheric methane content reflects the fact that emissions are caused by human actions and natural processes that are themselves affected by climate change. Lakes form one of the largest natural sources of methane. Lake methane production strongly increases in warmer and wetter conditions, leading to more methane entering the atmosphere, where it contributes to further warming. This is an important positive feedback mechanism that could have large impacts on future global climate. This climate-methane feedback is strongest at high latitudes, where lakes are very abundant and recent warming is most severe. However, because temperature is only one of several factors that are likely to affect methane release from lakes and wetlands, the extent of the methane feedback can only be understood through careful numerical modelling. In the past, warmer-than-present climatic conditions prevailed in interior Alaska between 11,000-6,000 years ago. If we can understand how methane behaved under these conditions, we will be in a better position to anticipate future change. We can do this by deriving data directly from lake sediment records coupled with a model to simulate the processes of methane generation and emission. Comparison of model output and observed data forms a powerful hypothesis-testing system that we can use to ascertain how much methane emissions have changed in the past, and why they changed. This study's observed record comes from dated lake sediments. Lake sediments accumulate continuously and preserve records of chemical and biological processes plus information about past climate. Studying these records will allow us to reconstruct information on past methane emissions. Key factors for methane emissions (temperature, water level, organic matter availability, oxygen regime) will also be reconstructed and modelled, which allows us to understand the processes behind lake methane emissions. Our study focuses on lakes in Alaska because this region is well-studied compared with other high-latitude areas, with extensive background information about past climate and carbon cycling. We will reconstruct methane emissions from lakes that were 2-5 degrees warmer 11,000-6,000 years ago, compared with today. We will use a new, quantitative tool for estimating past methane emissions from lakes based on the chemical composition of fossils in sediment records. We will also adapt an existing numerical model that simulates present-day methane emissions to estimate past and future methane emissions. Our integrated approach, combining geochemical measurements and modelling, will allow us to: (1) assess the magnitude of methane emissions through time, (2) identify the key factors driving methane emissions, (3) find critical values for these factors that lead to change, and (4) understand how factors interact to produce observed methane emissions. Our numerical methane model, refined through comparison with empirical observations, will then allow us to make robust estimates for how much greater a contribution lakes may have to atmospheric methane in the future.
- NERC Reference:
- NE/T007109/1
- Grant Stage:
- Awaiting Event/Action
- Scheme:
- Standard Grant FEC
- Grant Status:
- Active
- Programme:
- Standard Grant - NI
This grant award has a total value of £519,895
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DA - Estate Costs | DI - Staff | DA - Other Directly Allocated | DI - T&S |
|---|---|---|---|---|---|---|
| £42,530 | £163,619 | £63,800 | £37,650 | £143,129 | £25,892 | £43,273 |
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