3 Projects, page 1 of 1
Carbon dioxide and methane are the most important long-lived greenhouse gases causing global warming and climate change. These two gases, which are the major components of the global carbon cycle, are added to and removed from the atmosphere in a wide range of ways, from both natural and human activities. Wetlands are the largest natural source of methane and methane emissions from wetlands are expected to increase in a warming world. Further, in high northern latitudes, large amounts of carbon are stored in frozen soils or permafrost. The polar regions are warming faster than other parts of the Earth. As these soils warm causing the permafrost to thaw, the stored carbon can be converted by microbial activity over time and released to the atmosphere as carbon dioxide or methane, leading to further warming and hence a positive feedback. Combined with landscape changes, this may lead to the formation of new wetlands resulting in further emissions of methane. Wetlands and permafrost thaw are therefore important biogeochemical processes that need to be included in models of the Earth's climate. Through their inclusion, climate, or now Earth System, models will then account for the feedbacks that wetlands and permafrost thaw produce on the physical climate system (e.g., on future temperature changes). Following the international climate agreement in 2015 to limit future temperature rises to less than 1.5-2 degrees centigrade above pre-industrial levels, there is an urgent need to quantify this contribution of wetlands and permafrost thaw as this will constrain the accumulated emissions of greenhouse gases that can be released from human activities such as fossil fuel combustion if global temperatures are to be stabilised. In this study, we will use the UK community state-of-the-art land surface model, the Joint UK Land Environment Simulator (JULES) to model wetlands and permafrost thaw. We plan targeted development of the land-surface model to enhance its capability for considering wetlands, permafrost thaw, methane and carbon dioxide emissions in a more consistent and integrated manner. For this work, we will use this improved version of JULES with a simplified but robust climate emulator, IMOGEN. IMOGEN replicates the behaviour of a wide range of more complex and resource intensive climate and Earth System models that contributed to the latest climate change assessment of the IPCC. We will undertake model runs with the JULES-IMOGEN modelling system (a) to assess the impact of Arctic carbon releases that are not included in many climate models, (b) to quantify the corresponding climate feedbacks and the impact of these additional emissions on allowed human emissions for 1.5 or 2 degree C climate stabilisations. The research proposed will provide important evidence to support the commitments made in the Paris Agreement to 'strengthen the global response to the threat of climate change.... and to pursue efforts to limit the temperature increase to 1.5 degree C above pre-industrial levels'. The outputs of the work will include: * papers for publication in the scientific literature, which will be included in the special IPCC assessment of the IPCC * wetland methane emission datasets for current day and future conditions that will be of value for the atmospheric modelling community The project links to and will complement ongoing work at the Met Office, our project partner, for the UK government.
We all love the idea of having a robot to do our bidding. Scientists are realising that robot technology now offers exciting possibilities to observe our environment in ways we have only dreamt of. We will use a fleet of three robots roaming the ocean near Antarctica to answer science questions that are critical to our ability to predict and manage the ocean and its living resources in an era of unprecedented change. The robots we will use are called ocean gliders. Much like the familiar airborne gliders, they do not have a propeller. Batteries drive a pump to move fluid between one area within the glider and another outside its hull, thus changing whether the glider is denser than seawater, so it sinks, or less dense than seawater, so it rises to the sea surface. It glides up and down, communicating via mobile phone with the scientists controlling it each time it comes to the surface. Oil prices have risen sharply in recent years, and ships use a great deal of oil. Using gliders as part of our future ocean and climate observing systems will save tax-payers' money since some ocean observations can be done much more efficiently by remotely controlled gliders. Gliders can also observe the ocean when we'd really rather not be there with ships, such as in winter or in strong winds and heavy seas. This project plans to show that these possibilities are within our grasp. We have assembled a multidisciplinary team of scientists who together are grappling with puzzles about how the ocean system works around Antarctica. Dense cold water sinks around the continent of Antarctica when cold wind blows over the water and helps sea ice to form. We've known for nearly 100 years that this happens in the southern Weddell Sea. We think that this might now be happening in a new region, because of the recent collapse of the Larsen Ice Shelf. Our gliders will measure the amount of dense water spilling off the continental shelf. This is important because climate models suggest that the amount and properties of this dense water are likely to impact on the global ocean overturning circulation that controls our climate; we need to know if these are changing. This dense water spilling over the continental slope probably also affects where the ocean currents are. So these currents might be moving further onshore or offshore, as the dense water changes. We'll try to measure and understand this. These changes in the ocean currents also affect the animals living in the waters near Antarctica. Krill are shrimp-like creatures that form the prey for animals such as whales, seals and penguins, not to mention underpinning a multi-million pound krill fishing industry (ever had a krill pizza?). Krill lay their eggs around the Antarctic Peninsula, and are then carried across the Scotia Sea to South Georgia by the ocean currents. Whilst the west Antarctic Peninsula is well surveyed, we don't know how many krill are in the Weddell Sea, on the eastern side of the Peninsula, possibly spending the winter under sea ice. Might the changes in ocean current affect whether these krill reach South Georgia? If we can establish that the krill are surviving under the ice and could travel to South Georgia, it may be that marine mammals and the krill fishing industry will be less vulnerable to climate change than we have feared. In which case, krill may become a more important food resource for us humans too in an uncertain future; you never know, the krill pizza may find its way to your local supermarket before long!
The burning of fossil fuels is releasing vast quantities of extra carbon dioxide to the Earth's atmosphere. Much of this stays in the atmosphere, raising CO2 levels, but much also leaves the atmosphere after a time, either to become sequestered in trees and plants, or else to become absorbed in the oceans. CO2 staying in the atmosphere is a greenhouse gas, causing global warming; CO2 entering the sea makes it more acidic, and the ongoing acidification of seawater is seen in observational records at various sites where time-series data are collected. The changing chemistry of seawater due to ocean acidification is mostly well understood and not subject to debate. What is much less well known is the impact that the changing chemistry will have on marine organisms and ecosystems, on biogeochemical cycling in the sea, and on how the sea interacts with the atmosphere to influence climate. We will look to investigate these questions in terms of how the surface waters of the world's oceans, and the life within, will respond to ocean acidification. Most of what we know about biological impacts, and the source of the current concern about the impact on marine life, comes from experimental studies in which individual organisms (e.g. single corals) or mono-specific populations (e.g. plankton cultures) have been subjected to elevated CO2 (and the associated lower pH) in laboratory experiments. These laboratory experiments have the advantage of being performed under controlled conditions in which everything can be kept constant except for changes to CO2. So if a response is observed, then the cause is clear. However, there are also limitations to laboratory studies. For instance, organisms have no time to adapt evolutionarily, and there is no possibility of shifts in species composition away from more sensitive forms towards more acid-tolerant forms, as might be expected to occur in nature. Another shortcoming is the absence of food-web complexity in most experiments, and therefore the absence of competition, predation, and other interactions that determine the viability of organisms in the natural environment. We seek to advance the study of ocean acidification by collecting more observations of naturally-occurring ecosystems in places where the chemistry of seawater is naturally more acidic, and/or where it naturally holds more carbon,as well as locations which are not so acidic, and/or hold more usual amounts of carbon. By contrasting the two sets of observations, we will gain an improved understanding of how acidification affects organisms living in their natural environment, after assemblage reassortments and evolutionary adaptation have had time to play out. Most of the planned work will be carried out on 3 cruises to places with strong gradients in seawater carbon and pH: to the Arctic Ocean, around the British Isles, and to the Southern Ocean. As well a making observations we will also conduct a large number of experiments, in which we will bring volumes of natural seawater from the ocean surface into containers on the deck of the ship, together with whatever life is contained within, and there subject them to higher CO2 and other stressors. We will monitor the changes that take place to these natural plankton communities (including to biogeochemical and climate-related processes) as the seawater is made more acidic. A major strength of such studies is the inclusion of natural environmental variability and complexity that is difficult or impossible to capture in laboratory experiments. Thus, the responses measured during these experiments on the naturally-occurring community may represent more accurately the future response of the surface ocean to ocean acidification. In order to carry out this experimental/observational work programme we have assembled a strong UK-wide team with an extensive track record of successfully carrying out sea-going scientificresearch projects of this type.