CHALLENGE 1: HOW AND WHY HAS CLIMATE CHANGED THROUGH EARTH HISTORY? WHAT ARE THE LESSONS FROM THIS PALAEO-RECORD FOR 2050 AND BEYOND?

  54.  Under this challenge we want to understand the patterns, rates and causes of change in atmospheric CO2 levels over geologic time; the consequences of changes in palaeo CO2 levels for ocean temperature, sea water acidity and oxygenation; the processes (and feedbacks) in addition to CO2 change (eg, ocean circulation strength and mode) that control (amplify) rapid changes in climate; the impact of these past changes on continental ice volume (sea level), biogeochemical cycling and global biodiversity.

CHALLENGE 2: WILL THE ATLANTIC MERIDIONAL OCEAN CIRCULATION SLOW DOWN AS A RESULT OF ANTHROPOGENIC CLIMATE CHANGE?

  55.  The present Atlantic Ocean circulation carries warm upper waters northward through the Atlantic, the waters gradually cool on their journey northward giving up heat to the atmosphere; in the subpolar and polar regions the surface waters become cold enough and salty enough to sink to the bottom forming cold deep waters; and this cold deep water returns southward through the Atlantic. This circulation is called the meridional overturning circulation (MOC); its size is estimated to be about 17 Sv and it transports 1.3 PW of heat northward, heat that is given up to the atmosphere leading to the equitable climate of northwestern Europe.

  56.  There is a clear need for observations of the Atlantic MOC and how it is changing over time. Recent analysis of five hydrographic sections suggested that the MOC at 25(°N has slowed by 30% over the past 50 years.[37] But how variable is the MOC on seasonal to interannual time scales? Is the 30% slowdown within the range of natural variability? Has the change been gradual as suggested by models or was it abrupt, occurring over a decade or less? It is essential to establish a baseline measure of the MOC strength and its seasonal to interannual variability to put wide-ranging and longer time series of Atlantic observations into an overall context of Atlantic (and global) climate change.

  57.  Recent results from the NERC RAPID Programme have shown the necessity to acquire data with sufficient temporal and spatial resolution (4D) in order to be able to extract long term trends from short term variability. In particular it demonstrates the needs for continuous measurements (long term observatories) and the development of autonomous survey.

CHALLENGE 3: HOW WILL THE BIODIVERSITY OF THE OCEANS ALTER WITH A CHANGING CLIMATE?

  58.  The Palaeo record clearly shows how species have changed with climatic conditions and we expect the same to be true in the future and there are implications for organisms both in the upper water column and the deep ocean. What will be the responses of biota (eg coral reefs) to ocean acidification?

CHALLENGE 4: WHAT LONG TERM MEASUREMENTS OF OCEAN SYSTEMS ARE NEEDED TO FOLLOW CLIMATE CHANGE AND TO MAKE PREDICTIONS MORE ROBUST?

  59.  The long term ocean stations in the North Pacific (HOT) and Atlantic (BATS), and zooplankton collection (SAHFOS) have demonstrated how patterns of ecosystem change in the surface ocean can emerge from high quality long term records. The RAPID programme has shown the potential to follow important changes in heat fluxes at an ocean scale. Additionally, continuous records are the only way to effectively assess the impact of episodic events such as plankton bloom events that may account for much of the C flux at a particular site. Therefore there is a need for collection of long time series data, with station locations and sampling/data collection strategies need to be carefully optimised, and there is scope for international cooperation.

CHALLENGE 5: WHAT ARE THE LINKS BETWEEN SURFACE OCEAN BIOGEOCHEMICAL AND PHYSICAL PROCESSES AND THE DEEP OCEAN WITH RESPECT TO PRODUCTION, STORAGE AND FATE OF CLIMATICALLY IMPORTANT MATERIALS?

  60.  The production of organic C and biogases in the upper ocean are anticipated to have important impacts on atmospheric gas concentrations (eg carbon dioxide, dimethyl sulphide and halocarbons). Vertical transfer to deeper long residence time waters of organic carbon (the biological pump) and carbon dioxide physically dissolved at the surface, through mixing and vertical particle transfer will remove carbon from the atmosphere and upper ocean. Key biogases produced in the ocean and released to the atmosphere are proposed to have important feedbacks on climate so knowledge of their production and fate is essential.

CHALLENGE 6: WHAT MODELS ARE REQUIRED TO EFFECTIVELY DESCRIBE THE OCEAN SYSTEM FOR PREDICTIONS TO BE MADE, AND FOR INTERFACING WITH MODELS OF ATMOSPHERIC AND TERRESTRIAL SYSTEMS?

  12.  Presently the challenge is to integrate ocean physics models with models of biology at increasing resolution in order to provide more rigorous predictions of the behaviour of the ocean system. Mesoscale processes have been identified as important and hence the need for higher resolution. Models of atmospheric inputs of gases and particles to the ocean, and release of climatically important gases, need to be effectively interfaced with models describing the atmosphere and terrestrial components of the planet. There is an increasing need to incorporate the role of shelf seas/coastal oceans in larger-scale modelling.

CHALLENGE 7: WHAT ARE THE CURRENT AND PROJECTED CHANGES IN SEA-LEVEL, AND WHAT WILL BE THE REGIONAL EFFECTS OF SEALEVEL CHANGE AND WHAT ARE THE SOCIO-ECONOMIC IMPACTS?

  62.  Sea-level change is important since it would directly affect coastal regions. In addition, it has an often overlooked impact on inland flood hazards, since sea-level rise elevates the base-level of rivers. The melt-water influxes into the oceans that cause sea-level rise can also affect oceanographic circulation, and hence heat-transport to high latitudes (notably NW Europe). It is therefore imperative that we develop an understanding of both the longer-term history of sea-level change and its modern variability—including the various processes that govern regional and global sea-level change—to underpin evaluations of the large-scale impacts of global (greenhouse) climate change. We especially need to constrain the magnitude and rate of potential global ice-volume reduction and hence sea-level rise. There is a need to be able to translate global predictions to local scales to be used by government to plan and prepare for environmental change.

CHALLENGE 8: WHAT CONTROLS DEEP OCEAN BIODIVERSITY?

  63.  Although originally thought to be of low biodiversity, the deep ocean is now known to be very biodiverse, this diversity composed of species in the small macrofaunal and meiofaunal size range. Such biodiversity is supplemented by the very different faunas found at, inter-alia, hydrothermal vents and cold seeps. Our knowledge of this biodiversity is increasing but ecosystem functioning is still imperfectly understood, particularly at temporal scales. Recent studies of the Atlantic have shown large regime shifts but we can only speculate as to their causes. Deep-sea technology has now advanced sufficiently that, for the first time, experimental manipulations in the deep ocean are now possible. This provides an important opportunity to address fundamental questions relating to the functionality (trophic, respiratory, reproduction and competition) in deep ocean ecosystems.

CHALLENGE 9: HOW CAN WE UNDERSTAND MICROBIAL BIODIVERSITY AND PROCESSES IN CONTRASTING ECOSYSTEMS?

  64.  Microbes are central to ecosystem processes. Their genetic biodiversity is immense yet their tiny size means "out of sight is out of mind". Recent research has identified physiological functions and genes that code for these functions. Many functions are strategically important; for instance, genes for nitrogen fixation, and other uniquely prokaryotic aspects of the marine nitrogen cycle, are now known to be diverse, originating from several different bacterial and archaeal groups. We do not know the implications of this and we do not know how these relate to similar processes in other ecosystems. Is there a common phenotypic or genotypic microbial diversity across terrestrial, freshwater and marine ecosystems?

CHALLENGE 10: WHAT ARE THE MAJOR GEOLOGICAL NATURAL HAZARDS FACING THE GLOBAL COMMUNITY? WHAT ARE THE CONTROLS ON THEIR LOCATION, FREQUENCY AND CHARACTER? WHICH IF ANY OF THESE CAN WE USEFULLY PREDICT? HOW CAN WE ESTIMATE OCCURRENCE PROBABILITIES AND MAGNITUDES FOR RISK/HAZARD ASSESSMENT?

  65.  The growth of mega-cities, particularly in Asia, means that the first natural event causing over a million deaths due to a large earthquake or Tsunami in the next 30 years is now highly likely. We need to invest in the science to tackle the questions related to earthquakes, tsunami, continental slope slumping and volcanic hazards. NOCS believes (and as also articulated in the Natural Hazards Working Group report chaired by Sir David King in response to the 2004 earthquake and tsunami) that hazard assessment is necessary for the implementation of early warning systems, that we must understand the threats and processes underpinning these hazards, and that greater support is needed to improve scientific methods used to assess risk.

CHALLENGE 11: CAN GEOLOGICAL CO2 SEQUESTRATION BE ACHIEVED ON THE SCALE REQUIRED TO MAKE A SIGNIFICANT CONTRIBUTION TO THE GLOBAL CARBON BUDGET, AND HOW DO WE MONITOR IT?

  What is a sustainable energy budget for the earth? What are the implications for human society?

How do we responsibly exploit geological energy resources?

  How do we improve hydrocarbon exploration methods? How do we improve recovery from known oil and gas resources? How do we better exploit geothermal energy? How should we exploit coal resources?