Global climate change is amongst the most important scientifically-driven issues challenging policymakers around the world. In his article in Science, the UK Government's Chief Scientist - then Sir David King - stated his view that "climate change is the most severe problem that we are facing today more serious even than the threat of terrorism" [Policy Forum, Science, Vol 303, Jan 2004].

At the heart of the conflicting responses to the climate change issue is the need to establish and quantify the key mechanisms and feedback processes involved.

NPL has been involved in some of the key measurement issues in the climate change debate, and some examples of this research is given below:

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  NPL-NIWA FTIR
  intercomparisonRadiative Balance
  • The discrepancy between measured and modelled radiative transmission through the atmosphere is one of the major uncertainties in climate change research. A project has been carried out at NPL to address this issue by carrying out accurate ground-level measurements of the atmospheric transmission of incoming solar radiation and combining them with high-resolution radiative modelling.
  • The project was a collaboration combining the complementary expertises of the Quality of Life Division at NPL and the Meteorology Department at the University of Reading.
  • The instrument used for the measurements was the Analytical Science Team’s high-resolution Fourier Transform Infrared (FTIR) spectrometer with absolute radiative calibration provided by the Optical Radiation Measurement Team's Ultra-High Temperature Black Body (UHTBB) facility.
  • The results from the solar measurements were compared with the results of a detailed line-by-line radiative transfer model developed by the University of Reading to identify and quantify the discrepancies and assess the global impact of the results.
    
    
• Water Vapour Continuum
  • NPL is playing a major role in a new atmospheric science research project - Continuum Absorption in the Visible and Infrared and its Atmospheric Relevance (CAVIAR).
  • This Cross-Research Council (NERC, EPSRC) project also includes the University of Reading, Imperial College, the Met Office, RAL, UCL, University of Cambridge, and University of Leicester and runs from 2006 to 2010.
  • The project involves combined research from laboratory and theoretical spectroscopists, field measurement and atmospheric modelling groups to resolve a major uncertainty in climate change and atmospheric science – the water vapour continuum absorption across the infrared region.
  • NPL’s contribution involves measurements of solar transmission using the atmospheric sensing capabilities of the Analytical Science Team with radiometric calibration for all of the field measurements provided by the Optical Radiation Measurement Team.
    
    
• Trends in Atmospheric Species
  • A key element of the climate change issue is understanding the atmospheric behaviour of radiatively active gases (direct greenhouse gases), and also gases involved in the chemical production of greenhouse gases (indirect greenhouse gases).
  • Long-term measurements of such gases provide the experimental data to study the evolution of these gases and the changing sources and sinks. These data are often expressed in terms of an annual trend in the amount of a particular gas.
  • In order for these trend results to be used appropriately it is vital that the uncertainty associated with the trend value is properly quantified. An accurate determination of the trend value is challenging due to influence of large seasonal variations and other effects reflected in the data.
  • NPL has developed and implemented a trend analysis method to determine the annual trend and associated uncertainties, based on a statistical model that makes minimal assumptions about uncertainty distributions associated with the raw data.
  • The method has been applied to measurements of direct and indirect greenhouse gases measured by a network of ground-based solar Fourier Transform Infrared (FTIR) sites across Europe. These sites for part of a larger international framework - the Network for Detection of Atmospheric Composition Change (NDACC). This is a global network of research groups around the world making continuous long-term (20+ years) ground based atmospheric measurements, to monitor trends and use for satellite validation.
  • NPL also operate a reference travelling standard FTIR for NDACC. This reference instrumentation uses a well characterised high resolution spectrometer to measure the concentration profiles of a wide range of key atmospheric species involved in stratospheric and climatic change.
  • NPL's research ensures that these measurements are accurate, and intercomparable, and can be used for detecting long-term trends.
    
    
• Greenhouse Gas Emissions
  • NPL have provided measurement support and research looking at the measurement of emissions of key greenhouse gases (GHGs), including the development of high accuracy calibration standards of GHGs.
  • NPL has developed new measurement methods to quantify landfill emissions, enabling UK government to improve the UK National Emissions Inventory.
  • Recent research in collaboration with the University of Sheffield has looked at the possible emission of GHG’s from plants.

Please also see our Environmental Research and Policy page