I completed my PhD in 2001 at the University of East Anglia and have since worked in a mix of government, academia and research SMEs across 4 countries (UK, USA, Norway and Ireland). My main historical interests have been in the investigation of observed climate changes globally, with a particular emphasis upon temperature and humidity changes from in-situ measurements (marine, land and weather balloon). I have also undertaken publication on detection and attribution (which was the subject of my PhD thesis) and atmospheric reanalyses.

I am the chair of the International Surface Temperature Initiative which consists of an interdisciplinary effort to create a suite of improved Land Surface Air Temperature products to meet science needs and societal expectations in the era of climate services. The initiative has four principal aims:
  • Improving the completeness and provenance of available basic data holdings
  • Promoting the development of novel techniques of homogenization to the basic data holdings
  • Benchmarking the performance of candidate techniques of homogenization against synthetically produced analogs to the real world holdings
  • Provision of products, tools, and guidance to end-users
I am co-chair of the GCOS Working Group on the Global Climate Observing System Reference Upper Air Network (GRUAN). The GRUAN network aims to instigate a maintain on a multidecadal basis a high quality reference network of traceable and comparable measurement capabilities at a subset of global locations in support of monitoring, characterising broader aspects of the global observing system (including satellites) and process understanding. I am also the project lead on the Horizon 2020 GAIA-CLIM project which aims to use such measurements to better characterise satellite measurements.

I was a Lead Author on 5th Assessment report of the Intergovernmental Panel on Climate Change and the 2014 US National Climate Assessment. I was also a Lead Author on the US CCSP1.1 report on atmospheric temperature trends. Over 2009 to 2015 I was an editor on the global chapter of the annual State of the Climate series of reports in BAMS.