1. Institute of Education and Humanities, University of Wales Trinity Saint David, Lampeter, SA48 7ED, UK
2. Department of Geography, Swansea University, Singleton Park, Swansea SA2 8PP, UK
3. Laboratoire des Sciences du Climat et de L’Environnement, UMR 8212, L’Orme des Merisiers, Gif-sur Yvette, France.