The full programme book (PDF) - Royal Geographical Society

THEME 3: MEASURING AND UNDERSTANDING CLIMATE CHANGE
Measuring and understanding climate change: a brief retrospective
Danny McCarroll
Department of Geography, Swansea University, Singleton Park, Swansea SA2 8PP
Over the last 50 years, huge advances have been made in quantifying the magnitude and
rate of past climate changes and in understanding those changes. At glacial/interglacial
timescales the dominance of orbital forcing has now been clearly demonstrated using
evidence first from marine sediment cores and later from polar ice cores. At the scale of
the last glacial cycle there have been advances in our understanding of the extent and
timing of glaciation, and in the early days of the QRA the CLIMAP project attempted to
quantify the climate of the last glacial maximum, particularly away from the large ice
sheets. The large fluctuations in climate at the end of the last glaciation, resulting in the
‘Windermere interstadial’ and ‘Loch Lomond stadial’ have been a major focus of British
Quaternary research since the earliest days of the QRA. The swings in climate were first
demonstrated using pollen records, but it was fossil beetles (coleoptera) that illuminated
the magnitude and incredibly rapid rate of warming. The Lateglacial swings in climate
have now been investigated using every conceivable proxy, but enthusiasm to work on
this time period never wanes, despite arguments that it has limited relevance to our
understanding of current and future climate change.
It is unsurprising that the spectacular swings in climate of the glacial cycles and the
Lateglacial should have attracted so much interest, but the QRA also has a long history of
working on the much more muted changes of the Holocene. Given current concerns about
anthropogenic greenhouse warming the climate of the Holocene, and particularly the late
Holocene, has suddenly been thrown into focus. If we are to successfully model the
climate of the future we need to calibrate and test our models using climate
reconstructions under current boundary conditions. However, providing accurate and
precise quantification of the subtle climate changes of the Holocene pushes our available
techniques to and frequently well beyond their limits. Understanding why climate has
changed, and in particular deciphering the difference between forced and unforced
changes, and between the effects of changes in solar radiation, volcanism and
greenhouse gasses has become increasingly urgent and politicized.
Keywords: Climate Change; Lateglacial; Holocene