Final answer:
Proxy records are essential for understanding past climates and are not a limitation of large-scale climate reconstructions, despite other challenges such as time and expense, calibration requirements, and complex relationships with climate variables.
Step-by-step explanation:
When reconstructing large-scale climate data using proxy data, geologists face various limitations. However, the statement that 'Proxy records are meaningful records of environmental variables' is not one of those limitations. In fact, proxy records are invaluable for understanding past climates since the instrumental record is relatively short and doesn't provide a long-term perspective. Proxies such as foraminifera shells, ice cores, tree rings, and sediment cores give us insights into historical climate conditions. Despite being time-consuming and expensive, and requiring calibration, the relationship between proxy data and climate variables can also be complex, varying over time and sometimes lacking consensus among scientists on the exact formulas used for interpretation.