Final answer:
The southern hemisphere is significantly under-sampled in climate proxy records over the past 1000 years, leading to a geographical bias in the data. Ice cores, especially from Antarctica, are crucial for providing past climate information despite the under-sampling.
Step-by-step explanation:
The southern hemisphere is significantly under-sampled when considering proxy records of the climate for the past 1000 years. Proxy records such as tree rings, corals, and ice cores provide valuable data for reconstructing the Earth's climate history.
However, due to the abundance of the oceans and challenges in data collection, the southern hemisphere has not been sampled as extensively as the northern hemisphere.
This results in a geographical bias in the climate records. It's essential to address this under-sampling to obtain a more accurate understanding of global climate trends and anomalies, such as the Medieval Climate Anomaly and the Little Ice Age. Antarctic ice cores however, provide a valuable record of past climates, revealing information about temperature and carbon dioxide levels trapped within the ice.