Final answer:
Accelerated glacial melt leads to glacier retreat and contributes to rising sea levels. The melted glacier water contributes more to the lake's level than the iceberg since it adds new water to the system.
Step-by-step explanation:
When glacial ice melts at a faster rate than the glacier moves forward, the glacier experiences a net loss in mass. This imbalance can lead to glacier retreat, where the terminus or the end of the glacier moves back towards its source.
Because glaciers act as reservoirs of fresh water, their accelerated melting contributes to rising sea levels and changes in local ecosystems. In the given scenario, where an iceberg and a glacier near the North Pole are melting, the melted glacier water entering the lake will increase the level of water more than the melting iceberg.
This is because the iceberg is already floating on the water, whereas the glacier on land will add additional water to the lake that was previously stored as ice on land.