Natural Influences on Earth’s Climate
Glaciers are normally considered indicators of climate change, but they also have an influence on climate.
If glaciers melt they release tremendous amounts of fresh water into the oceans. This can alter fluctuation and temperature patterns and in turn influence climate. Thus, reduction in glacier size on the one hand reflect the fact of climate having become warmer. In addition, the resulting release of fresh water into the oceans leads to additional changes. Glaciers are thus amplifiers of climate change.
Major historical events of ice breaks breaking off, drifting south and releasing fresh water into the oceans are called Heinrich Events. They often coincided with climate changes.
Below is a chart with Heinrich events during the last 70,000 years. Interestingly, they occur during a rapid cold spells prior to rapid warming events in Earth’s climate. Thus they are not a result of a warming climate.
On the chart below the dark green vertical lines indicate the times of Heinrich events. The brighter vertical bars are alternative estimates.
The most frequent Heinrich event dates back more than 10,000 years.