Unusual Changes - How Do We Know?

The video discusses the history of Earth's temperature over the last millennium, focusing on the 'hockey stick' result, which synthesizes regional climate data into a single record. This record shows that recent warming is unusual compared to past periods like the Little Ice Age and the Medieval Warm Period. The entire planet has been warming in unison over the past century, forming the 'blade' of the hockey stick, while previous centuries showed moderate variations, forming the 'handle'.

What does the study suggest about the warming of the entire surface of the Earth?

Describe the difference between the 'blade' and the 'handle' of the hockey stick.