Temperature record of the past 1000 years

A reconstruction is needed because a reliable surface temperature record exists only since about 1850.

Studying past climate is of interest for scientists in order to improve the understanding of current climate variability and, relatedly, providing a better basis for future climate projections.

In particular, if the nature and magnitude of natural climate variability can be established, scientists will be better positioned to identify and quantify human generated climate variability.

Although temperature reconstructions from proxy data help us understand the character of natural climate variability, attribution of recent climate change relies on a broad range of methodologies in addition to the proxy reconstructions.

By far the best observed period is from 1850 to the present day.

Over this period the recent instrumental records, mainly based on direct thermometer readings, has approximately global coverage.

It shows a general warming in global temperatures.