**The Value of Multi-proxy Reconstruction of Past Climate**

**Data**:

- North hemisphere temperature data from climate model: data
- Volcanism: data
- Solar: data
- CO2: data
- 15 temperature series to generate synthetic tree rings – data
- 10 composite temperature series to generate synthetic pollen – data
- 5 composite temperature series to generate synthetic borehole profile – data
**R code for 40 reconstructions correponding to Figure 5**

**Five models**:

**(T)**Reconstruction using “oracle” proxy**(D)**Reconstruction using tree-ring**(DP)**Reconstruction using tree-ring and pollen**(DB)**Reconstruction using tree-ring and borehole**(DBP)**Reconstruction using tree-ring, pollen and borehole

**R files for each of five models under 2^3 factorial designs**:

(For each scenario, there is a **Common** R file that reads the data and define functions and is shared by five R files for each model)

- With forcings, without proxy noise, modeling T: Common, (T), (D), (DP), (DB), (DBP)
- Without forcings, without proxy noise, modeling T: Common, (T), (D), (DP), (DB), (DBP)
- With forcings, without proxy noise, modeling T1: Common, (T), (D), (DP), (DB), (DBP)
- Without forcings, without proxy noise, modeling T1: Common, (T), (D), (DP), (DB), (DBP)
- With forcings, with proxy noise, modeling T: Common, (T), (D), (DP), (DB), (DBP)
- Without forcings, with proxy noise, modeling T: Common, (T), (D), (DP), (DB), (DBP)
- With forcings, with proxy noise, modeling T1: Common, (T), (D), (DP), (DB), (DBP)
- Without forcings, with proxy noise, modeling T1: Common, (T), (D), (DP), (DB),(DBP)

**Supplement Material** (pdf)