The assessment of climate change impact is a challenging research theme because of the complex methodological issues linking different research themes. The complexity of the climate system itself as well as the difficulty of economically valuing the impact of climate change in the future has led to the scientific community producing Integrated Assessment Models (IAMs) that take into account, in stylised way, the different economic impacts of climate change

TIAM-UCL has been developed by the UK Energy Research Centre from the ETSAP-TIAM model. Two external modules are available in TIAM-UCL: a climate module (Anandarajah 2011) and a damage function module (Lehtila 2005). The climate module is a simplification of the climate system incorporating emissions of three major greenhouse gases (carbon dioxide, methane and nitrous oxide) to calculate radiative forcing and temperature changes. The results of the climate system (temperature change) can been linked to simplified damage functions to calculate future costs brought by climate change.

We have extracted damage functions from the integrated assessment model PAGE09 (Hope 2011). After a recalibration of the climate module of TIAM-UCL using the latest version of the MAGICC climate model (Meinshausen et al. 2011), we have extrapolated data from the 8 regions within PAGE onto the 16 regions included within TIAM-UCL to produce TIAM-UCL-IAM.

Comparing future costs to present investments

Abatement costs are incurred in the present if we want to reduce emissions to mitigate climate change, but damage costs from climate change will occur into the future.  How should we value those future costs at the present time? The concept of a discount rate is an important one for this kind of modelling since it provides a way of translating future costs into present value. A larger discount rate tends to favour doing little at the present time, while a smaller discount rate tends to favour policies that take significant immediate steps to reduce greenhouse gas emissions (thus avoiding damages and costs further down in time). We apply a specific discount rate to the damage costs from climate change in TIAM-UCL-IAM.

Model summary

Type: Bottom-up, technology-rich cost optimisation integrated assessment model
Purpose: Assess global decarbonisation pathways in terms of the global temperature change
Spatial scale: 16-region global model
Temporal scale: 3 seasons (summer, intermediate, winter), 2 intra-day (day, night)
Main contact: Olivier Dessens
Other contacts: Gabrial Anandarajah


The process to create TIAM-UCL-IAM is described in the conference paper below. TIAM-UCL and PAGE09 documentation are also available.


Conference papers

Dessens O. and Anandarajah G. (2012) Soft coupling between the integrated assessment models PAGE and TIAM-UCL: climate change damage function and greenhouse gas emissions abatement costs. IEW2012, Cape Town, South Africa, June 19-21.


Anandarajah G., Pye S., Usher W., Kesicki F. and McGlade C. (2011) TIAM-UCL Global Model Documentation. UK Energy Research centre, London, UK.

Hope, C. (2011) The PAGE09 integrated assessment model: A technical description. Cambridge Judge Business School Working Paper. Cambridge, UK.

Lehtila A., Loulou R. (2005) TIMES Damage Functions. ETSAP TIMES Version 2.0 User Note. IEA-ETSAP.

Meinshausen M., Raper S. C. B. and Wigley T. M. L. (2011) Emulating coupled atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6 - Part 1: Model description and calibration. Atmospheric Chemistry and Physics 11(4): 1417-1456.