*** IMPORTANT NOTICE ***

16 Dec 2004: A minor error has been found in the MAGICC code in the calculation of weights for aerosol patterns. This only affects results for output years 2098, 2099 and 2100 (or, for scenarios that are run beyond 2100, for the last three output years). It also only affects results when the 'with aerosol' option is used (although this should be most of the time).

To correct this problem, users need to replace the MAGTAR.EXE file. This is in the folder/directory "SG41/SCEN-41/MAGICC". When listing files this will normally show up as "Type: Application". (To view extensions you need to go to Control Panel, Folder Options. Under the View tab, uncheck "Hide file extensions for known file types".)

The corrected MAGTAR.EXE file may be downloaded by clicking here.

Alternatively, you may download the full software again. This now contains the corrected MAGTAR.EXE file. The corrected file was installed at 1145 MST on Dec. 16, 2004.

OVERVIEW: MAGICC and SCENGEN are coupled, user-friendly interactive software suites that allow users to investigate future climate change and its uncertainties at both the global-mean and regional levels. MAGICC carries through calculations at the global-mean level using the same upwelling-diffusion climate model that has been and is employed by the IPCC. The latest version gives the same global-mean warming and sea-level rise rise results as published in the IPCC Third Assessment Report (TAR). SCENGEN uses these results, together with results from a set of coupled Atmosphere/Ocean General Circulation Models (AOGCMs) and a detailed baseline climatology, to produce spatially-detailed information regarding future changes in temperature and precipitation, changes in their variability, and a range of other statistics.

In running MAGICC/SCENGEN, the user can intervene in the design of the global or regional climate change scenarios in the following ways:

Selecting and/or specifying the greenhouse gas and sulfur dioxide emissions scenarios;
Defining the values for a limited set of climate model parameters in MAGICC concerned with uncertainties in the carbon cycle, in the magnitude of sulfate aerosol forcing, in the overall sensitivity of the global climate system to changes introduced by humans, and ocean mixing rate;
Selecting which set of GCM results are to be used;
Specifying for which future period(s) during the twenty-first century the results are to be displayed.

MAGICC -- Model for the Assessment of Greenhouse-gas Induced Climate Change

MAGICC consists of a suite of coupled gas-cycle, climate and ice-melt models integrated into a single software package. This software allows the user to determine changes in greenhouse-gas concentrations, global-mean surface air temperature and sea-level resulting from anthropogenic emissions of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), reactive gases (CO, NOx, VOCs), the halocarbons (e.g. HCFCs, HFCs, PFCs) and sulfur dioxide (SO2). The years 1990 and 2100 are the default start and end output years used by the software, but they can be varied in MAGICC. The main aims of MAGICC are:

To compare the global climate implications of two different emissions scenarios. For convenience, MAGICC refers to one of these two scenarios as a "Reference" scenario and the other as a "Policy" scenario. However, any two emissions scenarios may be compared, whether or not they derive from the imposition of climate policies
To determine the sensitivity of the results for the different emissions scenarios to changes in the model parameters. Basic uncertainty ranges are calculated by default. In addition, the results of a given emissions scenario for a user-specified set of model parameters may be compared with those generated by the default set of parameter values. The software is also able to emulate the behavior of the seven AOGCMs used in the TAR warming and sea-level projections.

SCENGEN -- A Regional Climate SCENario GENerator

SCENGEN constructs a range of geographically-explicit climate change scenarios for the world by exploiting the results from MAGICC and a set of AOGCM experiments, and combining these with observed global and regional climate data sets. SCENGEN contains a set of greenhouse gas-induced patterns of regional climate change obtained from different AOGCM experiments and also sulfate aerosol-induced patterns of regional climate change obtained from a series of sulfate aerosol experiments performed with the University of Illinois at Urbana-Champaign GCM. Since the GCM experiments report results on different spatial grids, all GCM data have been interpolated onto a common 5° latitude/longitude grid.

A geographically-explicit climate change scenario is constructed by selecting a future time interval, a month or season, a variable (temperature or precipitation), and one or more of the AOGCMs in SCENGEN's library of model results. Pattern-scaling methods are employed to create the climate change fields at 5° resolution which can then be added to an observed 1961-90 baseline climate data set to obtain actual climate scenario values for the future time period in question. Beyond simple climate change scenario construction, this new version of SCENGEN produces spatial pattern results for: changes in variability; two different forms of signal-to-noise ratio (to assess the significance of changes); probabilistic output (with the default being the probability of an increase in temperature or, more interestingly, precipitation); and a wide range of validation statistics for individual models or combinations of models.

To obtain a copy of MAGICC/SCENGEN and its documentation, click below.

This version of MAGICC/SCENGEN was developed primarily with funding from the U.S. Environmental Protection Agency, but it rests on developments carried out over the past 15 years and funded by a number of organizations.

Installation instructions and download