A simple object-oriented and open source model for scientific and policy analyses of the global carbon cycle – Hector v0.1

Abstract

Abstract. Simple climate models play an integral role in policy and scientific communities. They are used for climate mitigation scenarios within integrated assessment models, complex climate model emulation, and uncertainty analyses. Here we describe Hector v0.1, an open source, object-oriented, simple global climate carbon-cycle model. This model runs essentially instantaneously while still representing the most critical global scale earth system processes. Hector has three main carbon pools: an atmosphere, land, and ocean. The model's terrestrial carbon cycle includes respiration and primary production, accommodating arbitrary geographic divisions into, e.g., ecological biomes or political units. Hector's actively solves the inorganic carbon system in the surface ocean, directly calculating air–sea fluxes of carbon and ocean pH. Hector reproduces the global historical trends of atmospheric [CO2] and surface temperatures. The model simulates all four Representative Concentration Pathways with high correlations (R>0.7) with current observations, MAGICC (a well-known simple climate model), and the Coupled Model Intercomparison Project version 5. Hector is freely available under an open source license, and its modular design will facilitate a broad range of research in various areas.

Warming the MATRIX: a Climate Assessment under Uncertainty and Heterogeneity

“…In this section, we present a climate box inspired by the HECTOR model. This includes a three-modules carbon cycle, i.e., atmosphere, land, and ocean (Hartin et al, 2015). In the climate box, any change in the atmospheric carbon depends on anthropogenic emissions (F A ), atmosphere-land carbon uxes (F L ), and atmosphere-ocean carbon uxes (F O ):…”

Uncertainty analysis in multi-sector systems: Considerations for risk analysis, projection, and planning for complex systems

“…SCMs, which for our purposes include all climate models other than full-scale Earth system models, span a large range of structures and complexities, from one-or few-line models that aim to emulate global responses of selected outcomes (for example, global mean surface temperature or sea-level rise), to intermediate complexity Earth system models that might be spatially resolved but with very coarse resolutions and highly parameterized representations of physical dynamics (Weber, 2010). Examples of prominent SCMs include MAGICC (Meinshausen et al, 2011), FAIR (Leach et al, 2021), and Hector (Hartin et al, 2015).…”

Reduced Complexity Model Intercomparison Project Phase 2: Synthesising Earth system knowledge for probabilistic climate projections

“…Hector is an open-source globally resolved, process-based carbon-climate model that calculates the annual energy fluxes between the ocean, atmosphere, and terrestrial biosphere (Hartin et al, 2015). As of Hector v2. )…”

“…The SCM4OPT v2.1 is designed to be lightweight and capable of being used in an integrated assessment model (IAM) with a large-scale optimization process. Compared to the older version (Su et al, 2017, we updated the ocean carbon cycle following Hector v1.0 (Hartin et al, 2015) and used the Diffusion Ocean Energy balance CLIMate (DOECLIM) model (Kriegler, 2005;Tanaka et al, 2007)…”