Simple model of the global economy, the global carbon cycle, and planetary energy balance.    The planetary energy balance model is a two-box model, with shallow and deep ocean heat reservoirs. The carbon cycle model is a 4-box model, with the atmosphere, shallow ocean, deep ocean, and terrestrial c
Simple model of the global economy, the global carbon cycle, and planetary energy balance.

The planetary energy balance model is a two-box model, with shallow and deep ocean heat reservoirs. The carbon cycle model is a 4-box model, with the atmosphere, shallow ocean, deep ocean, and terrestrial carbon. 

The economic model is based on the Kaya identity, which decomposes CO2 emissions into population, GDP/capita, energy intensity of GDP, and carbon intensity of energy. It allows for temperature-related climate damages to both GDP and the growth rate of GDP.

This model was originally created by Bob Kopp - https://insightmaker.com/user/16029 (Rutgers University) in support of the SESYNC Climate Learning Project.

Steve Conrad (Simon Fraser University) modified the model to include emission/development/and carbon targets for the use by ENV 221.
This simulation examines the linkages between cultural, material, spatial demographic, and hierarchical dynamics.
This simulation examines the linkages between cultural, material, spatial demographic, and hierarchical dynamics.
A detailed description of all model input parameters is available  here . These are discussed further  here  and  here .  Update 29 June 2016 (v2.6): Added historical emplacement for wind and PV capacity. The maximum historical emplacement rates are then maintained from year 114/115 until the end of
A detailed description of all model input parameters is available here. These are discussed further here and here.

Update 29 June 2016 (v2.6): Added historical emplacement for wind and PV capacity. The maximum historical emplacement rates are then maintained from year 114/115 until the end of the model period. This acts as a base emplacement rate that is then augmented with the contribution made via the feedback control mechanism. Note that battery buffering commences only once the additional emplacement via the feedback controller kicks in. This means that there is a base capacity for both wind and PV for which no buffering is provided, slightly reducing the energy services required for wind and PV supplies, as well as associated costs. Contributions from biomass and nuclear have also been increased slightly, in line with the earlier intention that these should approximately double during the transition period. This leads to a modest reduction in the contributions required from wind and PV.

Added calculation of global mean conversion efficiency energy to services on primary energy basis. This involves making a compensation to the gross energy outputs for all thermal electricity generation sources. The reason for this is that standard EROI analysis methodology involves inclusion of energy inputs on a primary energy equivalent basis. In order to convert correctly between energy inputs and energy service inputs, the reference conversion efficiency must therefore be defined on a primary energy basis. Previously, this conversion was made on the basis of the mean conversion efficiency from final energy to energy services.

Update 14 December 2015 (v2.5): correction to net output basis LCOE calculation, to include actual self power demand for wind, PV and batteries in place of "2015 reference" values.

Update 20 November 2015 (v2.4): levelised O&M costs now added for wind & PV, so that complete (less transmission-related investments) LCOE for wind and PV is calculated, for both gross and net output.

Update 18 November 2015 (v2.3: development of capital cost estimates for wind, PV and battery buffering, adding levelised capital cost per unit net output, for comparison with levelised capital cost per unit gross output. Levelised capital cost estimate has been substantially refined, bringing this into line with standard practice for capital recovery calculation. Discount rate is user adjustable.

Default maximum autonomy periods reduced to 48 hours for wind and 72 hours for PV.

Update 22 October 2015 (v2.2): added ramped introduction of wind and PV buffering capacity. Wind and PV buffering ramps from zero to the maximum autonomy period as wind and PV generated electricity increases as a proportion of overall electricity supply. The threshold proportion for maximum autonomy period is user adjustable. Ramping uses interpolation based on an elliptical curve between zero and the threshold proportion, to avoid discontinuities that produce poor response shape in key variables.

Update 23 September 2015 (v2.1): added capital investment calculation and associated LCOE contribution for wind generation plant, PV generation plant and storage batteries.

**This version (v2.0) includes refined energy conversion efficiency estimates, increasing the global mean efficiency, but also reducing the aggressiveness of the self-demand learning curves for all sources. The basis for the conversion efficiencies, including all assumptions relating to specific types of work & heat used by the economy, is provided in this Excel spreadsheet.

Conversion of self power demand to energy services demand for each source is carried out via a reference global mean conversion efficiency, set as a user input using the global mean conversion efficiency calculated in the model at the time of transition commencement (taken to be the time for which all EROI parameter values are defined. A learning curve is applied to this value to account for future improvement in self power demand to services conversion efficiency.**

The original "standard run" version of the model is available here.
Filling a tank with a pump. Tank is straight-walled (constant capacitance). Flow is laminar (linear flow relation.    Energy quantities have been added.
Filling a tank with a pump. Tank is straight-walled (constant capacitance). Flow is laminar (linear flow relation.

Energy quantities have been added.
This insight describes the interrelationship between carbohydrates, fats and proteins.    Each food source is used, stored and processed in different ways.     The balance of our food intake, our genetic characteristics that determine our ability to digest these sources and our activity levels, have
This insight describes the interrelationship between carbohydrates, fats and proteins.

Each food source is used, stored and processed in different ways.

The balance of our food intake, our genetic characteristics that determine our ability to digest these sources and our activity levels, have a significant impact upon our weight and performance.
Jevons Paradox says that energy
efficiency measures lead to an increase in energy use and not, as expected, to
a reduction. The same paradox applies to efforts to conserve energy. Those that
 try to conserve energy by walking to
work or line-dry their clothes  may feel satisfaction,
but their effort
Jevons Paradox says that energy efficiency measures lead to an increase in energy use and not, as expected, to a reduction. The same paradox applies to efforts to conserve energy. Those that  try to conserve energy by walking to work or line-dry their clothes  may feel satisfaction, but their efforts are probably in vain:  the energy saved will promptly be used  by others, especially as saving energy causes it to become cheaper.  This CLD tries to illustrate the dynamic that operates behind the paradox.

Please note that Tim Garrett, an atmospheric scientist, recently confirmed the validity of the Jevons Paradox which had already been proposed in 1865.

A simple Energy Balance Climate Model of the Earth with no atmosphere.  Explore the impact of changing the ocean's depth (i.e. heat capacity) and the pattern of solar radiation on the earth's temperature by using the sliders in the panel below.
A simple Energy Balance Climate Model of the Earth with no atmosphere.  Explore the impact of changing the ocean's depth (i.e. heat capacity) and the pattern of solar radiation on the earth's temperature by using the sliders in the panel below.