BBC HomeExplore the BBC
This page has been archived and is no longer updated. Find out more about page archiving.

24 September 2014

BBC Homepage

In Hot Topics:


Contact Us

You are here: BBC > Science & Nature > Hot Topics > Climate Change > Climate Challenge

Climate Challenge

Why make a game about climate change?

Currently there is a growing consensus amongst climate researchers that Earth's climate is changing in response to manmade greenhouse gas emissions. The main debate amongst scientists is focussed on the amount of climate change we can expect, not whether it will happen. With the current level of debate in mind, the BBC decided a game might be a good introductory route into climate change and some of the issues this creates for governments around the world.

The producers' primary goal was to make a fun, challenging game. At times it was necessary to strike a compromise between strict scientific accuracy and playability. For this reason, Climate Challenge should not be taken as a serious climate change prediction.

Wherever possible, real research has been incorporated into the game. This document describes the scientific sources used to create Climate Challenge and some of the compromises made by the producers. These sources are a good starting point for someone interested in learning more about climate change. This document also describes some of the compromises the producers made for the sake of playability.

Game focus and aims

Apart from the primary goal of creating a fun game, Climate Challenge's producers aimed to:

  • give an understanding of some of the causes of climate change, particularly those related to carbon dioxide emissions.
  • give players an awareness of some of the policy options available to governments.
  • give a sense of the challenges facing international climate change negotiators.

Players must respond to catastrophic events caused by climate change as well as natural and manmade events, which may or may not be linked to climate change. This aspect of the game is meant to give some idea of what could happen as the Earth's climate changes and also introduce the unpredictable nature of some natural events.

The science behind Climate Challenge

Carbon dioxide emissions

Climate Challenge uses the most commonly cited and accepted carbon dioxide emission forecasts, which are produced by the Intergovernmental Panel on Climate Change (IPCC).

The IPCC is open to all United Nations members and World Meteorological Organization and aims to openly and objectively assess "the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change," according to the IPCC website.

The IPCC publishes it's carbon dioxide forecasts in the Special Report on Emissions Scenarios (SRES).

The SRES maps seven primary future emissions scenarios and uses four narrative storylines to describe the forces driving and changing emissions and to add context for the scenario quantification. The figure below shows emissions per year for these scenarios.

Figure 1

Figure 1: CO2 emissions per year for the SRES scenarios

Some of the scenarios focus on emissions extremes. For example, the A1F1 scenario, which describes a fossil fuel-intensive future, predicts global carbon dioxide emissions rising to around 30 gigatonne of carbon (GtC) per year by 2100. We currently emit around 10 GtC per year, so this scenario predicts a three-fold increase in emissions, which is very high indeed, and could lead to global temperatures increasing by 4 - 6°C.

The lowest emissions scenario, B1, suggests carbon dioxide emissions increasing slightly in coming decades but then falling to lower than current levels by 2100. However, even this optimistic emissions scenario results in global temperatures increasing by 1 or 2°C, which will still have a huge impact globally.

Figure 2

Figure 2: Predicted temperature change for each SRES scenario

The second figure shows predicted temperature changes for each of the scenarios, starting with historical data from 1800. The important thing to note is that there has been almost no global warming for the past 200 years, and that all scenarios show some warming, although some are not as high as others.

The Climate Challenge game is based on the A1B scenario as it provides a good mid-line scenario for carbon dioxide output and economic growth, which leaves scope for the player to either improve or worsen emissions levels. The A1 storyline and scenario family describes a future world of very rapid economic growth. In this potential future, global population peaks mid-century and declines thereafter, and new and more efficient technologies are rapidly introduced. Major underlying themes are convergence among regions, capacity building, and increased cultural and social interactions, with a substantial reduction in regional differences in per capita income.

The A1 scenario family develops into three groups that each describe alternative changes in energy technology. The three A1 groups are distinguished by their technological emphasis: fossil fuel energy intensive (A1FI), non-fossil fuel energy intensive (A1T) and balanced across all energy sources (A1B). Here, balanced is defined as not relying too heavily on one particular energy source, on the assumption that similar improvement rates apply to all energy supply and end-use technologies.

The A1B scenario forms a basis for the effects of climate change in the game. The scenario, as can be seen in Figure 1, predicts carbon dioxide emissions increasing until around 2050 and then decreasing after that. This emissions curve is used as the baseline for CO2 in the game, so if the player does nothing at all, this is the level of emissions they will see.

The game producers also used the United Nations Environment Programme Java Climate Model to derive other data for the game from the IPCC scenarios.

Calculating global carbon dioxide emissions

Currently the European Union is responsible for approximately 16% of the world's greenhouse gas emissions (figures from the EU website). The producers used this figure to determine total global output of carbon dioxide to ensure that the player's actions would have a measurable effect. The producers took this approach because the purpose of the game is to give the player an understanding of policy options and, wherever possible, to leave them feeling in control. If each regional bloc's emissions had been tracked separately, this would not have been possible.

Comparing statistics

To maintain consistency, the statistics in the game are listed in the following units:

  • Money is measured in millions of euros.
  • Energy is measured in megawatt hours.
  • Food is measured in millions of tonnes.
  • Water is measured in trillions of litres of water
  • Carbon dioxide is measured in megatonnes (millions of tonnes), sometimes referred to as teragrammes.

Policy cards

Sources of cards

All policies are taken from actual government policy documents, except those near the end of the game, which are deliberately futuristic, such as Mining the Moon. The UK government's Climate Change Programme 2006 was a major source of policies, and the anticipated carbon dioxide reductions from each were transferred directly from the report into the game. The Potential for Microgeneration: Study and Analysis, carried out by the Energy Saving Trust for the Department for Trade and Industry (DTI), was also very useful in determining emissions reductions in many household-level policies.

Card duration

In testing, it was found that having policy cards lasting for several turns was too complex for the scale of the game. Therefore the duration of all the cards has been artificially compressed to give all their modifiers in one single turn. This means that a card's effects are much higher in the short term than would be the case in real life. Behind this there is also a necessary assumption about how many turns a card is in play. We have assumed that power and carbon dioxide effects are in play for five turns (50 years), and food and water effects for 10 turns (100 years).

Sources of crisis events

The crisis events that are caused by climate change are taken from the Impacts, Adaptation & Vulnerability Contribution of Working Group II to the Third Assessment Report of the IPCC. Other climate-related events, such as the climate concert, are inspired by real events.

Other resources in the game

Energy, food and water are the secondary resources that must be managed throughout the game. Data for these were taken from various sources, including the UNEP model mentioned above and the DTI website.

Spending money is set at 0.5% of the GDP of the economies, and the figures for power, water and food consumption and carbon dioxide emissions are also derived from data from the UNEP Java climate model.

Food and water statistics were hard to quantify, as the values needed for the game are not typically published by water companies and the food industry. In these instances, the producers used estimates derived in respect to other cards.

For areas where information was unavailable, the producers made use of secondary sources such as Wikipedia. Wikipedia is an excellent source of information, but much of the data is unverified, so must be used with caution. In these cases, only descriptive information was used, such as the description of fusion power on the fusion policy card.

Geographical blocks

The geographical blocks in the global policy section of the game were chosen partly to account for all global regions in a convenient number of blocks, each of a roughly similar size. They were also designed to keep the game relatively apolitical, and to avoid cultural stereotyping.

Note: The Climate Challenge game was authored in 2006. Therefore this article and the content of the game apply to knowledge about climate change up to this time.

Links to further information about climate change



Science Homepage | Nature Homepage
Wildlife Finder | Prehistoric Life | Human Body & Mind | Space
Go to top



About the BBC | Help | Terms of Use | Privacy & Cookies Policy