ARTICLES
An Online Climate Model to facilitate Depth-studies and
Science Extension
By Angela M. Maharaj, Ian Macadam and Alex Sen Gupta
ARC Centre of Excellence for Climate Extremes (CLEX);
Climate Change Research Centre (CCRC);
University of New South Wales (UNSW).
Simple online models of the Earth’s climate are being developed
by Australian universities and are increasingly being used as
teaching aids in high schools. This article describes one such
model developed by UNSW. “Carbonator” (www.carbonator.org)
is already being used as an inquiry tool for NSW Stage 6 depth
studies in Physics, Earth and Environmental Science (EES) and
Investigating Science (IS).
models. They provide data from the models to an international
project called the Coupled Model Intercomparison Project (CMIP)
(see https://www.wcrp-climate.org/wgcm-cmip). Data from CMIP
can be accessed by scientists around the world and used in
climate research. Results from CMIP inform many of the public
statements on climate change made by the Intergovernmental
Panel on Climate Change (IPCC), the United Nations body
charged with providing policymakers with regular assessments
on what we know about climate change. These statements can be
influential in determining government policies on climate change
and in international negotiations on how to combat it.
Recent changes in the NSW Stage 6 Science Syllabus encourage
inquiry-based learning through depth studies and a new Science
Extension subject. Simple models can be a useful means of
motivating student-led investigations, as well as educating
students about the models used by scientists. The Earth’s climate
is ideal for students to explore with simple models. Not only are
climate models a primary tool of scientists trying to understand
the climate system, but these models play a key role in informing
decision-making around climate change, arguably the most
important environmental challenge of the day.
‘Carbonator’: A simple climate model
‘Carbonator’ is a simple climate model that runs online in
seconds (see Box 2). It is much less detailed than a state-of-
the-art climate model, and does not produce maps of changes
in the climate. However, it uses many of the same principles to
simulate changes in global average temperature in response to
imbalances between the amount of energy that the Earth receives
from the Sun and the energy that it radiates into space. These
imbalances arise from climate “forcings” due to emissions of
greenhouse gases and aerosol pollutants into the atmosphere
by human activity, emissions of aerosols into the atmosphere by
volcanoes, variations in the energy received from the Sun and
changes in the reflectivity of the Earth’s surface. As with a state-
of-the-art climate model, carbonator must be provided with data
related to these forcings (e.g. a time series of annual human
emissions of carbon dioxide into the atmosphere for the years
1850 to 2100).
Climate system modelling
Greenhouse gases released into the atmosphere as a result of
human activity, most importantly the release of carbon dioxide
by the combustion of fossil fuels, are causing global warming
and driving other rapid changes to the Earth’s climate system.
The primary tool for understanding how this system works and
how it is likely to change in the future is the climate model (see
Box 1). In the 1950s, the first climate models run on computers
simulated just the circulation of the Earth’s atmosphere. Today,
state-of-the-art climate models have evolved to use some of the
world’s most powerful computers to simulate the atmosphere in
much more detail, and also include components that simulate
the ocean, land-surface and the ice on the Earth’s surface. Given
data representing a scenario for future emissions of greenhouse
gases and aerosol pollutants, they can provide scenarios for the
future climate of the planet. These are often communicated as
maps of changes in important aspects of the climate, such as
temperature. A typical simulation of this type running from the
present to 2100 takes several months to run on a supercomputer.
The effects of climate change are often summarised in terms of
changes in the global average temperature of the Earth’s surface.
As well as outputting these data, ‘carbonator’ also outputs other
data that help students understand the effects of greenhouse
gas emissions, including how additional carbon released into the
climate system is partitioned between the atmosphere, vegetation,
soil, the ocean and the size of the climate forcing resulting from
the atmospheric component. Other topical data outputted by the
model include changes in the sea level and the acidity of the
ocean.
Currently, approximately 40 research centres around the world
maintain and continually develop their own state-of-the-art climate
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SCIENCE EDUCATIONAL NEWS VOL 68 NO 3