This web interface allows you to use a simplified module of DEFINE (called DEFINE-CLIMATE) in order to explore how climate change is affected by the following key factors:
The rate of economic growth after 2022. With everything else given, the higher the rate of growth the higher the use of non-renewable energy and the higher the generation of carbon emissions. The default value is 2.7% which is close to the current rate of growth of the global economy.
The share of renewable energy in total energy after 2022. An increase in this share has a favourable effect on climate change because it permits the production of goods and services without relying on fossil fuel combustion. The default value is 14% which is close to the current share of renewable energy.
The energy intensity after 2022. This is defined as the use of energy (in exajoules) per GDP (trillion US$, 2017 prices). The higher the level of energy intensity the more adverse the impact of economic activity on climate change. The default value is 7.2 exajoules per trillion US$, which is close to the current level of energy intensity.
The equilibrium climate sensitivity parameter. This is defined as the increase in equilibrium temperature due to doubling of carbon concentration from pre-industrial levels. This parameter plays a key role in the dynamics of climate change but there is a lot of uncertainty about its exact value. The default value is 3.1 oC, which is a standard value used in related studies.
A brief description of the DEFINE-CLIMATE module, as well as of its equations, the values used in the interface and the steps via which the model can be simulated are available here.
Note: The module does not include the feedback effects of climate change on economic growth and the use of energy. These effects are incorporated in DEFINE, but have been assumed away in the interface for simplification purposes.