En-ROADS – A Path to 1.5°C Warming


The BAU (Business As Usual) scenario will bring the world’s average temperature warming to 4.1°C by the end of the century, while the “approximately safe” goal is to stabilize around 1.5°C, and the current value is now 1.1°C of heating above pre-industrial temperatures.


The En-ROADS Climate Change Solutions Simulator is a freely-available policy simulation model that provides policymakers, educators, businesses, the media, and the public with the ability to explore the likely consequences of various policies concerning energy, economic growth, land use, among others. The goal is to improve understanding of what can be done to limit global warming to 1.5°C by 2100.  En-ROADS has been used by the Obama White House, in the Beijing government, the UN, businesses, NGOs, “Town Halls” and local governments and universities. It’s been 10 years in the making by people associated with MIT’s Sloan business school, contains some 14,000 differential equations, and runs in a web browser.


En-ROADS is used to test what climate interventions are needed to effectively mitigate global warming by exploring the interrelated dynamics in available energy, land-use, transportation, carbon removal, population growth, economic transformations, and more. By using En-ROADS, you can see how these driving forces, and the policies which determine their behavior, affect a variety of climate effects, from temperature change to sea level rise. It’s an excellent means to validate assumptions. We’re going to show just such an example.


The Challenge


The first thing to understand about the climate challenge is that there is no single answer. Only a suite of policies and behavior change can move us toward the elusive 1.5°C end of century goal. The favorite choice of this-or-that political group may win elections, but no simple policy choice has had a positive effect on Greenhouse Gas emissions over the last 10 years. Many billions have been spent, with meagre results, or even with effects that have driven us backwards. Against this backdrop, let’s have a look at a real-world example.


A recent scientific paper about afforestation advocated the planting of trees everywhere where the climate permitted and where the land was not already used for urban development or agriculture or already forested. This was presented as a totally adequate solution to meet the Paris goals.


The En-ROADS team used their simulation tool to validate the paper’s conclusions. Their calculations and conclusions can be found here.


The key insight is that while afforestation does remove a critical mass of CO2 and reduces temperature, it is not a total solution. Forests, as well as removing carbon, can increase biodiversity, stabilize soil, retain groundwater, and increase resilience against flooding. But afforestation does not have “mind-blowing potential”, the trees do not “save us”, and they do not “save the climate”, as claimed. Using En-ROADS shows that some alternatives have a more positive effect on temperature containment.


Try the simulator. Learn how to use it. Join a group. Look at the different kinds of tools and documentation provided by Climate Interactive. Try to find a policy scenario that would work for your environment. It can be done!