The Global Calculator: Choosing Your 2 Degree Pathway at COP21

The Global Calculator helps users visualize the various impacts of climate action. Some countries, like Taiwan, have developed their own calculators to help guide decision making. Photo by Hsiuan Boyen/Flickr

TheCityFix is covering cities at COP21. Urban areas account for a large share of greenhouse gas emissions but are also tremendous agents of innovation to address climate change. Read our full coverage of the Paris Climate Conference as it relates to cities, buildings, and mobility.


From 1880 to 2012, the globe warmed by a total of .85°C, and without action, could warm by up roughly 3-6°C by 2100. With such a sharp increase in global temperature, it’s clear that we will need to make many changes to the way our planet operates in order to stay within the 2°C target. The question is, which changes should be prioritized, and how can we strategically optimize our decision making?

Launched in January 2015, the Global Calculator is an open-source, interactive model of the world’s energy, land and food systems that allows users to explore ways to reduce global emissions to 2050, and to visualize the impacts of these choices to 2100.  Different “levers” built into the tool allow users to test various levels of ambition and effort across sectors and observe the related impact on emissions. Using these levers, users can create unique climate “pathways” to the year 2050, getting a glimpse of how changing our diets, travel modes, and energy sources would directly affect the earth’s temperature.

A new tool that is sophisticated yet accessible, the Global Calculator shows how prioritizing low-carbon solutions now will majorly benefit our future. The Global Calculator is particularly effective at engaging the public, providing both clear data on how emissions are directly impacting the environment, and actions that we can take to prevent these damages. In short, it allows everyone to join the discussion as well-informed citizens, with access to the most up-to-date climate data.

Two Priorities for Driving Change: Cleaner Energy and More Efficient Land Use

Drawing on the Global Calculator, the UK’s Department of Energy and Climate Change (DECC) determined the major areas of change needed to improve quality of life and to keep the planet within the  2°C target. Analyzing selections that reflect lifestyle choices similar to the IEA 6 degree scenario–which is considered business as usual–they found that we must focus on two areas: (1) we must use more efficient technologies and low-carbon sources of energy, and (2) we must make smarter use of land.

Transitioning to more efficient technologies and adopting more sustainable sources of energy will require significant and immediate changes across multiple sectors, from electricity and buildings to transport and manufacturing. For example, the electricity sector will need to phase out coal, oil and gas by 2050 in favor of more renewable energy sources. Both private and public vehicles will need to be more efficient, and up to 35 percent of cars will need to be powered by electricity or hydrogen by 2050.

In terms of land use, expanding our forests is important since they serve as a carbon sink. At the same time, given that there will be 2.5 billion more people in cities by 2050, we will need to produce more food with limited land available. In order to manage this pressure and ensure an expansion of global forests, the amount of food that current crop lands yield would need to increase by 40 to 60 percent by 2050–requiring innovation and creative solutions. Livestock yields would similarly need to increase on a restricted amount of land.

Reducing the amount of average meat consumed is another way of reducing pressure on forests. For example, if the global population transitioned to the diet recommended by the World Health Organization (only 160 g of meat per day), we could save up to 15 GtCO2e per year by 2050, which is equivalent to ⅓ of all global CO2 emissions in 2011 (calculated using the ”consumer reluctance” pathway and comparing this with WHO healthy levels).

About the Calculator

Developed by a cohort of experts and international organizations – including World Resources Institute (WRI) – the Global Calculator provides emission data on individual sectors, allowing users to choose a future pathway for each sector based on four levels of effort (ranging from minimal to extremely ambitious). These levels let users explore the impacts of continuing business as usual versus pursuing ambitious measures to curb emissions through actions like reducing car usage, shifting to renewable energies, or improving plant yield efficiency.

The first calculator was developed by DECC, and was used to inform policy debate on trade-offs between different possible actions to reduce CO2 emissions. This tool is currently helping the UK to meet the legal requirement the country has set to reduce emissions by 80 percent by 2050 from 1990 levels. The Global Calculator drew upon the lessons learned from the UK calculator, and collected data to become global in scope.

Backed by data from a variety of countries across the world, the Global Calculator is useful for a diversity of groups, including businesses, NGOs and governments. Indeed, 14 countries have already published their own versions of the Calculator, with 13 more currently developing the tool. The tool can also be utilized on the local level; for example, WRI recently held a workshop in Washington DC with businesses, government employees, and NGOs to raise awareness on the Calculator.

Join us today (December 8th) in Paris at COP21, where DECC will give a demonstration of the Global Calculator. A panel of business and community leaders will test out the options and examine the opportunities using the Global Calculator, an interactive model of the world’s energy, land and food systems.

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