Reduce the Worst Greenhouse Gases

The Latest

• Schmidt DSE co-designed Kigali Sim with the United Nations (UN), a new data tool to help policymakers reach environmental and climate goals set by the Montreal Protocol.
• Using conservative estimates, Kigali Sim could help a hypothetical, middle-income nation formulate policies that could reduce overall greenhouse gas emissions by about 5% by 2040.
• Currently over a dozen countries are actively using the tool, with many more anticipated over the next year.
• Featured in global and local media coverage, including on NBC Bay Area. 

Our Impact

Kigali Sim helps optimize investments in the UN’s Multilateral Fund, so that countries tasked with reducing greenhouse gas emissions can do so more efficiently. Our conservative estimates show that using Kigali Sim may reduce emissions for a hypothetical middle-income nation by ~5% by 2040. For context, this would be the equivalent of the US cutting half of all agriculture-related emissions.

The 5% estimated reduction would represent around 10% of that country’s target for emissions reductions under the Paris Agreement given past commitments, long term goals, and expected cooling pressures. These approximations do not factor in additional co-benefits from reductions, including a country’s transition to more sustainable energy usage, which will likely produce greater environmental benefits overall. 

Watch

Check out this short simulation of Kigali Sim in action. Video was shot and edited by Ava Hu, DSE Graduate Student Fellow 2025-2026 from the UC Berkeley Graduate School of Journalism. 

Explore the story behind the tool and its early impact in this interview with Sam Pottinger and Bigad Shaban, Senior Investigative Reporter on NBC Bay Area.

Learn

Kigali Sim enables users to:

• Compare HFC regulatory policies and quickly simulate potential impacts on emissions, consumption, and equipment across multiple scenarios
• Optionally bring in an AI assistant to more quickly process input data from various sources and formats, explore policy ideas with the computer as a partner, and rapidly analyze simulation results using simple language questions and answers
• Run the tool locally on web browsers or desktops 

User-Centered Design

• Kigali Sim is free and open-source, and does not require previous coding experience.
• It was officially released at the UN’s 97th Meeting of the Executive Committee for the Implementation of the Montreal Protocol in December 2025, after more than a year of user-centered design and development with UN member countries, international NGOs and agencies, and other key users.
• During the beta testing phase, delegates and other experts from more than 12 countries used Kigali Sim in real time and provided critical feedback for improvements. This user community represented Article 5 countries, donor countries (which financially contribute to the Multilateral Fund), international nonprofits and agencies, and private consultants. 

Future Vision

To date we’ve worked closely with a small group of partner organizations and countries to rapidly co-design and launch Kigali Sim. Next up, we are scaling up this impact so that more users can engage in the tool. We have an exciting opportunity to work one on one with one large country as it uses Kigali Sim, which may result in additional external funding for our team.

Media Stories

To date Kigali Sim tool has been featured in 10 local and global media stories, including the NBC clip mentioned above: 

• Enviro News Nigeria: “New modeling tool provides UN with opportunity to achieve environmental goals” December 9, 2025.

• Hoodline: “UC Berkeley Unleashes Revolutionary Kigali Sim Tool to Boost UN's Fight Against Global Pollution” December 11, 2025.

• Inter Press Service (Spanish): “Asamblea sobre Medio Ambiente: ciencia y diplomacia se unen a favor del planeta” December 9 2025.

• NBC Bay Area: UC Berkeley offers tech to United Nations to fight global pollution (December 9 2025)

• NBC Bay Area: Interview with Bigad Shaban, Senior Investigative Reporter (December 9, 2025)

• NBC Bay Area: Interview with Raj Mathai, Anchor (December 9, 2025)

History of the Montreal Protocol and the Multilateral Fund

The landmark Montreal Protocol is the most successful global environmental treaty in history and is ratified by all UN member states. Signed in 1987, the agreement initially regulated ozone-depleting substances and greenhouse gases and consequently helped sidestep a potential catastrophe with the ozone layer. Since 2016 the treaty’s focus is to phase down the most detrimental greenhouse gases like hydrofluorocarbons (HFCs) in refrigeration, air-conditioning, and the food system. To date the UN Multilateral Fund has facilitated more than $4.3 billion to support developing nations (also known as “Article 5” countries) in reducing production and consumption of HCFs and ozone-depleting substances.