OUR PURPOSE PIONEERING SCIENCE 155 TASK FORCE ON CLIMATE-RELATED FINANCIAL DISCLOSURES STATEMENT BIOGEN 2021 YEAR IN REVIEW PATIENTS OUR PEOPLE ENVIRONMENT COMMUNITY REPORTING Risk Management TCFD recommendations for disclosures on Risk Management A. Describe the organization’s processes for identifying and assessing climate-related risks. B. Describe the organization’s processes for managing climate- related risks. C. Describe how processes for identifying, assessing and managing climate-related risks are integrated into the organization’s overall risk management. We identify and assess climate-related risks – both physical risks and transitional risks – by utilizing the Global Enabling Sustainability Initiative (GeSI)-CDP Scenario Analysis Toolkit (the Toolkit). Our 2020 assessment of physical risks included screening studies of two future climatic scenarios to explore our physical climate-related risks, notably water scarcity, inland/coastal floods, extreme heat, tornados, hurricanes and wildfires. This was updated in 2021. Representative Concentration Pathways (RCP) 4.5 (+2°C) and RCP 8.5 (+4°C) were the selected scenarios for this study with projected impacts out from 2020 to 2030 and 2040 or 2050 depending on the criteria data set available. These scenarios were applied to Biogen’s three manufacturing and R&D locations and 10 of the contract manufacturing organization sites we rely on to manufacture our products. Commercial sites, which consist of leased office space, were not included in the screening studies, because we determined that they posed a low material risk. The outcome of these 2020 studies across the 13 sites was combined with a revenue-based assessment to identify short-, medium- and/or long-term risks. Subsequently, in 2021, we expanded our assessment of physical risks to include our broader value chain, specific to our most critical suppliers. We also utilize the Toolkit to identify and assess the risks and opportunities associated with the transition to a low-carbon economy. For this purpose, in 2020, we adopted two climate scenarios: the IEA INDC Scenario (~3°C) as a base case and the IEA WEO 450 Scenario (~2°C) as a higher ambition case toward meeting the Paris Agreement to understand policy and technology impacts through 2040. Risks and opportunities were assessed at an enterprise level as well as specific to our biosimilar product segment. All identified material risks and opportunities are reported to the Enterprise Risk Management team and Healthy Climate, Healthy Lives Working Governance Committee, which report to the Executive Leadership Team and Board of Directors. Through this layered accountability, we consider and address those risks and opportunities that are financially material and may impact our business model, as well as mitigation measures that are in place or need to be adopted. Metrics and Targets TCFD recommendations for disclosures on Metrics and Targets A. Disclose the metrics used by the organization to assess climate- related risks and opportunities in line with its strategy and risk management process. B. Disclose Scope 1, Scope 2 and, if appropriate, Scope 3 greenhouse gas (GHG) emissions, and the related risks. C. Describe the targets used by the organization to manage climate- related risks and opportunities and performance against targets. There is increased attention and focus from consumers, investors and regulators on decarbonization of the medicines we make. Therefore our overall strategy to manage and mitigate climate-related risks includes focus on the following metrics and targets, which are consistent with the aims of the Paris Agreement and keeping temperature rise to 1.5ºC. – In 2020, we committed to reduce absolute Scope 1 and 2 emissions by 55% by 2032 compared to 2019 and 100% by 2040 through the Science Based Targets initiative. – We are also committed to working with our suppliers to reduce our indirect climate impacts from purchased goods, services and capital equipment, where 80% of suppliers by spend 1 will have a science- based target by 2025. We also are committed to strengthening our resilience through the mitigation of environmental and humanitarian