Mr. Cashel Meagher reports

CAPSTONE COPPER PUBLISHES 2024 SUSTAINABILITY REPORT

Capstone Copper Corp. has published its 2024 sustainability report, titled "Concentrating on Performance." The report has been prepared in accordance with the Global Reporting Initiative (GRI) standards and the SASB (Sustainability Accounting Standards Board) metals and mining sustainability accounting standard. The report details the company's performance on material sustainability topics across its operations for the period from Jan. 1, 2024, to Dec. 31, 2024.

Cashel Meagher, president and chief executive officer of Capstone, commented: "I am pleased to share Capstone Copper's 2024 sustainability report. Two thousand twenty-four was a year of responsible and prudent growth, as we made steady progress on our sustainable development strategy and continued to embed sustainability into our day-to-day operations, all while increasing production to meet the growing global demand for copper, a key metal in the advancement of decarbonization."

2024 sustainability report highlights

Throughout 2024, the company continued to build the capacity of its organization in pursuit of its business and sustainability goals. Capstone Copper worked collaboratively across the company to achieve sustainability milestones on multiple fronts, highlighted below:

• Inaugural production from Mantoverde concentrator unit: In 2024, Mantoverde reached a milestone on its path to becoming the company's flagship operation in supplying copper to meet the world's growing needs.
• Development of Capstone-wide standards for key areas of sustainability: Cross-functional and company-wide working groups for tailings and water, biodiversity, and communities made significant progress during 2024 in setting minimum performance standards connected to the company's sustainable development strategy priorities.
• Making progress on The Copper Mark: Pinto Valley signed a letter of commitment to participate in The Copper Mark assurance process in 2024 and was subsequently awarded The Copper Mark in 2025, joining Mantos Blancos and Mantoverde, both of which received the award in 2023.
• Launch of integrated health, safety and environment (HSE) management system: Capstone Copper's new eight-pillar integrated HSE management system consolidated existing systems, laying the foundation for a cohesive organizational approach.
• Embedding sustainability in the corporate culture: Capstone Copper conducted its first employee engagement and culture survey in 2024, achieving a high sustainable engagement score of 88 per cent, which reflects how connected, supported and energized Capstone employees feel at work.

Some 2024 data trends include:

• Achieved a 12-per-cent reduction in market-based GHG (greenhouse gas) emissions from fuel and power (compared with the company's recalculated 2021 baseline) in pursuit of Capstone Copper's target for a 30-per-cent reduction by 2030. Renewable energy as a percentage of total energy increased to 21 per cent in 2024, versus 9 per cent in 2023, primarily attributable to expanded purchasing of electricity from renewable sources -- 100 per cent of Capstone Copper's electricity purchases for Mantoverde and Mantos Blancos were from I-REC certified renewable sources in 2024. Total energy consumption increased by 5 per cent in 2024 compared with 2023, primarily due to higher energy consumption following the completion of the Mantoverde development project, however, energy intensity declined by 5 per cent based on copper equivalent tonnes produced;
• Increased the proportion of low-quality water withdrawals as a portion of total water withdrawals to 85 per cent, compared with the company's 2021 baseline of 81 per cent. Water intensity per copper equivalent tonne produced increased by 16 per cent in 2024 compared with 2023, reflecting a shift toward more water-intensive processing methods driven by changes in the minerology of deposits at Mantoverde and Mantos Blancos;
• Achieved 48-per-cent conformance with the Global Industry Standard for Tailings Management (GISTM) company wide, up from 33 per cent in 2023, in pursuit of its commitment to implement the GISTM across all tailings storage facilities by 2028;
• Per 200,000 hours in 2024, Capstone Copper's combined work force lost-time injury frequency rate (LTIFR) was 0.48 (up from 0.44 in 2023) and its total reportable injury frequency rate (TRIFR) was 0.91 (up from 0.73 in 2023). While incident rates were up for the year, Capstone Copper saw a material improvement in total safety program training hours and average hours of health, safety and emergency response training per worker, which increased 107 per cent and 163 per cent, respectively, in 2024 versus 2023;
• Capstone's combined work force decreased by 21 per cent in 2024 to 6,806 (versus 8,520 in 2023), primarily due to completion of the Mantoverde development project, which resulted in a 38-per-cent reduction in the number of contractors, partially offset by a 7-per-cent increase in number of employees. The proportion of women employees increased to 10 per cent in 2024 from 9 per cent in 2023. Global employee new hire rate (21 per cent) and turnover rate (15 per cent) remained relatively constant, which is an indication of a relatively stable employee work force;
• Achieved a 4-per-cent and 32-per-cent increase, respectively, in the number of employees and senior management from local communities in 2024 compared with 2023, and increased the proportion of spending on local suppliers by 51 per cent in 2024 compared with 2023.

The 2024 sustainability report is available on Capstone's website.

About Capstone Copper Corp.

Capstone Copper is an Americas-focused copper mining company headquartered in Vancouver, Canada. Capstone's operating portfolio of assets includes the Pinto Valley copper mine, located in Arizona, the Cozamin copper-silver mine, located in Zacatecas, Mexico, the Mantos Blancos copper-silver mine, located in the Antofagasta region, Chile, and the Mantoverde copper-gold mine, located in the Atacama region, Chile. Capstone's growth pipeline includes the fully permitted Santo Domingo copper-iron-gold project, located approximately 30 kilometres northeast of Mantoverde in the Atacama region, Chile, as well as a portfolio of exploration properties in the Americas.

Capstone Copper's strategy is to unlock transformational copper production growth while executing on cost and operational improvements through innovation, optimization, and safe and responsible production throughout its portfolio of assets. The company focuses on profitability and disciplined capital allocation to surface stakeholder value. It is committed to creating a positive impact in the lives of its people and local communities, while delivering compelling returns to investors by responsibly producing copper to meet the world's growing needs.

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