Mayor Karen Bass Appoints New Chief Heat Officer Amid Climate Challenges

Mayor Karen Bass’s administration has quietly appointed Daniela Simunovic as the new chief heat officer, following the dismissal of Marta Segura over a month ago. Simunovic assumed the role on May 31, having previously served as Bass’s senior director of climate and sustainability for three years.

The chief heat officer is tasked with managing the city’s response to extreme heat, a significant climate risk in California. Simunovic will also lead the Climate Emergency Mobilization Office, continuing the work started by Segura, despite previous intentions by Bass to dissolve the office due to a $1-billion budget shortfall. This proposal was ultimately rejected by the L.A. City Council, resulting in the office’s transfer from Public Works to the Emergency Management Department.

The city established this office in early 2021 to coordinate efforts in reducing greenhouse gas emissions and protect residents from climate disasters exacerbated by global warming. Eric Garcetti, the then-mayor, appointed Segura as its director.

In 2022, Los Angeles joined Phoenix and Miami as one of the few cities to appoint a chief heat officer. On particularly hot days, heat-related illnesses can account for nearly 1 in every 100 emergency department visits in L.A. County. The County recorded 10 heat-related deaths in 2025, according to recent dashboard data.

Marta Segura earned approximately $222,000 in 2025, whereas Daniela Simunovic received around $161,000 last year as the senior director of climate and sustainability. Before joining the city government, Simunovic was a senior advisor at the California Air Resources Board, which focuses on protecting the public from air pollution.

Simunovic’s appointment was initially reported by Substack Climate Colored Goggles, and later confirmed by a spokesperson from Mayor Bass’s office. The spokesperson expressed excitement among stakeholders and city partners about Simunovic taking the helm during the ongoing Extreme Heat Warning in Los Angeles.

The Climate Emergency Mobilization Office is collaborating with community partners to develop the City’s Heat Action and Resilience Plan, expected to be completed by early 2027. Despite previous plans to cut the office’s budget, Mayor Bass has advanced several climate goals, including achieving 100% renewable energy by 2035.

The Climate Action Plan released by Bass in April outlines objectives such as doubling local solar power by 2030, reducing fossil fuel reliance in buildings and city buses, and mitigating heat risks through increased tree planting for shade, establishing cooling centers, and developing the Heat Action and Resilience Plan.