BELÉM, Brazil — Gov. Gavin Newsom may be a climate president in waiting, but as a governor, he has one glaring weakness: He can’t sign treaties with other countries.

Newsom is returning to a time-tested technique to exercise soft power at COP 30 this week: signing voluntary agreements, joint statements and other pointedly non-binding memorandums of understanding.

Newsom and his administration inked new pacts with a bevy of governments both national and local, including Nigeria, the German state of Baden-Württemberg and the host Brazilian state of Pará. They join a long roster of agreements stretching back decades, including a program former Gov. Arnold Schwarzenegger set up to promote collaboration on forests and climate with governors from places like Mexico, Côte d’Ivoire and Indonesia and former Gov. Jerry Brown’s Under 2 Coalition, launched with Baden-Württemberg, to promote subnational climate action.

“It’s a part of a building,” Newsom told POLITICO while in Brazil. “It’s about continuity. It’s about calling cards. It’s about relationships.”

There are limits to the pacts that draw sniffs from some longtime climate diplomacy observers. Many of them focus on research, but California’s public universities, under pressure from Trump, haven’t necessarily rushed to defend international researchers. They also often mention trade, but nothing has emerged in terms of deals circumventing Trump’s tariffs.

But the agreements represent some of the only leverage California really has in the international arena. Brown sometimes required MOUs as a condition of meeting with the foreign officials clamoring for his time.

And Newsom likes them: He’s been a driving force behind an increase in bilateral pacts, aides said, this year alone with Denmark, Kenya and individual states in Brazil and Mexico. When he looked earlier this year at a map of agreements California had signed, he remarked on the number of jurisdictions that weren’t colored in, one said.

While in Brazil, he fielded on-the-fly pitches from business and NGO leaders for agreements on strengthening economic ties between Brazil and California and incorporating Indigenous perspectives into forest policy. “Let’s get it done,” he told Natural Resources Secretary Wade Crowfoot on Tuesday before slipping into an at-capacity room to excoriate Trump and promise California as a “stable and reliable partner” through changing administrations.

Some of the pacts do lead to policy and technical exchanges. California policy experts have hosted foreign counterparts or traveled abroad to influence policies such as the creation of new carbon markets; conversely, they’ve learned about wildfire fighting from places like Australia, and groundwater mapping from Denmark.

Some serve as symbolic markers: In Monday’s joint statement with Baden-Württemberg, the two states don’t promise any particular result, but rather to “encourage each other to be more ambitious.” Perhaps the most substantive agreement Newsom’s administration signed in Brazil was with Chile, whose environmental representatives he met in Belém on Wednesday. In the meeting, they talked about sharing data captured by methane-detecting satellites that California launched with the nonprofit Carbon Mapper and several universities and philanthropies.

“The utilization of that open data in Chile, with the resources that we’re providing in the absence of federal resources, is just a tangible example of those opportunities to highlight, promote and partner,” Newsom said in Brazil on Wednesday.

Notably absent from his agenda during his fly-by visit of the climate talks: any new joint major announcements or agreements with the U.S.-based climate alliances he’s formally chairing. Gov. Michelle Lujan Grisham of New Mexico was in Belém too, but Newsom left Wednesday for a trip deeper in the Amazon without issuing any joint statements.