On a Zoom call with roughly 300 climate-focused attendees, Shannon Fiume made the type of claim that has people stop what they are doing and pay close attention. She laid out her arguments during an SF Climate Week event that sparked questions, comments, and debate. Her main claim was bold: the world could potentially reach net zero by 2037 or 2038.
Fiume, a climate modeler and entrepreneur, was speaking during an online session titled What is Net Zero ASAP? Can we make it? What made the event interesting was not just the timeline itself, but what it suggested about the climate crisis more broadly. Fiume was not arguing that the world is waiting on some future breakthrough technology to solve the climate crisis. She was arguing that a faster path may already exist, and that the real problem is whether major institutions can coordinate with each other fast enough to make it happen.
At its most basic level, net zero means balancing the amount of carbon going into the atmosphere with the amount being removed from it. But Fiume framed that goal as a larger systemic problem and less as an abstract climate target. In her view, the bigger issue is not whether clean technology exists, but whether clean energy growth, financial restructuring, labor transitions, and fossil fuel retirement can happen simultaneously, rather than one step at a time.
“We’ve come up with the fastest net zero that we could find,” Fiume said, describing a framework she developed through “extensive, lengthy conversations” with ChatGPT. Her model is built around constraints — what has to scale, what has to be financed, and what has to be removed from the system. Rather than treating net zero as the total elimination of every emission source, she described it as getting emissions down to a much smaller “leftover” category, mostly from sectors that are especially difficult to clean up, like some marine shipping and specialized heavy-duty transportation. Those remaining emissions, she said, would then be balanced through carbon dioxide removal.
Fiume’s strongest point was that speed is now the real issue. “Speed isn’t a measure of the technology or technical availability,” Fiume said. “It’s how fast these institutions can clear the constraints.”
That was also where the audience began to push back. Ignacio Fernandez of the Climate Registry questioned whether carbon dioxide removal could realistically scale without a clearer market incentive. Fiume acknowledged the difficulty of that issue, saying, “That doesn’t translate to a direct financial incentive, but we will have to figure out those mechanisms,” especially if carbon dioxide removal is expected to scale after net zero. Later, attendee Pete Marsh challenged Fiume’s claim that geopolitical coordination was not necessary, arguing that entrenched fossil fuel interests still shape politics in major nations.
These reactions are just two examples of what gave the event its real weight. The session was not just about one ambiguous climate timeline, but about whether the systems that have long moved too slowly can be pushed towards a faster timeline. Fiume’s talk made the case that a more rapid path to net zero may already be in view. The harder question now is whether the institutions standing in the way are actually capable of changing fast enough to meet it.
