Scientists Ditch Worst-Case Climate Model Amid Green Energy Surge

(MENAFN) Climate scientists are stepping back from one of the most extreme global warming projections ever constructed, citing accelerating renewable energy adoption, tightening climate policy, and a measurable slowdown in carbon emissions growth as evidence the once-prominent scenario no longer reflects reality.

The model in question — RCP 8.5 — had for years served as a cornerstone of climate research, projecting a catastrophic 4.5–5°C (8.1–9°F) rise above pre-industrial temperatures by 2100 under conditions of unchecked greenhouse gas output.

A recent scientific study now deems that trajectory increasingly improbable, according to a Norwegian broadcaster, which reported Tuesday that declining clean energy costs, stronger governmental action, and decelerating global CO₂ growth are collectively undermining the scenario's plausibility.

Climate scientist Bjorn Samset pointed to a dramatic shift in emissions trends as a key driver of that reassessment.

"That's because green technology has taken off very well. Emissions are still increasing, but now they are increasing by perhaps up to 1 percent a year, compared to 3-4 percent a year, as they did in the early 2000s," Samset told the broadcaster.

He cautioned, however, that any forward-looking climate projection remains acutely sensitive to human choices — both political and behavioral.

"Maybe climate policy works very well and we cut emissions very quickly. Maybe climate policy doesn't work at all, there will be many big wars and the like. Then there will be very high emissions," Samset said.

Climate modeling relies on a spectrum of possible futures, spanning outcomes ranging from aggressive emissions cuts to scenarios in which governments wholly fail to restrain greenhouse gas output.

Samset indicated that RCP 8.5 is poised to carry significantly less weight in the upcoming assessment cycle of the Intergovernmental Panel on Climate Change (IPCC).

"Green technology has taken off very well. Emissions are still increasing, but now they are increasing by perhaps up to 1% a year, compared to 3–4% a year, as they did in the early 2000s. In that sense, the world is definitely doing well. It is a positive sign that it is now more relevant to think about the middle scenarios," he said.

Despite the cautiously optimistic shift, researchers stressed that significant unknowns persist — particularly surrounding the climate system's sensitivity to rising emissions concentrations.

"One thing is how much we emit, another is how strongly the climate reacts to the emissions. There are some scientists who say that perhaps we have underestimated how strongly the climate is changing," Samset said.

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