Key facts
- Emissions from natural sources like thawing permafrost and wildfires could worsen global heating by 20% to 30% by the end of the century.
- This additional warming could raise global average temperatures by an estimated 0.2C to 0.4C.
- Current climate models likely underestimate future warming and overestimate permissible carbon emissions.
- The study analyzed emissions from permafrost, wetlands, freshwaters, and wildfires.
Rising global temperatures are causing natural environments like forests, wetlands, and tundra to release greenhouse gases, potentially amplifying global warming by up to 30% by the end of the century, according to a new study published in Environmental Research Letters. These "feedback loops," where warming triggers further emissions, are not adequately accounted for in current climate projections.
The research, led by Sam Abernethy of Spark Climate Solutions Research, found that emissions from thawing permafrost, intensifying wildfires, and warming wetlands and lakes could add between 0.2C and 0.4C to global average temperatures. This "hidden multiplier" means that climate models guiding policy may be underestimating future warming and overestimating the remaining carbon budget.
Rob Jackson, a Stanford University scientist and co-author, described the findings as a "wake-up call" that must be integrated into future climate policies to achieve global climate goals. The study highlights that even small temperature increases can lead to more severe climate impacts, such as heatwaves and floods.
The United Nations has acknowledged that the goal of limiting global temperature rise to 1.5C above pre-industrial levels is likely to be breached soon. The new research suggests that the actual increase in global temperature could be even larger than anticipated due to these natural feedback mechanisms. However, the study also emphasizes that reducing fossil fuel pollution remains crucial, as it will lessen the additional emissions from these natural sources. Under an optimistic scenario of rapid emissions cuts, natural sources would add 0.2C, while a higher emissions scenario could see an additional 0.4C of warming.