A new study published in Science has shed light on how subtle shifts in Earth’s orbit around the Sun have historically triggered massive climate changes, including ice ages.
According to the research, the next glacial period would naturally begin in around 11,000 years—unless human-caused global warming disrupts these natural cycles.
Scientists analyzed a million-year climate record, focusing on ice sheets in the Northern Hemisphere and deep ocean temperatures. By studying variations in Earth’s tilt, wobble, and orbit shape, they determined how these factors drive long-term climate shifts.
Lead author Stephen Barker of Cardiff University explained that previous challenges in dating past climate events made it difficult to pinpoint which orbital factors triggered glacial transitions. However, by analyzing the shape of past climate patterns, the team was able to make new breakthroughs in understanding ice age cycles.
Without human interference, the study suggests the next ice age would have lasted for 66,000 years. However, due to rising carbon dioxide levels, human-driven climate change may completely override these natural cycles.
If emissions continue unchecked, Antarctica could melt within 8,000 years, causing sea levels to rise by 70 meters, warned Barker.
Co-author Lorraine Lisiecki from the University of California, Santa Barbara, emphasized that while Earth’s climate cycles are predictable, the impact of human activity is not.
Looking ahead, researchers plan to explore how human-driven climate change could permanently alter the planet’s natural climate systems.