Scientists at TUM have developed a new method for the early detection of climate tipping points.
From the end of the last Ice Age until about 6,000 years ago, the area now known as the Sahara was a fertile, green landscape teeming with life. This era, known as the “African Humid Period,” ended suddenly, transforming the once vibrant region into the dry, desolate desert we see today.
Scientists have long puzzled over how slow changes in solar radiation due to changes in Earth’s orbit could cause such an abrupt, large-scale climate change. This puzzle highlights the larger challenge of understanding and predicting abrupt changes in natural systems – which are often associated with tipping points.
A new study by Andreas Morr and Prof. Niklas Boers, researchers at TUM and PIK, presents an advanced early detection method that provides more accurate and reliable early warnings, especially under more realistic external conditions. Traditional methods assume that random disturbances in a system are temporally uncorrelated.
However, this is not realistic for climate systems because it is assumed that each day’s weather is independent of the previous day’s weather. In reality, tomorrow’s weather depends heavily on today’s. This discrepancy reduces the reliability of conventional methods for early warning signals. Morr and Boers’ new method overcomes this limitation by developing system stability estimators specifically designed for more realistic climate conditions.
Early warnings and turning points
Applying their methods to desertification in Western Sahara, they found that there was a clear early warning of vegetation loss, consistent with the crossing of a tipping point.
“Our results suggest that the abrupt end of the African humid period was probably caused by a weakening of the stability of the system as the Earth’s orbit changed and the system gradually moved toward a tipping point,” says Andreas Morr. Niklas Boers adds: “The advanced detection method we developed improves our ability to monitor and respond to potential tipping points in various natural systems. Our results suggest that large-scale climate tipping events like this one are in principle predictable, hopefully enabling timely intervention.”
By improving the accuracy By analyzing early warning signals, research supports better preparedness and response strategies and ultimately helps protect ecosystems and human society from the severe impacts of potential climate tipping points that could be exceeded due to human-induced climate change.
Reference: “Detection of Approaching Critical Transitions in Natural Systems Driven by Red Noise” by Andreas Morr and Niklas Boers, 4 June 2024, Physical Examination X.
DOI: 10.1103/PhysRevX.14.021037
