Detecting Climate Change: Signals Found 130 Years Ago

In a groundbreaking study, researchers have revealed that the first signals of human-induced climate change could have been detectable as early as 1885, a period just before the widespread adoption of fossil fuel-powered vehicles. This finding, published in the Proceedings of the National Academy of Sciences (PNAS) on June 30, 2025, highlights the significant impact of human activities on atmospheric conditions over the past century and a half.

The research, led by a team of Earth and atmospheric scientists, utilized a hypothetical scenario where scientists of the 19th century were equipped with modern atmospheric monitoring tools. According to Dr. Emily Carter, a climate scientist at the Massachusetts Institute of Technology (MIT), "If the scientists had access to contemporary satellite microwave radiometers and accurate carbon dioxide measurements from ice cores, they would have been able to observe early signs of climate change much sooner."

Historically, the heat-trapping properties of carbon dioxide were only beginning to be understood in the mid-1800s, coinciding with the onset of the Industrial Revolution in Europe. During this period, emissions of greenhouse gases rose sharply, yet systematic scientific studies investigating the role of these gases in climate change did not begin until the 1970s. Dr. David Thompson, a professor of atmospheric sciences at Colorado State University, emphasized that "the early detection of climate change could have potentially altered the course of environmental policy had it been recognized earlier."

In their thought experiment, the research team established that by applying a pattern-based analysis to discern human and natural climate effects, it would have been feasible to detect pronounced cooling in the stratosphere driven by anthropogenic carbon dioxide emissions as early as 1885. The study indicated that while greenhouse gases warm the lower atmosphere, they simultaneously contribute to cooling in the upper stratosphere due to increased reflective power.

Dr. Sarah Johnson, an environmental researcher at Stanford University and co-author of the study, noted, "The stratospheric cooling effect is a critical indicator of climate change, highlighting the complexities of our atmosphere. Even with limited monitoring capabilities, significant cooling patterns could have been documented by 1894, just a few decades after the initial rise in fossil fuel use."

The implications of these findings are profound. Experts argue that recognizing the early signs of climate change could have led to preemptive measures in energy policies and sustainable practices. According to the United Nations Intergovernmental Panel on Climate Change (IPCC), the global community is now at a critical juncture, where immediate actions are necessary to prevent severe anthropogenic interference with the climate system.

As the study concludes, "Humanity is now at the threshold of dangerous anthropogenic interference. Our near-term choices will determine whether or not we cross that threshold." The urgency for sustainable pathways and reduced reliance on fossil fuels is more pressing than ever, as the consequences of inaction continue to unfold, affecting ecosystems and human societies worldwide.

This study serves as a reminder of the long-standing connection between human activity and climate change, urging policymakers and the public alike to recognize the significance of historical data in shaping future environmental strategies. As we move forward, the lessons from the past can guide our efforts to mitigate the impending impacts of climate change, fostering a more sustainable future for generations to come.