In 2008, the research team, headed by Benjamin D. Santer, made a puzzling discovery. Their results found that stratospheric cooling, an impact of human-induced climate change, may have been detectable starting as early as 1885. Those results were recently published in the Proceedings of the National Academy of Sciences. They show that the impact of humanity on the Earth’s atmosphere is not a recent phenomenon. The research, which has the DOI 10.1073/pnas.2500829122, draws on an innovative mix of real-world observations, environmental science theory and state-of-the-art computer modeling.
More recent analyses confirm that human activity—especially the burning of coal, wood and similar biomass—have been changing the stratosphere for more than a century. These emissions alone have changed the complexion of our atmosphere. This study is particularly important because it sheds light on a timeline that has generally gone unnoticed. It fundamentally upends the former consensus on how carbon emissions drive climate change.
Study Insights and Methodology
Santer and his multi-institutional team focused on analyzing climate data from as far back as 1860, marking the beginning of the industrial age. The goal was to recreate the stratosphere’s state at that time. In order to accomplish this they combined historical data with nine climate models in order to forecast the impacts of human-based emissions on temperatures within this atmospheric layer.
What the researchers found was actually quite astounding. They concluded that anthropogenic evidence of stratospheric changes could have been detected as long ago as 1885. The role of carbon in amplifying climate change was first highlighted by scientists in the 1850s. Unfortunately, it wasn’t until almost another hundred years later that a consensus developed on its role in accelerating global warming.
Implications for Climate Research
As climate change is already at the forefront of public discourse, the implications from Santer’s study carry enormous weight in establishing an accurate historical record. The detectable influence of anthropogenic cooling in the stratosphere goes back to the late 1800s. Alongside previous research, this finding underscores the urgent need for climate models to seriously consider historical emissions. In other words, this research stretches the bounds of our current climate literature. It opens the door to exploring early industrial emissions and their long-lasting effects on global temperatures.
Further, by creating a more defined timeline of the human impact, the study hopes to better inform current and future climate policy. Recognizing how past industrial processes have altered the atmosphere can inform future actions taken to limit continued alteration.
Future Research Directions
The research team led by Santer acknowledges that while this study provides a historical perspective on human influence on climate, further investigations are essential. From here, future studies can build off this groundwork. They’ll model the complex interactions between these different greenhouse gases and their joint influences on the stratosphere and troposphere.