Had 19th-century scientists possessed today’s advanced atmospheric tools, they might have detected the earliest signs of climate change caused by human activity—specifically, the burning of coal and wood.
Scientists Suggest Climate Change Could Have Been Detected as Early as 1885
In a recent thought experiment, a group of Earth and atmospheric scientists concluded that, with the right instruments, the initial signs of human-driven warming could have been observed as early as 1885—years before the invention of fossil fuel-powered cars.
The study indicates that human influence on global temperatures has likely been detectable for more than 130 years.
At the time, the heat-trapping effects of carbon dioxide were just being uncovered, and CO₂ emissions were already climbing due to the Industrial Revolution. However, it wasn’t until the 1970s that scientific research began to clearly link rising carbon levels to human-induced climate change.
In their imagined scenario, the researchers assumed that by 1860, scientists had access to precise tools for monitoring global atmospheric changes—tools on par with modern satellite microwave radiometers and current estimates of CO₂ levels obtained from ice cores and stratospheric balloon data.
“We then used a pattern-based ‘fingerprint’ technique to separate human influences from natural climate variability,” the authors stated.
Early Climate Change Signs Showed Up as Stratospheric Cooling, Not Warming
Interestingly, though greenhouse gases are known for warming the planet, the earliest detectable signal of climate change would have appeared as cooling in the stratosphere. This cooling is a direct result of increased carbon dioxide and other greenhouse gas emissions, as well as ozone depletion caused by human activity.
While greenhouse gases trap heat in the lower atmosphere (the troposphere), they also enhance the reflective qualities of the stratosphere. This causes heat to be deflected back toward Earth, warming the surface while cooling the upper layers.
At the same time, ozone depletion reduces the stratosphere’s ability to absorb heat from radiation, further contributing to its cooling—while the troposphere beneath it begins to warm.
Stratosphere’s Stability Makes It Ideal for Tracking Long-Term Climate Change
Because the stratosphere is less influenced by the day-to-day variability of weather in the troposphere, it’s a more stable layer for detecting long-term climate trends—something ground-level observations often struggle to capture.
According to the researchers, “Significant cooling in the middle to upper stratosphere—mainly caused by human-driven increases in carbon dioxide—would have been clearly detectable by around 1885, even before gasoline-powered vehicles existed.”
They add that even with limited observation coverage in 1860—focused solely on mid-latitudes in the Northern Hemisphere—detecting human-induced stratospheric cooling would still have been possible by 1894, just 34 years after climate monitoring was assumed to begin.
Barring the invention of a time machine, we’ll never know whether early detection of climate change could have prevented the widespread damage caused by unchecked fossil fuel use throughout the 20th and 21st centuries—impacts we’re only beginning to fully experience today. Despite over 50 years of awareness, humanity has yet to break its dependence on fossil fuels.
“We have strong evidence that following sustainable pathways is essential to avoid harmful human impact on the climate,” the researchers state. “In both the mid- to upper stratosphere and the troposphere, the projected changes over the next 26 years are expected to exceed those seen during the 39-year span from 1986 to 2024.”
They warn, “Humanity stands on the brink of dangerous climate disruption. The decisions we make now will determine whether we step over that line—or pull back from it.”
Read the original article on: Science Alert
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