Based on the difference in summer and winter temperatures, researchers have discovered that human-induced climate change can be traced back to the late 19th century. In collaboration with leading experts from the UK and Germany, scientists from the Institute of Atmospheric Physics have found that the human impact on the climate actually goes back much further than what was previously realized.
As climate studies reveal more and more about the potentially devastating consequences of climate change, there is also a growing collection of evidence that human activities are to blame.
The Intergovernmental Panel on Climate Change (IPCC), for example, recently concluded with “high confidence” that human activities are responsible for the continuing rise of global warming since the 1950s. The new study, however, has pushed this back far beyond what was expected.
“It is well known that humans are driving global warming, but when did this begin?” said study lead author Dr. Jianping Duan. “Our study has shown that anthropogenic influence on climate change started much earlier than we previously believe.”
Anthropogenic climate change is usually focused on rising surface air temperatures and an increase in the frequency of climate extremes. The team led by Dr. Duan has found that the amplitude of seasonal temperature fluctuations has been decreasing widely, and this trend can be traced back to the late 19th century.
The experts discovered that temperature seasonality was stable until 1860s. Since that time, however, there has been a continuous downward trend across northern hemisphere mid-high latitudes.
Using a formal detection and attribution analysis, the team used the latest climate model simulations to show that increased greenhouse gas concentrations and anthropogenic aerosols are the main contributors to a downward trend in climate instability.
The study is published in the journal Nature Sustainability.
By Chrissy Sexton, Earth.com Staff Writer
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