Nearly 40 years of global temperature data amassed by satellites reveal the atmospheric fingerprint of climate modification.
An assessment of decades of satellite data has confirmed how humans are altering seasonal cycles in the lower atmosphere.
The gathering of greenhouse gases produced by burning fossil fuels has enhanced air temperatures in summer and prompted larger annual temperature swings in the northern hemisphere.
The modern study, which implements satellite temperature records from 1979 to 2016, is the first to pinpoint seasonal shifts in the atmosphere. The odds that natural weather variance can account for the enormity of the temperature changes over the course of the satellite record are around 5 in a 1,000,000.
“In the biological world, lots of people have been looking for and finding these changes, so we decided to take a look at the satellite data,” says chief author Benjamin Santer, an atmospheric scientist at the Lawrence Livermore National Laboratory in California. “What we see is profound evidence of the human impact on climate, not only in the annual temperatures but also in the seasonal cycle.”
Santer’s team utilized computer models to simulate the planetary climate over thousands of years, with and without greenhouse-gas emanations. This enabled them to predict telltale ‘fingerprints’ of human impact on atmospheric conditions.
The researchers then compared said patterns with satellite temperature data accumulated since 1979. That revealed that natural fluctuations in Earth’s climate couldn’t account for all of the ascertained changes in seasonal climate cycles.