If humans are causing global warming, we should see a number of unique climate patterns. Sure enough, these “human fingerprints” have been observed all over our planet. The human fingerprints confirm that humans are the main driving force behind global warming, and also rule out natural causes such as changes in solar activity.
The earliest prediction of what human fingerprints should look like dates as far back as 1865. Physicist John Tyndall predicted that if greenhouse gases were driving warming, then winters should warm faster than summers, and nights should warm faster than days. In recent decades, scientists have observed these very patterns.
A number of other human fingerprints have also been observed across our planet. If increased greenhouse gases are trapping heat, satellites should see less heat escaping to space. This has been measured over the last few decades of the satellite era.
At the same time, we should also see more heat returning back to the Earth’s surface. This has also been observed by surface measurements.
Another tell-tale human fingerprint is seen in the very structure of the atmosphere. As greenhouse gases trap heat in the lower atmosphere, the upper atmosphere should cool. Both satellites and weather balloons have measured this pattern. One of the consequences of this cooling is the upper atmosphere has been shrinking. Satellites brushing the top of the atmosphere have felt it falling away. The sky is literally falling.
However, one persistent myth is that global warming is caused by the Sun rather than by humans. This myth commits the error of cherry picking – failing to take into account the full body of evidence.
If the sun were causing global warming, we would expect to see specific patterns of global warming. Solar warming should cause summers to warm faster than winters, and days to warm faster than nights. We’re seeing the opposite.
The human fingerprints confirm that human activity is the main driver of recent global warming. They also rule out natural drivers of climate such as the sun.