Ever since we have become aware of global warming, most assumed human-caused climate change had begun roughly during the 20th Century.
But a new study, published on Wednesday reveals that the humans started affecting global temperatures much earlier than that.
The researchers used paleoclimate records beginning with the year 1500 AD. They discovered that major changes occurred during the mid-nineteenth century – when the industrial era began.
The increased temperatures affected both tropical oceans and land mass surface temperatures in the Northern Hemisphere.
The findings would indicate that greenhouse gases were the culprits for this increase in temperatures even backed then.
Up until this point, the only systematic recordings scientists had regarding climate dated back to the 1880s. These recordings were very useful in understanding 20th century climate change, since they provided a means of comparison. But they didn’t help when it came to earlier centuries.
But now, 25 researchers across the world managed to map out climate change patters all over the globe. They did this by looking at the information contained within coral reefs, tree rings and ice caps.
Climate changes leave a kind of chemical fingerprint, that scientists can then use to spot patterns. By using these new paleoclimate records, they could see what global temperatures were like before, and after the beginning of the industrial era.
Not All Scientists Agree These Are the Signs of Human-Caused Climate Change
Michael Mann, a professor at Pennsylvania University argues that the increase in global temperatures might not be entirely the result of human activities.
Both the study, and Mann note that during the 1800s, a large volcano erupted in Indonesia. This eruption had a cooling effect on global temperatures.
Mann argues that the researchers responsible for the study are underestimating the effects of this global cooling. In a comment sent to the Washington Post, Mann said, “There was certainly some anthropogenic warming prior to the late 19th century. But the authors overstate how much, and how early, by incorrectly conflating early 1800s warming caused by the recovery from these eruptions with early greenhouse warming”.
He argues that what the scientists are noticing is in fact the climate change that came as a result of this global cooling.
Human-caused climate change might have contributed to the rise in global temperatures. But it’s more likely that the reason they are noticing a spike in global temperatures is because they had cooled down before that.
The researchers disagree. They believed this cooling theory at first as well. But after extensive testing, they realized these eruptions couldn’t explain the rise in global temperatures.
The results of this study would indicate that climate change has already caused more damage to the planet than we previously thought.
It also shows that the Earth’s atmosphere is much more delicate, and susceptible to human actions than we believed.
These findings will possibly help us make prediction for the future, and help us deal with global warming. It can also provide authorities with a renewed motivation to pursue more eco-friendly policies.
Image Source: Pixabay