One cannot really blame Mother Nature’s mood swings for the series of record-setting heat waves in recent years, as proven by a new study.
An international team of meteorologists argued that record temperatures in the last 150 years were extremely unlikely to have happened without human-induced climate change.
According to the findings published in the Nature Scientific Reports journal, there is a slim 1 in 5,000 to 1 in 170,000 odds that natural climate swings caused the record-breaking heat that hit parts of the world. Figures for 2015 – proclaimed the hottest year on Earth – even made the odds slimmer.
For author and meteorology professor Michael Mann, the scientists quoted in press reports about recent global temperature records did not perform a rigorous estimate.
"Natural climate variability causes temperatures to wax and wane over a period of several years, rather than varying erratically from one year to the next," Mann said in a statement.
The team examined Northern Hemisphere and global temperatures using a mix of observations and simulations of climate models. Part of their focus was 13 out of the warmest 15 years since 2000.
In all scenarios, the odds of warming patterns taking place without human influence – or by chance alone – were low.
Putting human-caused warming into consideration, the probability of nine of the 10 warmest years happening since the dawn of the 21st century is 88 percent for the Northern Hemisphere.
The researchers noted that recent record temperature years are 600 to 130,000 times more likely to have occurred because of man-made conditions. These findings prove that human activity has a significant impact on extreme temperature changes.
Author and ocean physics professor Stefan Rahmstorf pinpointed that 2015 being the warmest year so far added even more weight to their results. Their data analysis, he explained, echoed the role of human greenhouse-gas emissions in multiplying the risk of extremely high temperatures.
Last week, a report from NASA confirmed that 2015 was indeed the world’s hottest year since 1880, reinstating a previous forecast from the World Meteorological Organization.
Data shows that since the 19th century, the average surface temperature of Earth has risen by as much as 1.0 degree Celsius or 1.8 degrees Fahrenheit. Science points to the increase in carbon dioxide and other man-made emissions in the atmosphere as the culprits for this unprecedented warming.
The increasing temperatures were discovered to have taken place in the last 35 years.
Photo: Andrea Della Adriano | Flickr