A study finds that the “hockey stick” is the best proxy for human-caused global warming
By David JacobsonJune 21, 2017 8:12:00A new study finds the hockey stick is the “best proxy for global warming” because it captures how the Earth’s climate responds to various factors.
The study, which was published online on Wednesday in the journal Nature Geoscience, examined data collected from more than 15,000 climate scientists over the last decade.
It found that a hockey-stick-like shape emerged as the most accurate proxy for warming trends.
Using the data, the researchers estimated that over the period from 1997 to 2012, the average global surface temperature increase was 1.4 degrees Celsius (2.3 degrees Fahrenheit).
That’s about 2.5 degrees Fahrenheit (1.7 degrees Celsius) higher than the average for the entire 20th century, they found.
In addition, the trend in global temperature increased by 0.2 degrees Celsius per year from 1997 through 2016.
The researchers say the study demonstrates that the hockey-shade shape is indeed a reliable proxy for the average climate change trend.
“It’s quite a good proxy, and it’s very sensitive to the number of data points that you include,” lead author Peter Wadhams, a climatologist at the University of East Anglia in the UK, told CNN.
“It’s a very good proxy because it’s fairly well-known that you get the signal from a lot of different sources.”
Wadhams and colleagues compared the temperature trend from the past 15 years with the global temperature reconstruction from the satellite-derived HadCRUT4 data, which has since been revised.
The team used the latest satellite data from 2016 and compared that with data from the 1979 to 2009 data.
Wadmans and his team also looked at how the data varied from year to year.
“For example, we look at the year to the year difference between the [1979 to 2009] data and the current data,” he said.
“So we find that, actually, the data has moved over the past 25 years and that is a big effect of the data.”
Wadal said the study provides a new benchmark for how well scientists are able to interpret climate data.
“If you look at any kind of temperature data, if you look for trends over time, it’s going to be a little bit easier to interpret,” he told CNN’s State of the Union.
“The fact that we’re able to do that with this new dataset is really remarkable.”
The findings were based on the satellite temperature data that the scientists collected.
“We looked at what the temperature was doing when it was on land and the temperature when it’s on sea,” Wadham said.
“And so it’s really a little more difficult to do this on land.”
Wads team found that when they compared the data from different regions of the world, it showed that the Earth was getting warmer.
They also found that the average temperature was increasing faster than the long-term average trend, which suggests that humans are playing a large role in climate change.
“The fact is, it looks like humans are causing a significant increase in the amount of heat that’s being absorbed into the atmosphere,” Wadam said.
Wads said that the data also suggests that the current climate change is “very extreme.”
“It is quite dramatic,” he added.
“In fact, it is quite extreme.”
The study was funded by the European Commission’s Seventh Framework Programme.