"There is a warming in extreme temperatures over China, and this warming cannot be explained by natural variation," said Qiuzi Han Wen, an author on this paper and a researcher at the Institute of Atmospheric Physics in Beijing, China.
A diminished water source near the village Shanqian in Yunnan-province, China. (Credit: Bert van Dijk)
"It can only be explained by the anthropogenic external forcings. These findings indicate very clearly that climate change is not just an abstract number for the globe; it is evident at regional scale."
The study was recently published in Geophysical Research Letters—a journal of the American Geophysical Union.
To identify the human influence on temperatures, researchers from Beijing and Toronto compared data from climate change models with actual observations from 2,400 weather stations in China gathered between 1961 and 2007.
"The climate model produces historical simulations to mimic what would have happened under different influences—such as human-induced greenhouse gas emissions and volcanic activities—and produces many possible outcomes"," said Xuebin Zhang, an author on the paper and a researcher in the Climate Research Division of Environment Canada in Toronto. "If we average these possible outcomes, the day-to-day weather noise cancels out, leaving us with a general trend."
The climate model reproduces China's present reality only if human emissions are included, indicating that global warming is indeed the culprit for China's warmer day and nighttime temperatures and not natural weather fluctuations, Zhang said.
"Actually seeing a warming trend in a single location is hard," Zhang said. "It's like trying to see the tide change when you're in a rowboat going up and down on the waves. You need a lot of data to distill the day-to-day weather noise from the general trend."
But the key to cracking the warming trend in China, Zhang said, was the vast amounts of data that the research team distilled from the thousands of weather stations, over more than four decades. The researchers estimate that human emissions likely increased the warmest annual extreme temperatures—the daily maximum and daily minimum for the hottest day and night of the year—by 1.7 degrees Fahrenheit (0.92 degrees Celsius) and 3°F (1.7°C), respectively. They also found that human emissions likely raised the coolest annual extreme temperatures—the daily maximum and daily minimum for the coldest day and night of the year—by 5.1°F (2.83°C) and 8.0°F (4.44°C), respectively.
In addition to calculating the overall trend, Wen, Zhang and their colleagues separated the effect of each anthropogenic input. Carbon dioxide emissions had the highest impact on warming, explaining 89 percent of the increase in the daily maximum temperatures and 95 percent of the daily minimum temperatures.
Wen asserts greenhouse gases already in the atmosphere will continue to affect China's climate for years to come, regardless of mitigation measures taken to reduce future emissions. "As a result, we expect warming in China will continue into the future, and consequently warming in extreme temperatures will also continue," Wen said. "This will have huge implications for China, as heat waves and drought have already become more and more of an issue in our country. We would expect more hardship for dry-land farming as water supply is already stressed, higher demand on energy for cooling, and increasing heat-induced health issues."
Zhang stresses that the results of this study highlight that climate change is an urgent issue for China and that warming is already taking a toll on the country.
"There are heat waves almost everywhere in China and we're seeing more droughts," Zhang said. "China is getting much warmer, and people are very concerned."
This study was funded by the National Basic Research Program of China and benefited from a collaboration between the Meteorological Service Canada and the China Meteorological Administration.
Notes for Journalists
Journalists and members of the public can download a PDF copy of this accepted article by clicking on this link: http://onlinelibrary.wiley.com/doi/10.1002/grl.50285/abstract
Or, you may order a copy of the final paper by emailing your request to Sarah Charley at firstname.lastname@example.org. Please provide your name, the name of your publication, and your phone number.
Neither the paper nor this press release are under embargoTitle:
Contact information for the authors:Qiuzi Han Wen, Email: email@example.com
Peter Weiss | American Geophysical Union
Clear as mud: Desiccation cracks help reveal the shape of water on Mars
20.04.2018 | Geological Society of America
Hurricane Harvey: Dutch-Texan research shows most fatalities occurred outside flood zones
19.04.2018 | European Geosciences Union
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy