Summary: While the ongoing
coronavirus pandemic continues to threaten millions of lives around the world,
the first half of 2020 saw an unprecedented decline in carbon dioxide emissions
-- larger than during the financial crisis of 2008, the oil crisis of the 1979,
or even World War II.
While the ongoing coronavirus
pandemic continues to threaten millions of lives around the world, the first
half of 2020 saw an unprecedented decline in CO2 emissions --
larger than during the financial crisis of 2008, the oil crisis of the 1979, or
even World War II. An international team of researchers has found that in the
first six months of this year, 8.8 percent less carbon dioxide was emitted than
in the same period in 2019 -- a total decrease of 1551 million tonnes. The
groundbreaking study not only offers a much more precise look at COVID-19's
impact on global energy consumption than previous analyses. It also suggests
what fundamental steps could be taken to stabilize the global climate in the
aftermath of the pandemic.
"What makes our study unique
is the analysis of meticulously collected near-real-time data," explains
lead author Zhu Liu from the Department of Earth System Science at Tsinghua
University in Beijing. "By looking at the daily figures compiled by the
Carbon Monitor research initiative we were able to get a much faster and more
accurate overview, including timelines that show how emissions decreases have
corresponded to lockdown measures in each country. In April, at the height of
the first wave of Corona infections, when most major countries shut down their
public life and parts of their economy, emissions even declined by 16.9 %.
Overall, the various outbreaks resulted in emission drops that we normally see
only on a short-term basis on holidays such as Christmas or the Chinese Spring
Festival."
The study, published in the
latest issue of Nature Communications, shows which parts of the
global economy were most impacted. "The greatest reduction of emissions
was observed in the ground transportation sector," explains Daniel Kammen,
professor and Chair of the Energy and Resources Group and also professor in the
Goldman School of Public Policy, University of California, Berkeley.
"Largely because of working from home restrictions, transport CO2 emissions
decreased by 40 % worldwide. In contrast, the power and industry sectors
contributed less to the decline, with -22 % and -17 %, respectively, as did the
aviation and shipping sectors. Surprisingly, even the residential sector saw a
small emissions drop of 3 %: largely because of an abnormally warm winter in
the northern hemisphere, heating energy consumption decreased with most people
staying at home all day during lockdown periods."
To paint this comprehensive and
multidimensional picture, the researchers based their estimates on a wide array
of data: precise, hourly datasets of electricity power production in 31
countries, daily vehicle traffic in more than 400 cities worldwide, daily
global passenger flights, monthly production data for industry in 62 countries as
well as fuel consumption data for building emissions in more than 200
countries.
The researchers also found strong
rebound effects. With the exception of a continuing decrease of emissions
stemming from the transportation sector, by July 2020, as soon as lockdown
measures were lifted, most economies resumed their usual levels of emitting CO2.
But even if they remained at their historically low levels, this would have a
rather minuscule effect on the long-term CO2 concentration in
the atmosphere.
Thus, the authors stress that the
only valid strategy to stabilize the climate is a complete overhaul of the
industry and commerce sector. "While the CO2 drop is
unprecedented, decreases of human activities cannot be the answer," says
Co-Author Hans Joachim Schellnhuber, founding director of the Potsdam Institute
for Climate Impact Research. "Instead we need structural and
transformational changes in our energy production and consumption systems.
Individual behavior is certainly important, but what we really need to focus on
is reducing the carbon intensity of our global economy."
Source:
Potsdam Institute for Climate Impact Research (PIK)
Journal Reference:
Zhu Liu, Philippe Ciais, Zhu Deng, Ruixue Lei, Steven J. Davis, Sha Feng, Bo Zheng, Duo Cui, Xinyu Dou, Biqing Zhu, Rui Guo, Piyu Ke, Taochun Sun, Chenxi Lu, Pan He, Yuan Wang, Xu Yue, Yilong Wang, Yadong Lei, Hao Zhou, Zhaonan Cai, Yuhui Wu, Runtao Guo, Tingxuan Han, Jinjun Xue, Olivier Boucher, Eulalie Boucher, Frédéric Chevallier, Katsumasa Tanaka, Yimin Wei, Haiwang Zhong, Chongqing Kang, Ning Zhang, Bin Chen, Fengming Xi, Miaomiao Liu, François-Marie Bréon, Yonglong Lu, Qiang Zhang, Dabo Guan, Peng Gong, Daniel M. Kammen, Kebin He, Hans Joachim Schellnhuber. Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-18922-7