Nav: Home

How much carbon the land can stomach with more carbon dioxide in the air

September 02, 2019

About 600 petagrams, or 600 billion tons of carbon (the weight of about 100 billion really big elephants), was emitted as carbon dioxide from 1750-2015 due to fossil fuel burning, cement production and land-use change. About one-third of this was absorbed by land ecosystems.

Plants pull carbon dioxide out of the atmosphere by "eating" it, i.e., converting the carbon dioxide into sugars and starches, aka photosynthesis. Fortunately, plants' appetite for carbon dioxide is pretty good: The more carbon dioxide we have in the air, the faster the plants eat.

When a terrestrial ecosystem absorbs more carbon from human carbon dioxide emissions than it emits, it is called a carbon sink; otherwise, it is a carbon source. Scientists have found that rising carbon dioxide concentration in the air enhances land carbon sink, a process known as carbon dioxide fertilization. Quantifying carbon dioxide fertilization is critical for understanding and predicting how climate will affect and be affected by the carbon cycle.

Recently, researchers from 28 institutions in nine countries succeeded in quantifying carbon dioxide fertilization for the past five decades, using simulations from 12 terrestrial ecosystem models and observations from seven field carbon dioxide enrichment experiments.

They found that the sensitivity of northern temperate carbon sink to rising carbon dioxide concentration is linearly related to the site-scale sensitivity across the models. Based on this emergent relationship and field experiment observations as a constraint, the study estimated that for every 100-ppm increase in carbon dioxide in the air (equivalent to about one flea per one liter of water), terrestrial carbon dioxide sink increases by 6.4 billion tons (equivalent to 1.4 billion really big elephants) of carbon per year in the temperate Northern Hemisphere, and 35 billion tons of carbon per year globally. The team also revealed that carbon dioxide fertilization is primarily responsible for the observed increase in global terrestrial carbon sink.

"This study reduces uncertainty in the understanding of the carbon dioxide fertilization effect on terrestrial carbon sink," said co-author Dr. PIAO Shilong of the College of Urban and Environmental Sciences at Peking University. "The new approach and techniques in this study will be very useful to the scientific community in future research and studies."

"To explain further mechanisms underlying the carbon dioxide fertilization effect, more longer-term field experiments are required, particularly in boreal and tropical ecosystems. Joint effort between experimentalists and modelers is also necessary," said Dr. LIU Yongwen, lead author of the study and a research scientist at the Institute of Tibetan Plateau Research, Chinese Academy of Sciences.

Studies have shown the capacity of terrestrial ecosystems to absorb carbon dioxide is growing. This is good news since the process can slow the accumulation of carbon dioxide in the air and thus the pace of climate change. Credit should go to carbon dioxide fertilization, the extended growing season for vegetation, and reforestation, all of which help pull carbon from the atmosphere. At the same time, however, factors such as fire, heat waves and permafrost thawing - among other increasingly common global warming ills - are changing previous carbon sinks into carbon sources.
-end-
This research was supported by the Strategic Priority Research Program (Pan-TPE) of the Chinese Academy of Sciences.

Chinese Academy of Sciences Headquarters

Related Atmosphere Articles:

New study detects ringing of the global atmosphere
A ringing bell vibrates simultaneously at a low-pitched fundamental tone and at many higher-pitched overtones, producing a pleasant musical sound. A recent study, just published in the Journal of the Atmospheric Sciences by scientists at Kyoto University and the University of Hawai'i at Mānoa, shows that the Earth's entire atmosphere vibrates in an analogous manner, in a striking confirmation of theories developed by physicists over the last two centuries.
Estuaries are warming at twice the rate of oceans and atmosphere
A 12-year study of 166 estuaries in south-east Australia shows that the waters of lakes, creeks, rivers and lagoons increased 2.16 degrees in temperature and increased acidity.
What makes Saturn's atmosphere so hot
New analysis of data from NASA's Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn's moons, spark the auroras and heat the planet's upper atmosphere.
Galactic cosmic rays affect Titan's atmosphere
Planetary scientists using the Atacama Large Millimeter/submillimeter Array (ALMA) revealed the secrets of the atmosphere of Titan, the largest moon of Saturn.
Physics: An ultrafast glimpse of the photochemistry of the atmosphere
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
Using lasers to visualize molecular mysteries in our atmosphere
Molecular interactions between gases and liquids underpin much of our lives, but difficulties in measuring gas-liquid collisions have so far prevented the fundamental exploration of these processes.
The atmosphere of a new ultra hot Jupiter is analyzed
The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) and from the University of La Laguna (ULL) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.
An exoplanet loses its atmosphere in the form of a tail
A new study, led by scientists from the Instituto de Astrofísica de Canarias (IAC), reveals that the giant exoplanet WASP-69b carries a comet-like tail made up of helium particles escaping from its gravitational field propelled by the ultraviolet radiation of its star.
Iron and titanium in the atmosphere of an exoplanet
Exoplanets can orbit close to their host star. When the host star is much hotter than our sun, then the exoplanet becomes as hot as a star.
Astronomers find exoplanet atmosphere free of clouds
Scientists have detected an exoplanet atmosphere that is free of clouds, marking a pivotal breakthrough in the quest for greater understanding of the planets beyond our solar system.
More Atmosphere News and Atmosphere Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.