Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Crops play a major role in the annual CO2 cycle increase

20.11.2014

Each year, the planet balances its budget. The carbon dioxide absorbed by plants in the spring and summer as they convert solar energy into food is released back to the atmosphere in autumn and winter. Levels of the greenhouse gas fall, only to rise again.

But the budget has gotten bigger. Over the last five decades, the magnitude of this rise and fall has grown nearly 50 percent in the Northern Hemisphere, as the amount of the greenhouse gas taken in and released has increased. Now, new research shows that humans and their crops have a lot to do with it, highlighting the profound impact people have on the Earth's atmosphere.

In a study published Wednesday, Nov. 19, in Nature, scientists at Boston University, the University of New Hampshire, the University of Michigan, the University of Minnesota, the University of Wisconsin-Madison and McGill University show that a steep rise in the productivity of crops grown for food accounts for as much as 25 percent of the increase in this carbon dioxide (CO2) seasonality.

It's not that crops are adding more CO2 to the atmosphere; rather, if crops are like a sponge for CO2, the sponge has simply gotten bigger and can hold and release more of the gas.

With global food productivity expected to double over the next 50 years, the researchers say the findings should be used to improve climate models and better understand the atmospheric CO2 buffering capacity of ecosystems, particularly as climate change may continue to perturb the greenhouse gas budget.

"This is another piece of evidence suggesting that when we (humans) do things at a large scale, we have the ability to greatly influence the composition of the atmosphere," says UW-Madison's Chris Kucharik, a co-author of the study and professor in the College of Agricultural and Life Sciences Department of Agronomy and the Nelson Institute for Environmental Studies.

Since the 1960s in the Northern Hemisphere, maize (corn), wheat, rice and soybeans have seen a 240 percent spike in production, particularly concentrated in the midwestern U.S. and in Northern China, the study found.

But until this point, scientists missed the connection between crops and the CO2 seasonality increase.

"Global climate models don't represent the important details of agroecosystems and their management very well," says Kucharik.

It was fall 2013 when the study's lead authors at Boston University approached the UW-Madison scientist and asked him to lend his agricultural land management, carbon cycling and agricultural technology expertise to their examination of the cycle.

Kucharik helped the team determine how the amount of carbon absorbed by the leaves, stems, roots and food-portion of crops may have changed over time. He helped ensure the methodology the team used properly represented agricultural lands and the management practices that drive changes in the carbon balance.

The study found that, while the area of farmed land has not significantly increased, the production efficiency of that land has. Intensive agricultural management over the last 50 years has had a profound impact.

Kucharik attributes this to improvements in plant breeding, post-World War II fertilization innovations, irrigation and other human-powered technologies.

"You get more bang for your buck, more crop per drop," he says.

Cropland makes up just six percent of the vegetated, or green, area of the Northern Hemisphere and yet, it is a dominant contributor to the 50 percent increase in the CO2 seasonality cycle. This, despite the fact that forests and grasslands have also been more productive as the planet has warmed and growing seasons have lengthened.

"That's a very large, significant contribution, and 2/3 of that contribution is attributed to corn," says Kucharik. "Corn once again is king, this time demonstrating its strong influence on the seasonal cycle of atmospheric CO2."

Earlier work at UW-Madison enabled the research team to make the necessary calculations to incorporate agriculture into the new modeling approach, Kucharik says.

"The person that led the charge was Navin Ramankutty at SAGE (the Nelson Institute Center for Sustainability and the Global Environment), in Jon Foley's group in the late '90s and early 2000s," says Kucharik. "Those first global maps of agricultural land use over time came out of SAGE and the Nelson Institute."

Ramankutty, a co-author of the study, is now a geography professor at the University of British Columbia while Foley, not an author on the study, is now the executive director of the California Academy of Sciences.

CONTACT: Chris Kucharik, 608-890-3021, kucharik@wisc.edu

--Kelly April Tyrrell, ktyrrell2@wisc.edu, 608-262-9772

Chris Kucharik | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>