Navigation Links
Geoengineering and global food supply
Date:1/22/2012

Washington, D.C. -- Carbon dioxide emissions from the burning of coal, oil, and gas have been increasing over the past decades, causing the Earth to get hotter and hotter. There are concerns that a continuation of these trends could have catastrophic effects, including crop failures in the heat-stressed tropics. This has led some to explore drastic ideas for combating global warming, including the idea of trying to counteract it by reflecting sunlight away from the Earth. However, it has been suggested that reflecting sunlight away from the Earth might itself threaten the food supply of billions of people. New research led by Carnegie's Julia Pongratz examines the potential effects that geoengineering the climate could have on global food production and concludes that sunshade geoengineering would be more likely to improve rather than threaten food security. Their work is published online by Nature Climate Change January 22.

Big volcanoes cool the planet by placing lots of small particles in the stratosphere, but the particles fall out within a year and the planet heats back up. One proposal for cooling the planet is to use high-flying airplanes to constantly replenish a layer of small particles in the stratosphere that would scatter sunlight back to space. But such so-called sunshade geoengineering could have unintended consequences for climate, and especially for precipitation.

Although scientists know that climate change in recent decades has negatively impacted crop yields in many regions, the study by Pongratz and colleagues is the first to examine the potential effect of geoengineering on food security. Pongratz's team, which included Carnegie's Ken Caldeira and Long Cao, as well as Stanford University's David Lobell, used models to assess the impact of sunshade geoengineering on crop yields.

Using two different climate models, they simulated climates with carbon dioxide levels similar to what exists today. A second set of simulations doubled carbon-dioxide levels levels that could be reached in several decades if current trends in fossil-fuel burning continue unabated. A third set of simulations posited doubled carbon dioxide, but with a layer of sulfate aerosols in the stratosphere deflecting about 2% of incoming sunlight away from the Earth. The simulated climate changes were then applied to crop models that are commonly used to project future yields.

The team found that, in the model, sunshade geoengineering leads to increased crop yields in most regions, both compared with current conditions and with the future projection of doubled carbon dioxide on its own. This is because deflecting sunlight back to space reduces temperatures, but not CO2. "In many regions, future climate change is predicted to put crops under temperature stress, reducing yields. This stress is alleviated by geoengineering," Pongratz said. "At the same time, the beneficial effects that a higher CO2 concentration has on plant productivity remain active."

Even if the geoengineering would help crop yields overall, the models predict that some areas could be harmed by the geoengineering. And there are other risks that go beyond the direct impact on crop yields. For example, deployment of such systems might lead to political or even military conflict. Furthermore, these approaches do not solve the problem of ocean acidification, which is also caused by carbon dioxide emissions.

"The real world is much more complex than our climate models, so it would be premature to act based on model results like ours," Caldeira said. "But desperate people do desperate things. Therefore, it is important to understand the consequences of actions that do not strike us as being particularly good ideas."

"The climate system is not well enough understood to exclude the risks of severe unanticipated climate changes, whether due to our fossil-fuel emissions or due to intentional intervention in the climate system," Pongratz said. "Reducing greenhouse gas emissions is therefore likely a safer option than geoengineering to avert risks to global food security."


'/>"/>
Contact: Ken Caldeira
kcaldeira@carnegie.stanford.edu
650-704-7212
Carnegie Institution
Source:Eurekalert

Related biology news :

1. Testing geoengineering
2. Survey finds public support for geoengineering research
3. Ocean geoengineering scheme no easy fix for global warming
4. Time to lift the geoengineering taboo
5. Symposium to discuss geoengineering to fight climate change at the ESA Annual Meeting
6. Nanotechnology in Medical Applications: The Global Market
7. Ecologists gain insight into the likely consequences of global warming
8. New report reviews plan for US Global Change Research Program
9. Forest health versus global warming: Fuel reduction likely to increase carbon emissions
10. Hellbender salamander study seeks answers for global amphibian decline
11. Global resource for clinical microbiologists and immunologists debuts
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/2/2016)... The Weather Company , an IBM Business (NYSE: IBM ... which consumers will be able to interact with IBM Watson ... or text and receive relevant information about the product or ... long sought an advertising solution that can create a one-to-one ... valuable; and can scale across millions of interactions and touchpoints. ...
(Date:5/16/2016)... 16, 2016   EyeLock LLC , a market ... opening of an IoT Center of Excellence in ... the development of embedded iris biometric applications. ... convenience and security with unmatched biometric accuracy, making it ... from DNA. EyeLock,s platform uses video technology to deliver ...
(Date:4/28/2016)... 28, 2016 First quarter 2016:   ... compared with the first quarter of 2015 The gross ... M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) , ... is unchanged, SEK 7,000-8,500 M. The operating margin for ...
Breaking Biology News(10 mins):
(Date:6/23/2016)...  The Prostate Cancer Foundation (PCF) is pleased to announce 24 ... for prostate cancer. Members of the Class of 2016 were selected from a ... Read More About the Class of 2016 PCF Young Investigators ... ... ...
(Date:6/23/2016)... ... 2016 , ... STACS DNA Inc., the sample tracking software company, today announced ... has joined STACS DNA as a Field Application Specialist. , “I am thrilled ... COO of STACS DNA. “In further expanding our capacity as a scientific integrator, Hays ...
(Date:6/23/2016)... , June 23, 2016 ... Hematology Review, 2016;12(1):22-8 http://doi.org/10.17925/OHR.2016.12.01.22 ... , the peer-reviewed journal from touchONCOLOGY, Andrew ... escalating cost of cancer care is placing an ... result of expensive biologic therapies. With the patents ...
(Date:6/23/2016)... ... June 23, 2016 , ... Velocity Products, a division of ... and optimized exclusively for Okuma CNC machining centers at The International Manufacturing Technology ... among several companies with expertise in toolholding, cutting tools, machining dynamics and distribution, ...
Breaking Biology Technology: