Study: expanding Brazilian sugarcane for ethanol could reduce global CO2 emissions by up to 5.6%
24 October 2017
Vastly expanding sugarcane production in Brazil for conversion to ethanol could reduce current global CO2 emissions by as much as 5.6%, according to a new study by an international team led by researchers from the University of Illinois.
This would be a massive undertaking, involving the conversion of hundreds of thousands of square miles—at its most ambitious, more than the combined land area of Texas and California—to sugarcane fields. However, it could be accomplished without impinging on environmentally sensitive areas in Brazil and while allowing for the expansion of other agricultural crops and human needs, the researchers report in a paper in the journal Nature Climate Change. The carbon-related costs of converting the land to sugarcane fields were included in the analysis.
The team looked at three scenarios that would increase the sugarcane footprint in Brazil between 37.5 million and 116 million hectares (144,788 to 447,879 square miles).
We show that Brazilian sugarcane ethanol can provide the equivalent of 3.63–12.77 Mb d−1 of crude oil by 2045 under projected climate change while protecting forests under conservation and accounting for future land demand for food and animal feed production. The corresponding range of CO2 offsets is 0.55–2.0 Gigatons yr−1. This would displace 3.8–13.7% of crude oil consumption and 1.5–5.6% of net CO2 emission globally relative to data for 2014.—Jaiswal et al.
The research relied on a new approach to modeling the precise behavior of sugarcane crops growing in regions that vary in soil composition, temperature, rainfall and numerous other parameters, said Stephen P. Long, a University of Illinois professor of crop sciences and plant biology who led the analysis with colleagues including included scientists from the University of São Paulo in Brazil.
Most models used to predict future crop production are statistical models that really don’t take full account of the way changes in water, carbon dioxide and temperature interact to affect sugarcane production. We’ve used a mechanistic model here that grows the plant, so it’s driven by the factors that the plant is responding to on an hourly basis.—Stephen Long
The Brazilian government has mapped out ecologically sensitive lands that cannot be used for agriculture, industry or other types of development, Long said. The proposed expansion of sugarcane production is within the area that can be legally converted.
Brazil already has accomplished a lot with its sugarcane-to-ethanol industry, said study co-author Amanda De Souza, a postdoctoral researcher at Illinois and the University of São Paulo.
Unlike in the US, Brazil uses almost all of the sugarcane plant for energy, extracting the sugar to make ethanol but also burning the stem residue, known as bagasse, to power the mill, with the excess being used to generate and sell electricity. The conversion of the cellulose component of the bagasse to ethanol is also likely to become cost-effective in Brazil. Sugarcane-based ethanol production in Brazil today is much more efficient than corn ethanol, and generates only 14%of the carbon dioxide emissions of petroleum.—Amanda De Souza
To reduce its carbon footprint even further, the government of Sao Paulo, the major ethanol-producing state in Brazil, recently outlawed the burning of sugarcane before harvest. A practice still common in the US sugarcane industry, burning removes the leaves and reduces the bulk of material that must be hauled to the mill, but adds particulate pollution to the atmosphere and reduces soil organic matter, the researchers said.
Deepak Jaiswal, Amanda P. De Souza, Søren Larsen, David S. LeBauer, Fernando E. Miguez, Gerd Sparovek, Germán Bollero, Marcos S. Buckeridge & Stephen P. Long (2017) “Brazilian sugarcane ethanol as an expandable green alternative to crude oil use” Nature Climate Change doi: 10.1038/nclimate3410
Expand cellulose ethanol then make E85 more available.
Posted by: SJC | 24 October 2017 at 10:20 AM
It would inevitably involve unseen habitat destruction.
Better produce efuels from solar and wind.
Will eventually be much cheaper and much less destructive
Posted by: Alain | 24 October 2017 at 11:49 AM
Agree; also, many believe burning gross amounts of alcohol instead of fossil fuel will produce smog of a different gas makeup but just as damaging to air, land, water and human health.
Posted by: Lad | 24 October 2017 at 12:20 PM
They don't need more land, just use the stalk for cellulose biofuels.
Posted by: SJC | 24 October 2017 at 06:13 PM
Insane or embarrassing is an accurate description for this University of Illinois report.
With transport sector contributing 12-14% globally to which can be added extraction refining and non transport uses of petroleum products.
It is not credibly possible that somehow growing sugarcane for fuel can magic away ~ 15-50% of global transport sector emissions as the headline would suggest when claiming a 1.5 - 5.6% reduction in global CO2 emissions.
If they meant a more believable 1.5- 5.6%b improvement in road transport emissions ( a concept that can be considered in the real world) then they should say just that.
I could make the claim of 100% reduction in emissions from renewable energy sourced BEV's but while that may be a very fair claim - any extra kilometres driven would contribute to unmeasurable extra CO2 emissions - there would be some extra costs for tyres road maintenance vehicle depreciation and replacement etc.
Why are we reading public so often treated as brain damaged? Could there be better disclosure of the financial incentive to guild the lily here? Illinois produces more corn ethanol than any other state and has a very close association between the University and various aspects of the ethanol industry.
I wouldn't worry too much about the destruction of large swathes of Brazil that's not the objective here.
Posted by: Arnold | 24 October 2017 at 08:00 PM
Current hydrofracking in the USA for producing oil and gas is also insane.
Posted by: Peter_XX | 24 October 2017 at 11:32 PM
Vastly expanding sugarcane production in Brazil for conversion to ethanol could reduce current global CO2 emissions by as much as 5.6%, according to a new study by an international team led by researchers from the University of Illinois. soundcloud downloader
Posted by: Jennifer Brownz | 29 June 2018 at 11:43 PM