Global Food System Emissions Alone Threaten Warming Beyond 1.5°c

Global Food System Emissions Alone Threaten Warming Beyond 1.5°c  Pajtica/Shutterstock

How people grow food and the way we use the land is an important, though often overlooked, contributor to climate change. While most people recognise the role of burning fossil fuels in heating the atmosphere, there has been less discussion about the necessary changes for bringing agriculture in line with a “net-zero” world.

But greenhouse gas emissions from the global food system are growing. Unless there are significant changes in the way we produce and deliver food from fields to tables, the world will miss the climate targets of the Paris Agreement, even if we immediately phase out fossil fuel use.


 Get The Latest By Email

Weekly Magazine Daily Inspiration

In a new paper, my colleagues and I explored how food system emissions fit into remaining carbon budgets which are intended to limit global warming to 1.5 or 2°C above pre-industrial levels. We estimated that if global food systems continue to develop at their current rate – known as a “business as usual” trajectory – the resulting increase in emissions from this alone would likely add enough extra warming to take Earth’s average temperature beyond a 1.5°C rise in the 2060s.

The good news is that this outcome is not inevitable. There are improvements to what we eat and how we farm it that are achievable, and can be pursued right now.

Carbon budgets

Thanks to the Paris Agreement, the world has an internationally agreed target of keeping global warming below 2°C, and striving for 1.5°C.

To meet any given temperature target, there’s a fixed carbon budget – a finite amount of CO₂ that can be emitted before global temperatures surpass the limit. This surprisingly straightforward link between CO₂ emissions and global temperature helps scientists set useful targets for reducing emissions. Achieving this temperature target means keeping total CO₂ emissions within the carbon budget, by phasing out fossil fuel burning so that we reach net-zero emissions before exceeding the budget.

The same applies to CO₂ emissions from agriculture. We have to switch the energy sources powering farms and food production from fossil fuels to renewables, while halting the deforestation that creates new farmland.

But here things get complicated, as CO₂ is only a relatively small part of the total emissions from food systems. Agricultural emissions are dominated by nitrous oxide (N₂O), mostly from fertilisers spread on fields (both synthetic and animal manures), and methane (CH₄), largely produced by ruminant livestock such as cows and sheep, and rice farming. So how do these two gases fit into our carbon budgets?

Global Food System Emissions Alone Threaten Warming Beyond 1.5°c The methane burps of cows and other livestock are a signficant contributor to global warming. Fernando filmmaker/Shutterstock

Nitrous oxide lasts in the atmosphere for around a century, making it relatively long-lived (though still a lot shorter than CO₂ on average). Each N₂O emission subtracts from the carbon budget in a similar way to CO₂ itself.

Methane only survives in the atmosphere for around a decade once emitted. Each emission causes a significant but fairly short burst of warming, but doesn’t contribute to long-term warming and reduce the available carbon budget in the same way as CO₂ or N₂O. To account for this, we used a new approach, which treats methane differently to longer-lived gases, in order to incorporate it in carbon budgets.

Keeping warming below 2°C

Using this new framework, we considered how food system emissions might affect the world’s remaining carbon budget in lots of different scenarios. These included what might happen if we made the typical diet more or less sustainable, if people wasted less food, or if farms produced more food from the same amount of land.

Given that there’s an increasing human population that is, on average, eating more food – and more emissions-intensive types of food such as meat and dairy – the world is on track to exceed the carbon budget for limiting warming to 1.5°C due to these food system emissions alone, and take up a large share of the 2°C budget.

But there are many changes we can make to avoid this. Switching to healthier diets that are more plant-based and lower in calories or reducing food waste could allow the same number of people to be fed with less overall food production and a smaller environmental footprint. Improved farming methods, including more efficient use of fertilisers, could help produce more food with fewer resources. These are achievable changes which would significantly reduce food system emissions.

Even better, implementing all of these measures could actually expand the total carbon budget the world has left. If the amount of food the world needs and how it was produced were carefully planned, more land could be freed for other purposes. That includes rewilding, which would expand wild habitats on former farmland, encouraging biodiversity and fixing carbon from the atmosphere into plants.Global Food System Emissions Alone Threaten Warming Beyond 1.5°c On the Knepp estate in Sussex, UK, land once used for farming has been allowed to rewild. SciPhi.tv/Shutterstock

People will always have different dietary preferences, and climate change could limit how much we’re able to improve agricultural efficiency, even if warming remains below 1.5°C. But even if some strategies are only partially fulfilled, pursuing multiple approaches simultaneously could still significantly reduce food system emissions overall.

Keeping global warming to 1.5°C gives the world very little wiggle room. It’s essential that emissions from burning fossil fuels are eliminated as rapidly as possible. The world must build on the plunge in emissions that occurred during the COVID-19 pandemic, and force similar declines every year onwards.

We have shown that if – and it is a big if – the world does actually manage to decarbonise this quickly, we have a good chance of keeping food system emissions low enough to limit warming to between 1.5 and 2°C. We can waste no more time in achieving this.The Conversation

About The Author

John Lynch, Postdoctoral Researcher in Physics, University of Oxford

Related Books

Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming

by Paul Hawken and Tom Steyer
9780143130444In the face of widespread fear and apathy, an international coalition of researchers, professionals, and scientists have come together to offer a set of realistic and bold solutions to climate change. One hundred techniques and practices are described here—some are well known; some you may have never heard of. They range from clean energy to educating girls in lower-income countries to land use practices that pull carbon out of the air. The solutions exist, are economically viable, and communities throughout the world are currently enacting them with skill and determination. Available On Amazon

Designing Climate Solutions: A Policy Guide for Low-Carbon Energy

by Hal Harvey, Robbie Orvis, Jeffrey Rissman
1610919564With the effects of climate change already upon us, the need to cut global greenhouse gas emissions is nothing less than urgent. It’s a daunting challenge, but the technologies and strategies to meet it exist today. A small set of energy policies, designed and implemented well, can put us on the path to a low carbon future. Energy systems are large and complex, so energy policy must be focused and cost-effective. One-size-fits-all approaches simply won’t get the job done. Policymakers need a clear, comprehensive resource that outlines the energy policies that will have the biggest impact on our climate future, and describes how to design these policies well. Available On Amazon

This Changes Everything: Capitalism vs. The Climate

by Naomi Klein
1451697392In This Changes Everything Naomi Klein argues that climate change isn’t just another issue to be neatly filed between taxes and health care. It’s an alarm that calls us to fix an economic system that is already failing us in many ways. Klein meticulously builds the case for how massively reducing our greenhouse emissions is our best chance to simultaneously reduce gaping inequalities, re-imagine our broken democracies, and rebuild our gutted local economies. She exposes the ideological desperation of the climate-change deniers, the messianic delusions of the would-be geoengineers, and the tragic defeatism of too many mainstream green initiatives. And she demonstrates precisely why the market has not—and cannot—fix the climate crisis but will instead make things worse, with ever more extreme and ecologically damaging extraction methods, accompanied by rampant disaster capitalism. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

This article is republished from The Conversation under a Creative Commons license. Read the original article.

MOST READ

No Visits and Barely Any Calls: The Pandemic and People with a Family Member In Prison
No Visits and Barely Any Calls: The Pandemic and People with a Family Member In Prison
by Alexander Testa and Chantal Fahmy, The University of Texas at San Antonio
The US Electric Power Sector Is Halfway To Zero Carbon Emissions
The US Electric Power Sector Is Halfway To Zero Carbon Emissions
by Bentham Paulos, Lawrence Berkeley National Laboratory et al
Why QAnon Hasn't Gone Away
Why QAnon Hasn't Gone Away
by Sophie Bjork-James, Vanderbilt University
The Long Term Benefit Of Lifting Children Out Of Poverty Today
The Long Term Benefit of Lifting Children Out of Poverty Today
by Diane Whitmore Schanzenbach, Northwestern University et al
What’s The Difference Between Misinformation, Disinformation and Hoaxes?
What’s The Difference Between Misinformation, Disinformation and Hoaxes?
by Michael J. O'Brien and Izzat Alsmadi, Texas A&M
Why Not Make Paper Out Of Something Other Than Trees?
Why Not Make Paper Out Of Something Other Than Trees?
by Beverly Law, Oregon State University
Why Do People Believe In Conspiracies?
Why Do People Believe In Conspiracies?
by Mathew Marques, La Trobe University et al
How to Meet the Ambitious Target of Conserving 30% of Earth by 2030
How to Meet the Ambitious Target of Conserving 30% of Earth by 2030
by Matthew Mitchell, University of British Columbia

New Attitudes - New Possibilities

InnerSelf.comClimateImpactNews.com | InnerPower.net
MightyNatural.com | WholisticPolitics.com
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.