What does a staple food such as bread have to do with global warming? For a start, to make loaves on an industrial scale, you’ll need powerful milling and kneading machines and a huge oven, heated to 230℃ or more. This uses a lot of energy. The flour, yeast and salt must also be shipped in and, finally, the finished loaves are delivered to stores – all in trucks powered by petrol. 
But it isn’t milling or baking or transport that accounts for most of the environmental impact of bread. In a new a study published in the journal Nature Plants, colleagues and I looked at the entire supply chain of a regular loaf – from seed to sandwich, via mill and bakery. We found that more than half its environmental impact arises not from food processing but from the production of the raw material, the wheat grain.
Food causes about a third of total greenhouse gas emissions. Yet the supply chains can be so complex that it is difficult to determine what part of the process is responsible – and without this information neither the industry nor consumers will know what to do about it. This is why it’s useful to take a zoomed-out look at the entire process.
Howard Walker / PAThanks to a collaboration with a bread manufacturer we had accurate “primary” data for every stage of their particular brand of 800g loaf. We found that ammonium nitrate fertiliser alone accounts for 43% of all the greenhouse gas emissions, dwarfing all other processes in the supply chain including baking and milling. These emissions arise from the large amounts of energy and natural gas needed to produce fertiliser, and from the nitrous oxide released when it is degraded in the soil.
For crops to grow big and fast, they need nitrogen, usually through fertiliser. It is the key ingredient of intensive agriculture. Without fertiliser, either we produce less food or we use much more land to produce the same amount, at greater economic and environmental cost. That is the fix we are in.
We could reduce the use of fertiliser by recycling agricultural and human waste as manure, in order to retain the nitrogen in the same cycle. We could also harness the best of organic farming by, for example, using “green manures” or rotating crops with legumes that “fix” nitrogen in the soil. Precision agriculture can be used to only apply fertiliser where and when it is needed, using new sensor technologies including drones to monitor the nutritional status of soils and plants.
And we can even develop new varieties of crops that are able to use nitrogen more efficiently by, for instance, harnessing fungi in the soil or getting soil microbes to release less nitrous oxide.
oticki / shutterstockBut technology isn’t the only solution – we could also change our diets. Meat, in particular, is a very inefficient use of nitrogen, as cows or chickens use up energy and nutrients simply staying alive before being slaughtered.
Cereal crops such as wheat are a much more efficient way of converting nitrogenous fertiliser into nitrogen in food protein. Studies show emphatically that low-meat diets are also good for the environment.
But whose responsibility is it to reduce fertiliser use? After all, fingers could be pointed at the fertiliser manufacturer, the farmer, or even the retailers and consumers who demand cheap bread.
With goods like electronics or car tyres there is a growing recognition for a notion of extended producer responsibility where manufacturers are held responsible for the continuing impact of their products, often including disposal. This could be extended to fertilisers too.
Consumers could pay more for “greener bread” or apply pressure to use less fertiliser. But things can be confusing as people are usually entirely unaware of the environmental impacts embodied in the products they consume. This is particularly the case for food, where the mains concerns are over human health or animal welfare – not emissions. Many will be surprised that wheat cultivation has a greater environmental impact than baking or milling.
This highlights one of the key conflicts in the food security challenge. The agriculture industry’s primary purpose is to make money, not to provide sustainable food for the whole world. Profits for farmers and retailers rely on highly productive crops – which require lots of relatively cheap fertiliser. However the environmental impact of this fertiliser is not costed within the system and so there are currently no real incentives to fix things.
Feeding seven billion people fairly and sustainably is therefore not only a question of technology but also one of political economy. We need incentives to use less fertiliser – and we could start with bread.
Peter Horton, Chief Research Advisor, Grantham Centre for Sustainable Futures, University of Sheffield
This article was originally published on The Conversation. Read the original article.
President Donald Trump has the environmental community understandably concerned. He and members of his Cabinet have questioned the established science of climate change, and his choice to head the Environmental Protection Agency, former Oklahoma Attorney General Scott Pruitt, has sued the EPA many times and regularly sided with the fossil fuel industry. 
Even if the Trump administration withdraws from all international climate negotiations and reduces the EPA to bare bones, the effects of climate change are happening and will continue to build.
In response to real threats and public demand, cities across the United States and around the world are taking action to address climate change. We might think this is happening only in large, coastal cities that are threatened by sea-level rise or hurricanes, like Amsterdam or New York.
Research shows, however, that even in the fly-over red states of the U.S. Great Plains, local leaders in small- to medium-size communities are already grappling with the issue. Although their actions are not always couched in terms of addressing climate change, their strategies can provide insights into how to make progress on climate policy under a Trump administration.
My colleagues and I did a survey of over 200 local governments in 11 states of the Great Plains region to learn about steps they’re taking to mitigate the effects of climate change and to adapt to them. We found local officials in red states responsible for public health, soil conservation, parks and natural resources management, as well as county commissioners and mayors, are concerned about climate change, and many feel a responsibility to take action in the absence of national policy.
paytonc/flickr, CC BY-SABut because it is such a complex and polarizing topic, they often face public uncertainty or outrage toward the issue. So while these local officials have been addressing climate change in their communities over the past decade, many of these policy activities are specifically not framed that way. As one respondent to our survey said:
“It is my personal and professional opinion that the conservation community is on track with addressing the issue of climate change but is way off track in assigning a cause. The public understands the value of clean water and clean air. If the need to improve our water quality and air quality was emphasized, most would agree. Who is going to say dirty water and dirty air is not a problem? By making the argument ‘climate change and humans are the cause’ significant energy is wasted trying to prove this. It is also something the public has a hard time sinking their teeth into.”
In order to address the vulnerabilities facing their communities, many local officials are reframing climate change to fit within existing priorities and budget items. In a survey of mayors, we asked: “In your city’s policy and planning activities (for energy, conservation, natural resources management, land use, or emergency planning, etc.) how is climate change framed?” The following quotes give a sense of their strategies.
“In terms of economic benefit & resource protection. This framing was deliberate to garner support from residents who did not agree with climate change.”“We frame the initiative as: energy savings (=$ savings), as smart growth/good planning, and as common sense natural resource management. Climate change is only explicitly referenced in our Climate Protection Plan adopted in 2009. Most initiatives fall under the "sustainability” umbrella term.“
"We mask it with sustainability, we call it P3 (People, Planet, Prosperity)”
“The initial interest in climate change came about as a result of concern about the potential for poor air quality affecting economic development in the City. Air quality and climate change were framed as being extremely related issues.”
“Climate change is framed as one of several benefits of conservation measures. Other benefits of conservation, recycling, walking, etc. include it’s ‘good for the earth’ (regardless of climate change), healthful, economical, etc.”
The results show that energy, economic benefits, common sense and sustainability are frames that are providing opportunities for local leaders to address climate change without getting stuck in the political quagmire. This strategy is being used across the Great Plains states, which include some of the most climate-skeptical areas of the country.
Every region of the U.S. will need to address practical questions of how states and local communities can reduce emissions and adapt to climate impacts. Under the Trump administration, it is likely any progress on U.S. climate policy will continue at these subnational levels. That’s why a variety of experts argue that we should encourage the types of pragmatic strategies now being employed by local leaders in red states.
In the Great Plains in particular, local officials are facing severe impacts from higher temperatures, which will place greater demands on water and energy.
Minnesota Pollution Control Agency, CC BY-NCIn our research we found local leaders focus on regional and local issues such as drought, energy and flooding. These are problems that are tied to climate change, but are already a priority on the local level. And the sought-for improvements, such as energy savings, health benefit and flood management, fit well with local needs and values.
For example, Fargo, North Dakota mitigates some of its greenhouse gas emissions and created a new source of city revenue by capturing the methane from its landfill facility and selling that gas to the electricity company. The city trash is now providing renewable energy for local residents and an industrial facility.
Perhaps the question facing us is: Should we reframe climate change and other environmental problems to fit the Trump administration’s priorities with a strong focus on practical solution ideas? For example, Trump has stated that infrastructure projects will be a high priority. That could easily translate into fixing the drinking water crisis experienced by Flint, Michigan and many other cities where it is likely to happen; Trump has also highlighted mass transit, which could help reduce air pollution and carbon emissions.
With an administration eager to expand fossil fuel development and consumption, the outlook for federal action on reducing climate-altering greenhouse gases is dire. Given that, reframing climate change to address cobenefit issues seems a logical strategy, and we can look for local government leaders in red states to show the way.
Rebecca J. Romsdahl, Professor of Environmental Science & Policy, University of North Dakota
This article was originally published on The Conversation. Read the original article.
In recent weeks, California has experienced unusually heavy rainfall. California is also earthquake-prone, hosting the great San Andreas fault zone. 
