One of the bright spots of this year’s COP26 climate change conference was the commitments from the business sector to reducing their impact on climate change. In fact, according to Greenbiz, a US-based sustainable business outlet, the Glasgow event could be termed ‘Business COP’ for the efforts put in by the corporate world to be part of the solution. Read more
Kraft Heinz has pledged to achieve net zero greenhouse gas emissions across its operational footprint and entire global supply chain by 2050, reaffirming its commitment to reducing the ongoing threat of climate change. Read more
In times past, farmers were at the mercy of the elements to determine a successful yield of crops. As the global population grows and consumer preferences evolve, today’s modern farmer must also consider the scarcity of natural resources, the threat of climate change and the growing problem of food waste.
The oldest human industry has undergone a transformation like no other. The 1800s saw the use of chemical fertilizers, while farmers began to plan their work using satellites in the late 1900s. Today, the world needs to produce more food against a background of climate change, which is adversely affecting crop yields and encouraging crop diseases. So, how can we produce 70 per cent more food to meet the needs of a growing population, while significantly reducing greenhouse gas emissions? Smart farming offers a solution.
Using remote sensors to avoid costly manual monitoring, informed decisions can be made using real time data. This allows farmers to manage their inputs, such as water and animal feeds, more effectively to increase yields while maintaining minimal labor costs.
In the last few decades we’ve seen the rise of indoor urbanised farming, the use of aquaponic farming, and a vast departure from the traditional field cattle farming of old. The Third Agricultural Revolution, which we are arguably in the midst of, is based upon IT solutions, the Internet of Things (IoT), robotics, sensors, and drones.
The use of robotics for repetitive tasks is a trend across many industries. In farming, farmbots are employed to perform once laborious manual tasks including seeding, planting, watering, weeding and harvesting. Farmdrones are also utilized for monitoring purposes and data on plant health and soil conditions are fed back into the system.
When making significant upgrades to a system, power quality issues must be addressed. Although robotic systems and sensor networks have practical benefits, they often use electrical and electronic components that can introduce harmonic currents into electrical networks. If the harmonic levels in an electrical system are too high, this can cause load failure. To mitigate against power failure and unplanned downtime, ABB’s capacitors and filters product portfolio offers a range of solutions.
In particular, the ABB PQF active filters tackle the problems caused by harmonic currents, load unbalance and reactive power demand, while offering a host of system benefits in low voltage networks. Compliance with the strictest power quality regulations is not something that farmers should overlook. ABB’s solutions are rigorously tested to ensure filtering efficiency and system reliability, so that smart farms can operate with uninterrupted systems for maximum productivity.
Smart farming has the power to increase yield and efficiency, raising overall productivity of the supply chain without requiring significantly more land investment. With this, farmers are able to reliably and sustainably produce yields to maintain the growing global population, without being at the mercy of increasingly unpredictable climates.
To discover ABB’s wide range of high, medium and low voltage capacitors and filters, visit their product area of the website and explore how to address power considerations that arise through smart farming
When it comes to putting this season into perspective, Riverina grower Roy Hamilton has 128 years of rainfall records to show that, for his family’s property, this year is one of the driest since 1890.
The Australian government’s Grains Research and Development Corporation explains that research is important in fighting climate change – something that Hamilton is well aware of too.
The grain and fat lamb producer from Rand in southern New South Wales said 2018 was the third driest year on record on his property, behind 1982 and 2002, with just 110mm of growing rain received this season against a long-term average of 290mm.
The Hamilton family has owned Bogandillan Pastoral Company, a 4400-hectare mixed farming operation for more than 90 years and was one of the early adopters of minimum tillage, direct drill and controlled traffic farming.
Hamilton said these practices, along with a growing understanding of how to store soil moisture, control weeds effectively and manage nutrition, have meant even in really dry times there was still crop planted that would reach harvest.
“In the past, a season like this would have meant bare paddocks, but major improvements in how we do things on-farm, driven by quality research, have meant we can now plant on just 10mm of rainfall and still get crop establishment with limited moisture and take it through with some harvest potential,” he said.
“The key difference between then and now is our understanding of how to store moisture. Twenty years ago, we would never have had a boom spray in the same paddock as a harvester, but now it’s standard practice, because we know early weed control preserves soil moisture for the next crop.
“So essentially, research has changed the way we farm and improved critical elements like our water use efficiency and made it possible to get a crop planted and through to harvest in some of the toughest years we’ve had,” said Hamilton.
Hamilton, who is also a Grains Research and Development Corporation northern region panel member, credits the organisation with continuing to help growers build their knowledge and understanding of strategies to cope with drier years.
“Our records show the past two decades have been significantly more variable in terms of annual rainfall than the century before.”
The corporation needs to keep pushing into new frontiers and playing a vital part in developing on-farm management tactics that help us deal with seasonal challenge, he said.
“As a grower I feel the evidence is there to show our climate is becoming increasingly volatile and extreme, so we need all the tools we can get in terms of research and development to manage this and stay in the farming game,” said Hamilton.
The corporation’s chairman John Woods said often yields in a good year are talked about, but arguably it is more important to have a small crop in a tough season.
“We need to continue this work to mitigate climate effects and raise productivity in marginal years, as these years often coincide with very rewarding prices,” said Woods.
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.
Thanks 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 / shutterstock
But 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.
There is no incentive to ditch fertiliser
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.
Climate change and extreme weather events are already impacting our food, from meat and vegetables, right through to wine. This series on the Climate and Food now looks at what this means for the food chain.
The concentration of carbon dioxide in our atmosphere is increasing. Everything else being equal, higher CO₂ levels will increase the yields of major crops such as wheat, barley and pulses. But the trade-off is a hit to the quality and nutritional content of some of our favourite foods.
In our research at the Australian Grains Free Air CO₂ Enrichment (AGFACE) facility, we at Agriculture Victoria and The University of Melbourne are mimicking the CO₂ levels likely to be found in the year 2050. CO₂ levels currently stand at 406 parts per million (PPM) and are expected to rise to 550PPM by 2050. We have found that elevated levels of CO₂ will reduce the concentration of grain protein and micronutrients like zinc and iron, in cereals (pulses are less affected).
The degree to which protein is affected by CO₂ depends on the temperature and available water. In wet years there will be a smaller impact than in drier years. But over nine years of research we have shown that the average decrease in grain protein content is 6% when there is elevated CO₂.
Because a decrease in protein content under elevated CO2 can be more severe in dry conditions, Australia could be particularly affected. Unless ways are found to ameliorate the decrease in protein through plant breeding and agronomy, Australia’s dry conditions may put it at a competitive disadvantage, since grain quality is likely to decrease more than in other parts of the world with more favourable growing conditions.
There are several different classes of wheat – some are good for making bread, others for noodles etc. The amount of protein is one of the factors that sets some wheat apart from others.
Although a 6% average decrease in grain protein content may not seem large, it could result in a lot of Australian wheat being downgraded. Some regions may be completely unable to grow wheat of high enough quality to make bread.
But the protein reduction in our wheat will become manifest in a number of ways. As many farmers are paid premiums for high protein concentrations, their incomes could suffer. Our exports will also take a hit, as markets prefer high-protein wheat. For consumers, we could see the reduction in bread quality (the best bread flours are high-protein) and nutrition. Loaf volume and texture may be different but it is unclear whether taste will be affected.
The main measure of this is loaf volume and texture, but the degree of decrease is affected by crop variety. A decrease in grain protein concentration is one factor affecting loaf volume, but dough characteristics (such as elasticity) are also degraded by changes in the protein make-up of grain. This alters the composition of glutenin and gliadin proteins which are the predominant proteins in gluten. To maintain bread quality when lower quality flour is used, bakers can add gluten, but if gluten characteristics are changed, this may not achieve the desired dough characteristics for high quality bread. Even if adding extra gluten remedies poor loaf quality, it adds extra expense to the baking process.
Nutrition will also be affected by reduced grain protein, particularly in developing areas with more limited access to food. This is a major food security concern. If grain protein concentration decreases, people with less access to food may need to consume more (at more cost) in order to meet their basic nutritional needs. Reduced micronutrients, notably zinc and iron, could affect health, particularly in Africa. This is being addressed by international efforts biofortification and selection of iron and zinc rich varieties, but it is unknown whether such efforts will be successful as CO₂ levels increase.
What can we do about it?
Farmers have always been adaptive and responsive to changes and it is possible management of nitrogen fertilisers could minimise the reduction in grain protein. Research we are conducting shows, however, that adding additional fertiliser has less effect under elevated CO₂ conditions than under current CO₂ levels. There may be fundamental physiological changes and bottlenecks under elevated CO₂ that are not yet well understood.
If management through nitrogen-based fertilisation either cannot, or can only partly, increases grain protein, then we must question whether plant breeding can keep up with the rapid increase in CO₂. Are there traits that are not being considered but that could optimise the positives and reduce the negative impacts?
Selection for high protein wheat varieties often results in a decrease in yield. This relationship is referred to as the yield-protein conundrum. A lot of effort has gone into finding varieties that increase protein while maintaining yields. We have yet to find real success down this path.
A combination of management adaptation and breeding may be able to maintain grain protein while still increasing yields. But, there are unknowns under elevated CO₂such as whether protein make-up is altered, and whether there are limitations in the plant to how protein is manufactured under elevated CO2. We may require active selection and more extensive testing of traits and management practices to understand whether varieties selected now will still respond as expected under future CO₂ conditions.
Finally, to maintain bread quality we should rethink our intentions. Not all wheat needs to be destined for bread. But, for Australia to remain competitive in international markets, plant breeders may need to select varieties with higher grain protein concentrations under elevated CO2 conditions, focusing on varieties that contain the specific gluten protein combinations necessary for a delicious loaf.
Climate change and extreme weather events are already having impacts on our food, from meat and vegetables, right through to wine. In our series on the Climate and Food, we’re looking at what this means for the food chain.
While increases in population and wealth will lift global demand for food by up to 70% by 2050, agriculture is already feeling the effects of climate change. This is expected to continue in coming decades.
Scientists and farmers will need to act on multiple fronts to counter falling crop yields and feed more people. As with previous agricultural revolutions, we need a new set of plant characteristics to meet the challenge.
When it comes to the staple crops – wheat, rice, maize, soybean, barley and sorghum – research has found changes in rainfall and temperature explain about 30% of the yearly variation in agricultural yields. All six crops responded negatively to increasing temperatures – most likely associated with increases in crop development rates and water stress. In particular, wheat, maize and barley show a negative response to increased temperatures. But, overall, rainfall trends had only minor effects on crop yields in these studies.
As temperatures rise, rainfall patterns change. Increased heat also leads to greater evaporation and surface drying, which further intensifies and prolongs droughts.
A warmer atmosphere can also hold more water – about 7% more water vapour for every 1°C increase in temperature. This ultimately results in storms with more intense rainfall. A review of rainfall patterns shows changes in the amount of rainfall everywhere.
Crop yields around Australia have been hard hit by recent weather. Last year, for instance, the outlook for mungbeans was excellent. But the hot, dry weather has hurt growers. The extreme conditions have reduced average yields from an expected 1-1.5 tonnes per hectare to just 0.1-0.5 tonnes per hectare.
But the story is larger than this. Globally, production of maize and wheat between 1980 and 2008 was 3.8% and 5.5% below what we would have expected without temperature increases. One model, which combines historical crop production and weather data, projects significant reductions in production of several key African crops. For maize, the predicted decline is as much as 22% by 2050.
Feeding more people in these changing conditions is the challenge before us. It will require crops that are highly adapted to dry and hot environments. The so-called “Green Revolution” of the 1960s and 1970s created plants with short stature and enhanced responsiveness to nitrogen fertilizer.
Now, a new set of plant characteristics is needed to further increase crop yield, by making plants resilient to the challenges of a water-scarce planet.
Developing resilient crops for a highly variable climate
Resilient crops will require significant research and action on multiple fronts – to create adaptation to drought and waterlogging, and tolerance to cold, heat and salinity. Whatever we do, we also need to factor in that agriculture contributes significantly to greenhouse gas emissions (GHGs).
Scientists are meeting this challenge by creating a framework for adapting to climate change. We are identifying favourable combinations of crop varieties (genotypes) and management practices (agronomy) to work together in a complex system.
We can mitigate the effects of some climate variations with good management practices. For example, to tackle drought, we can alter planting dates, fertilizer, irrigation, row spacing, population and cropping systems.
Genotypic solutions can bolster this approach. The challenge is to identify favourable combinations of genotypes (G) and management (M) practices in a variable environment (E). Understanding the interaction between genotypes, management and the environment (GxMxE) is critical to improving grain yield under hot and dry conditions.
Genetic and management solutions can be used to develop climate-resilient crops for highly variable environments in Australia and globally. Sorghum is a great example. It is the dietary staple for over 500 million people in more than 30 countries, making it the world’s fifth-most-important crop for human consumption after rice, wheat, maize and potatoes.
‘Stay-green’ in sorghum is an example of a genetic solution to drought that has been deployed in Australia, India and sub-Saharan Africa. Crops with stay-green maintain greener stems and leaves during drought, resulting in increased stem strength, grain size and yield. This genetic solution can be combined with a management solution (e.g. reduced plant population) to optimise production and food security in highly variable and water-limited environments.
Other projects in India have found that alternate wetting and drying (AWD) irrigation in rice, compared with normal flooded production, can reduce water use by about 32%. And, by maintaining an aerobic environment in the soil, it reduces methane emissions five-fold.
Climate change, water, agriculture and food security form a critical nexus for the 21st century. We need to create and implement practices that will increase yields, while overcoming changing conditions and limiting the emissions from the agricultural sector. There is no room for complacency here.
Andrew Borrell, Associate Professor, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland; Centre Leader, Hermitage Research Facility; College of Experts, Global Change Institute, The University of Queensland
Top image: Shutterstock
Australia’s wheat yields more than trebled during the first 90 years of the 20th century but have stalled since 1990. In research published today in Global Change Biology, we show that rising temperatures and reduced rainfall, in line with global climate change, are responsible for the shortfall.
This is a major concern for wheat farmers, the Australian economy and global food security as the climate continues to change. The wheat industry is typically worth more than A$5 billion per year – Australia’s most valuable crop. Globally, food production needs to increase by at least 60% by 2050, and Australia is one of the world’s biggest wheat exporters.
There is some good news, though. So far, despite poorer conditions for growing wheat, farmers have managed to improve farming practices and at least stabilise yields. The question is how long they can continue to do so.
While wheat yields have been largely the same over the 26 years from 1990 to 2015, potential yields have declined by 27% since 1990, from 4.4 tonnes per hectare to 3.2 tonnes per hectare.
Potential yields are the limit on what a wheat field can produce. This is determined by weather, soil type, the genetic potential of the best adapted wheat varieties and sustainable best practice. Farmers’ actual yields are further restricted by economic considerations, attitude to risk, knowledge and other socio-economic factors.
While yield potential has declined overall, the trend has not been evenly distributed. While some areas have not suffered any decline, others have declined by up to 100kg per hectare each year.
We found this decline in yield potential by investigating 50 high-quality weather stations located throughout Australia’s wheat-growing areas.
Analysis of the weather data revealed that, on average, the amount of rain falling on growing crops declined by 2.8mm per season, or 28% over 26 years, while maximum daily temperatures increased by an average of 1.05℃.
To calculate the impact of these climate trends on potential wheat yields we applied a crop simulation model, APSIM, which has been thoroughly validated against field experiments in Australia, to the 50 weather stations.
Climate variability or climate change?
There is strong evidence globally that increasing greenhouse gases are causing rises in temperature.
Recent studies have also attributed observed rainfall trends in our study region to anthropogenic climate change.
Statistically, the chance of observing the decline in yield potential over 50 weather stations and 26 years through random variability is less than one in 100 billion.
We can also separate the individual impacts of rainfall decline, temperature rise and more CO₂ in the atmosphere (all else being equal, rising atmospheric CO₂ means more plant growth).
First, we statistically removed the rising temperature trends from the daily temperature records and re-ran the simulations. This showed that lower rainfall accounted for 83% of the decline in yield potential, while temperature rise alone was responsible for 17% of the decline.
Next we re-ran our simulations with climate records, keeping CO₂ at 1990 levels. The CO₂ enrichment effect, whereby crop growth benefits from higher atmospheric CO₂ levels, prevented a further 4% decline relative to 1990 yields.
So the rising CO₂ levels provided a small benefit compared to the combined impact of rainfall and temperature trends.
Closing the yield gap
Why then have actual yields remained steady when yield potential has declined by 27%? Here it is important to understand the concept of yield gaps, the difference between potential yields and farmers’ actual yields.
An earlier study showed that between 1996 and 2010 Australia’s wheat growers achieved 49% of their yield potential – so there was a 51% “yield gap” between what the fields could potentially produce and what farmers actually harvested.
Wheat farmers are closing the yield gap. From harvesting 38% of potential yields in 1990 this increased to 55% by 2015. This is why, despite the decrease in yield potential, actual yields have been stable.
Impressively, wheat growers have adopted advances in technology and adapted them to their needs. They have adopted improved varieties as well as improved practices, including reduced cultivation (or “tillage”) of their land, controlled traffic to reduce soil compaction, integrated weed management and seasonally targeted fertiliser use. This has enabled them to keep pace with an increasingly challenging climate.
What about the future?
Let’s assume that the climate trend observed over the past 26 years continues at the same rate during the next 26 years, and that farmers continue to close the yield gap so that all farmers reach 80% of yield potential.
If this happens, we calculate that the national wheat yield will fall from the recent average of 1.74 tonnes per hectare to 1.55 tonnes per hectare in 2041. Such a future would be challenging for wheat producers, especially in more marginal areas with higher rates of decline in yield potential.
While total wheat production and therefore exports under this scenario will decrease, Australia can continue to contribute to future global food security through its agricultural research and development.
The sustainability consulting group Quantis has launched an initiative to develop Guidance on accounting for greenhouse gas (GHG) emissions from deforestation and other types of land use.
This pre-competitive global initiative aims to provide a methodological guide with credible references that companies can use to account for the climate change impacts of their efforts on sustainable forests and agriculture in an accurate and credible manner.
A group of leaders from diverse industries have already joined the initiative: Barry Callebaut, Ferrero, General Mills, Lenzing, L’Oreal, LVMH, Mars, Pirelli, Philip Morris International, Tetra Pak, and Yara as well as non-profits, governments, and academic institutions such as ADEME, C-AGG, CIRAD, Ecofys, Rainforest Alliance, South Pole Group, Textile Exchange, and The Sustainability Consortium.
“Companies understand the need to reduce the impacts of their supply chains and are increasingly interested in communicating about their efforts. Credible metrics are critical for achieving both,” Jon Dettling, Quantis US Managing Director and project lead explained. “A GHG accounting method that is conducive to corporate goal setting and supply chain management will allow companies to achieve progress and to communicate credibly on these efforts.”
The scientific community estimates that deforestation and impacts from land use account for over 20 per cent of GHG emissions. With pressure to set science-based GHG targets as well as to establish deforestation-free supply chains, organizations realize the urgent need for guidance on how to include GHG emissions from deforestation in corporate GHG goals.
“Mars is excited to be part of this initiative – we believe better and more consistent quantification of GHG emissions from deforestation will help accelerate global efforts to reduce both deforestation and GHG emissions,“ said Kevin Rabinovitch, Global Sustainability Director, Mars, Incorporated.
For companies dealing with products of agriculture and forestry, management of forests and other land types is often identified as one of the highest priorities for addressing climate change. To include emissions from deforestation and other types of land use within GHG reduction goals, guidance on how to measure this GHG impact and how to track progress over time is needed.
This initiative will fill this need by developing a Guidance on how to calculate GHG emissions from land use and land use change such as deforestation, and how to apply this within corporate supply chain assessments and product assessments, such as tracking changes and progress toward goals.
It is often claimed that a vegetarian diet is better for the environment, because grazing animals such as cattle and sheep produce a lot of methane, a far more potent greenhouse gas than carbon dioxide.
The areas needed for livestock grazing can also be much larger than those used for crops to produce an equivalent amount of food, so more land is cleared for meat than crops, which causes more carbon to be lost from the landscape.
But wait. As is often the case with complex environmental cycles, particularly those altered by human activities, this is only part of the story. While it is true that ruminants emit a lot of methane, and this is currently the greatest slice of the agricultural emissions pie, it is also true that these are not the only emissions associated with human agriculture.
Cropland generally uses more inorganic fertiliser than pasture, which means that the more plants you eat, the more of your greenhouse footprint comes from nitrous oxide – another potent greenhouse gas linked to use of industrially produced fertiliser.
Unfortunately, this means that sticking to a climate-friendly diet isn’t always just a matter of giving up steak and lamb chops. You also have to consider the soil types and farming practices in the places where your food is produced. And the bad news for Europeans is that eating meat is much harder to justify than it is in Australia, for instance, where livestock tends to be less intensively farmed.
Emissions and soils
Nitrous oxide emissions come from the turnover of nitrogen compounds in the soil, which in turn come from both organic matter (manure, soil organic matter) and synthetic fertilisers (primarily inorganic nitrogen).
This means that the biggest greenhouse impact would come from eating livestock animals that are disconnected from the soil, kept in barns and fed on crops (for instance, beef cattle fed on corn meal) rather than extensively grazing on pastures. This represents a climate double whammy because the crops lead to nitrous oxide emissions and the animals then produce methane.
The other greenhouse gas to consider is, unsurprisingly, carbon dioxide. Healthy soils contain lots of organic matter, which helps to reduce erosion, boosts water storage capacity (and therefore drought resilience), and acts as a storehouse for nutrients (thereby reducing the need for fertiliser).
When land is cleared for agriculture, the amount of soil organic matter can decline dramatically. And because carbon makes up around 50-55% of soil organic matter, this land clearing not only depletes soil health but releases greenhouse gas, as the soil organic carbon is converted to carbon dioxide and released.
Soil organic matter can be restored by plants, which take up atmospheric carbon dioxide as they grow. When they die, their biomass is then (partially) incorporated into the soil and converted into soil organic matter.
So does farming help soils?
The soil organic carbon pool is the largest land-based carbon store and the most dynamic globally of the non-living carbon pools. There is at least twice as much carbon stored in the world’s soils as there is in the atmosphere.
So planting crops to store more carbon sounds like an attractive idea. Unfortunately, however, cultivated soils contain up to 70% less soil organic matter than natural soils, so croplands are actually a net greenhouse emitter.
Conversely, soils used for grazing animals have much higher soil organic matter content than in cropped systems, and roughly the same amount as natural soils. This is probably because many grazed systems are permanent pastures, where plants constantly grow and add to the soil carbon pool (even after the animals have eaten their fill).
But this distinction is not captured by official figures from the Intergovernmental Panel on Climate Change (IPCC), which only reports non-CO₂ emissions from agriculture, and assumes the CO₂ emissions from agriculture to be net zero (CO₂ emissions due to soil carbon loss appear in the “Forestry and other land use” category).
This means that the greenhouse emissions due to crops, and carbon storage in pasture lands, may both be underestimated. This issue is highlighted by our research, which shows that carbon losses from cropped soil extend far deeper than previously believed.
Previous estimates assumed that only the topsoil (generally the top 30 cm) was affected, but we have shown that, in Australia at least, this is not the case – the lower carbon content of cropped soil is detectable all the way down the soil profile. We also found that, at these deeper depths, natural and grazing soils contained very similar amounts of carbon.
As if that were not all complicated enough, there is yet another factor: when livestock manure is returned to the soil, this also boosts soil carbon, making for healthier soils and partially offsetting the animals’ greenhouse emissions. Declining use of animal manure on European crops has beenassociated with a reduction in soil carbon storage.
Food for thought
So what does this all mean? Well, 90% of our energy intake comes directly from the soil, so agricultural practices obviously have a big effect on soil health. If you care about conserving soils as well as minimising your greenhouse emissions, it’s not as simple as just going vegetarian.
Grazing animals can be good for soils, even though their methane emissions are bad for the atmosphere. Working out where the balance sits is a fiendishly tricky question. This is because agricultural emissions are related to individual site factors (such as climate or soil type) as well as agricultural practices (such as fertiliser regime or grazing intensity).
Perhaps the best approach is try to source your food from local suppliers (to reduce your food miles) who do not use intensive agricultural practices (such as frequent tillage or indoor mass-rearing of animals).
If you eat meat, choose free-range, grass-fed animals instead of those fed in barns using food from crops. Get to know how your food is produced, and choose the most sustainable options, whether meaty or not. Small choices can help to save our soils.
Each year our terrestrial biosphere absorbs about a quarter of all the carbon dioxide emissions that humans produce. This a very good thing; it helps to moderate the warming produced by human activities such as burning fossil fuels and cutting down forests.
But in a paper published in Nature today, we show that emissions from other human activities, particularly food production, are overwhelming this cooling effect. This is a worrying trend, at a time when CO₂ emissions from fossil fuels are slowing down, and is clearly not consistent with efforts to stabilise global warming well below 2℃ as agreed at the Paris climate conference.
To explain why, we need to look at two other greenhouse gases: methane and nitrous oxide.
The other greenhouse gases
Each year, people produce about 40 billion tones of CO₂ emissions, largely from burning fossil fuels and deforestation. This has produced about 82% of the growth in warming due to greenhouses gases over the past decade.
The planet, through plant growth, removes about a quarter of this each year (another quarter goes into the oceans and the rest stays in the atmosphere and heats the planet). If it didn’t, the world would warm much faster. If we had to remove this CO₂ ourselves, it would cost hundreds of billions of dollars each year, so we should be very grateful that the Earth does it for free.
Apart from CO₂, there are two other main greenhouse gases that contribute to global warming, methane (CH₄) and nitrous oxide (N₂O). In fact, they are both more potent greenhouse gases than CO₂. The global warming potential of methane and nitrous oxide is 28 and 265 times greater than that of CO₂, respectively.
The human emissions of these gases are largely associated with food production. Methane is produced by ruminants (livestock), rice cultivation, landfills and manure, among others.
Other human-induced emissions of methane come from changes to land use and the effects of climate change on wetlands, which are major producers of global methane.
Nitrous oxide emissions are associated with excessive use of fertilisers and burning plant and animal waste. To understand how much excess nitrogen we are adding to our crops, consider that only 17 of 100 units of nitrogen applied to the crop system ends up in the food we eat.
Sinks and sources
Just as humans pump greenhouse gases into the atmosphere, the land also produces and absorbs them. If the land absorbs more of a gas than it produces, we think of it as a “sink”. If it produces more than it absorbs, we call it a “source”. The ability of the land to absorb and produce greenhouse gases is affected by human activity.
We wanted to know how human activities on the land are affecting these sinks and sources. Globally, the land currently absorbs more CO₂ than it produces (we don’t include fossil fuels in this), so it is considered a carbon sink. But we found that this is overwhelmed by production of methane and nitrous oxide, so overall the land is a source of greenhouse gases.
This study highlights the importance of including all three major greenhouse gases in global and regional climate impact assessments, mitigation options and climate policy development.
Another recent study calculated that the size of this combined greenhouse gas source is about equivalent to the total fossil fuel emissions of CO₂ in the 2000s. Looking at the chart below, if you add up the carbon emissions from the “LUC gross source” (emissions from deforestation) and the emissions from methane and nitrous oxide (in blue and green), then you can see they are roughly equivalent to those from the combustion of fossil fuels.
So it’s a huge part of our contribution to climate change.
Importantly, CO₂ emissions from deforestation together with methane and nitrous oxide emissions are mainly associated with the process of making land available for food production and the growing of food in croplands and rangelands.
Unfortunately, there has been limited discussion about major commitments to decarbonise the food production system, as there has been about decarbonising the energy system.
Countries, particularly emerging and developing economies, have shown little interest in placing the food system at the forefront of climate negotiations. One reason is what’s at stake: feeding their people.
A continuation of the current growth trends in methane and nitrous oxide emissions, at a time when growth of CO₂ fossil fuel emissions is slowing, constitutes a worrying trend. The greenhouse gas footprint of food is growing while the role of the food system in climate mitigation is not receiving the attention that it urgently needs.
Opportunities for mitigation in this sector are plentiful, but they can only be realised with a concerted focus.
Pep Canadell is Senior Principal Research Scientist, and Executive Director of the Global Carbon Project, CSIRO.
Hanqin Tian is Director, International Centre for Climate and Global Change Research, Auburn University.
As agriculture and farmers around the world work to mitigate and adapt to the complex challenges posed by climate change, Monsanto Company today announced plans to make its operations carbon neutral by 2021 through a unique program targeted across its seed and crop protection operations, as well as through collaboration with farmers.
“Climate change is one of the biggest issues we face in agriculture, as well as one of the most pressing challenges facing humanity,” said Hugh Grant, Monsanto chairman and chief executive officer.
“That’s why we have pledged to do our part within our own business and to help support farmers and others. While progress has been made to reduce agriculture’s carbon footprint, we must work collectively to do even more if we are going to sustainably feed 9.6 billion people by 2050. Agriculture is uniquely positioned to deliver climate change solutions, and we hope that policy makers recognize the role agriculture, farmers and crops can play in mitigating carbon emissions.”
The company said its efforts focus on several key areas including:
Seed Production – Monsanto will drive carbon neutral crop production in its own seed production operations by leveraging diverse products and agronomic approaches, such as breeding, plant biotechnology, data science, conservation tillage and cover cropping systems, with the goal of eliminating that portion of its carbon footprint altogether. Working with outside experts in data science on extensive modeling, Monsanto has shown that utilising these practices and innovations can make an important difference, allowing corn and soybeans to be grown such that soil absorbs and holds greenhouse gases equal to or greater than the total amount emitted from growing those crops – reinforcing agriculture’s unique role in climate change mitigation. The company also will work with farmers to promote and drive the increased adoption of these carbon neutral crop production methods.
Crop Protection – The company also is targeting its crop protection business to be carbon neutral by 2021. Previously, Monsanto announced a goal to reduce the operational greenhouse gas emissions intensity in its crop protection operations and has continued to make steady progress against its commitment. To offset the remainder of its crop protection and other non-seed production operations, Monsanto is working to develop a program to provide incentives to farmer customers who adopt carbon neutral crop production methods – in exchange for part of their carbon reduction value. Monsanto will use those reductions as offsets to neutralise its remaining carbon footprint.
Sharing Data, Increasing Adoption of Best Practices – Monsanto has developed the carbon neutral crop models with the help of external experts and will share their data and modeling results with the broader agriculture, climate modeling and other communities to help drive the adoption of best practices and to reinforce the role crops can play in reducing carbon emissions. To date, these models are focused on the U.S. Corn Belt, where the most accurate data on crop yields, soil types, crop rotations and best management practices are publicly available. The models indicate that high yielding, carbon neutral corn and soybean production, in the United States alone, has the potential to reduce crop production emissions equivalent to 100 million metric tons of carbon dioxide, which is equal to reducing 233 million barrels of oil consumption per year.
At the center of achieving and verifying carbon neutral crop production is the advancement of data science in agriculture. Innovations from The Climate Corporation, a division of Monsanto, and other data scientists have allowed farmers to plant and harvest crops more precisely than ever. Examples include the use of satellite imagery to precisely target emerging pest problems or the development of sophisticated algorithms that model the exact fertilizer needs of each field. The continued integration of this data allows farmers to make more precise decisions, and when used in conjunction with agronomic best practices, can lead to carbon neutral crop production.
“This program is a critical step in agriculture’s overall effort to mitigate climate change,” said Dr. Chuck Rice, Distinguished Professor, Kansas State University and an author of the Intergovernmental Panel on Climate Change (IPCC) report. “The recent IPCC report indicated that agriculture is a significant pathway to mitigating greenhouse gases. Similar to other formalized carbon offset and renewable energy credit programs, organisations have started to invest in verified offsets originating from agricultural activities. Agriculture can be a positive force in the fight against climate change, and it’s important to see Monsanto stepping forward in this way.”
Farmers’ interest in adoption of these practices will require ongoing demonstration of the best practices and benefits related to carbon neutral cropping program, according to Monsanto.
Nestlé has been acclaimed as a ‘world leader’ for its work to tackle climate change by sustainability ratings agency CDP, with the company one of only 64 out of over 2000 to claim the highest possible score in the prestigious annual ranking.
Nestlé heads CDP’s (formerly Carbon Disclosure Project’s) Climate A List with a 100 A score, for actions including the introduction of technologies to further optimise energy use to reduce emissions, including greenhouse gases (GHGs).
Nestlé is working with farmers to help them use water more efficiently, and has lent financial support to buy biogas digesters at dairy farms, to generate renewable energy and cut methane emissions. The company is also committed to preserving natural capital, and ensuring suppliers respect its ‘No Deforestation’ commitment.
Food waste is a major generator of GHG emissions, and Nestlé recently strengthened its commitment to reduce it, by announcing that it would achieve zero waste for disposal at its sites by 2020.
“Nestlé is committed to providing leadership on climate change, and we’re honoured to receive this accolade from CDP, which shows we’re on the right track,” said Magdi Batato, Executive Vice President and Head of Operations.
With the world’s water resources under threat from climate change, CDP recently commended Nestlé separately on the ‘excellent’ results of its water stewardship activities, which are also guided by public commitments.
Over the past decade, Nestlé said it has invested heavily in water-saving projects at factories, and a further CHF 62 million on community water projects with international agencies.
The CDP award comes after Nestlé received an industry-leading score of 99 per cent in the ‘environmental dimension’ of the 2015 Dow Jones Sustainability Index.
The price, quality and seasonality of Australia’s food is increasingly being affected by climate change with Australia’s future food security under threat, a ground-breaking report by the Climate Council has revealed.
Australia’s food supply chain is highly exposed to disruption from increasing extreme weather events driven by climate change with farmers already struggling to cope with more frequent and intense droughts and changing weather patterns, the Feeding a Hungry Nation: Climate Change, Food and Farming in Australia report found.
The Climate Council’s Professor Lesley Hughes said Australia’s agricultural competitiveness in many agricultural markets will be challenged by the warming climate and changing weather patterns.
"Australia is one of the most vulnerable developed countries in the world to climate change impacts," she said.
"This is already posing very significant challenges to food production. Food prices will continue to go up, the quality of food could be compromised and the seasonality of food could change as the climate continues to warm and weather patterns become more unpredictable.
"Many of our favourite foods, including milk, fruit, vegetables, wine and beef are already being affected by climate change and these impacts will grow as weather extremes get worse."
The report also found:
Climate change impacts are already being observed in many of Australia’s favourite foods, including rice, lamb, milk, beef, stone fruits and wine grapes
Climate change is projected to worsen drought conditions with severe implications for farmers and food prices
Climate change is affecting the quality and seasonal availability of many foods in Australia. Up to 70% of Australia’s wine-growing regions with a Mediterranean climate (including iconic locations such as the Barossa Valley and Margaret River) are becoming less suitable for grape growing with higher temperatures causing earlier ripening and reduced grape quality
More frequent and intense heatwaves are already affecting food prices in Australia. Food prices during the 2005-2007 drought increased at twice the rate of the Consumer Price Index (CPI) with fresh fruit and vegetables the worst hit, increasing 43% and 33% respectively. Cyclone Larry destroyed 90% of the North Queensland banana crop in 2006, affecting supply for nine months and increasing prices by 500%
“All animals struggle during heatwaves and dairy cows are particularly vulnerable. It’s not unusual for their milk production to drop overnight by up to 40%,” Illawarra dairy farmer Lynne Strong said.
“We’ve taken lots of small steps on our farm, including putting in thousands of shade trees and installing sprinklers in the dairy, to protect the cows during these extreme weather events. However, if they continue to increase the only option for many dairy farmers will be to house their cows in air-conditioned sheds. If this happens, milk may become a luxury item.
“Farmers can play a really important role in delivering climate change solutions through producing their own renewable energy and implementing sustainable farming systems that increase carbon storage in vegetation and soils.
“But we can’t fight climate change alone. We need to be backed by greater action to reduce greenhouse gas emissions if we’re to protect both the livelihood of farmers and the integrity of Australia’s food supply.”
Professor Tim Flannery said there was no room for complacency in planning for our future food security.
“Large parts of Australia are currently in drought including a record 80 per cent of Queensland,” he said.
“We are watching the realities of a warming world unfold before our eyes and the impacts on everyday Australian households as food prices and food availability become more volatile and affect the economies and social fabric of those communities that rely on agricultural production.
“Australian farmers have demonstrated great resilience in the face of harsh physical and social challenges. But if the present rate of climate change continues, there will be many challenges to which adaptation is simply not possible.
“We must urgently transition to a new low carbon economy if we are to adequately safeguard our food supply.”