Climate change was responsible for just over one-third of the simultaneous soya bean crop failures across Argentina, Brazil and the US in 2012, according to a new attribution study.
The research, published in Communications Earth & Environment, analyses the impact of hot and dry extreme weather that hit the three countries in 2012.
Although soya beans are an important crop for global food supplies most often in the form of animal feed – their production is concentrated in just three countries, leaving them susceptible to weather-related disruption.
Using climate and crop models, the researchers determine what the yield of the crop would have been in a world without warming.
They find that the impact of climate change – through warmer temperatures and drier soils – accounted for 35% of the yield reduction in 2012.
Furthermore, they warn, the impacts of similar events will only become stronger as the world continues to warm.
One researcher, who was not involved in the study, tells Carbon Brief that the novel application of existing methods in the study is “new and noteworthy”.
Soya bean shock
Soya is one of the “big four” staple crops – along with maize, rice and wheat – that together comprise almost 65% of global calories consumed and 45% of the world’s planted farmlands.
In 2021, the world produced nearly 365m tonnes of soya beans. Less than 4% of this harvest fed humans directly, with the vast majority of it being processed into animal feed, vegetable oil or biofuel.
Just three countries – Argentina, Brazil and the US – grow nearly three-quarters of the world’s supply of soya beans, the study says. The concentration of production in these three countries “makes the global soybean supply vulnerable to regional production shocks” – and especially those due to extreme weather events, the authors write.
Such was the case in 2012, when hot and dry extremes across the Americas caused a 10% drop in global production. This production drop was accompanied by record-high price spikes.
The strength of the 2012 simultaneous failure was a primary reason for studying it, despite the fact that the event happened more than a decade in the past, says lead author Dr Raed Hamed, a climate scientist at Vrije Universiteit Amsterdam.
Another reason is that the selected soya-growing regions have well-understood links to El Nino-Southern Oscillation (ENSO), the large-scale climate pattern in the Pacific Ocean that influences global weather patterns and crop yields.
The low yield in 2012 came at the end of a three-year La Niña event. La Niña is the “cold phase” of ENSO, marked by cooler temperatures in the Pacific Ocean, but it is known to cause hotter- and drier-than-normal conditions in south-eastern South America and the US, respectively. According to the US National Oceanic and Atmospheric Administration, the 2012 La Niña was the third-warmest such event on record.
The charts below show the annual global production of soya as absolute totals (left) and relative to a baseline adjusted for the long-term production trend over 1980-2014 (right).
Soya storylines
In order to tease out the effects of climate change on the 2012 growing season, the researchers use a “storyline” approach.
Many attribution studies take a “probabalistic” approach, running climate models both with and without warming thousands of times to determine how climate change affected the duration, likelihood or intensity of an event.
By contrast, the storyline approach imposes a fixed atmospheric circulation – in this case, the 2012 La Niña event – on top of three different levels of warming: a pre-industrial world, the factual 2012 world and a world that has warmed by 2C. Hamed explains:
“So we remove the question of how likely it is, but we say: ‘Given a similar event in a warmer climate, what would the impact be like?’”
This approach was necessary, Hamed says, because “there is a big question mark” around how further warming will impact ENSO and, in particular, the atmospheric circulation.
Then, the researchers use the temperature and soil moisture outputs from each warming scenario to calculate the soya bean yield in three major growing regions: the US, central Brazil and south-eastern South America, which encompasses parts of Brazil and Argentina. By comparing the actual yield changes in 2012 to those from the pre-industrial model runs, they quantify how much of the lower yield can be attributed to climate change.
They find that, overall, climate change – in the form of warmer temperatures and drier soils – was responsible for 35% of the “production deficit” during the 2012 failure.
However, the impact of the hot-and-dry event differed significantly between regions. In the US, warming caused a 3.5% decrease in production, compared to a world with no climate change, while in south-east South America, production fell by 222%. In central Brazil, climate change actually improved production by 14%.
While this type of approach is not necessarily “novel”, the “application is new and noteworthy”, says Dr Dáithí Stone, a climate scientist at New Zealand’s National Institute of Water and Atmospheric Research. Stone, who was not involved in the study, adds:
“Soya bean is one of the [main] staple crops on the planet and one that’s very much growing in demand. So it’s very important and there are susceptibilities. We do have these sensitivities, these risks, if we have production concentrated in these three areas.”
Future yields
In addition to comparing the event to one in a pre-industrial climate, the researchers use the same approach to project the potential impacts of the same event occurring in a world with 2C of warming above pre-industrial temperatures.
While the effects of the 2012 event were mainly concentrated in the south-east South America region, the impacts are felt in each of the three regions. Furthermore, at higher temperatures, the impact of the interactions between temperature and soil moisture becomes more significant, particularly in the south-east South America region.
The chart below shows the soya bean production anomaly for each region under (left to right) the pre-industrial climate, the actual climate in which the event occurred and the climate with 2C of warming.
The “simple” setup of the analysis means there are many caveats to the study, Hamed says. For example, there is no consideration of adaptation, such as the possibility of farmers planting a larger area or implementing an irrigation system.
It also does not consider future improvements to technology and yields. (Global soya bean yield has been steadily climbing since the 1960s, although, Stone points out, “you can only increase the yield so much”.)
Stone tells Carbon Brief:
“These sorts of studies which look at the impacts of extreme weather in the context of climate change are very useful.
“The impacts of climate change tend to be in these extreme events. They’re the things that stress test us normally, so they’re stress testing us more. And so understanding these events and how their impacts cascade down the system as well…is becoming increasingly important as we enter a warmer world.”
The post ‘One-third’ of 2012 soya crop failure in the Americas was due to climate change appeared first on Carbon Brief.
‘One-third’ of 2012 soya crop failure in the Americas was due to climate change
A new storm recovery charge could soon hit Georgia Power customers’ bills, as climate change drives more destructive weather across the state.
Hurricane Helene may be long over, but its costs are poised to land on Georgians’ electricity bills. After the storm killed 37 people in Georgia and caused billions in damage in September 2024, Georgia Power is seeking permission from state regulators to pass recovery costs on to customers.
Gov. Mikie Sherrill says she supports both AI and lowering her constituents’ bills.
With New Jersey’s cost-of-living “crisis” at the center of Gov. Mikie Sherrill’s agenda, her administration has inherited a program that approved a $250 million tax break for an artificial intelligence data center.
Amid Affordability Crisis, New Jersey Hands $250 Million Tax Break to Data Center
Gabrielle Dreyfus is chief scientist at the Institute for Governance and Sustainable Development, Thomas Röckmann is a professor of atmospheric physics and chemistry at Utrecht University, and Lena Höglund Isaksson is a senior research scholar at the International Institute for Applied Systems Analysis.
This March scientists and policy makers will gather near the site in Italy where methane was first identified 250 years ago to share the latest science on methane and the policy and technology steps needed to rapidly cut methane emissions. The timing is apt.
As new tools transform our understanding of methane emissions and their sources, the evidence they reveal points to a single conclusion: Human-caused methane emissions are still rising, and global action remains far too slow.
This is the central finding of the latest Global Methane Status Report. Four years into the Global Methane Pledge, which aims for a 30% cut in global emissions by 2030, the good news is that the pledge has increased mitigation ambition under national plans, which, if fully implemented, could result in the largest and most sustained decline in methane emissions since the Industrial Revolution.
The bad news is this is still short of the 30% target. The decisive question is whether governments will move quickly enough to turn that bend into the steep decline required to pump the brake on global warming.
What the data really show
Assessing progress requires comparing three benchmarks: the level of emissions today relative to 2020, the trajectory projected in 2021 before methane received significant policy focus, and the level required by 2030 to meet the pledge.
The latest data show that global methane emissions in 2025 are higher than in 2020 but not as high as previously expected. In 2021, emissions were projected to rise by about 9% between 2020 and 2030. Updated analysis places that increase closer to 5%. This change is driven by factors such as slower than expected growth in unconventional gas production between 2020 and 2024 and lower than expected waste emissions in several regions.
Gas flaring soars in Niger Delta post-Shell, afflicting communities
This updated trajectory still does not deliver the reductions required, but it does indicate that the curve is beginning to bend. More importantly, the commitments already outlined in countries’ Nationally Determined Contributions and Methane Action Plans would, if fully implemented, produce an 8% reduction in global methane emissions between 2020 and 2030. This would turn the current increase into a sustained decline. While still insufficient to reach the Global Methane Pledge target of a 30% cut, it would represent historical progress.
Solutions are known and ready
Scientific assessments consistently show that the technical potential to meet the pledge exists. The gap lies not in technology, but in implementation.
The energy sector accounts for approximately 70% of total technical methane reduction potential between 2020 and 2030. Proven measures include recovering associated petroleum gas in oil production, regular leak detection and repair across oil and gas supply chains, and installing ventilation air oxidation technologies in underground coal mines. Many of these options are low cost or profitable. Yet current commitments would achieve only one third of the maximum technically feasible reductions in this sector.
Recent COP hosts Brazil and Azerbaijan linked to “super-emitting” methane plumes
Agriculture and waste also provide opportunities. Rice emissions can be reduced through improved water management, low-emission hybrids and soil amendments. While innovations in technology and practices hold promise in the longer term, near-term potential in livestock is more constrained and trends in global diets may counteract gains.
Waste sector emissions had been expected to increase more rapidly, but improvements in waste management in several regions over the past two decades have moderated this rise. Long-term mitigation in this sector requires immediate investment in improved landfills and circular waste systems, as emissions from waste already deposited will persist in the short term.
New measurement tools
Methane monitoring capacity has expanded significantly. Satellite-based systems can now identify methane super-emitters. Ground-based sensors are becoming more accessible and can provide real-time data. These developments improve national inventories and can strengthen accountability.
However, policy action does not need to wait for perfect measurement. Current scientific understanding of source magnitudes and mitigation effectiveness is sufficient to achieve a 30% reduction between 2020 and 2030. Many of the largest reductions in oil, gas and coal can be delivered through binding technology standards that do not require high precision quantification of emissions.
The decisive years ahead
The next 2 years will be critical for determining whether existing commitments translate into emissions reductions consistent with the Global Methane Pledge.
Governments should prioritise adoption of an effective international methane performance standard for oil and gas, including through the EU Methane Regulation, and expand the reach of such standards through voluntary buyers’ clubs. National and regional authorities should introduce binding technology standards for oil, gas and coal to ensure that voluntary agreements are backed by legal requirements.
One approach to promoting better progress on methane is to develop a binding methane agreement, starting with the oil and gas sector, as suggested by Barbados’ PM Mia Mottley and other leaders. Countries must also address the deeper challenge of political and economic dependence on fossil fuels, which continues to slow progress. Without a dual strategy of reducing methane and deep decarbonisation, it will not be possible to meet the Paris Agreement objectives.
Mottley’s “legally binding” methane pact faces barriers, but smaller steps possible
The next four years will determine whether available technologies, scientific evidence and political leadership align to deliver a rapid transition toward near-zero methane energy systems, holistic and equity-based lower emission agricultural systems and circular waste management strategies that eliminate methane release. These years will also determine whether the world captures the near-term climate benefits of methane abatement or locks in higher long-term costs and risks.
The Global Methane Status Report shows that the world is beginning to change course. Delivering the sharper downward trajectory now required is a test of political will. As scientists, we have laid out the evidence. Leaders must now act on it.
The post Curbing methane is the fastest way to slow warming – but we’re off the pace appeared first on Climate Home News.
Curbing methane is the fastest way to slow warming – but we’re off the pace
-
Greenhouse Gases7 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Climate Change7 months ago
Guest post: Why China is still building new coal – and when it might stop
-
Greenhouse Gases2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Climate Change2 years ago
Bill Discounting Climate Change in Florida’s Energy Policy Awaits DeSantis’ Approval
-
Climate Change2 years ago
Spanish-language misinformation on renewable energy spreads online, report shows
-
Climate Change2 years ago嘉宾来稿：满足中国增长的用电需求 光伏加储能“比新建煤电更实惠”
-
Climate Change Videos2 years ago
The toxic gas flares fuelling Nigeria’s climate change – BBC News
-
Carbon Footprint2 years agoUS SEC’s Climate Disclosure Rules Spur Renewed Interest in Carbon Credits