Countries that pump out large amounts of greenhouse gases could “retain or expand” their fossil fuel industries while treating such emissions as “inevitable” in their net-zero accounting, according to a new study.
Some sectors, such as livestock farming and heavy industry, are viewed as particularly hard to decarbonise. This is due, in part, to a perceived lack of cheap technological solutions.
Any “residual emissions” from these practices will have to be balanced by removals from the atmosphere, if nations want to claim they have achieved their net-zero goals.
The new study, published in One Earth, analyses the strategies that nations have submitted to the UN to understand their approach to these emissions, and how they define them.
It finds significant uncertainty, with just 26 out of 71 countries with long-term plans having outlined how much they expect to still be emitting by 2050.
These nations alone say their residual emissions could be up to 2.9bn tonnes of carbon dioxide equivalent (GtCO2e) – equivalent to around 5% of the current global total.
Fossil-fuel producing nations, such as Australia and Canada, plan to continue producing large volumes of emissions – before removing them via carbon capture technologies or paying for them to be offset elsewhere.
The study authors warn that the slow development and rollout of CO2 removal technologies means this approach could lead to net-zero ambitions ending in “failure”.
Hard-to-abate?
“Residual” emissions are defined as those that remain once a nation, or some other entity, has gone as far as it thinks is possible to cut greenhouse gas emissions.
The concept is closely tied with the net-zero targets that many nations have set for the middle of the century. A country must remove CO2 from the atmosphere that is equivalent in volume to its residual emissions, in order to say it has reached net-zero.
The amount of residual emissions each country is left with therefore dictates how much it will have to invest in CO2 removal – either by planting trees or building machines that directly remove the CO2 from the atmosphere.
So far, countries have shown very little progress in developing technologies to remove CO2.
Yet, as the new study explains, “there is a tendency to treat residual emissions as inevitable”. One key reason for this is that these emissions are expected to largely come from so-called “hard-to-abate” sectors.
These sectors are generally framed as those that lack cheap and widely available technologies to drastically cut their emissions. Examples include steel production, aviation and many aspects of livestock agriculture, such as rearing cows, growing rice and using fertilisers..
Yet, despite these common framings, in practice, both residual emissions and hard-to-abate sectors remain poorly defined. Moreover, there is a growing body of evidence suggesting that even “hard-to-abate” sectors can feasibly be decarbonised using available technologies.
According to Prof Naomi Vaughan, a climate change researcher at the University of East Anglia (UEA) and one of the new study’s co-authors, this means “net-zero can hide a multitude of sins”. Speaking to Carbon Brief, she asks:
“What are you choosing – as an industry or as a country – to decide is hard to abate…And what genuinely is?”
In order to interrogate this, the team led by Harry Smith, a UEA PhD student focusing on the role of CO2 removal in climate policy, set out to understand what different countries were describing as “residual emissions” and how they were justifying this description.
Big residuals
Under the Paris Agreement, nations are encouraged to submit long-term low-emission development strategies (LT-LEDS). If a country has a mid-century net-zero target, this document will explain how it intends to get there.
In their study, Smith and his colleagues analyse every LT-LEDS submitted to the UN by October 2023 – covering a total of 67 countries. They also include four extra long-term strategies produced by EU member states, but not submitted to the UN.
The 71 nations with long-term strategies for tackling climate change cover 71% of global emissions, the study notes.
However, the majority – 41 in total – do not quantify residual emissions at all in their plans. These include major emitters with net-zero targets, such as China, India and Russia.
The researchers identify 26 countries that have calculated the amount of emissions they expect to still be producing at the point they reach net-zero.
In total, this amounts to between 2.6-2.9GtCO2e, excluding emissions from land use, land-use change and forestry (LULUCF). (The range results from countries including several different scenarios in their strategies.)
The study also compares the scale of each nation’s residual emissions to the highest level its emissions have reached in a year. If countries are yet to peak, data from 2021 was used.
The authors conclude that, on average, the 16 developed “Annex I” countries assessed in this study plan on still producing 21% of their peak emissions when they reach net-zero.
Meanwhile, the nine developing and emerging “Annex II” economies expect to continue producing 34% of their peak emissions, the study finds. This estimate excludes Cambodia, which plans to keep increasing its emissions but cancelling them out by turning its extensive forests into a net carbon sink.
The chart below shows residual emissions (red) as a share of each nation’s peak emissions (blue) – or its most recent annual emissions, if its emissions have not yet peaked. Residual emissions from the US alone are set to be higher than the total emissions of nearly every other country.
Justifying emissions
To understand more about how governments justify the residual emissions in their strategies, the researchers analyse the sectors where emissions remain high out into the second half of this century.
Overall, agriculture is expected to see the least progress in emissions reductions, contributing roughly one-third of residual emissions across all the nations assessed, the study finds.
Methane from livestock and emissions from fertilisers are frequently cited as some of the “hardest-to-abate”. Developed countries only expect their agricultural emissions to drop 37%, on average, by the time they hit net-zero.
(International aviation and shipping, while viewed as some of the hardest sectors to decarbonise, are simply excluded from most countries’ long-term plans, meaning they do not feature prominently in this analysis.)
The researchers also look in greater depth at the rationales given by each country for defining emissions as “residual” or “hard-to-abate”, by analysing 357 statements on the topic within the long-term strategies. They group the statements into different categories, based on which sectors are described and the type of language used.
As the chart below shows, countries frequently provide no justification at all for their continued production of residual emissions in particular sectors.
The definition of “residual” varies considerably between countries, with governments focusing on different aspects depending on their circumstances. Smith tells Carbon Brief:
“What you find is this range of rationales [that are] not just technical…They’re not just political either…It’s a kind of pick your buffet of rationales.”
The most common arguments concern residual emissions from industry and transport – particularly the production of cement and steel, the emissions of F-gases and domestic aviation and shipping. (The researchers note a “mismatch” here, with arguments explaining residual emissions from agriculture often overlooked, despite it being the largest contributor.)
Countries most frequently cite the lack of new technologies and limits to existing ones as the reasons for continued emissions from these sectors.
Despite these assertions, hundreds of industry leaders from the heavy industry and heavy-duty transport sectors have described net-zero goals as “technically and financially possible by mid-century”.
For example, a recent report by the International Renewable Energy Agency (IRENA) concluded that “the technologies to decarbonise hard-to-abate sectors have seen significant progress in recent years and are today largely available”.
‘Retain or expand’
The large amounts of residual emissions in most nations’ long-term strategies reveals that many are expecting to lean heavily on carbon removal to meet their net-zero targets, the study says.
The study notes that this “risks the credibility of their target[s] and risks a failure to meet national and global net-zero”, given the known limits to carbon removals.
In some cases, this could also mean shifting responsibility elsewhere by purchasing carbon offsets from other countries.
Moreover, the study adds that some nations “may attempt to retain or expand their fossil fuel production”, and pass off resulting emissions as “residual”. Vaughan explains that countries may lean towards looser definitions of residual emissions, if it benefits them:
“If you have a country with a very significant investment in the fossil fuel industry or extraction industries, then there is an incentive to imagine getting to net-zero where you still have quite a lot of emissions – but you’re using lot’s of CO2 removal to get there.”
The authors highlight Australia and Canada, two nations that currently produce large amounts of fossil fuels. Both include scenarios in their net-zero strategies – albeit at the high end of several potential outcomes – where emissions only fall by around half by 2050.
In Australia’s case, this scenario relies on purchasing large amounts of carbon offsets from other countries. Canada relies on very high use of CO2 removal technologies.
Prof Holly Jean Buck, a climate researcher at the University of Buffalo who published an initial investigation into residual emissions in countries’ LT-LEDS last year, but was not involved in this research. She says tackling the “ambiguity” around these emissions is key:
“We don’t know if countries are planning to phase out fossil fuels…We have infrastructure that has long lifetimes in terms of how long it takes to build it and how long it will be in operation. Without specificity around which sectors or activities we hope to fully decarbonise and electricity, it’s hard for countries to do that planning.”
More political
Experts tell Carbon Brief the new study is a welcome contribution to a relatively sparse literature on residual emissions.
Buck says it is a “thorough and careful” study that expands on her work, both by increasing the number of strategies assessed and broadening the scope of the analysis.
Her assessment only focused on high-ambition strategies for LT-LEDS from Annex I countries. The new research led by Smith and his colleagues includes a broader range of scenarios, and suggests that residual emissions could be even higher in 2050 than thought.
The study proposes a number of measures to tighten the definition of “residual” emissions and help countries better address them. This includes stronger reporting requirements for national strategies.
The researchers also propose separate targets for emissions reductions and CO2 removals, in order to prevent countries continuing to burn fossil fuels while simply pledging to remove emissions.
Dr William Lamb, a researcher at the Mercator Research Institute on Global Commons and Climate Change who was not involved in the study, tells Carbon Brief he supports this idea and adds:
“I would also like to see the discussion of residual emissions become more political than it currently is. If countries were asking questions such as ‘how fast can we phase out fossil fuels?’ and ‘what human needs and services do we need to deliver, at minimum impact to the climate?’ then their long-term strategies would look very different.”
The post Major emitters ‘may retain or expand’ fossil fuels despite net-zero plans appeared first on Carbon Brief.
Major emitters ‘may retain or expand’ fossil fuels despite net-zero plans
Claver Gatete is Executive Secretary of the UN Economic Commission for Africa. Jason Veysey is Energy Modeling Program Director and Senior Scientist at the Stockholm Environment Institute. Lisa Sachs is Director of the Columbia Center on Sustainable Investment at Columbia University.
The case for global energy transition has rarely been clearer. The closure of the Strait of Hormuz earlier this year exposed the cost of unplanned, fossil-dependent systems, while the falling cost of renewables, the rising penetration of electric vehicles, and the growing value of demand flexibility have made the direction of travel obvious. The benefits of a clean, secure, integrated system are no longer in dispute. What remains unclear is how to build it.
Countries around the world have called for faster renewable energy deployment and alternative energy arrangements. A secure, affordable, resilient, decarbonised system requires specific investments in specific places in a specific sequence, optimised across sectors and borders. But very few governments have the analytical foundation to translate those imperatives into investment.
The two instruments that are supposed to determine investment priorities for decarbonisation – Nationally Determined Contributions (NDCs) and country platforms – cannot answer the most basic question facing any country undertaking an energy transition: what should the energy system look like?
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To close this gap, every country needs a bankable, economy-wide optimisation model for its energy system. A model is not a plan, but it can help answer the critical question of what the future energy system should look like. It shows how optimal scenarios vary as assumptions and policies are adjusted, calculates investment requirements and sequencing, and quantifies how system costs are affected by assumptions, policies, and exogenous variables like trade policy and financing terms.
Tool for efficient investment
Optimisation is a simplified way of simulating an energy system, but it can be an extremely powerful tool for moving energy planning from reactive (how do we manage the disparate actions in the energy system?) to intentional (what energy system underpins our national objectives?). A model can show how optimal scenarios vary as assumptions and policies are adjusted, and how investment requirements are quantified and sequenced.
Optimisation models can treat the energy system and the sectors it serves as an integrated whole, optimising across sectors and projects in ways that can be mutually reinforcing. If considered independently, growth in industrial demand, transport electrification, and digital infrastructure can add stress to the energy system. But an optimised plan can arrange these and other changes in an efficient, synergistic way.
Two to tango: How governments can unlock private investment for national climate goals
New load can be added where low-cost power is available; industrial customers can ensure the viability of investments in energy supply; electric vehicle charging policy can smooth load curves and reduce costs for all consumers.
Additionally, optimisation modeling can also change the financeability of investments. Taken alone, each project faces uncertainty about the rest of the system, which raises the cost of capital and causes projects to stall or unwind after contracts are signed. A coherent, optimised plan makes visible the coordination that private capital would otherwise have to bet on: identified offtake, sequenced and committed transmission, contracted power supply, and so on.
What COP31 and COP32 should do
The upcoming COPs in Turkey and Ethiopia can shift the center of gravity of international climate cooperation from fragmented commitments to planning. Three moves are urgently needed.
First, optimised, economy-wide, long-term energy system planning must be the foundation on which any meaningful NDC, country platform, or finance commitment rests. NDCs are typically drafted by environment or single-line ministries, with limited cross-sectoral input from ministries of energy, finance, and planning. They contain targets, derived from sectoral strategies or national commitments, not from an analytically grounded picture of what the energy system should look like and what investments would make it work. Country platforms are generally a portfolio of investments assembled from existing project pipelines, rather than derived from a system-level analysis of what an optimised, decarbonised energy system would require.
Second, recognise regions as a key planning unit. Modern integrated energy systems are inherently regional. Renewable endowments are unevenly distributed; balancing variable supply across borders lowers aggregate cost, reduces redundant backup capacity, and unlocks economies of scale no individual nation can achieve. Many energy investments in Southeast Asia, East Africa, Southern Africa and Central Asia may only be financeable in a regional context. Assessing domestic infrastructure without regional optimisation perpetuates the perception that decarbonisation is more expensive than it is.
COP31 leaders unveil global targets, with spotlight on electrification
Third, finance the planning capacity. A coordinated commitment by multilateral development banks, bilateral donors, and philanthropic partners to help every region and its constituent countries develop and maintain their own modelling capability, with open-source tools and regional analytical hubs, would close the most consequential gap in the current architecture. The cost is small relative to current spending on country platforms, failed project preparation, and misallocated infrastructure investment.
This includes supporting regional institutions such as the ASEAN Centre for Energy, the African Energy Commission, regional power pools, and the Latin American and Caribbean Energy Organization to determine what optimised regional systems require. Country-by-country pledging, repeated at every COP, will not deliver what meaningfully integrated systems can.
The 2026 energy crisis made the cost of unplanned, fossil-dependent systems newly visible. That window of clarity will close. The international community should seize the moment to build the planning foundation that has been missing for thirty years, rather than commissioning another round of NDCs or pledges, striving for outcomes neither was designed to deliver.
The post Every country needs a model to help optimise its energy transition appeared first on Climate Home News.
Every country needs a model to help optimise its energy transition
The world is currently experiencing what is expected to become the strongest El Niño on record – dubbed a “super El Niño” by many.
El Niño is the warm phase of a recurring climate pattern in the tropical Pacific that releases heat from the ocean into the atmosphere.
This temporarily raises global temperatures and reshapes rainfall and extreme weather around the world – impacting the lives of billions of people.
The current El Niño event began in June and is expected to last into 2027.
El Niño is part of a wider climate pattern called the El Niño-Southern Oscillation (ENSO) cycle.
The ENSO cycle also has a cool phase, known as La Niña, as well as a “neutral” phase. El Niño and La Niña events typically last between nine and 12 months, but can go on longer.
Below, Carbon Brief explains how the ENSO cycle works, its impacts on extreme weather and global temperatures and why this El Niño event is projected to be the most intense since records began.
The post Explainer: How the ‘super El Niño’ will reshape the world’s weather appeared first on Carbon Brief.
https://interactive.carbonbrief.org/el-nino-explainer/index.html
The second-largest reservoir in the US reached a record-low water height on Saturday – just days after the country’s largest reservoir broke its own record.
Both Lake Mead and Lake Powell are located on the Colorado River.
They provide water for populations across seven US states in the south-western US, with around 40 million people getting some or all of their municipal water from the Colorado River.
The river also provides water for around 5.5m acres (22,258 square kilometres) of farmland across Colorado, Arizona, California and the other states in the river basin.
Experts tell Carbon Brief that climate change, population growth and over-consumption are all contributing to the current record-low levels of the reservoirs.
Record lows
At full capacity, Lakes Mead and Powell can hold a combined 68 cubic kilometres of water – enough to supply all household consumption in the contiguous US for nearly 1.5 years. However, the water level in both reservoirs has been declining for decades.
The chart below shows the water level of Lake Mead, in metres above mean sea level. The reservoir, which began to fill in 1935 following the construction of the Hoover Dam, has a “full pool” maximum capacity of 347.60 metres. The water level in Lake Mead reached a record low of 317.11 metres on 7 August.
The following chart shows the water level of Lake Powell, in metres above mean sea level. Lake Powell’s full-pool level is 1,127.76 metres.
While the reservoir reached its maximum capacity several times in the 1980s, it has not done so since. On 15 August, the water level in Lake Powell was recorded at a new record-low of 1,072.87 metres.
Both reservoirs have continued to decline in the days since breaking their respective records. The downward trend will largely continue in both lakes until next spring, when the snowpack in the mountains of the Upper Colorado River Basin begins to melt, says Dr Jack Schmidt, a senior research scientist at Utah State University’s Center for Colorado River Studies. He tells Carbon Brief:
“The big dilemma of the moment is that we’re only in the middle of August, and we have no assurance of what the coming winter will be. The only thing we can be sure of is that we will be depleting overall total basin reservoir storage from now until, roughly, early April.”
Compounding factors
The record lows across the two reservoirs are the result of several compounding factors, experts tell Carbon Brief.
Since the turn of the 20th century, the amount of water flowing along the Upper Colorado River has declined by about 20%. Research suggests that half of this decline can be attributed to human-induced climate change.
Most of the river’s streamflow comes from the snowpack of the Upper Colorado River Basin, which stretches across five western US states but is primarily located in Colorado and Utah.
This region has been gripped by a historic “megadrought” for more than a quarter of a century. Nearly half of the megadrought’s intensity over 2000-18 is attributable to climate change, according to a 2020 study.
At the same time, the increasing population in the US south-west has put added pressure on the Colorado River’s water supply. The number of people obtaining some or all of their water from the Colorado system has grown by 15 million (around 60%) since 1992.
Schmidt tells Carbon Brief:
“There’s an ultimate cause of the present water crisis, and there’s a proximate cause. The ultimate cause is a warming climate, a warming planet and a pretty clear correlation between warming conditions and decreased runoff in the Colorado River Basin.
“The proximate cause is that in this messy democratic republic of ours, big policy decisions that match the variability of the climate occur painfully slowly – with intense political negotiations – and only incrementally.”
On 31 July, the US Bureau of Reclamation, which manages water resources in the western US, released an environmental impact statement on its proposed post-2026 strategy for managing Lakes Powell and Mead. The strategy itself has not been released yet.
Schmidt notes that the statement does appear to give the Bureau flexibility to “respond to crisis” by reducing the delivery of water to several states. However, he adds:
“They acknowledge it won’t work if we just stay critically dry, and of course every climate model for the 21st century, especially with a continually warming planet, says that that’s exactly what’s going to happen.”
The post Analysis: The two largest reservoirs in the US have hit record-low levels appeared first on Carbon Brief.
Analysis: The two largest reservoirs in the US have hit record-low levels
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