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dairy cows are methane producing machines

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Authors: Milena Bojovic, PhD Candidate, Macquarie University


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

Milena Bojovic, Macquarie University

New Zealand’s dairy sector faces an uncertain future due to several challenges, including water pollution, high emissions, animal welfare concerns and market volatility.

All of these issues are building tensions and changing public perceptions of dairy farming.

In my new research, I argue the time has come for the dairy sector to adopt a “just transition” framework to achieve a fair and more sustainable food future and to navigate the disruptions from alternative protein industries.

The concept of a just transition is typically applied to the energy sector in shifting from fossil fuels to renewable energy sources.

But a growing body of research and advocacy is calling for the same principles to be applied to food systems, especially for shifting away from intensive animal agriculture.

Aotearoa New Zealand’s dairy sector is an exemplary case study for examining the possibilities of a just transition because it is so interconnected in the global production and trade of dairy, with 95% of domestic milk production exported as whole-milk powder to more than 130 countries.

Environmental and economic challenges

New Zealand’s dairy sector faces significant threats. This includes environmental challenges such as alarming levels of nitrate pollution in waterways caused by intensive agriculture.

The sector is also a major source of emissions of biogenic methane from the burps of almost six million cows in the national dairy herd.

Debates about how to account for these emissions have gone on for many years in New Zealand. But last month, the coalition government passed legislation to keep agriculture out of the Emissions Trading Scheme.

This means livestock farmers, agricultural processors, fertiliser importers and manufacturers won’t have to pay for on-farm emissions. Instead, the government intends to implement a pricing system outside the Emissions Trading Scheme by 2030. To meet emissions targets, it relies on the development of technologies such as methane inhibitors.

A cheese board with soem bread and a cheese made from cashews
The development of plant-based and fermentation proteins poses another threat to the dairy sector. Getty Images

In addition to environmental challenges, global growth and domestic initiatives in the development of alternative dairy products are changing the future of milk production and consumption.

New Zealand dairy giant Fonterra is pursuing the growth of alternative dairy with significant investments in a partnership with Dutch multinational corporation Royal-DSM. This supports precision fermentation start-up Vivici, which already has market-ready products such as whey protein powder and protein water.

Fonterra’s annual report states it anticipates a rise in customer preference towards dairy alternatives (plant-based or precision-fermentation dairy) due to climate-related concerns. The company says these shifting preferences could pose significant business risks for future dairy production if sustainability expectations cannot be met.

Pathways to a just transition for dairy

What happens when one the pillars of the economy becomes a major contributor to environmental degradation and undermines its own sustainability? Nitrate pollution and methane emissions threaten the quality of the land and waterways the dairy sector depends on.

In my recent study which draws on interviews with people across New Zealand’s dairy sector, three key transition pathways are identified, which address future challenges and opportunities.

  • Deintensification: reducing the number of dairy cows per farm.

  • Diversification: introducing a broader range of farming practices, landuse options and market opportunities.

  • Dairy alternatives: government and industry support to help farmers participate in emerging plant-based and precision-fermentation industries.

While the pathways are not mutually exclusive, they highlight the socioeconomic and environmental implications of rural change which require active participation and engagement between the farming community and policy makers.

The Ministry of Business, Innovation and Employment recently published a guide to just transitions. It maps out general principles such as social justice and job security.

But the guide is light on advice for agricultural transitions. My work puts forward recommendations to shape future policy for a more just and sustainable dairy future. This includes issues such as navigating intensification pressures, supporting the development of alternative proteins and fundamentally supporting farmer agency in the transition process.

For the dairy transition to be fair and sustainable, we need buy-in from leadership and support from government, the dairy sector and the emerging alternative dairy industry to help primary producers and rural communities. This needs to be specific to different regions and farming methods.

The future of New Zealand’s dairy industry depends on its ability to adapt. Climate adaptation demands balancing social license, sustainable practices and disruptions from novel protein technologies.The Conversation

Milena Bojovic, PhD Candidate, Macquarie University

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

Carbon trading

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Author:

Kate Dooley, Senior Research Fellow, School of Geography, Earth and Atmospheric Sciences, The University of Melbourne

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

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Negotiators at the COP29 climate conference in Baku have struck a landmark agreement on rules governing the global trade of carbon credits, bringing to a close almost a decade of debate over the controversial scheme.

The deal paves the way for a system in which countries or companies buy credits for removing or reducing greenhouse gas emissions elsewhere in the world, then count the reductions as part of their own climate efforts.

Some have argued the agreement provides crucial certainty to countries and companies trying to reach net-zero through carbon trading, and will harness billions of dollars for environmental projects.

However, the rules contain several serious flaws that years of debate have failed to fix. It means the system may essentially give countries and companies permissions to keep polluting.

What is carbon offsetting?

Carbon trading is a system where countries, companies or other entities buy or sell “credits”, or permits, that allow the buyer to offset the greenhouse gas emissions they produce.

For example, an energy company in Australia that produces carbon emissions by burning coal may, in theory, offset their impact by buying credits from a company in Indonesia that removes carbon by planting trees.

Other carbon removal activities include renewable energy projects, and projects that retain vegetation rather than cutting it down.

Carbon trading was a controversial part of the global Paris climate deal clinched in 2015.

The relevant part of the deal is known as “Article 6”. It sets the rules for a global carbon market, supervised by the United Nations, which would be open to companies as well as countries. Article 6 also includes trade of carbon credits directly between countries, which has begun operating even while rules were still being finalised.

Rules for carbon trading are notoriously complex and difficult to negotiate. But they are important to ensure a scheme reduces greenhouse gas emissions in reality, not just on paper.

A long history of debate

Over the past few years, annual COP meetings made some progress on advancing the carbon trading rules.

For example, COP26 in Glasgow, held in 2021, established an independent supervisory body. It was also tasked with other responsibilities such as recommending standards for carbon removal and methods to guide the issuing, reporting and monitoring of carbon credits.

But the recommendations were rejected at COP meetings in 2022 and 2023 because many countries viewed them as weak and lacking a scientific basis.

At a meeting in October this year, the supervisory body published its recommendations as “internal standards” and so bypassed the COP approval process.

At this year’s COP in Baku, the Azerbaijani hosts rushed through adoption of the standards on day one, prompting claims proper process had not been followed

For the remaining two weeks of the conference, negotiators worked to further develop the rules. A final decision was adopted over the weekend, but has attracted criticism.

For example, the Climate Land Ambition and Rights Alliance says the rules risk “double counting” – which means two carbon credits are issued for only one unit of emissions reduction. It also claims the rules fail to prevent harm to communities – which can occur when, say, Indigenous Peoples are prevented from accessing land where tree-planting or other carbon-storage projects are occurring.

Getting to grips with carbon removal

The new agreement, known formally as the Paris Agreement Trading Mechanism, is fraught with other problems. Most obvious is the detail around carbon removals.

Take, for example, the earlier scenario of a coal-burning company in Australia offsetting emissions by buying credits from a tree-planting company in Indonesia. For the climate to benefit, the carbon stored in the trees should remain there as long as the emissions produced from the company’s burning of coal remains in the atmosphere.

But, carbon storage in soils and forests is considered temporary. To be considered permanent, carbon must be stored geologically (injected into underground rock formations).

The final rules agreed to at Baku, however, fail to stipulate the time periods or minimum standards for “durable” carbon storage.

Temporary carbon removal into land and forests should not be used to offset fossil fuel emissions, which stay in the atmosphere for millennia. Yet governments are already over-relying on such methods to achieve their Paris commitments. The weak new rules only exacerbate this problem.

To make matters worse, in 2023, almost no carbon was absorbed by Earth’s forests or soils, because the warming climate increased the intensity of drought and wildfires.

This trend raises questions about schemes that depend on these natural systems to capture and store carbon.

Temporary carbon removal into land and forests should not be used to offset fossil fuel emissions.
Temporary carbon removal into land and forests should not be used to offset fossil fuel emissions.

What next?

Countries already can, and do, trade carbon credits under the Paris Agreement. Centralised trading will occur under the new scheme once the United Nations sets up a registry, expected next year.

Under the new scheme, Australia should rule out buying credits for land-based offsets (such as in forests and soil) to compensate for long-lasting emissions from the energy and industry sectors.

Australia should also revise its national carbon trading scheme along the same lines.

We could also set a precedent by establishing a framework that treats carbon removals as a complement — not a substitute — for emissions reduction.The Conversation

Ilulissat Greenland, midnight sun. Photo: Cody Whitelaw

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Authors:

Laurie Menviel, Post-doctoral Research Fellow, Climate Change Research Centre, UNSW Sydney and Gabriel Pontes, Post-doctoral Research Fellow, Climate Change Research Centre, UNSW Sydney

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

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A vast network of ocean currents nicknamed the “great global ocean conveyor belt” is slowing down. That’s a problem because this vital system redistributes heat around the world, influencing both temperatures and rainfall.

The Atlantic Meridional Overturning Circulation funnels heat northwards through the Atlantic Ocean and is crucial for controlling climate and marine ecosystems. It’s weaker now than at any other time in the past 1,000 years, and global warming could be to blame. But climate models have struggled to replicate the changes observed to date – until now.

Our modelling suggests the recent weakening of the oceanic circulation can potentially be explained if meltwater from the Greenland ice sheet and Canadian glaciers is taken into account.

Our results show the Atlantic overturning circulation is likely to become a third weaker than it was 70 years ago at 2°C of global warming. This would bring big changes to the climate and ecosystems, including faster warming in the southern hemisphere, harsher winters in Europe, and weakening of the northern hemisphere’s tropical monsoons. Our simulations also show such changes are likely to occur much sooner than others had suspected.

The Atlantic Meridional Overturning Circulation (AMOC): what is it and why is it so important? (National Oceanography Centre)

Changes in the Atlantic Meridional Overturning Circulation

The Atlantic ocean circulation has been monitored continuously since 2004. But a longer-term view is necessary to assess potential changes and their causes.

There are various ways to work out what was going before these measurements began. One technique is based on sediment analyses. These estimates suggest the Atlantic meridional circulation is the weakest it has been for the past millennium, and about 20% weaker since the middle of the 20th century.

Evidence suggests the Earth has already warmed 1.5ºC since the industrial revolution.

The rate of warming has been nearly four times faster over the Arctic in recent decades.

Meltwater weakens oceanic circulation patterns

High temperatures are melting Arctic sea ice, glaciers and the Greenland ice sheet.

Since 2002, Greenland lost 5,900 billion tonnes (gigatonnes) of ice. To put that into perspective, imagine if the whole state of New South Wales was covered in ice 8 metres thick.

This fresh meltwater flowing into the subarctic ocean is lighter than salty seawater. So less water descends to the ocean depths. This reduces the southward flow of deep and cold waters from the Atlantic. It also weakens the Gulf Stream, which is the main pathway of the northward return flow of warm waters at the surface.

The Gulf Stream is what gives Britain mild winters compared to other places at the same distance from the north pole such as Saint-Pierre and Miquelon in Canada.

Our new research shows meltwater from the Greenland ice sheet and Arctic glaciers in Canada is the missing piece in the climate puzzle.

When we factor this into simulations, using an Earth system model and a high-resolution ocean model, slowing of the oceanic circulation reflects reality.

Our research confirms the Atlantic overturning circulation has been slowing down since the middle of the 20th century. It also offers a glimpse of the future.

Simplified schematic of the Atlantic Meridional Overturning Circulation in the North Atlantic
As they travel northwards, the Gulf Stream and North Atlantic Current cool as they lose heat to the atmosphere. The waters then become dense enough to sink to depth and form North Atlantic deep water, which travels southward at depth and feeds the other ocean basins. Modified from Nature Reviews Earth & Environment (2020)

Connectivity in the Atlantic Ocean

Our new research also shows the North and South Atlantic oceans are more connected than previously thought.

The weakening of the overturning circulation over the past few decades has obscured the warming effect in the North Atlantic, leading to what’s been termed a “warming hole”.

When oceanic circulation is strong, there is a large transfer of heat to the North Atlantic. But weakening of the oceanic circulation means the surface of the ocean south of Greenland has warmed much less than the rest.

Reduced heat and salt transfer to the North Atlantic has meant more heat and salt accumulated in the South Atlantic. As a result, the temperature and salinity in the South Atlantic increased faster.

Our simulations show changes in the far North Atlantic are felt in the South Atlantic Ocean in less than two decades. This provides new observational evidence of the past century slow-down of the Atlantic overturning circulation.

Infographic showing how the North Atlantic is connected to the South Atlantic by the overturning circulation
The addition of meltwater in the North Atlantic leads to localised cooling in the subpolar North Atlantic and warming in the South Atlantic. https://www.nature.com/articles/s41561-024-01568-1


What does the future hold?

The latest climate projections suggest the Atlantic overturning circulation will weaken by about 30% by 2060. But these estimates do not take into account the meltwater that runs into the subarctic ocean.

The Greenland ice sheet will continue melting over the coming century, possibly raising global sea level by about 10 cm. If this additional meltwater is included in climate projections, the overturning circulation will weaken faster. It could be 30% weaker by 2040. That’s 20 years earlier than initially projected.

Such a rapid decrease in the overturning circulation over coming decades will disrupt climate and ecosystems. Expect harsher winters in Europe, and drier conditions in the northern tropics. The southern hemisphere, including Australia and southern South America, may face warmer and wetter summers.

Our climate has changed dramatically over the past 20 years. More rapid melting of the ice sheets will accelerate further disruption of the climate system.

This means we have even less time to stabilise the climate. So it is imperative that humanity acts to reduce emissions as fast as possible.The Conversation

Timing of insurance retreat

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After a series of natural disasters – from the Canterbury earthquakes to Cyclone Gabrielle – real doubt hangs over the insurance options available to some New Zealand homeowners.

Increasingly, homes in certain areas are becoming uninsurable – or difficult to insure, at least. Insurers have decided the risk is too high to make covering it financially viable, leaving affected homeowners vulnerable.

The question of how insurers can continue to offer policies – all the while managing the growing risk from natural disasters – is becoming hard to ignore.

Insurers will have to explore alternative models and innovate if New Zealand is to adapt to future change.

Cautious insurers

There’s no general requirement in New Zealand that insurers cover anyone’s home, or that anyone’s home actually be insured.

Body-corporate groups are one exception. They must insure the units they manage. Mortgage lenders can also require borrowers to take out home insurance as part of their lending conditions.

When homeowners do get insurance, the risk of certain losses from natural disasters is automatically covered by the Natural Hazards Commission (previously known as the Earthquake Commission).

Even if a home insurance policy were to contain wording that, on the face of it, excluded this public natural-disaster cover, the law would treat the cover as included. At the same time, payouts are only managed by insurers, not financed by them.

The Canterbury earthquakes cost insurers NZ$21 billion and the Natural Hazards Commission $10 billion. And the risk of natural disasters more generally may be making insurers too cautious. They’re increasingly pulling out of areas they consider “high risk”.

That said, there are changes on the horizon. From mid-2025, insurers will have a general duty to “treat consumers fairly”. The Financial Markets Authority – the body responsible for enforcing financial-markets law – may potentially regard refusing home insurance to any consumer as a breach of the duty.

In other words, the Financial Markets Authority may end up forcing insurers to cover most of the country’s homes.

Billion-dollar payouts: liquefaction in the Christchurch suburb of Bexley after the 2011 earthquake. Getty Images

New insurance options

Future-proofing home insurance options will depend on the public and private sectors working together.

Many of the potential solutions are specific to how insurers take risk on. An insurer may decrease your premiums as an incentive for you to “disaster-proof” your home. If you don’t, the insurer may increase your premiums and limit its payouts to you, with individualised excesses or caps.

The insurer may even offer “parametric” insurance, which pays out less than traditional insurance, but faster.

For example, imagine a home insurance policy that covers any earthquake having its epicentre within 500 kilometres of your home, and measuring magnitude six or higher.

A traditional policy would pay out based on how much loss was caused (according to a loss adjuster). A parametric policy would simply pay out a small, pre‑agreed sum, based on the fact the earthquake occurred at all.

A parametric policy wouldn’t require you to prove any actual “loss” – beyond the inconvenience of having your home in the disaster zone.

While parametric insurance is relatively new worldwide, it’s an efficient solution for managing the risk of natural-disaster damage.

Reinsurance, co-insurance and ‘cat bonds’

An insurer may also transfer risk to one or more other insurance businesses – such as a “reinsurer”. If the insurer has to make a payout to you for a claim, the reinsurer then has to make a payout to the insurer for a portion of it.

The insurer may even “co‑insure” the risk. Co‑insurance is where two or more insurers cover different portions of the same risk. So, if you have your home co‑insured, you will have two or more insurers, each responsible for a portion of any claim.

Then there is the potential to transfer insured risk to entities that aren’t even insurance businesses. In some countries (such as Bermuda, the Cayman Islands and Ireland), the insurer can turn the risk into a “catastrophe bond” (also known as a “cat bond”).

Under a cat bond, the insurer arranges for expert investors to lend it capital in return for interest on the loans. The insurer eventually repays the capital, unless there is a specific natural disaster. In that case, the insurer keeps the capital, enabling it to pay out to the affected customers.

The insurer may even use the cat bond to create a “virtuous cycle”. More specifically, the insurer may reinvest the capital in “a project that reduces or prevents loss from the insured climate-related risk” (such as flooding).

Disaster-proofing the insurance industry

Key to improving the situation will be the public and private sectors working together to make climate-related disasters less frequent – and less serious when they occur.

The United Nations’ Intergovernmental Panel on Climate Change has advised on how the sectors could minimise climate-related risk. But they also have similar progress to make to minimise the risk of natural-disaster damage more generally, particularly from earthquakes.

It is important to build homes that are better disaster-proofed. And it is also important to address a major problem that many people don’t necessarily view as related to insurance – the cost of housing.

If New Zealanders wishing to own their homes didn’t have to invest as much of their money in housing as they do, the risk of damage to housing might be of less concern. Natural disaster wouldn’t have to mean financial disaster as much as it does today.

In the meantime, innovative insurance options will become more and more necessary.The Conversation

Christopher Whitehead, Lecturer in Law, Auckland University of Technology

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

Under a microscope, a tiny elongate poppy seed, small tan spikemoss megaspores and black soil fungus spheres found in soil recovered from under 2 miles of Greenland’s ice. Halley Mastro/University of Vermont, CC BY-ND

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Top image: Under a microscope, a tiny elongate poppy seed, small tan spikemoss megaspores and black soil fungus spheres found in soil recovered from under 2 miles of Greenland’s ice. Halley Mastro/University of Vermont, CC BY-ND Paul Bierman, University of Vermont and Halley Mastro, University of Vermont

 

As we focused our microscope on the soil sample for the first time, bits of organic material came into view: a tiny poppy seed, the compound eye of an insect, broken willow twigs and spikemoss spores. Dark-colored spheres produced by soil fungi dominated our view.

These were unmistakably the remains of an arctic tundra ecosystem – and proof that Greenland’s entire ice sheet disappeared more recently than people realize.

These tiny hints of past life came from a most unlikely place – a handful of soil that had been buried under 2 miles of ice below the summit of the Greenland ice sheet. Projections of future melting of the ice sheet are unambiguous: When the ice is gone at the summit, at least 90% of Greenland’s ice will have melted.

Four maps of Greenland show ice loss at various stages, calculated by model
Results of an ice sheet model show how much of Greenland’s ice sheet survives when the ice is gone from the Camp Century (white dot), GISP2 (red dot) and DYE-3 (black dot) ice coring sites. Modified from Schaefer et al., 2016, Nature

In 1993, drillers at the summit completed the Greenland Ice Sheet Project 2 ice core, or GISP2, nicknamed the two-mile time machine. The seeds, twigs and spores we found came from a few inches of soil at the bottom of that core — soil that had been tucked away dry, untouched for three decades in a windowless Colorado storage facility.

Our new analysis builds on the work of others who, over the past decade, have chipped away at the belief that Greenland’s ice sheet was present continuously since at least 2.6 million years ago when the Pleistocene ice ages began. In 2016, scientists measuring rare isotopes in rock from above and below the GISP2 soil sample used models to suggest that the ice had vanished at least once within the past 1.1 million years.

Now, by finding well-preserved tundra remains, we have confirmed that Greenland’s ice sheet had indeed melted before and exposed the land below the summit long enough for soil to form and for tundra to grow there. That tells us that the ice sheet is fragile and could melt again.

Drill dome on Greenland ice sheet
The GISP2 ice drilling camp at the Greenland ice sheet summit has an average temperature today of minus 7 degrees Fahrenheit (minus 22 Celsius). Christine Massey, CC BY
A rocky landscape with ice nearby.
The frozen plant remains suggest that the center of Greenland probably once looked like this dry rocky tundra, photographed in northwest Greenland. Paul Bierman/University of Vermont, CC BY-ND

A landscape with Arctic poppies and spikemosses

To the naked eye, the tiny bits of past life are unremarkable – dark flecks, floating between shiny grains of silt and sand. But, under the microscope, the story they tell is astounding. Together, the seeds, megaspores and insect parts paint a picture of a cold, dry and rocky environment that existed sometime in the past million years.

Above ground, Arctic poppies grew among the rocks. Atop each stalk of this small but tenacious herb, a single cupped flower tracked the Sun across the sky to make the most of each day’s light.

A photo of a yellow poppy next to a photo of a seed
The seed we found in the frozen soil retrieved from under 2 miles of ice, right, is from an arctic poppy, left. Arterra/Universal Images Group via Getty Images (left), Halley Mastro/University of Vermont (right)

Tiny insects buzzed above mats of diminutive rock spikemoss, creeping across the gravelly surface and bearing spores in summer.

A photo of spike moss and a photo shot under a microscope showing spheres that are spores.
Modern rock spikemoss (left) and rock spikemoss megaspores (tan spheres, right) from the GISP2 soil sample. J.F. Clovis/Courtesy of Smithsonian Institution (left), Halley Mastro/University of Vermont (right)

In the rocky soil were dark spheres called sclerotia, produced by fungi that team up with plants’ roots in soil to help both get the nutrients they need. Nearby, willow shrubs adapted to life in the harsh tundra with their small size and fuzzy hair covering their stems.

A photo of Arctic willow shrubs, which look nothing like willow trees, and a photo of a tiny wood piece under a microscope.
Three fragments of wood, shown under a high-power electron microscope, right, were Arctic willow – not from grand trees but rather the remains of ankle-high shrubs, left, that characterize Greenland’s tundra today. Peter Prokosch; (left), Barry Rock/University of New Hampshire (right)

Each of these living things left clues behind in that handful of soil – evidence that told us Greenland’s ice was once replaced by a hardy tundra ecosystem.

Greenland’s ice is fragile

Our discoveries, published on Aug. 5, 2024, in the Proceedings of the National Academy of Sciences, demonstrate that Greenland’s ice is vulnerable to melting at atmospheric carbon dioxide concentrations lower than today. Concerns about this vulnerability have driven scientists to study the ice sheet since the 1950s.

In the 1960s, a team of engineers extracted the world’s first deep ice core at Camp Century, a nuclear-powered Army base built into the ice sheet over 100 miles from the northwest Greenland coast. They studied the ice, but they had little use for the chunks of rock and soil brought up with the bottom of the core. Those were stored and then lost until 2019, when they were rediscovered in a lab freezer. Our team was among the scientists called in to analyze them.

A man in a fur-lined coat removes a long ice core about as wide as his hand
George Linkletter, working for the U.S. Army Corps of Engineers Cold Regions Research and Engineering Laboratory, examines a piece of ice core in the science trench at Camp Century. The base was shut down in 1966. U.S. Army Photograph

In the Camp Century soil, we also found plant and insect remains that had been frozen beneath the ice. Using rare isotopes and luminescence techniques, we were able to date them to a period about 400,000 years ago, when temperatures were similar to today.

Two microscope images show tiny plant parts. One a moss stem and the other a sedge seed.
Exquisitely preserved remains of 400,000-year-old moss, on the left, and a sedge seed, on the right – found in the soil core from beneath the Greenland ice sheet at Camp Century – help tell the story of what lived there when the ice was gone. Halley Mastro/University of Vermont

Another ice core, DYE-3 from south Greenland, contained DNA showing that spruce forests covered that part of the island at some point in the past million years.

The biological evidence makes a convincing case for the fragility of Greenland’s ice sheet. Together, the findings from three ice cores can only mean one thing: With the possible exception of a few mountainous areas to the east, ice must have melted off the entire island in the past million years.


Losing the ice sheet

When Greenland’s ice is gone, world geography changes – and that’s a problem for humanity.

As the ice sheet melts, sea level will eventually rise more than 23 feet, and coastal cities will flood. Most of Miami will be underwater, and so will much of Boston, New York, Mumbai and Jakarta.

Today, sea level is rising at more than an inch each decade, and in some places, several times faster. By 2100, when today’s kids are grandparents, sea level around the globe is likely to be several feet higher.


Using the past to understand the future

The rapid loss of ice is changing the Arctic. Data about past ecosystems, like we have collected from under Greenland’s ice, helps scientists understand how the ecology of the Arctic will change as the climate warms.

When temperatures rise, bright white snow melts and ice shrinks, exposing dark rock and soil that soaks up heat from the Sun. The Arctic is becoming greener with every passing year, thawing underlying permafrost and releasing more carbon that will further warm the planet.

The authors share their research and images of the ice core drilling. Quincy Massey-Bierman/University of Vermont.

Human-caused climate change is on pace to warm the Arctic and Greenland beyond temperatures they have experienced for millions of years. To save Greenland’s ice, studies show the world will need to stop greenhouse gas emissions from its energy systems and reduce carbon dioxide levels in the atmosphere.

Understanding the environmental conditions that triggered the ice sheet’s last disappearance, and how life on Greenland responded, will be crucial for gauging the future risks facing the ice sheet and coastal communities around the world.The Conversation

Paul Bierman, Fellow of the Gund Institute for Environment, Professor of Natural Resources and Environmental Science, University of Vermont and Halley Mastro, Graduate Fellow of the Gund Institute for Environment. Graduate Research Assistant in Natural Resources and Environmental Science, University of Vermont

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

carbon dioxide emissions

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This article is republished from The Conversation under a Creative Commons license. Read the original article.
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The COP28 climate summit in Dubai has adjourned. The result is “The UAE consensus” on fossil fuels.

This text, agreed upon by delegates from nearly 200 countries, calls for the world to move “away from fossil fuels in energy systems in a just, orderly and equitable manner”. Stronger demands to “phase out” fossil fuels were ultimately unsuccessful.

The agreement also acknowledges the need to phase down “unabated” coal burning and transition towards energy systems consistent with net zero emissions by 2050, while accelerating action in “the critical decade” of the 2020s.

As engineers and scientists who research the necessary changes to pull off this energy system transition, we believe this agreement falls short in addressing the use of fossil fuels at the heart of the climate crisis.

Such an approach is inconsistent with the scientific consensus on the urgency of drastically reducing fossil fuel consumption to limit global warming to 1.5°C.


‘Abated’ v ‘unabated’

The combustion of coal, oil and gas accounts for 75% of all global warming to date – and 90% of CO₂ emissions.

So what does the text actually ask countries to do with these fuels – and what loopholes might they exploit to continue using them well into the future?

Those countries advocating for the ongoing use of fossil fuels made every effort to add the term “unabated” whenever a fossil fuel phase-down or phase-out was proposed during negotiations.

“Abatement” in this context typically means using capture capture and storage technology to stop CO₂ emissions from engines and furnaces reaching the atmosphere.

However, there is no clear definition of what abatement would entail in the text. This ambiguity allows for a broad and and easily abused interpretation of what constitutes “abated” fossil fuel use.

Will capturing 30% or 60% of CO₂ emissions from burning a quantity of coal, oil or gas be sufficient? Or will fossil fuel use only be considered “abated” if 90% or more of these emissions are captured and stored permanently along with low leakage of “fugitive” emissions of the potent greenhouse gas methane, which can escape from oil and gas infrastructure?

This is important. Despite the agreement supposedly honouring “the science” on climate change, low capture rates with high residual and fugitive emissions are inconsistent with what research has shown is necessary to limit global warming to the internationally agreed guardrails of 1.5°C and 2°C above pre-industrial temperatures.

In a 2022 report, the Intergovernmental Panel on Climate Change (IPCC) indicated that almost all coal emissions and 33%-66% of natural gas emissions must be captured to be compatible with the 2015 Paris agreement.

That’s assuming that the world will have substantial means of sucking carbon (at least several billion tonnes a year) from the air in future decades. If these miracle machines fail to materialise, our research indicates that carbon capture would need to be near total on all fuels.

The fact that the distinction between “abated” and “unabated” fossil fuels has not been clarified is a missed opportunity to ensure the effectiveness of the Dubai agreement. This lack of clarity can prolong fossil fuel dependence under the guise of “abated” usage.

This would cause wider harm to the transition by allowing continued investment in fossil fuel infrastructure – new coal plants, for instance, as long as some of the carbon they emit is captured (abated) – thereby diverting resources from more sustainable power sources. This could hobble COP28’s other goal: to triple renewable energy capacity by 2030.

By not explicitly defining these terms, COP28 missed the chance to set a firm, scientifically-backed benchmark for future fossil fuel use.

The coming age of carbon dioxide removal

Since the world is increasingly likely to overshoot the temperature goals of the Paris agreement, we must actively remove more CO₂ from the atmosphere – with reforestation and direct air capture (DAC), among other methods – than is emitted in future.

Some carbon removal technologies, such as DAC, are very early in their development and scaling them up to remove the necessary quantity of CO₂ will be difficult. And this effort should not detract from the urgent need to reduce emissions in the first place. This balanced approach is vital to not only halt but reverse the trajectory of warming, aligning with the ambitious goals of the Paris agreement.

There has only really been one unambiguously successful UN climate summit: Paris 2015, when negotiations for a top-down agreement were ended and the era of collectively and voluntarily raising emissions cuts began.

A common commitment to “phase down and then out” clearly defined unabated fossil fuels was not reached at COP28, but it came close with many parties strongly in favour of it. It would not be surprising if coalitions of like-minded governments proceed with climate clubs to implement it.