It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, November 04, 2021
Determining where the wild bears are
by German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Illustration of the general workflow of the r package enerscape. The energy landscape is computed starting from a raster of the digital elevation model and animal body mass using a locomotory model to calculate the energy costs of transport (ECOT). The ARC model (Pontzer, 2016) for legged, terrestrial animals is displayed as green lines, with blue circles showing the empirical data used for validation. Credit: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Large land animals have a significant impact on the ecology and biodiversity of the areas they inhabit and traverse. If, for example, the routes and stopping places of cattle, horses, sheep, and also those of wolves or bears overlap with those of people, this often leads to conflicts. Knowing and being able to predict the movement patterns of animals is, therefore, of utmost relevance. This is not only necessary for nature and landscape protection, and to safeguard agriculture and forestry, but also for the safety of human travelers and the security of human infrastructures.
Example—the brown bear
The Abruzzo region of Italy, the location of the Sirente Velino Regional Park, is home to the endangered and therefore protected Marsican brown bear (Ursus arctos marsicanus). Recording the bears' patterns of movement in the 50,000 hectare, partly populated area is especially important for their own protection, but also for that of the people living there and the sensitive flora. Movement pattern maps can be used to determine the bears' roaming routes and places of refuge more effectively. These can then be adequately protected and, if necessary, adjusted.
Traditional methods are expensive
Traditional maps of animal movements are mostly based on long-term surveys of so-called telemetry data; this comes from individuals fitted with radio transmitters. This type of map-making is often time consuming and expensive, and lack of radio contact in some areas means that no data can be collected at all. That was also the case in the vast and isolated Sirente Velino national park.
Researchers developed an alternative
Researchers from iDiv, the Friedrich Schiller University Jena, Aarhus University and the University of Oxford have developed software—named ENERSCAPE—with which maps can be created easily and cost-effectively. Dr. Emilio Berti is post-doctoral researcher with the Theory in Biodiversity Science research group at iDiv and the Friedrich Schiller University Jena. As first author of the study he stressed: "What's special is that the software requires very little data as a basis." The energy an animal needs to expend to travel a certain distance is calculated, based on the weight of that animal and its general movement behavior. This energy expenditure is then integrated with the topographical information of an area. "From this information we can then create 'energy landscape maps' for individuals as well as for groups of animals. Our maps are calculated rather than measured and thus represent a cost-effective alternative to traditional maps. In particular applications, such as the conditions in the Italian national park, our method makes the creation of movement pattern maps actually possible at all," said Berti.
Software helps with the designation of protection zones
Using ENERSCAPE, the researchers found that bears choose paths that require less energy expenditure. These paths often lead through settlements, so that the bears encounter humans—which frequently ends fatally for the animals. The software also predicts, that bears wanting to save energy will tend to stay in valleys, far away from human settlements. Bear conflict as well as protection zones can now be identified using ENERSCAPE. Its maps can also be used to check whether landscape elements are still well-connected enough to enable the animals to move around the area sufficiently.
ENERSCAPE is freely available and adaptable
The researchers' software ENERSCAPE is based on the widely used and openly accessible programming language 'R'. It has a modular structure and can therefore process animal movement and topographical data from a wide variety of ecosystem types. "This makes it possible for both researchers and wildlife managers to adapt the software to a wide variety of landscapes and animals," said Prof Fritz Vollrath from the Zoology Department of the University of Oxford and senior author of the study, emphasizing the special nature of ENERSCAPE. "This means that the number of maps of animal movement in landscapes will increase in just a short time. With significantly more cartographical data, the understanding of the behavioral ecology of a species in a certain habitat will also fundamentally change. This will primarily benefit nature conservation and, in particular, rewilding measures—the reintroduction of wild animals," said Vollrath.
More information:Emilio Berti et al, The r package enerscape : A general energy landscape framework for terrestrial movement ecology,Methods in Ecology and Evolution(2021).DOI: 10.1111/2041-210X.13734
Last year, researcher Randi Grønnestad received a great deal of attention for her research carried out at the Granåsen Ski Centre in Trondheim, Norway. She found hormonal disorders and changes in the brains of bank voles in the area and linked them to fluorine-containing compounds called PFAS.
“Previously we showed that these PFAS most likely originate from the use of fluorinated glide wax,” said Grønnestad, who took her PhD from the Norwegian University of Science and Technology's (NTNU) Department of Biology.
The fluorinated compounds end up in the environment at the popular ski area, and the substances never degrade and disappear. They are also linked to several adverse health effects in humans.
Bank voles can ingest PFAS through food, such as earthworms. The voles at Granåsen had higher levels of PFAS in their bodies along with higher levels of the neurotransmitter dopamine in their brains. The male voles also had lower levels of the hormone testosterone.
Lab confirms effects on dopamine system
Grønnestad wasn’t satisfied with the fieldwork in Granåsen and the control area by Jonsvatnet, an area around Trondheim's drinking water reservoir where the Nordic ski traffic is considerably lower.
“Since the research results are from a field study where we can’t control all other variables that in theory could also affect the systems I studied, I wanted to reproduce the effects we found in Granåsen under controlled conditions in the lab,” says Grønnestad.
In the lab, the scientists were confident that no other environmental toxins would cause the effects they were measuring.
“In the lab experiment, we used laboratory mice that we fed with a feed mixture having the same amount and composition of PFAS added as we’d measured in the earthworms from Granåsen. The mice were exposed to this feed for 10 weeks. We also had a control group that was fed with the same food, but without the added PFAS mixture,” says Grønnestad.
The research group also found that the dopamine system was affected in the mice that received the PFAS mixture in their feed.
“We found significant effects on the levels of dopamine in the brain and on the genetic expression of enzymes that are important for producing dopamine, although it seems that slightly different molecular mechanisms were affected in the two studies,” says Grønnestad.
This difference indicates that the effects they measured in the dopaminergic system in the bank voles from Granåsen were due to PFAS exposure.
No change in testosterone
Unlike at Granåsen, however, the researchers found no changes in hormone levels in the laboratory mice.
“We saw no effects of PFAS exposure on the concentrations of testosterone, oestrogen, or 11-ketotestosterone in either sex,” says Grønnestad.
This could indicate that the apparent correlations between low testosterone levels and PFAS in the voles from the field study are due to other variables in nature that the researchers did not measure, rather than PFAS.
However, the scientists found a different disturbing effect of PFAS in the laboratory instead.
Larger livers indicate environmental toxins
“In the lab we discovered that male mice from the PFAS-exposed group had larger livers, relative to their body mass, than the control group did. The liver is a known indicator of toxicity for environmental toxins,” says Grønnestad.
Some studies suggest that males are more sensitive to the effects of PFAS exposure. In addition, the male mice had higher levels of PFAS in the liver than the female mice because they had eaten more food. They may thus simply have been exposed to higher concentrations of PFAS.
The research group is also investigating other effects on the liver, but these results are not yet ready. At this point, it appears that the composition of fatty acids in the liver has changed.
Possible consequences
“The study results thus indicate that we’re seeing effects on brain chemistry and the composition of fatty acids in the liver of exposed mice with the same amount of PFAS that we found at Granåsen. This could have serious consequences,” says Grønnestad.
Exactly what biological effects the finding might have is difficult to say, she says. Further behavioural studies or long-term studies are needed to determine that.
Grønnestad mentions as possible examples that effects on animals’ dopaminergic systems could potentially lead to disturbances in regulating fear and anxiety, thermoregulatory processes and the ability to protect themselves. The changes could also impact their reproductive system.
Elevated or decreased levels of dopamine are also associated with mood swings and motor and cognitive changes.
Grønnestad is currently an advisor for air quality in the Trondheim municipality, Miljøenheten.
A red deer in the Alladale Wilderness Reserve. Credit: Dr. Chris Sandom
New research suggests that wild herbivore numbers are not unnaturally high in the UK or the rest of the World despite what many conservationists believe, with data implying that, if anything, they are much lower than expected for healthy ecosystems.
A study co-authored by Dr. Chris Sandom at the University of Sussex, suggests that at comparable levels of natural productivity there are typically less wild herbivores in Europe compared to Africa, where ecosystems are more intact.
The findings, published in the Journal of Applied Ecology, challenge the commonly held perception that the density of wild grazing and browsing species is 'too high' and causing damage to ecosystems.
Dr. Sandom, senior lecturer in biology at the University of Sussex, worked on the study led by Dr. Camilla Fløjgaard and colleagues at Aarhus University, Denmark. He said: "Diverse and abundant large herbivore communities like red, roe and fallow deer aren't the enemy of conservation or restoration, the problem is the degraded ecosystems humans are forcing them to live in.
"Our research shows that, naturally, densities of large herbivores are likely to be much higher than is commonly perceived. This, combined with the diverse and abundant communities of predators and vegetation, is what intact ecosystems should look like.
"The problems we're seeing, like the lack of tree regeneration, are likely because few remaining trees mean there is a limited seed source. Dense cover of grass, heather, and bracken mean there are few places for trees to germinate. The absence of large predators disrupting grazing and browsing pressure mean the few saplings that do establish don't stand a chance. This combination of factors needs to be kept in mind when we think about nature recovery. We can't just blame the herbivores."
The findings show that many nature reserves outside of Africa are depleted in large-herbivore biomass. According to the authors, nature restoration in these places needs to be focused on restoring functional ecosystems that include diverse and abundant wild large herbivores. This may include reducing herbivore numbers in the short-term, but could see spectacular and beneficial returns in the future.
"Even though large herbivores have been wandering the landscape for millions of years, it seems that we have become accustomed to landscapes almost completely devoid of them, and we have come to accept this as the natural state of things," says Camilla Fløjgaard, from the Department of Ecoscience at Aarhus University.
The study comes at a crucial time for the planet, with the commencement of COP26 in Glasgow and the UN's Decade of Ecosystem Restoration, which runs until 2030. The global initiative is described as 'a rallying cry' for the protection and revival of ecosystems around the world, for the benefit of both people and nature.
The authors of the study believe that, where we can strive for large-scale nature-recovery we should be aiming to rewild large herbivores and allow nature to manage their numbers without setting predefined targets.
Rasmus Ejrnæs, senior researcher from Aarhus University, said: "Bringing back big animals is crucial to restoring self-sustaining ecosystems and conserving biodiversity, but it is not going to be easy. Large animals are troublesome, because they damage crops, disrupt traffic and generally just get in the way. It will require political commitment and careful physical planning, including fenced reserves."
Dr. Sandom said: "Herbivores are important because they help increase the diversity of nature as a whole by grazing and browsing, bark stripping and branch breaking, rooting and dunging, when they are in ecosystems that also include a mixed mosaic of vegetation types and large predators.
"In places, restoring nature may well involve reducing large herbivore numbers now, but this should be seen as an opportunity to restore the ecosystem to allow richer and more abundant nature across the board in the future, from plants to predators and including large herbivores.
More information:Camilla Fløjgaard et al, Exploring a natural baseline for large‐herbivore biomass in ecological restoration,Journal of Applied Ecology(2021).DOI: 10.1111/1365-2664.14047
At the Glasgow COP26 climate talks overnight, Australia and 123 other countries signed an agreement promising to end deforestation by 2030.
The declaration's signatories, which include global deforestation hotspots such as Brazil, Indonesia and the Democratic Republic of the Congo, have committed to "working collectively to halt and reverse forest loss and land degradation by 2030 while delivering sustainable development and promoting an inclusive rural transformation."
This declaration should be welcomed for recognizing how crucial forest loss and land degradation are to addressing climate change, biodiversity decline and sustainable development.
But there have been many such declarations before, and it's hard to feel excited about yet another one.
What really matters is changing policy domestically; if countries don't change what they are doing at home to bring emissions from fossil fuels to zero and restore degraded lands, declarations like this are meaningless.
The good parts
The declaration does a good job of joining up interrelated issues that for too long have been treated as separate problems.
Signatories say they will "emphasize the critical and interdependent roles of forests of all types, biodiversity and sustainable land use in enabling the world to meet its sustainable development goals; to help achieve a balance between anthropogenic greenhouse gas emissions and removal by sinks; to adapt to climate change; and to maintain other ecosystem services."
Biodiversity is key to forest conservation and sustainable land use.
From there, the signatories promise to "reaffirm our respective commitments, collective and individual, to the UN Framework Convention on Climate Change and the Paris Agreement, the Convention on Biological Diversity, the UN Convention to Combat Desertification, the Sustainable Development Goals; and other relevant initiatives."
To see commitments under several UN declarations recognized in one place is somewhat of a breakthrough; forests, biodiversity and land-use are often siloed despite the critical links in dealing with these issues.
It is also promising to see recognition that conserving existing forests and other terrestrial ecosystems is the priority, and signatories committing to accelerate their restoration (as opposed to just planting new trees).
A vast body of research shows planting new trees as a climate action pales in comparison to protecting existing forests. As I have written before, "restoring degraded forests and expanding them by 350 million hectares will store a comparable amount of carbon as 900 million hectares of new trees […] Forest ecosystems (including the soil) store more carbon than the atmosphere. Their loss would trigger emissions that would exceed the remaining carbon budget for limiting global warming to less than the 2℃ above pre-industrial levels, let alone 1.5℃, threshold."
Once intact forests are gone, we can't regain the carbon lost. It is known as "irrecoverable carbon". So protecting existing forests is the top priority, especially given the critical time frame we are in now to keep climate change under the 1.5℃ or even 2℃ thresholds.
The declaration also mentions trade, promising to "facilitate trade and development policies, internationally and domestically, that promote sustainable development, and sustainable commodity production and consumption, that work to countries' mutual benefit, and that do not drive deforestation and land degradation"
Here, we are starting to get to the real drivers of deforestation. For a long time, there has been too much focus on local drivers of deforestation including local communities. But research shows the leading drivers of deforestation are internationally traded agricultural commodities such as beef, soy, palm oil and timber.
The overall rate of commodity-driven deforestation has not declined since 2001. We can't tackle forest loss without tackling the trade drivers behind it.
Research shows the leading drivers of deforestation are internationally traded agricultural commodities such as beef, soy, palm oil and timber. Credit: Shutterstock
The not-so-good parts
The main deficiency in the text is that not enough attention is paid to the rights of Indigenous peoples and local communities.
It is mentioned the countries will "recognize" and "support" the rights of Indigenous peoples but many of these signatories do not have adequate—or, in some cases, any—legislation that actually recognizes those rights.
Subjugation of these rights to national law has been a problem in previous international agreements.
The challenge in many countries is regulatory reform to bring national recognition of land, tenure and other collective rights into line with the internationally recognized rights of Indigenous Peoples.
The track records of some of these signatories bring into question what policy change they will be making back home to ensure this declaration isn't just for show.
As a global land clearing hotspot, Australia will need to enact rapid policy change to bring its current practices in line with what it has signed on to. Australia remains the only developed nation on the list of global deforestation fronts. This is due to weakening land clearing legislation in New South Wales and Queensland, mostly for expansion of grazing lands.
As a signatory to this new declaration, Australia must strengthen land clearing laws, end native forest logging, and restore degraded ecosystems—just planting new trees will not get us there. Australia has the potential to restore large areas of degraded land. Experts have proposed how this could be done for relatively little investment.
The European Union has signed on too; it has been a global leader on developing trade policies designed to end illegal logging and reduce deforestation. But it recently backpedaled on its commitment to a program of forest governance and law enforcement in timber-producing countries that allow access to the EU timber market.
If they are serious about this declaration, the EU must reaffirm its commitment to partner countries to address illegal logging in traded timber.
In Brazil, the Bolsonaro government has been winding back previous legislation to recognize Indigenous peoples' land rights. Deforestation rates have soared in the past few years. Perhaps the first action Brazil could take as a signatory to this declaration is to prioritize the landmark case (currently on hold) before Brazil's Supreme Court to protect Indigenous land rights.
Ending deforestation and restoring forests is not enough
This is the latest in a series of similar declarations. A pledge made at COP24 in Katowice, the New York Declaration on Forests, and Sustainable Development Goal 15 (Life on Land) all include similar commitments to end deforestation by 2030 or earlier.
This week's COP26 declaration ends with the importance of "pursuing efforts to limit it to 1.5℃, noting that the science shows further acceleration of efforts is needed if we are to collectively keep 1.5℃ within reach."
The fact is, we won't achieve this through ending deforestation and restoring forests. These efforts are critically needed to address biodiversity loss and rural sustainability, but for limiting warming to 1.5℃, fossil fuel emissions need to come down to zero—nowWhy COP26 agreement will struggle to reverse global forest loss by 2030
Minister Raharinirina and British Ambassador David Ashley discuss efforts to slow deforestation with people living near Madagascar’s rainforest. Credit: Forest4Climate&People, Author provided
The countries that have signed the agreement contain 85% of the world's forests. The announcement includes £14 billion (US$19.2 billion) of public and private funds for conservation efforts. In addition, 28 countries have committed to ensuring trade in globally important commodities such as palm oil, cocoa and soy, does not contribute to deforestation.
Saving the world's dwindling forests is essential if we are to avoid dangerous climate change. Forests soak up carbon from the atmosphere and cutting them down releases it. On balance, forests removed about 7.6 billion tons of carbon every year over the last two decades. This is roughly 15% of global emissions.
But forests around the world are moving from net sinks of carbon, which soak up more than they release, to net sources. While the Amazon rainforest as a whole remains a carbon sink (for now), ongoing land clearance in parts of the Brazilian Amazon mean forests there are already emitting more carbon than they absorb. Increasing global temperatures are causing more forest fires too, further raising emissions from forests and so driving global temperatures higher.
Given that the window for keeping global warming below 1.5°C, or even 2°C, is rapidly closing, humanity desperately needs remaining forests to stay standing. So is the Glasgow leaders' declaration on forests and land use up to the task?
Past failures
This is only the most recent commitment to stop forest loss in a series of similar initiatives. Back in 2005, the UN Forum on Forests committed to "reverse the loss of forest cover worldwide" by 2015. In 2008, 67 countries pledged to try and reach zero net deforestation by 2020. This was followed by the New York declaration on forests in 2014 which saw 200 countries, civil society groups and indigenous peoples' organizations commit to halve deforestation by 2020 and end it by 2030.
These earlier efforts clearly failed to meet their targets. On average, rates of forest loss have been 41% higher in the years since the New York agreement was signed. It's almost impossible to know what deforestation rates would have been without these pledges.
It is important not to vilify those clearing tropical forests. In most cases, whether it's oil-palm plantation workers in southeast Asia, or the owner of a family-run cocoa farm in Ghana, these are just ordinary people trying to make a living. Where those clearing forest are poor subsistence farmers with few alternatives, such as many in Madagascar for example, preventing forest clearance can mean some of the poorest people on the planet are bearing the cost of tackling climate change. Given that such people contribute relatively few emissions, this isn't very fair.
What we do know is that progress on slowing deforestation has been wildly inadequate. The good news is Brazil, Russia and China, who did not sign the 2014 declaration, have this time. However, words are cheap, actually slowing deforestation is difficult to achieve.
Why is it so hard to slow deforestation?
The causes of forest loss vary from place to place, but the problem boils down to a conflict between those who benefit from deforestation and those who benefit from keeping forests intact, and whose ability to influence what happens on the ground wins out.
Conserving forests benefits everybody by stabilizing the climate. But logging, or clearing a patch of forest for farming, benefits the people involved in a much more direct and tangible way. Ultimately, to keep forests intact, those who benefit from forests (that's all of us) need to fund efforts to conserve them.
Just before flying to Glasgow, Madagascar's minister of environment and sustainable development, Dr. Baomiavotse Vahinala Raharinirina, visited a village to ask people their views on what would make forest conservation more effective. They spoke about the lack of alternative livelihoods, the need for more support to help them manage the forest sustainably, and the fact that local communities often lack the ability to exclude those who wish to exploit forests.
Raharinirina said: "Madagascar has contributed relatively little to climate change, but our people are suffering the consequences. For example, a million people in the south are in need of food aid because of the effects of a drought caused by climate change. We are trying to do our bit to reduce emissions by conserving and restoring our forests and have signed the Glasgow Leaders Declaration, however this won't be achieved without more resources… We will need support from the international community to help us achieve this."
I am cautiously impressed with how much attention is being paid to the question of fairly reducing tropical deforestation at COP26. The first event in the UK-led program brought forest communities and indigenous people together to discuss lessons from the last decade of forest conservation.
Dolores de Jesus Cabnal Coc, an indigenous leader from Guatemala, shared my cautious optimism, saying: "It's a slow process and will continue to be, but ever since [COP21 in Paris in 2015] there has been a big difference in that there is now a platform to help ensure more inclusive actions…"
Perhaps I am naive, but I sense a helpful change in tone among world leaders, from assuming that forest conservation inevitably delivers triple wins which benefit the climate, biodiversity and local livelihoods, to a more honest acknowledgement that often, there are winners and losers. Only by finding ways for conservation to benefit those who live alongside forests can the world hope to keep those forests absorbing emissions for years to come.
At the United Nations climate summit in Glasgow, more than 90 nations signed a global pledge led by the United States and United Kingdom to cut methane emissions. However, Australia was not among them.
China, Russia, India and Iran also declined to sign the pledge, which aims to slash methane emissions by 30% before 2030.
Methane is emitted in coal and gas production, from livestock and other agricultural activity, and when organic waste breaks down in landfill.
Almost half of Australia's annual methane emissions come from the agriculture sector. Defending the federal government's decision, Energy and Emissions Reduction Minister Angus Taylor said Australia had pledged net-zero greenhouse gas emissions by 2050 and would not set specific targets for each sector.
Days out from COP26, National Party leader Barnaby Joyce had claimed signing the pledge would be a disaster for coal mining and agriculture, saying "the only way you can get your 30% by 2030 reduction in methane on 2020 levels would be to grab a rifle and go out and start shooting your cattle."
Australia's position on the pledge is inconsistent with methane reductions the Intergovernmental Panel on Climate Change (IPCC) says are required to keep Earth below 1.5 degrees Celsius warming this century.
The debate also highlights how the shorthand phrase "net-zero emissions" conceals and distorts the real challenges in avoiding dangerous climate change.
It focuses attention on the wrong time frame for action—the next decade is far more important for climate action than 2050. It also addresses the means of action—emissions reduction—rather than the desired goal, which is to avoid dangerous climate change.
And importantly, simply through delaying action, the world could feasibly reduce emissions to net-zero by 2050, but still fail to meet the goals of the Paris Agreement—keeping average global temperature rise below either 1.5 degrees Celsius or 2 degrees Celsius this century.
Net-zero is both too much, and not enough
The IPCC report released in August painted a clear picture of how different trajectories for various greenhouse gases translate to global temperature increases.
Carbon dioxide (CO₂) emissions last a very long time in the atmosphere so they accumulate. Consequently, net CO₂ emissions need to decline sharply as soon as possible if we're to limit temperatures to 1.5 degrees Celsius or 2 degrees Celsius above pre-industrial levels.
However, CO₂ emissions not only need to reach net-zero—the IPCC says CO₂ emissions need to go "net-negative." This will require a massive scaling up of methods and technologies to remove existing CO₂ in the atmosphere.
In other words, when it comes to CO₂, net-zero is not enough. It is a way point, not the end point.
So how do we remove CO₂ from the atmosphere? Some methods, such as mass tree planting, are already widely implemented. Some are difficult to implement at scale, such as substantial increases in soil carbon.
Each option has advantages, disadvantages and limits. The "net-zero by 2050" terminology obscures this complexity. It also conceals the need for crucial discussions about feasibility, governance and support for research and development that's needed now.
Credit: The Conversation
Meanwhile, the situation is quite different for shorter-lived gases such as methane and nitrous oxide. In those cases, going all the way to net-zero is not needed to meet the Paris goals.
According to the IPCC report, an illustrative scenario consistent with 1.5 degrees Celsius warming would involve methane emission reductions of about 30% by 2030, 50% by 2050 and just over 60% by 2100.
This is consistent with the global methane pledge signed at COP26 overnight. For nitrous oxide, the illustrative reductions would be about 30% by 2050.
So, for methane and nitrous oxide, net-zero is too much.
Targets based on science
It should be noted, to keep temperature rise to 1.5 degrees Celsius, there are many possible combinations of emission-reduction trajectories for various greenhouse gases. The extent to which CO₂, methane or nitrous oxide is reduced is interchangeable and the final mix will be a function of political decisions.
A clear and integrated assessment of the economic, environmental and social consequences of different emission-reduction pathways is needed to inform those decisions. Without that, inefficient and inequitable economic responses may result.
For example, methane (from livestock) and nitrous oxide (from fertilizer use) make up a high proportion of agriculture emissions. But options for completely stopping these emissions are limited.
Farmers could offset their emissions by planting trees or rehabilitating vegetation on their properties to increase carbon stores. But this would prevent them from selling those emissions reductions on carbon markets, thus removing a potential source of farm income.
So an economy-wide target of net-zero for all key greenhouse gases might mean agriculture must make far more effort in emissions reduction, at much greater cost, than other sectors which largely emit CO₂ and where decarbonisation options are more readily available.
New Zealand has recognized this, and treats agricultural emissions separately.
Carving agriculture out of national emissions-reduction goals would place a greater requirement to act onto other sectors. For example, emission reductions in the transport sector may have to be greater than otherwise, to compensate for the lack of progress in agriculture.
But is isolating agriculture from emission reductions necessary? A recent study assessed new emission reduction options for livestock, including several approaches that together may reduce emissions at the rate required by the methane pledge. They involve more efficient production, technological advances, changes in demand for livestock-related products and land-based carbon storage.
Targets for methane and nitrous oxide reductions should be set using the IPCC science—and don't have to be set at net-zero. That would leave sectors emitting these gases with a feasible (but still challenging) pathway to reducing emissions in line with the Paris goals.
And where appropriate, we should start describing effective climate action as being "Paris-aligned." Clearly, over-use of the term "net-zero emissions" misdirects attention from where it's needed.
