The latest Intergovernmental Panel on Climate Change (IPCC) report on how land use contributes to climate change and how climate change affects the land has been finalised in Geneva.
The report looks into the interplay between climate change and sustainable land management, food security, desertification, land degradation (including extremes like floods and droughts), and land-based greenhouse gas sources and sinks.
The SMC gathered expert comments on the report.
Dr Andy Reisinger, Deputy Director, New Zealand Agricultural Greenhouse Gas Research Centre, comments:
"The Special Report on Climate Change and Land shows that New Zealand is not alone in the challenges it faces. Many of the issues that we’re grappling with in terms of how to reduce emissions, making our land more resilient to climate change, and how to achieve the best outcomes across the landscape are shared by governments around the world – that’s why they asked the IPCC to prepare this report.
"A key message from the report for me is the need for integrated responses that comprise not just how we produce food but stretch across the food and energy system. This is critical to improve resilience globally and to ensure we use land in a way that can both feed people and reduce net emissions.
"Currently, about 2 billion people are overweight or obese while more than 800 million are undernourished. Those figures show that we can grow enough food – it’s not a question of producing more but improving access to and stability of food supply. There is an important synergy between more diverse and healthy diets and achieving lower emissions and more climate resilient food systems, and freeing up land for carbon sequestration.
"That doesn’t tell us what New Zealand’s role should be in this global challenge but it does tell us that we need to keep an eye on this bigger picture in our conversations."
Conflict of interest statement: Andy is the New Zealand Vice Chair of the IPCC, and has been finalising the report in Geneva the past week.
Associate Professor Anita Wreford, AERU, Lincoln University, comments:
"The Special Report on Climate Change and Land synthesises and presents the key evidence relating to the interactions between land and climate. It represents an enormous body of literature and expertise from an international team of scientists, conducted over more than two years. It covers an extensive range of topics and issues around: how our activities on land affect the climate; how a changing climate is and will increasingly affect how we use the land, and; policy instruments and mechanisms to address these interactions.
"It highlights that we rely on the land for food, energy, water, health and well-being, but it is already under pressure, and climate change will exacerbate these pressures.
"The report is highly relevant for New Zealand as we grapple with the trade-offs involved with reducing greenhouse gas emissions, adapting to the impacts of climate change, managing the areas we value and maintaining and supporting our communities and societies in this process. The report puts these issues in the wider context of global climate and land.
"The report highlights the importance of carefully designed policies that do not contradict each other or lead to unintended consequences, and careful planning and consideration of the long term in decision-making. Early action will be less costly than delaying action, and will generate opportunities to address wider issues beyond climate, including sustainable livelihoods, maintaining biodiversity, addressing societal inequalities and improving our health. However, the report emphasises that while better land management can help to tackle climate change, it cannot do it all – we still need steep greenhouse gas reductions across all sectors.
"This report will provide policy-makers with the synthesised evidence, and examples from around the world, of the implications of decisions they make regarding land and climate change. It is of critical relevance to New Zealand given the contribution of the land-based sector to our economy, as well as its dominance in our emissions profile."
Conflict of interest statement: Anita was one of the authors of Chapter 7 of the report (Risk management and decision making in relation to sustainable development).
Dr Bronwyn Hayward, Associate Professor, Political Science and International Relations, University of Canterbury, comments:
"This new IPCC land report is a stark reminder that everything we do affects our climate. For New Zealanders, one immediate and striking recommendation is to change our diets, traditionally high in meat and dairy to ones more balanced around more plant-based food choices that require less land and water to produce and involve the emission of fewer greenhouse gases. The report also notes the value of moving towards more sustainable, less intensive farming in the global North.
"This report underscores the importance of understanding how land-use changes, like the shift from native forest to pasture grass, affects our climate as well as our soils. We all have to be more thoughtful in land-use change – whether it is the conversion of farmland from sheep to dairy; from dairy to forest, or from food production to housing. All these decisions matter and have serious and far-reaching consequences for our environment and climate.
"At the same time the report doesn’t let other sectors off the hook, while noting the use of land and related bio-genic methane has important impacts on climate, the report is at pains to point out that reducing carbon use also is crucial, especially noting the importance of cutting back on fossil fuels in urban transport.
"We can no longer point the finger at agriculture or at cities and blame each other for not doing enough for climate change. This report reminds us we all have to take action for a fairer, more sustainable future.
"I also extend thanks and congratulations to Associate Professor Anita Wreford, the sole NZ author, and Dr Andy Resinger, the NZ vice chair, because undertaking these projects is a huge commitment and they have worked incredibly hard."
No conflict of interest declared. Note: Bronwyn has been an author on previous IPCC reports.
Dr Mike Harvey, NIWA principal scientist - Atmosphere, comments:
"Given our strong association with the land of New Zealand, thinking has developed on sustainable land management for the future wealth and wellbeing and so this IPCC report on climate change and land has special relevance. We see that food systems globally account for about a quarter of net greenhouse gas emissions, with agricultural emissions of both methane and nitrous oxide trending upwards.
"In New Zealand, agriculture accounts for about half of gross emissions of greenhouse gases but there has not been a strong upward trend as agricultural systems have become more efficient. In many ways, New Zealand has been leading with early consideration and research on sustainable land management under climate change and the implications for greenhouse gas emissions.
"However, many challenges lie ahead to meet emission reductions required for the move to a low-carbon world whilst maintaining food security and the long-term productive potential of land. Many issues of relevance to New Zealand are highlighted: research is at an early stage (e.g. CarbonWatchNZ) in understanding and maintaining carbon stocks in soils. There is difficulty in distinguishing anthropogenic from natural fluxes of carbon dioxide from land which makes quantifying efficacy of actions difficult.
"Although it is a small land area in New Zealand, careful carbon conservation of high-carbon ecosystems such as peatlands and wetlands is needed and rising temperatures will reduce the ability to sequester carbon in soils.
"The report highlights the potential benefits of a mix of policies, the integration of local and indigenous knowledge, a coordinated approach considering mitigation and adaptation together to move forward more sustainably. Nationally, we may face the pressures of increased export demand particularly if food supply instabilities increase as predicted with more severe impacts of climate change in some major food producing regions. The report is very timely."
No conflict of interest.
Prof Andreas Neef, Professor of Development Studies, University of , comments:
"The IPCC’s Climate Change and Land report reaffirms the drastic impact of global land use systems on climate change, but also reminds us of how future land use and our food system will be affected by accelerated climatic changes.
"The reports suggests that farming, forestry and other land use activities combined accounted for 13% of global carbon dioxide emissions (more than six times the CO2emissions from global air travel), 44% of methane emissions (primarily from ruminants, such as cattle and sheep) and 82% of nitrous oxide emissions (predominantly caused by fertiliser use on cropland and pastures) over the ten-year period from 2007-2016.
"The warming of the global temperature has already affected global food security through greater frequency of droughts, floods, storms and other extreme weather events and has led to shifts of climate zones for many plant and animal species. Another worrying finding of the report is that about 25% of our planet’s ice-free land mass is subject to human-induced degradation."
"Improved management of cropland and pastures with the aim of reducing greenhouse gas emissions will be key for land-based mitigation efforts in New Zealand. This can be achieved by reducing the stock density – the number of farm animals kept on a unit of land – in areas where livestock farming has already reached unsustainable levels. This will have important co-benefits in terms of fewer agrochemical effluents into rivers and oceans and reduced erosion and soil degradation. Greenhouse gas emissions from cropland can be reduced by greater fertiliser efficiency and/or conversion into low-input and organic cropping systems.
"For such changes in the agricultural sector to be viable, they should be supported by societal efforts to reduce food loss and waste (estimated at more than 100,000 tonnes per year in New Zealand and contributing up to 10% of human-induced greenhouse gas emissions globally!) and by encouraging consumers to reduce their meat and dairy intake and switch to more balanced, diversified and predominantly plant-based diets.
"The IPCC report emphasises that such a nutritional diversification would not only combat climate change but also reduce other environmental pressures and contribute to improved public health.
"The IPCC report also has important implications for the New Zealand government’s multi-million tree planting programme. The report reminds policymakers that while afforestation can lead to effective carbon sequestration during the time when the trees grow, mature tree vegetation reaches saturation levels where no additional CO2 is removed from the atmosphere. Hence, a long-term forest management plan has to be in place for what to do with mature trees, e.g. converting wood pellets into sustainable bioenergy."
"Preparations for a warmer Aotearoa New Zealand with higher frequency and intensity of extreme weather events will require a great deal of anticipatory governance. The agricultural and forestry sectors need to become more ‘climate-smart’ by diversifying cropping systems and improving forest fire management.
"While the country enjoys a rich endowment of freshwater resources per capita, future heatwaves and extended drought periods can lead to localised water shortages for agriculture and human consumption, as recently experienced in parts of Central Europe. Diversifying and extending water storage capacities and improving water use efficiency will be critical to avoid a future water crisis.
"Where urban expansion has led to the conversion of farmland and losses in food production, urban and peri-urban farming and gardening should be encouraged by local councils. This can create new employment opportunities as an important co-benefit. The IPCC report also recommends building urban green infrastructure to reduce the impact of future heat waves and other climatic risks in cities.
"In conclusion, these mitigation and adaptation efforts can only be successfully implemented in a concerted effort of national government, local councils, private sector and civil society. Starting now and accelerating these efforts over time can help turn our current ‘climate emergency’ into a climate opportunity."
No conflict of interest.
Dr Judy Lawrence, Senior Research Fellow, Climate Change Research Institute, Victoria University of Wellington, comments:
"The value of this report is that it gives decision-makers a good steer on how the different development scenarios affect climate change impacts for the land and environment and the role sectors can play in reducing tradeoffs for society as a whole. This enables the consequences of their decisions for the global and local communities to be made transparent.
"By highlighting the role institutional fragmentation and the lack of engagement with and coordination across the wide range of sectors in the land use food chain, the report identifies where further focus by decision-makers is necessary to avert negative consequences of the many sector decisions taken at individual, local and national scale.
"The consequences of delaying action is highlighted. It is now up to governments at all levels and across all sectors to take the assessment and chart development pathways that can avert disruptive pathways for the whole community from the impacts of climate change. "
No conflict of interest declared.
Dr Jim Salinger, NZ climate scientist, Visiting Professor, University of Florence, comments:
"This is a very significant IPCC report especially pertinent to New Zealand’s land use of food production and forestry.
"The first major point is that the area in drought and desertification has increased over 50% globally between 1961 and 2013. Particularly hard hit is South and East Asia, and North Africa and the Middle East. The latter area is currently the major area of war and conflict, with up to 75% of global fatalities occurring in Syria, Afghanistan and Iraq (over 60,000 fatalities in 2017). In North Africa, the Middle East and India, heatwaves with high 40C and low 50C days are ever on the increase with desertification. The low rainfall means that daytime land temperature increases are among the highest rates on the globe, with the frequency of droughts increasing.
"Agriculture, forestry and other land use dominate in the production of methane and nitrous oxide. Especially pertinent to New Zealand is that agriculture, forestry and other land use activities account for 44% of methane, and 82% of nitrous oxide emissions globally.
"This means that the agricultural sector cannot ignore calls for maximum reductions in methane and nitrous oxide emissions as the international focus will now be on New Zealand’s response. The land-based emissions are estimated to be 23% of total net anthropogenic GHG emissions.
"Both methane and nitrous oxide have increased, and the main culprit is livestock farming globally. The globally averaged atmospheric concentration of methane shows a steady increase between the mid-1980s and early 1990s, slower growth thereafter until 1999, a period of no growth between 1999-2006, followed by a resumption of growth in 2007. Biological sources make up a larger proportion of emissions than they did before 2000. Ruminants and the expansion of rice cultivation are important contributors to the rising concentration.
"Anthropogenic nitrous oxide emissions from soils are primarily due to nitrogen application including inefficiencies (over-application or poorly synchronised with crop demand timings). There has been a major growth in emissions from managed pastures due to increased manure deposition. Livestock on managed pastures and rangelands accounted for more than one half of total anthropogenic nitrous oxide emissions from agriculture in 2014."
"The section on combating drought and desertification is very positive. The Convention to Combat Drought and Desertification (UNCCD), to which New Zealand is a signatory, has many solutions. Many land-related responses that contribute to climate change adaptation and mitigation can also combat desertification and land degradation, and enhance food security. The potential for land-related responses and the relative emphasis on adaptation and mitigation is context-specific, including the adaptive capacities of communities and regions. While land-related response options can make important contributions to adaptation and mitigation, there are some barriers to adaptation and limits to their contribution to global mitigation."
No conflict of interest.