When the IPCC Sixth Synthesis Report1 was published on 20th March 2023, the IPCC Chair stated, “This Synthesis Report underscores the urgency of taking more ambitious action and shows that, if we act now, we can still secure a liveable sustainable future for all”.2 So what does this Synthesis Report say about nature? A cursory glance would suggest little, as the press release makes no mention of biodiversity and only two about nature. In the 36-page report, nature is mentioned only 4 times. However, a closer inspection demonstrates a clear recognition of the interconnection between nature and climate. We discuss this in more detail below.
Another IPCC warning
The latest Intergovernmental Panel on Climate Change (IPCC) report released on 20 March, was a Synthesis Report based the content of three Working Groups Assessment Reports3 and the three Special Reports.4 This is the fourth and final instalment of the Sixth Assessment Report (AR6), which draws together the key findings of these preceding reports. This latest report does not contain new science but does provide a useful recap of the main findings of these previous publications, reducing numerous of pages of analysis into a ‘Summary for Policymakers’.
This report is regarded as particularly significant, as AR6 is expected to be the last IPCC report released while limiting the Earth’s warming to a 1.5°C (2.7°F) increase still remains possible. However, the IPCC could be ordered to write a shorter report – a full assessment is a multi-year endeavour – this decade, but none are presently planned.
Where does nature feature?
If we examine the full summary report for policymakers we can identify many references to climate, 179 in total. Although the word nature is sparsely used, references associated with nature are numerous – see Table 1.
Table 1: References to nature related issues in the IPCC AR6 Synthesis Report
Source: IPCC AR6 SYR, Planet Tracker
Below we categorise the main climate and nature-related themes which are prevalent throughout the report.
1. Clear interdependencies
Almost immediately, this report “recognizes the interdependence of climate, ecosystems and biodiversity, and human societies”.5 It notes the close linkages and “increasing diversity of actors involved in climate action”6 making particular mention of climate change adaptation and mitigation, ecosystem health, human well-being and sustainable development. This is a continuation of the work initiated by the IPCC and the IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) when the first co-sponsored workshop report on biodiversity and climate change was launched in June 2021. The main goal was to examine the synergies and trade-offs between the activities and polices of biodiversity protection and climate change mitigation and adaptation.7
Observing that global greenhouse gas emissions have continued to increase, the authors recognise that ongoing contributions arise from not only unsustainable energy use, but also land use and land-use change, lifestyles and patterns of consumption and production to which it attributes a high confidence level.8
There is a stark warning on the impact of climate change on nature. “As warming levels increase, so do the risks of species extinction or irreversible loss of biodiversity in ecosystems including forests (rated as medium confidence), coral reefs (very high confidence) and in Arctic regions (high confidence)”.9
This close relationship between climate and nature is particularly apparent when the IPCC report considers forests. Forests – and related terms such as afforestation, agroforestry, deforestation and reforestation – are mentioned 32 times in the report and their importance in providing adaptation and mitigation benefits is highlighted. The report mentions that “conservation, improved management, and restoration of forests and other ecosystems offer the largest share of economic mitigation potential, with reduced deforestation in tropical regions having the highest total mitigation potential”.10 In terms of effective adaptation, options recommended include agroforestry alongside farm and landscape diversification and cultivar improvements.
The co-dependency of climate and nature is clearly presented in this report as both are used to assess climate impacts and risks (cascading effects) as well as promoting long- and near-term solutions.
Figure 1: Demand-side potential mitigation options by 2050
Source: IPCC AR6 (page 28)
2. Healthy diets
Having acknowledged the overlap between climate, nature and people, it is unsurprising that the IPCC report recognises the importance of healthy diets. The authors reference “sustainable healthy diets” as one of the co-benefits of accelerated climate action.11 The report provides a section on health and nutrition.12
The importance of the food system in demand-side measures such as shifting to healthy diets and reducing food loss/waste, along with sustainable agriculture, which in turn reduces ecosystem conversion, methane and nitrous oxide emissions and frees up land for reforestation and ecosystem conversion, are all recognised.13
Interestingly, the report also points out the importance of healthy diets on “all dimensions of individuals’ health and well-being; have low environmental pressure and impact; are accessible, affordable, safe and equitable and are culturally acceptable”.
The co-dependency of climate, nature and society is clear.
3. Land and sea as one
Food security is often divided into land and ocean-based categories. At Planet Tracker, we view these as interlinked, as does the IPCC.14 Not only do the authors comment on land use and agriculture, but also fisheries – “rebuilding overexploited or depleted fisheries reduces negative climate change impacts on fisheries (medium confidence) and supports food security, biodiversity, human health and well-being (high confidence)”.15
The importance of ocean warming and acidification is highlighted as having adversely affected food production from fisheries and shellfish aquaculture in some oceanic regions. This comment carries a high confidence rating.16
The IPCC views fisheries as an economically climate-exposed sector alongside agriculture, forestry, energy and tourism.17 Importantly, the reports also mentions that food security is affected by both crop and fishery failures, although details are not included in this Synthesis Report.18
4. Water insecurity
Climate change has not only reduced food security, but also water security. Together these hinder “efforts to meet Sustainable Development Goals (high confidence)”.19 In turn, nearly half of the world’s population currently experiences “severe water scarcity for at least part of the year due to a combination of climatic and non-climatic drivers (medium confidence)”.20 Furthermore human mortality and morbidity is being affected by climate related food-borne and water-borne diseases. This is rated by the IPCC as very high confidence.21
The water systems referenced by the IPCC include freshwater, cryosphere (i.e. the frozen parts of the planet), as well as coastal and open ocean ecosystems. When considering physical water availability, the following factors need to be taken into consideration: balance of water available from various sources including ground water, water quality and demand for water.
The IPCC expects continued global warming, with a high confidence rating, to “further intensify the global water cycle, including its variability, global monsoon precipitation, and very wet and very dry weather and climate events and seasons”.22
The IPCC has a clear message, “Vulnerability of ecosystems will be strongly influenced by past, present, and future patterns of unsustainable consumption and production, increasing demographic pressures, and persistent unsustainable use and management of land, ocean, and water”.23
The UN Secretary-General, António Guterres, commented that the “IPCC report is a how-to guide to defuse the climate time-bomb…In short, our world needs climate action on all fronts — everything, everywhere, all at once”.24 To achieve this goal, a number of intertwined factors need to be addressed by policymakers alongside climate change. This includes nature and its ecosystems.
1 IPCC AR6 Synthesis Report: Climate Change 2023
2 Press release – IPCC Assessment Report 6 – Synthesis Report
3 Working Group I – The Physical Science Basis (2021); Working Group II – Impacts, Adaptation and Vulnerability (2022); Working Group III – Mitigation of Climate Change (2022)
4 Global Warming of 1.5°C (2018) ; Climate Change and Land (2019); The Ocean and Cryosphere in a Changing Climate (2019).
5 PCC AR6 Synthetic Report – page 3,line 10
6 IPCC AR6 Synthetic Report – line 12
7 IPBES/IPCC co-sponsored workshop report
8 IPCC AR6 Synthetic Report – page 4,line 4, A.1
9 IPCC AR6 Synthetic Report – page 19, lines 41-43
10 IPCC AR6 Synthetic Report – lines 20-22
11 IPCC AR6 Synthetic Reports – page 27, lines 20-22
12 IPCC AR6 Synthetic Reports – page 32, section C3.7
13 IPCC AR6 Synthetic Reports – page 31, lines 23-27
14 IPCC AR6 Synthetic Reports – page 31, section C 3.5
15 IPCC AR6 Synthetic Reports – page 31, lines 41-43
16 IPCC AR6 Synthetic Reports – pages 5-6, lines 47-3
17 IPCC AR6 Synthetic Reports – page 6, lines 16-17
18 IPCC AR6 Synthetic Reports – page 17, lines 19-21
19 IPCC AR6 Synthetic Reports – page 5, line 43
20 IPCC AR6 Synthetic Reports – page 6, lines 1-3
21 IPCC AR6 Synthetic Reports – page 6, lines 5-7
22 IPCC AR6 Synthetic Reports – page 12, lines 29-30
23 IPCC AR6 Synthetic Reports – page 15-16, pages 37-1
24 UN press release SG/SM/21730 20 March 2023