2.1
78 Safronov, 2020.
79 van Oldernborgh et al., 2021.
80 State of Conservation Information System: https://whc.unesco.org/en/soc/3618.
81 State of Conservation Information System: https://whc.unesco.org/en/soc/4128.
82 State of Conservation Information System: https://whc.unesco.org/en/soc/4174.
83 Using 2018 emissions according to CAIT data on Climate Watch (www.climatewatchdata.org).
84 State of Conservation Information System: https://whc.unesco.org/en/soc/4263.
85 The Pantanal is the largest tropical wetland in the world and extends mainly into the Brazilian states of Mato Grosso do Sul and Mato Grosso, and into national territories of the Plurinational State of Bolivia and of Paraguay. In 2000, part of this ecoregion, the Pantanal Conservation Area, accounting for 1.3% of the Brazilian Pantanal, was inscribed on the UNESCO World Heritage List. That same year, 26.4 million hectares were named a UNESCO Biosphere Reserve.
Since the mid-2010s, intense wildfires associated with extreme temperatures and drought
conditions78,79 have been a cause of high emissions at some sites. The most prominent examples are wildfires in the Russian Federation’s Lake Baikal in 201680, and in Australia’s Tasmanian Wilderness81 and Greater Blue Mountains Area in 2019 and 202082. Each of these wildfires generated greenhouse gases emissions above 30 Mt CO2e in a single year, higher than the national annual emissions from fossil fuels of more than half of the countries in the world (Figure 8)83. Other recent fires have burned tropical forest ecosystems where fire has historically been rare, such as in Bolivia’s Noel Kempff Mercado National Park in the Amazon Basin.
Source: Analysis (Box 1) of Harris et al., 2021 among selected World Heritage sites. Selection of sites with fire activity is based on the reactive monitoring process of the World Heritage Convention and the IUCN World Heritage Outlook of 2020.
In some cases, wildfires are ignited outside World Heritage site boundaries, where effective fire management is weaker, rather than inside84. Consequently, emissions from fires inside World Heritage sites (as estimated in this report) likely represent only a small portion of total fire emissions from the larger forest landscape that burned. For instance, emissions stemming from the 2020 fires that affected the Pantanal Conservation Area World Heritage site in Brazil account for less than 5% of the emissions that year from the broader biome located in the Pantanal Biosphere Reserve85 (Figure 9, Box 4).
2001 ‘02 ‘03 ‘04 ‘05 ‘06 ‘07 ‘08 ‘09 ‘10 ‘11 ‘12 ‘13 ‘14 ‘15 ‘16 ‘17 ‘18 ‘19 ‘20
GHG emissions (Mt CO2e)
0 5 10 15 20 25 30
35 Lake Baikal Tasmanian
Wilderness Greater
Blue Mountains
Noel Kempff
Mercado NP Pantanal
Figure 8: Estimated annual gross forest greenhouse gas emissions among select natural and mixed UNESCO World Heritage sites with substantial fire activity
18
World Heritage forests Carbon sinks under pressure
Source: Copernicus. Imagery acquired by Copernicus Sentinel-2 satellites on August 14, 2020
Figure 9: Satellite image showing wildfires close to the Pantanal Conservation Area World Heritage site in Brazil on 14 August 2020. By early October 2020, the wildfires had encroached on a small portion of the site.
As climate change causes warmer and drier conditions that lead wildfires to become more intense and droughts more severe86, the ability of some forests to fully recover from such events may become increasingly hampered, potentially exacerbated by past or present land management practices. Recovery may be difficult even in areas where recurring wildfires constitute an integral part of ecosystem dynamics because human-induced climate change impacts disrupt these dynamics.
More intense fires could lead to short-term emissions spikes and reduced capacity for sequestration in the longer term, thus reducing overall carbon storage in sites that do not have a history of fires.
Some sites, such as the Greater Blue Mountains Area (Australia), Yosemite National Park (United States), and Waterton Glacier International Peace Park (Canada/United States) have experienced such intensification, frequency and elongation of fire seasons since 2000 that they have become net carbon sources (Table 4, Figure 10)87.
86 Seidl et al., 2017.
87 van Oldenborgh et al., 2021.
Other climate-related events, such as storms, can also lead to considerable loss of tree cover, for
example, at Morne Trois Pitons National Park (Dominica) following Hurricane Maria in 2017. While forests here are adapted to hurricanes and will slowly recover over time, the higher frequency and severity of storms may reduce forests’ ability to permanently store the same amount of carbon as they did when disturbances were less frequent and severe.
19
88 Based on data from the State of Conservation Information System and in the IUCN World Heritage Outlook of 2020.
89 Osipova et al., 2020.
Increased land-use pressures from human activities weakens forest carbon sinks
Despite their globally recognized and protected status at the national level, land-use pressures associated with specific human activities (e.g. illegal logging, wood harvesting, and agricultural encroachment due to livestock farming/grazing and crops) have been reported to occur inside about 60% of all World Heritage sites88 (examples shown in Figure 11). Resource extraction is associated with illegal activities in the majority of cases and is becoming one of the most prevalent threats to sites in Africa, Asia and the Pacific, and Latin America and the Caribbean89.
2.2
Figure 11: Human pressures at the Virunga National Park World Heritage site in the Democratic Republic of the Congo:
illegal land clearance inside the park (left) and farmland at the park’s edge (right)
© Andreas Brink
© Andreas Brink
Figure 10: Wide aerial views over the Grose Valley in the Greater Blue Mountains Area World Heritage site in Australia before (top) and after (bottom) massive wildfires. Brown areas indicate burn scars.
© Steve Heap / Shutterstock.com*
© Ilian Torlin / Shutterstock.com*
Before
After
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World Heritage forests Carbon sinks under pressure
Source: Analysis (Box 1) of Harris et al., 2021 among selected World Heritage sites. Selection of sites with land use pressures is based on the IUCN World Heritage Outlook of 2020.
Figure 12: Estimated annual gross forest greenhouse gas emissions at select natural UNESCO World Heritage sites subject to land-use pressures
2001 ‘02 ‘03 ‘04 ‘05 ‘06 ‘07 ‘08 ‘09 ‘10 ‘11 ‘12 ‘13 ‘14 ‘15 ‘16 ‘17 ‘18 ‘19 ‘20
GHG emissions (Mt CO2e)
Rio Platano
Tropical Rainforest Heritage of Sumatra
Virunga
Sites such as Río Plátano Biosphere Reserve (Honduras), Virunga National Park (Democratic Republic of the Congo) and Tropical Rainforest Heritage of Sumatra (Indonesia) have lost around 20%, 10% and 5%, respectively, of their tree cover since 200190. The extraction of forest biomass in these sites has led to increased emissions since 2001, weakening the forest carbon sinks that would have been stronger in the absence of these human-caused disturbances (Figure 12). Greenhouse gas emissions at forested sites such as Tropical Rainforest Heritage of Sumatra (Indonesia) and Río Plátano Biosphere Reserve (Honduras) have been so sizeable that, over the past twenty years, emissions have exceeded removals and they have been net carbon sources, with average net emissions of 3.0 Mt CO2e/yr and 1.2 Mt CO2e/yr, respectively.
Substantial portions of these emissions may be due to expansion of agricultural commodity production91.
In addition to land-use pressures occurring inside World Heritage sites, pressures from outside can also affect the carbon inside those sites. The persistent loss and fragmentation of biodiverse and ecologically productive habitats due to land use in areas adjacent to some World Heritage sites92 likely result in emissions that are not quantified in the data underlying this analysis. Landscape fragmentation can disrupt ecological connectivity, including some essential ecological processes and the unimpeded movement of species. Loss of connectivity leads to landscape “patchiness,” that is, isolated “islands”93 that can undergo ecosystem decay in the form of tree mortality and reduced resilience to climate change and anthropogenic disturbances94. The result is persistent emissions95,96. Biodiversity loss and defaunation as a result of poaching can also have wide implications for broader ecosystem functioning and the stability of carbon stocks. For example, the disappearance of forest elephants, which is being driven by poaching97, could result in economic losses estimated at around US$43 billion and a loss of as much as 7% of the carbon stocks in Central African forests due to carbon-rich tree species being out-competed98.
90 This is one of the reasons why these sites have been inscribed on the UNESCO List of World Heritage in Danger.
91 Analyzed with Curtis et al., 2018.
92 Decisions 44 COM 7B.97, 7B.99, 7B.105, 7B.114, 7B.174, 7B.188 of the World Heritage Committee: https://whc.
unesco.org/en/decisions/
Source: Hansen et al., 2013 Tree cover loss and tree cover extent in the vicinity of World Heritage sites and other protected areas, as provided by UNEP-WCMC and IUCN, 2021.
Figure 13: Buffer zone management can reduce pressures on sites. Tree cover loss around (A) Dja Faunal Reserve (Cameroon), which does not have a buffer zone, has been significantly higher than in (B) Sangha Trinational (Cameroon, Central African Republic, Republic of the Congo), which does have a buffer zone.
Integrated land management and buffer zones can provide a layer of protection for sites and engage local stakeholders in planning and economic activities. Moreover, well managed buffer zones can also act as net carbon sinks. For example, the Dja Faunal Reserve (Cameroon) in Africa’s Congo Basin is an example of a site without a buffer zone that is threatened by reduced landscape connectivity99. Urban development, agricultural activities and roads intervene between the World Heritage site and the closest other protected areas (Figure 13a). While the immediate surrounding area remains a net carbon sink, forest emissions are substantial just outside the site due to urban development and rubber plantations, and some of this land-use change may be expected to produce emissions within the site itself. On the other hand, Sangha Trinational (0.75 Mha of forest in Cameroon, the Central African Republic, the Republic of the Congo) is surrounded by a buffer zone (1.8 Mha of forest) where sustainable logging is practiced, and the net carbon sink of the buffer zone is more than twice as large as the World Heritage site itself (4.6 Mt CO2e/yr. vs. 2.1 Mt CO2e/yr, respectively) (Figure 13b).
99 Decisions 43 COM 7B.29 and 44 COM 7B.173 of the World Heritage Committee:
https://whc.unesco.org/en/decisions/
22
World Heritage forests Carbon sinks under pressure
3.1
100 Osipova et al., 2020.
101 https://www.wettropics.gov.au/climate-adaptation-plan-for-the-wet-tropics-20202030
102 https://whc.unesco.org/document/133484
103 Schmidt et al., 2018.
104 Osipova et al., 2020.
105 https://whc.unesco.org/en/review/74