In recent years, due to lower productivity and value of rubber, small-holders are shifting from natural rubber towards more profitable and productive palm-oil (Indonesia Investments, 2018; Grow Asia, 2020). This has led to an emerging transition to larger, private, monoculture plantations of rubber in Indonesia (Warren-Thomas et al., 2015). In the future this may lead to greater concerns surrounding nutrient loading, habitat loss and invasive species (Potapov et al., 2021). Interestingly, since primary forest is now scarce in Sumatra, conserving rubber agro-forests on small-holdings is now considered one of the few options for successfully supporting biodiversity and reducing emissions on the island (Villamor et al., 2014). However, current increases in the profitability of other land-uses, such as palm oil are pushing farmers away from this land management technique (Ibid, 2014).

However, it should be noted that the last year saw the lowest deforestation rates since records begun (-75%) in Indonesia (Jong, 2021). This has followed changes to moratoriums on clearing primary forest and licencing for forest clearance (notably related to palm oil production), although other factors must be accounted for such as wetter season, decline in palm-oil prices and the Covid-19 pandemic (ibid, 2021). Resurgence in these levels following this year should be monitored to see whether the governments new policies are having a positive impact on deforestation in the country (ibid, 2021).

Before recent years, despite commitments from the government of Indonesia and the international community, deforestation rates have not stabilised or decreased in the years since REDD+’s introduction in 2007 (Enrici & Hubacek, 2018). Additionally, despite some major company’s efforts to implement sustainable rubber within Indonesia (See Michelin Tyres x WWF; Otten et al., 2020) the impact has been limited and it is clear that currently it is ineffective and unsustainable for the communities (Otten et al., 2020).

The current political and development situation of Indonesia does increase the risk of this material:

“Under Indonesia’s NDC, the government allows up to 325,000 hectares (803,000 acres) of deforestation per year to reach its emissions reduction goal while leaving room for economic development. That means that by the 2030 deadline for the Paris Agreement, Indonesia could potentially clear 3.25 million hectares (8 million acres) of rainforest, an area larger than Belgium, and still call it a success. A 2018 report by the NGO Rainforest Foundation Norway shows this won’t be enough to cap the average global temperature increase at 1.5° Celsius as mandated under the Paris Agreement.” - Jong, 2021

What is needed is drastic legal measures to be taken for this industry to change but also be economically sufficient for the people who are part of it.

Currently there is limited consistent messaging around the carbon sequestration potential of rubber trees, with different systems and regions having different potentials (Li et al., 2008; Annamalainathan et al., 2011; Yiping et al., 2014; Villamor et al., 2014; Blagodatsky et al., 2016; Brahma et al., 2017). However, it is understood that despite the carbon sequestration of rubber trees they cannot make up the emissions or biodiversity losses encountered from converting intact forest and even degraded forests (Warren-thomas et al., 2018).

In relation to other forms of pollution, it is likely that the impact in the region is low if the traditional practices are being carried out on the rubber plantations as well as the continued jungle forest techniques for production in the main producing regions of Indonesia. However, as pressure mounts to increase production of rubber and access to more modern techniques spreads, the threat from other pollution is likely to increase (e.g., soil erosion due to lower density leaf crown, increased machinery use, and increased chemical use). Another factor that should be considered is the chemicals needed to process latex into rubber e.g. ammonia and formic acid in waste waters, which paired with the low EPI 2020 ranking (68/134) of Indonesia’s wastewater management may pose an environmental threat. However, there is limited information on this impact.

It should also be considered that the sole does consist of other, smaller amounts of materials that are currently less understood and known including, 10% unspecified fillers (likely to be plastic based), 3% additives (likely to be an anti-UV agent to prevent yellowing) and 1% pigments (for colouring). The likely presence of plastic within this material does increase concern for energy use and plastic pollution however, it should be recognised that aspect climate projects have tried as far as possible to eliminate plastic from their product.

The threat from climate change, as currently projected for Sri Lanka, means that in the future the yield of coconuts from the Sri Lanka may be reduced impacting the future sustainability of supplying coconut waste from this region in the future (Ranasinghe, n.d.). However, due to the reliance of the region on coconuts for food security it is likely that they will work hard to increase resilience in this industry over time (Erandathie, 2016).

Something that should be considered is that due to this material largely consisting of coconut fibres, it is mixed with natural latex to increase the comfort of the material for the insole. However, it is currently unknown how much natural latex is used to mix with the coconut husk, with the 12.7%consisting of both the coconut and the latex together. Therefore, as previously discussed for natural rubber, the natural latex industry unless sustainably sourced possess a huge risk to global biodiversity. The risk is largely attributable to the high ecosystem value of Malaysia, which is home to a range of endangered and endemic species, and the land pressure in the region from other cash crops, notably palm oil. However, it is understood that the percentage content of this material is believed to be low and that understanding the difficult trade-off faced by aspect climate projects to reduce petroleum-based plastics in their supply chain, which would traditionally be used.

Something that should be considered is that due to this material largely consisting of plant-based material (72%) it must be mixed with something more durable, in this case (10%) polyurethane was used by the brand company Piñatex. This has implications for microplastic pollution. However, by reinforcing the material with this as stated, the durability of the shoe increases and thus the lifespan of the shoe.

Furthermore, it must be considered that alternatively the upper would be made from either a much higher percentage of plastic or leather which research suggests would have a much greater negative impact on the environment in all categories of risk (Rosegrant and Sombilla, 2019). Furthermore, as the material largely consists of plant-based material (including the bioplastic, polylactic acid (18%))at the end of the materials life 90% of it will be biodegradable.

There is a gap in knowledge of how much energy is used to produce PU coating, though we have assumed that non-renewable energy sources were used to make and there is no carbon sequestration potential for this material, thus the threat is high for this material.

Plastic pollution is a very well-known problem that humanity faces. Throughout the lifespan of the PU micro-plastics will be shred into the environment and will eventually end up in our water systems. It is widely accepted in public debate that microplastics are a huge cause for concern to marine ecosystems and the persistence of endangered species. Laboratory based research suggests micro-plastics have a negative impact on marine life (Cole et al., 2013; Browne et al., 2013; Setälä etal., 2014). However, their impact on aquatic life in the natural world is suggested to be less conclusive(Nelms et al., 2019; Botterell et al., 2019). Furthermore, the threat of micro-plastic pollution from shoes(especially such that have been produced with such a low quantity of plastic) is low compared to other products, notably clothing that is frequently washed.

Although rPET reduces the amount of new plastic waste in the environment, it still contributes to the accumulation of micro-plastic pollution in the environment during the manufacturing process and during use, which as previously discussed has impacts on marine life (Cole et al., 2013; Browne et al.,2013; Setälä et al., 2014; Nelms et al., 2019; Botterell et al., 2019). However, the release of micro-plastics during the use of the shoe is likely to be low due to the low external wear of the rPET as it is part of the inner lining and there is a lower likelihood that the shoes will be washed in a washing machine.

Ultimately it is important to note that aspect climate projects have a low amount of plastic present within their shoes compared to alternative shoes on the market. aspect climate projects have made the trade-off between using more petroleum-based materials or using smaller amounts of plastic to increase the durability of less durable plant-based materials - in this instance, reinforcing the corn-based lining – to increase the long-term sustainability of their supply chain, by utilising renewable materials where possible.

The high ecosystem value of these managed habitats for ecology and climate change mitigation has led to cork trees being identified as a priority species by WWF/ANP. However, due to a loss of traditional knowledges and practices in the industry, cork woodlands are at threat of being abandoned and replaced by more intensively farmed crops and rural abandonment (Essen et al.,2019). These habitats can only continue through constant balanced management. Without sustainable management, soil degradation, invasive species and forest fires would prevail, significantly reducing the carbon storage and biodiversity value of these habitats (Riberio et al., 2011). Therefore, by investing in this industry aspect climate projects are increasing the likelihood that this highly valuable habitat will be safe guarded from being lost. Furthermore, the sourcing of organic cork is likely to help protect against unsustainable management.