Environment | Value natural resources
Action3: Expand and diversify renewable resources

Merely reducing the raw material consumption (Action 1) and using recycled resources (Action 2) will not be enough to ensure a reliable supply of products and services needed to meet the continuously increasing global demand. By further expanding and diversifying the renewable resources it uses to make its products (Action 3), the Bridgestone Group can help build a truly sustainable society.

The approach to using sustainable materials is based on the assumption of striking a balance with the Earth’s resource capacity, and the notion that simply switching from non-renewable materials to plant-derived renewable resources is not enough. Taking natural rubber as an example, the Group is working to diversify its renewable material resources by developing guayule and other new natural rubber sources, while working on improving the productivity of cultivated rubber trees, which is currently the primary source of natural rubber used for tires.

By helping boost the productivity of small farms (see Enhancing contribution for details), as well as by both improving productivity and diversifying its current supply sources through innovative technological development, the Group is working to ensure the future sustainability of its sources.

Natural rubber accounts for a large proportion of the tire's essential raw materials. Currently, almost all of the rubber used in industries is produced from natural rubber tree called Hevea brasilliensis. The cultivation areas of natural rubber trees are limited to areas around the equator, and Southeast Asia accounts for 93 percent of the world’s natural rubber supply. To protect tropical forests and reduce disease risk, the Group needs to increase the productivity of natural rubber trees and to research alternative plants that can be grown in wider areas.

The Bridgestone Group has succeeded in producing natural rubber from guayule on a commercial scale and conducting research to continue improvement.

Natural rubber is a key component of all tires. But growing and cultivating rubber presents challenges. Specifically, Para rubber tree supply is geographically concentrated, subject to disease and climate change, and labor intensive to cultivate.

But alternatives are on the horizon. Guayule shows significant promise as a solution to diversify natural rubber supply across different plant species and into various climates.

Guayule is an evergreen shrub in the aster family. The highly drought-tolerant plant is native to the Chihuahuan Desert in northern Mexico and the southwest U.S. It accumulates rubber in the bark layer as a stress response to cold, almost identical to natural rubber harvested from Para rubber tree. Importantly, guayule does not compete with food crops and is suitable to mechanization. Planting more guayule also could expand green land that contributes to increased CO₂ absorption.

To put guayule into practical use, the Bridgestone Group has been investing in a research and development effort to focus on guayule since 2012 and has accumulated technologies and knowledge related to agriculture, processing and use in tires, including the development of tires with 100% of its natural rubber-containing components derived from guayule and large-scale propagation through open innovation as the Group strives to achieve its commitment for "Ecology: Committed to advancing sustainable tire technologies and solutions that preserve the environment for future generations" stated in the “Bridgestone E8 commitment.”

As a new initiative, in Central Arizona, Bridgestone Americas (BSAM) is expanding the number of local farmers it works with. They are working to convert their farmland to harvest guayule, which has served as an alternative to previously failing crops due to growing water shortages. In 200 acres of new fields guayule will be planted in 2022. This initiative is a direct result of BSAM’s agreement with the Environmental Defense Fund, an NGO actively involved in water shortage solutions for the Colorado River which is used for irrigation in this area. The Group will continue driving with the aim of practical use of guayule by 2026, and its full-scale production and commercialization by 2030.

As a new crop, growing, harvesting and using guayule requires new processes. The Group has already established growing protocols that maximize the amount of rubber produced per acre. The rubber extraction process has been successfully demonstrated and potential end-market uses for the non-rubber co-products are being identified.

In addition to natural, sustainable rubber, guayule processing produces distinct co-products that will provide benefits to other industries. To maximize this opportunity, the Group is building a new partner ecosystem with agriculture, energy, cosmetics and other companies; nonprofit organizations; funders; governments and others to fill knowledge gaps, open markets and reduce risks.

Through open-innovation and co-creation of this exciting biodiversity opportunity, the Group will diversify its rubber resources, reduce risks of its natural rubber supply chain, and further contribute to the sustainable production of natural rubber.

In 2017, BSAM began collaborating with Versalis S.p.A. of Italy to make full use of the latest genetic technologies to develop highly productive varieties of guayule. Its co-development agreement leverages Bridgestone’s leadership position in guayule agronomy, agricultural biotechnology, manufacturing production technologies with Versalis’ strength in process engineering and market development for renewable materials.

BSAM has also been engaged in a four-year collaboration with genomic big data solutions company NRGene to improve guayule varieties for commercialization since 2017. BSAM announced the results of this collaborative project in January 2021. They were able to fully sequence and assemble a guayule genome, making it possible to identify genes for important traits. The Bridgestone Group developed mapping populations that allowed NRGene to construct a genetic and physical map by successfully identifying the correct order of DNA fragments. The joint work also successfully combined multiple guayule genomes to construct pseudochromosomes, paving the way towards selecting genes from inherent genetic diversity to breed highly productive varieties of guayule. (For more information, see news release)

Furthermore, Bridgestone Corporation is developing a new technological innovation to increase the productivity of guayule farms through a joint project with Kirin Holdings. Combining the world-class biotechnologies of Kirin Holdings and the guayule cultivation expertise of Bridgestone, the project aims to deliver large-scale propagation of guayule plants from high-quality seeds. Bridgestone will field test the modern technology on guayule seedlings grown at its 287-acre Agro Operations Research Farm in Eloy, Arizona. The new technology may also be used to support the guayule breeding process to more rapidly increase a desired genotype for testing and production. (For more information, see news release)

BSAM's guayule research also includes the following initiatives:

• In 2017, the Bridgestone Group became the industry partner in a United States Department of Agriculture (USDA), Agriculture Food Research Initiate (AFRI) sponsored grant “The Sustainable Bioeconomy for Arid Regions (SBAR).” The other partners include, The University of Arizona, New Mexico State University, USDA-ARS, Colorado State University. It is a 15 million USD grant over five years. The company is participating in two irrigation studies designed to examine the effect of long periods of drought stress on rubber content and yields. Other important studies are also included in this grant.

• BSAM signed an agreement with Environmental Defense Fund (EDF), an NGO actively involved in water shortage solutions for the Colorado River, which is used for irrigation in Central Arizona, to jointly grow guayule on farmers’ fields (BSAM splits the cost and uses the shrub for processing). Guayule is considered as a low water use crop that can replace high water use crops currently grown in the region.

• BSAM is engaged in talks with Native American tribes to grow guayule on their lands. Even though the tribes have higher water allotments, they have expressed interest in growing guayule as a low water use crop.

The Bridgestone Group is diversifying the regions where it produces natural rubber while also expanding the range of renewable resources of reinforced plant fibers it uses for securing raw materials. Synthetic rubber and carbon black, which are made from finite resources, are instead synthesized from renewable resources. The Group is working on establishing a research and development system, basic technologies and commercialization.