What does ‘corporate sustainability’ even mean?
When people think about a company’s environmental impact and corporate sustainability efforts, they tend to think of the emissions from manufacturing plants, the amount of electricity it uses to power its factories and offices, or the number of electric vehicles (EVs) in its fleet.
But for most large firms (i.e, Apple, Microsoft, General Motors), these visible pieces are only the tip of the iceberg when it comes to carbon emissions. A company’s outsourced, indirect emissions — or Scope 3 emissions — often account for the majority of its environmental impact, and are the hardest to reduce.
What are emission scopes?
Image Source: https://ghgprotocol.org/sites/default/files/standards/Corporate-Value-Chain-Accounting-Reporing-Standard_041613_2.pdf
The current standard is for companies to track their emissions in three different categories: Scope 1, Scope 2, and Scope 3.
- Scope 1: Direct emissions
Scope 1 covers the direct emissions from sources the reporting company owns or controls: its factories, vehicle fleets, boilers, and refrigerant gases. These are generally the easiest emissions to measure and reduce, and in the GHG scope diagram above, they correspond to the emissions that come directly from a company’s own operations.
- Scope 2: Indirect emissions from utilities needed for the company’s own use
Scope 2 reflects the indirect emissions from purchased electricity, steam, heating, or cooling used to power operations. As shown in the picture above, these are part of the upstream activities of the reporting company, since they are generated at the power source. Scope 2 emissions are generally mitigated by reducing energy consumption, improving energy efficiency, and/or switching to renewable energies.
- Scope 3: All other outsourced, indirect emissions
Scope 3 encompasses all other indirect emissions linked to a company’s activities but occurring outside its direct control, both upstream and downstream. The Greenhouse Gas Protocol defines fifteen Scope 3 categories, ranging from the production of purchased goods and services to the transportation of materials, business travel, product use, and the end-of-life treatment of what a company sells. Examples include the electricity a customer uses to power a laptop, the transport emissions from shipping goods to retailers, or the disposal of packaging after a product is consumed.
This is also the category that matters most: according to the World Resource Institute, on average, roughly 75% of a company’s total emissions fall under Scope 3, making it the true center of gravity of corporate climate impact and a crucial aspect of corporate sustainability strategies.
Why are Scope 3 emissions special?
As the scope definitions above showed, companies can usually measure and influence their Scope 1 and 2 emissions easily since those come from their own operations and purchased energy. In contrast, Scope 3 covers emissions that occur both upstream and downstream of operations, which the company can’t control. This is also where most of the total greenhouse gas output sits in many sectors such as technology, retail, apparel, food, automotive, and even finance, according to the World Resources Institute.
Because of this practical difference, Scope 3 emissions are, by their nature, messy, difficult to quantify, and often daunting to reduce. Because modern economies are so deeply interconnected, the underlying data comes from thousands of independent sources (raw-material suppliers, component manufacturers, logistics networks, retailers, and customers), none of whom a company directly controls. Emissions arise across borders and across sectors: in factories and farms, on shipping routes, in consumers’ homes, and in waste systems that a company neither owns nor manages. These value chains involve actors with widely varying technical capacities, reporting practices, and incentives, which makes a degree of uncertainty both expected and unavoidable. In some cases, Scope 3 estimates rely on behavioral assumptions (how long a customer uses a product, how frequently they charge it, how they dispose of it) rather than strictly measurable quantities.
Yet difficulty does not imply impossibility. According to a PWC report from 2023, companies can use hybrid accounting models that combine supplier-specific data with industry-average emissions factors to estimate and disclose this essential part of their net footprint. Hence, it would be incorrect to interpret this uncertainty in Scope 3 accounting as a flaw. It’s more of a reflection of the reality of modeling complex systems, much like economic forecasting or climate modeling. If those disciplines operate successfully despite uncertainty, businesses increasingly can too, especially with the emergence of new assessment tools, databases, and reporting platforms.
The importance of scope 3 emissions reporting
If most of a company’s climate impact sits outside its direct operations, then any meaningful sustainability strategy must engage with where that impact actually occurs. Focusing solely on Scope 1 and 2 may make internal reporting look clean, but it offers an incomplete and often misleading picture of a company’s true environmental footprint.
Companies often rationalize ignoring Scope 3 by noting these emissions are “someone else’s Scope 1 or 2”. And in practice, this mindset is reflected in the numbers: while Scope 3 accounts for most emissions, only around 40% of companies report it at all, plus it’s hard to estimate the share of organizations that actually include this scope in their net-zero targets. Unsurprisingly, most pledges focus only on the categories that are easiest to measure and influence. However, we can’t solve a global problem by passing the hot potato around; we all have a common responsibility.
Beyond the ethical dimension, ignoring Scope 3 is also strategically flawed. Companies that overlook supply-chain or downstream emissions risk misallocating capital. A choice of investing heavily to decarbonize a facility that contributes only 5% of their footprint while neglecting material or design changes that could shrink emissions by 30–50% just displays shortsightedness. Organizations also take a passive role on climate action by overlooking scope 3, when they could leverage and capitalize on all those 15 categories that define it.
There is a competitive dimension as well; firms that take Scope 3 seriously tend to build stronger supplier relationships, improve resilience, anticipate regulatory shifts, and position themselves ahead of peers who wait for mandates. It is clear that treating scope 3 as optional and someone else’s problem is a strategic liability.
What can organizations do to address these emissions?
Companies have a broad set of tools available to address Scope 3 emissions, beginning with transparency. Publicly disclosing value-chain emissions, even imperfectly, signals accountability and builds trust with stakeholders. Beyond disclosure, firms can use their buying power to influence upstream emissions by working with suppliers over several years to co-develop reduction strategies, improve measurement practices, and incorporate climate criteria into contracts and purchasing decisions. Many companies already do this: Walmart’s Sustainability Hub, for example, has helped suppliers collectively avoid more than 1.19 metric gigatons of CO2 emissions.
Downstream, efforts can be made through product design and use-phase innovation, creating products that consume less energy, last longer, or use lower-carbon materials. Designing for durability, repairability, and recyclability can further shrink lifecycle emissions. For example, Nike’s “Move to Zero” initiative includes product take-back and recycling programs (Nike Grind) that ultimately reduce end-of-life emissions.
And when all feasible reductions have been pursued, companies may turn to carbon markets to address the remaining portion of their footprint. Offsetting should not be the primary strategy, but it can complement direct reductions. Organizations should bear in mind that frameworks apply to this option. The VCMI’s Scope 3 Action Code allows only a limited share of high-quality credits to be used (up to 25 percent of the Scope 3 “gap”), and that offsets do not count toward the Science Based Targets initiative (SBTi) net-zero goals except for residual emissions. In simple terms, companies can no longer outsource their climate responsibility to the offset market; real reductions must happen inside their supply chains.
Regulatory switches advocating for proactivity
From a regulatory level, scope 3 emissions reporting is moving from optional to expected, and companies have strong incentives to act even before they are formally required to. A useful example is Europe’s Durability Index, which scores electronic devices based on how easily they can be repaired. Although not framed as a climate policy, it pushed major tech companies like Apple and Samsung to redesign products, extend software support, and provide spare parts. These cuts improved upstream material emissions and downstream waste (two major Scope 3 categories) and showed how targeted regulation can reshape entire value chains.
In the United States, federal rules still do not require Scope 3 reporting. The SEC’s 2024-2025 climate disclosure rule excludes value-chain emissions, even as California’s SB 253 and SB 261 moved in the opposite direction by trying to mandate Scope 1, 2, and 3 reporting for large companies doing business in the state. Political pushback has slowed implementation, but at least the signal is clear: we are beginning to follow the European model. In the EU, the Corporate Sustainability Reporting Directive (CSRD) requires companies to disclose Scope 3 emissions, reflecting a more mature regulatory landscape that is already influencing global firms. Moreover, investors are increasingly asking for full chain emissions in order to assess transition risks. Major asset managers such as BlackRock and State Street increasingly request value-chain emissions to assess transition risk, supply-chain risk, and regulatory exposure. Scope 3 is moving into mainstream governance because of clear financial, legal, and operational realities. For companies, becoming proactive now, rather than scrambling later, brings clear benefits: reduced risk, lower long-term costs, and stronger brand credibility.
Conclusion
Scope 3 emissions shouldn’t be considered a side issue when a company evaluates its climate impact and emission reduction levers. By looking beyond their own walls and engaging with the real sources of their net emissions, companies can end up with clearer strategies, stronger supply chains, and fewer surprises from regulators or investors. The sooner firms treat Scope 3 as part of everyday business, and there are many ways to do so, the easier the transition away from high-carbon emissions will be.
Reader Question
Do you believe companies should be legally required to report and reduce Scope 3 emissions?