Net Zero by 2050: The Maths Nobody Shows You
Thousands of companies have pledged net zero. Only 7% meet minimum requirements for a credible commitment (Net Zero Stocktake 2025). The gap between pledge and plan is where risk lives.
At a Glance
▸ SBTi net zero = 90% absolute reduction, not offsets, not intensity improvements
▸ For 100,000 tCO2e today: ~3,600 tCO2e reduction per year, every year, for 25 years
▸ Decarbonisation is front-loaded in easy wins and back-loaded in hard abatement
▸ Credible 2030 interim targets matter more than a 2050 pledge
Net zero by 2050 is the most widely adopted climate commitment in corporate history. According to the Net Zero Stocktake 2025, 1,245 Forbes Global 2000 companies now have net zero targets, up from 769 entities in 2020. It is also the least scrutinised corporate commitment in history. Say the words, set a target date 25 years out, and the market rewards you today. But a target without a pathway is a press release. Only 7% of companies meet the minimum requirements for a credible net zero commitment, and one in three Forbes Global 2000 companies with targets have no clear roadmap behind them (Net Zero Stocktake 2025).
This piece walks through what net zero actually requires when you run the numbers, why the maths breaks down in the middle years, and what matters more than a 2050 headline.
What Net Zero Actually Requires
SBTi defines net zero as reducing value chain emissions by at least 90% from a validated base year, with remaining residual emissions neutralised through permanent carbon removal. Not temporary offsets. Not avoided emissions credits. Permanent removal.
90% absolute reduction. Not intensity improvement per unit of revenue. Not offset by purchasing credits from a project somewhere else. Actual reduction in the total tonnes of CO2 equivalent your organisation and its value chain emit. Across Scope 1, 2, and 3. From a validated base year.
For a company emitting 100,000 tCO2e today, that means reducing to 10,000 tCO2e by 2050. At a linear rate, that requires cutting roughly 3,600 tCO2e per year. Every year. For 25 years. No pauses. No flat years. Consistent, measurable reduction.
But decarbonisation is not linear. And this is where most net-zero strategies fall apart.
Where the Maths Breaks Down
| Phase | What Happens | Reduction | Difficulty |
|---|---|---|---|
| Years 1-5 | Renewable electricity, fleet electrification, building efficiency | 20-30% | Moderate (often pays for itself) |
| Years 5-15 | Scope 3: supplier engagement, procurement redesign, logistics | 30-40% | Hard (requires changing how you buy) |
| Years 15-25 | Industrial process heat, cement, steel, aviation | 20-30% | Very hard (tech may not exist yet) |
Phase 1 is where most progress happens and most confidence is built. Switch to renewable electricity. Electrify the vehicle fleet. Upgrade building management systems. These interventions are well understood, commercially available, and often have a positive business case. A company can achieve 20-30% reduction in the first five years and feel like net zero is achievable.
Phase 2 is where most organisations stall. Scope 3 emissions, predominantly from purchased goods, services, and transport, typically represent 70-90% of total emissions. Reducing them means changing how you buy, who you buy from, and how your supply chain operates. It requires supplier engagement at scale, procurement criteria that include carbon intensity, and logistics redesign. This is not a technology problem. It is an organisational change problem. And it takes years.
Phase 3 is where the entire economy stalls. Industrial process heat for cement and steel. Long-haul aviation. Chemical feedstocks. These sectors require technologies that either do not exist at commercial scale or are not yet cost-competitive. Green hydrogen, direct air capture, sustainable aviation fuels - all are in development but none are ready for the scale required. Companies with exposure to these sectors need to be honest about what their pathway looks like post-2040.
Most net-zero pledges were made without modelling the specific reduction pathway. The pledge came first. The plan - if it comes at all - comes later. And when the plan does come, Phase 2 is often a blank page.
Why 2030 Matters More Than 2050
SBTi now requires near-term targets (5-10 years) alongside the long-term commitment. AASB S2 requires disclosure of the transition pathway. These are not optional additions. They are the mechanisms that turn a 2050 aspiration into a series of measurable commitments.
A credible 2030 target does three things that a 2050 pledge does not:
| 1 | It forces the organisation to model specific, costed interventions rather than aspirational curves. What exactly will you do, what will it cost, and what reduction will it deliver? |
| 2 | It creates accountability within current management tenure. A 2050 target is someone else's problem. A 2030 target is this leadership team's problem. |
| 3 | It provides a measurable benchmark for investors, regulators, and stakeholders to assess whether the organisation is actually on track or just on message. |
The Offset Question
Carbon credits cannot substitute for reduction under any credible net-zero framework. SBTi is explicit: offsets apply only to the residual 10% after 90% absolute reduction has been achieved.
Any net-zero plan relying on offsets for more than 10% is not a net-zero plan. It is a net-hope plan. And the voluntary carbon market faces its own integrity questions. ICVCM's Core Carbon Principles now set the quality bar, and many existing credits do not meet it.
What Credible Looks Like
Five requirements for a defensible net-zero pathway:
- Validated base year with complete Scope 1, 2, and 3 inventory
- Near-term targets (2030) with specific, costed abatement measures
- Scenario modelling showing the pathway under different assumptions
- Annual progress tracking against the reduction trajectory
- Residual emissions strategy for the final 10% using permanent removal
Without all five, a net-zero pledge is aspirational at best and misleading at worst. The regulatory environment is shifting toward requiring evidence behind the pledge. AASB S2 requires transition plan disclosure. The EU's CSRD requires detailed decarbonisation pathways. Saying 'net zero by 2050' without a plan is becoming a compliance risk, not just a credibility risk.
SustainQHow teams are building credible pathways