How to Model and Evaluate Profitable Decarbonization Projects with a MACC
Every decarbonization effort eventually runs into the same wall. Which projects deserve the capital? Which ones pay back? Which can wait? Cost-effective decarbonization is how climate teams answer those questions, and the marginal abatement cost curve, or MACC, is the tool most of them now reach for.
The pressure to get those calls right keeps building within sustainability teams. The IEA estimates energy investment in its net-zero scenario needs to climb to around USD 4.8 trillion per year over the next decade, up from USD 3.3 trillion today. Verdantix's 2025 Global Corporate Decarbonization Survey put a number on the pressure: 41% of firms call competitive pressure and cost concerns significant risks to their near-term climate targets.
"Corporations are starting to realize what is realistic and what is not, as they consider putting capital towards decarbonization initiatives." – Verdantix 2025 Global Corporate Decarbonization Survey.
That is the shift from net-zero ambition to profitable decarbonization. The logic is the same as any capital allocation question. Find the projects that pay back, run them first, and the rest of the strategy gets cheaper to fund. This holds even for firms that have walked back formal net-zero commitments. Operational decarbonization continues to advance because the financial case stands on its own.
Profitable Decarbonization
This is the second article in my series on Profitable Decarbonization. The first covered how to build the business case for climate investment and get CFO alignment across all three scopes. This one goes a level deeper: once leadership is aligned, how do you decide which projects actually deserve the capital?
How a MACC helps decide which projects deserve investment
A MACC is a chart that lists every decarbonization project a company could run and ranks them by the cost to remove 1 tonne of CO2e. The wider the bar, the more emissions that project can cut. The lower the bar sits, the cheaper the abatement.
McKinsey built the first one for a Swedish utility in 2007. The framework has since been picked up by the UK Committee on Climate Change, the WBCSD, and most enterprise climate planners.
What makes a MACC useful is the order. The cheapest tonnes show up on the left, usually energy efficiency and electrification. The more expensive ones sit to the right. Some projects come in with negative costs, meaning they save the company money over their lifetime. Others cost real dollars per tonne. A marginal abatement cost curve is what turns a backlog of project ideas into a capital plan a CFO will actually look at.
What data should be modeled before calculating abatement cost
A MACC is only as good as the data behind it. Three inputs matter most: activity data at the facility or equipment level (kWh, liters of fuel, refrigerant leakage), the cost to run the project (CAPEX, OPEX, financing), and the abatement volume each project will deliver against a baseline.
Verdantix says it plainly in their February 2026 Future of Digital Decarbonization Technology report: "activity data is king." Reporting-focused systems were not built to support investment decisions. Without granular activity data, MACC results collapse into averages that hide the projects actually worth funding.
Without granular activity data, MACC results collapse into averages that hide the projects actually worth funding. That data needs to come in at the facility level, mapped to the correct emissions category, and updated on a recurring basis. Utility bills are among the most common sources of gaps: inconsistent formats, multiple providers, and manual uploads create errors before modeling even starts.
How to define the emissions baseline for each project
The baseline is a forecast of what emissions would have been if the project never happened, modeled across its useful life. It should account for equipment-level energy use, expected production volumes, grid emission factors that shift over time (the grid keeps getting cleaner in most regions), and any regulatory changes that move the goalposts. Get the baseline wrong and the whole curve lies to you.
How to calculate whether a project is cost-effective
The formula is simple: marginal abatement cost equals annualized net project cost divided by tonnes of CO2e abated over the project's lifetime. Negative numbers mean the project pays for itself. Positive numbers tell you what you are paying per tonne to make it happen.
Most CFOs will want more than one number. Each project also needs an NPV, IRR, payback period, and CAPEX/OPEX phasing. These are the same financial tests finance teams already run on every other capital project. This is what climate financial planning software is built for. Abatement cost has to be reconciled with cash flow, depreciation, and competing capital priorities, or it does not make it past the budget meeting.
How to compare short-term savings with long-term decarbonization value
Cheap tonnes today are not always the right tonnes. A lighting retrofit pays back fast but only removes a small slice of total emissions. A fuel switch or process electrification requires more upfront capital and a longer payback window. The trade-off is that it removes the kind of emissions that actually move the needle on long-term targets.
Scenario modeling is how teams reconcile the two. The exercise compares business-as-usual emissions with reduction pathways that vary in pace, technology mix, and carbon price assumptions. McKinsey makes a similar point about dynamic MACCs. A curve frozen at one point in time gets outdated fast. A MACC that updates as grids decarbonize, technology costs fall, and policies change tells a more honest story about what is worth funding.
How MACC results should feed into a climate transition plan
A MACC is a prioritization tool, not a strategy. The output is a ranked list of carbon reduction projects with positive ROI and real abatement potential. That list needs to plug into a broader climate transition plan that defines sequencing, financing, project ownership, and target years. Climate transition planning software closes the loop by linking the MACC to facility-level execution, supplier engagement, and reporting against frameworks such as SBTi and CSRD.
This is the operational layer Verdantix describes as the future of decarbonization technology. Investment planning sits alongside reporting, with activity data flowing in from energy, building, and supply chain systems.
SINAI's Reduce module was built for this. The platform was recognized in Verdantix's August 2025 Smart Innovators report for market-leading MACC modeling. It combines AI-driven project recommendations with facility-level MACCs and project NPV, IRR, payback, and CAPEX/OPEX modeling, then feeds those outputs into a tailored climate transition plan. Natura, the global cosmetics brand, uses the platform to map a cost-effective pathway to its 2030 net-zero target. That is the bridge from a deck slide to a funded roadmap, where cost-effective decarbonization quietly becomes profitable decarbonization.
See it in action
.jpg)
