# Science-Based Target Reduction Pathway Calculator

> Source: https://netray.co/tools/science-based-target-reduction-pathway-calculator
> Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems.
> Section: Free Tools

## Short answer

Compute the required Scope 1 and 2 emissions for any year on a linear annual reduction path and test your progress.

## Category

ehs-workforce

## Audience

- Sustainability lead
- EHS manager
- CFO
- Operations director

## Tool

**Kind:** calculator

**Inputs:**

#### Base year emissions (Scope 1 + 2)

**Key:** base

**Type:** number

**Default:** 20000

**Min:** 0

**Step:** 100

**Unit:** tCO2e

#### Base year

**Key:** base_year

**Type:** number

**Default:** 2022

**Min:** 2015

**Max:** 2030

**Step:** 1

#### Current year

**Key:** cur_year

**Type:** number

**Default:** 2026

**Min:** 2016

**Max:** 2050

**Step:** 1

#### Actual emissions in current year

**Key:** actual

**Type:** number

**Default:** 17500

**Min:** 0

**Step:** 100

**Unit:** tCO2e

#### Annual linear reduction

**Key:** rate

**Type:** select

**Default:** 4.2

**Options:**

##### 4.2% per year (1.5C aligned, Scope 1+2)

**Value:** 4.2

##### 2.5% per year (well-below 2C)

**Value:** 2.5

##### 7% per year (aggressive)

**Value:** 7

#### Target year

**Key:** target_year

**Type:** number

**Default:** 2030

**Min:** 2025

**Max:** 2050

**Step:** 1

**Outputs:**

#### Years since base year

**Key:** elapsed

**Expr:** cur_year - base_year

**Format:** integer

#### Required emissions this year

**Key:** required

**Expr:** max(0, base * (1 - rate / 100 * elapsed))

**Format:** integer

**Description:** tCO2e allowed on the linear path.

#### Gap to pathway

**Key:** gap

**Expr:** actual - required

**Format:** integer

**Primary:** true

**Description:** Positive means above the path.

#### Actual reduction vs base

**Key:** actual_cut

**Expr:** if(gt(base, 0), (1 - actual / base) * 100, 0)

**Format:** percent

#### Reduction required by target year

**Key:** target_cut

**Expr:** min(100, rate * (target_year - base_year))

**Format:** percent

#### Target year emissions

**Key:** target_emis

**Expr:** max(0, base * (1 - target_cut / 100))

**Format:** integer

**Primary:** true

#### Tonnes still to cut by target year

**Key:** tonnes_to_cut

**Expr:** max(0, actual - target_emis)

**Format:** integer

**Chart:**

#### Required emissions on the pathway

**Type:** line

**X:** cur_year

**From:** 2022

**To:** 2040

**Steps:** 19

**Series:**

- required

**Disclaimer:** Illustrative linear model of the absolute contraction approach. Official target validation uses current criteria from the Science Based Targets initiative, including base year recalculation rules and scope coverage.

## Content

**Intro:** A science-based target sets a fixed yearly percentage cut in absolute emissions from a base year. This calculator draws that linear pathway for your Scope 1 and 2 emissions and shows how far you are from it today.

**Sections:**

#### How to use the calculator

**Body:** Enter base year emissions and the base year itself from your verified inventory. Choose the annual linear reduction; the near-term Scope 1 and 2 pathway aligned to 1.5C is commonly cited as 4.2% per year, and 2.5% per year for well-below 2C. Add your actual emissions for the current year and the target year. The output shows the allowed level this year, the gap, and how many tonnes remain to be cut by the target year.

**Bullets:**

- Use location-based and market-based figures consistently
- Recalculate the base year after acquisitions or methodology changes
- Include all Scope 1 sources, including fugitive refrigerants

#### The math

**Body:** Linear absolute contraction takes a fixed share of the base year emissions off each year. Required emissions in year t equal base times one minus rate times (t minus base year). The total required reduction by the target year is rate times the number of years, so 4.2% over eight years gives 33.6%. The gap is actual minus required, and tonnes to cut equal actual minus target year emissions, floored at zero. This differs from a compounding percentage cut, which declines more slowly.

#### Reading the result

**Body:** In the default case, the 2026 pathway allows 16,640 tonnes and actual emissions of 17,500 leave a gap of 860 tonnes, so the company is behind. To reach 13,280 tonnes in 2030 it still needs about 4,200 tonnes of cuts. Translate that into projects using the other calculators in this set, such as fuel switching, solar and leak repair, then rank them by cost per tonne using your carbon price.

#### Common mistakes

**Body:** Do not mix inventories with different boundaries between the base year and the current year. Avoid cherry picking a base year with unusually high output. Remember that Scope 3 targets follow different required rates, and net zero standards add long term targets and limits on offsets. Keep dated inventory versions, emission factor tables and methodology notes in a controlled place so progress claims can be audited.

**Bullets:**

- Freeze the base year inventory
- Document recalculations
- Track progress annually, not at the end

**Cta:** Netray can help consolidate fuel, electricity and production data from your ERP into an inventory that feeds this kind of pathway tracking, hosted privately if you need it.

**Faq:**

#### Where does 4.2% per year come from?

**Answer:** The Science Based Targets initiative's absolute contraction approach for a 1.5C aligned near-term Scope 1 and 2 target uses a linear annual reduction of 4.2% of base year emissions. Check the current criteria before submitting a target, as the rules are updated.

#### Is the reduction linear or compounding?

**Answer:** Linear. The same absolute tonnage, equal to the rate times the base year emissions, is removed each year. That makes the required cut larger in later years than a compounding percentage of the shrinking total.

#### Does this validate my target?

**Answer:** No. Target validation is done by the standard-setting body against its criteria. This tool only models the pathway so you can plan, track and communicate progress internally.

#### Which emissions belong in the base year?

**Answer:** Include all Scope 1 and the chosen method of Scope 2 for the boundary you report. Keep the same boundary each year and recalculate the base year when structural changes exceed your significance threshold.

## Search terms

science based target calculator, SBTi linear reduction 4.2 percent, emissions reduction pathway calculator, absolute contraction approach, 1.5C target pathway, net zero pathway calculator, scope 1 and 2 target tracking, emissions on track calculator

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