How do I keep emissions data accurate and consistent?

Use source records, the same methods every year, and a second person to check the numbers. Most errors come from units, missing months and changed methods, not from difficult calculations. A few simple controls prevent most of them.

At the source

• Use original records. Take figures from invoices, meter readings and fuel cards, not from summaries that someone typed up.
• Keep the units. Record the unit with every number, for example kWh or litres. Many errors are mix-ups between kWh and MWh, or between litres and kilograms.
• Collect monthly. A missing or odd month is easier to see and to fix soon after it happens.

In the method

• Write down your methods. Record the boundary, the emission factors, the GWP values and every assumption.
• Keep factors consistent. Use the same source for the same activity each year. If you change, explain why and show the effect.
• Prefer specific data. Use supplier-specific or measured data for your largest sources. Use averages only where the effect is small.

In review

• Compare. Check each source against the same month last year and against similar sites. Investigate changes above a set level, for example 10%.
• Check by hand. Recalculate your 3 largest sources yourself.
• Use 2 people. The person who enters data should not be the only one who approves it.
• Keep an audit trail. Every reported number must trace back to a record.

Over time

• Recalculate the base year when a large change, such as an acquisition or a method change, would make comparisons misleading.
• Train the people who provide data. A short guide for each data owner prevents repeated mistakes.
• Review the process each year. List the errors that you found and fix their causes.

Avoid greenwashing

Accurate data supports honest claims. Do not describe estimates as measured data. Do not subtract credits from your gross emissions, and do not claim renewable electricity without the certificates or contracts that support it.

Step 5: Collect activity data explains data quality in more detail.

In Carbon GPT

Requests collects data through forms with fixed fields and units. You review and approve each submission before it becomes a measure.

Sources

• GHG Protocol Corporate Standard, chapters 1, 5 and 7
• GHG Protocol Corporate Value Chain (Scope 3) Standard, chapter 7