Derek Markolf spent 22 years at LRQA leading GHG verifications across manufacturing, agriculture, energy, and nearly every other sector. Now he runs his independent verification practice while slow-traveling the world with his wife — conducting verifications remotely from wherever they happen to be living that month.

In this conversation, Derek shares what two decades of looking inside other organizations' GHG inventories actually teaches you — the patterns that show up everywhere, the mistakes that keep getting made, and the emerging issues that practitioners need to get ahead of right now.

We cover:

→ Why the smallest sources are the biggest pain — and why this surprises first-time reporters every time

→ The "levers" problem: why spend-based and industry-average data removes your ability to show real emissions reductions

→ Base year recalculation — the most under-enforced GHG Protocol requirement, and why verifiers are giving it a lot more attention now that companies are nearing their target years

→ What inventory management plans need to contain to survive staff turnover

→ Why AI-assisted tools are creating a new challenge for verifiers: "We can't verify a black box"

→ What separates organizations that build solid, verification-ready inventories from those that struggle — and why it almost always starts with leadership commitment.

🎙️ Carbon Management & Accounting Podcast | New episodes every other Tuesday

Sponsored by North Star Carbon & Impact — northstarcarbon.com

Mandi McKay joined Sierra Nevada Brewing Company as a part-time sustainability coordinator — literally driving a forklift and collecting banana peels for the worm bin — and over 17 years grew into her current role as Chief Sustainability and Social Impact Officer. In this episode, she pulls back the curtain on what carbon accounting really looks like at one of America's most sustainability-forward breweries, including the honest story of their first Scope 3 inventory: a 25-tab spreadsheet that took over a year to complete and left her team swearing they wouldn't attempt it again for five years.

We get into the practical realities of carbon accounting across the full beer supply chain — from barley farmers and energy-intensive maltsters to refrigerated cold chain logistics and packaging decisions. Mandi shares how materiality thinking has evolved from their first attempt in 2018 to today, how supplier conversations are actually shifting upstream data quality, and why Sierra Nevada's family ownership structure enables long-term sustainability bets that publicly traded companies simply can't make.

Plus: the story behind Hop Forward — Sierra Nevada's sustainability campaign, annual impact report, and a beer that lets customers literally taste climate leadership.

• How Mandi grew from sustainability coordinator to C-suite over 17 years at Sierra Nevada

• Why their first Scope 3 inventory took over a year — and what they do differently now

• The carbon hotspots in beer: barley, malt, packaging, and refrigerated cold chain

• How materiality thinking should guide Scope 3 data collection decisions

• How supplier conversations are changing upstream data quality

• The cold chain nuance most sustainability teams miss

• How family ownership enables long-term sustainability investments

• The Western North Carolina Brewery Recycling Cooperative and industry collaboration

• Hop Forward: Sierra Nevada's sustainability platform, impact report, and annual beer

Andrew Griffiths is Director of Policy and Partnerships at Planet Mark, a sustainability certification that supports organisations and real estate to measure and continually reduce carbon emissions and increase their social value. Andrew co-founded the Carbon Accounting Alliance (CAA) representing 300+ organisations in the industry. He also sits on Advisory Boards, Councils and Committees for the Institute of Directors (IoD), BSI Greenhouse Gas Management Standards, and UK-Government backed initiatives like UK Business Climate Hub and Project Perseus. Having delivered a TEDx talk on the power of meaningful networking, he is a big believer in the power of communication and how it can be used to drive climate action.

Andrew Joins the Carbon Accounting and Management Podcast to Discuss:

• Objectives of the Carbon Accounting Alliance (CAA)
• Ensuring consistency in carbon accounting methodologies
• Professionalization of the sector
• Engagement with policymakers and standard setters
• Public vs proprietary emission factors

Andrew's Listener Takeaway: If there's only one thing that our guests take away from this conversation, what do you think it should be?

If you're in carbon accounting, play nicely with everyone else. Come and play nicely with everyone else. If you're not in carbon accounting, it's an interesting question if this isn't a relevant sphere for you. I think the climate crisis requires radical collaboration. Carbon accountants have one role to play in this journey, but literally every other profession has its role to play. If there isn't an industry forum or a professional forum bringing together people within your area of specialty and expertise, whether that is you are an artist, you are an engineer, you are a logistics company, you are a waste company, whatever it might be, if you don't have some form of forum bringing you together with your peers to collectively solve the biggest, most challenging problems that you're facing, do it. There are going to be some really naughty problems that are going to take massive collaboration to solve.There are classic examples of that for things like green steel. Steel manufacturers, many of them are now getting together. They're pooling resources and money together to invest in trying to evolve technologies, because none of them have the budgets to do it independently and come up with some magical solution. They've come together to try to do stuff. We have to see that in more places and in more sectors and in more industries. So find your allies, that's the overall takeaway that is true for everyone. If you're a carbon accountant, hopefully we can help signpost a whole bunch of those to you. We now have over a thousand people at the alliance. We've got 570 member organizations, but over a thousand people. Plenty of allies for you there. If those aren't your allies, find them within your business. There will be allies in different professions, different specialties. One of the first things I encourage people within companies to do is just go and start talking to people, because you will find that there are people who care about this just as much as you do, and you can form a rebel alliance inside your business. I've seen so many examples of grassroots activations inside businesses causing quite big companies to have to up their game in sustainability, because the staff are demanding it. They're coming and going, we've got a proposal, we want to become a B Corp, we want to measure our carbon footprint, we want to have a net zero target. If a big enough group of you get together and say that to your board, they're going to struggle to ignore you for very long because they don't want to lose you, you have power, and there's power in numbers. There's power in coming together. Find your allies.

Timestamps:

04:47 Collaborative Climate Crisis Solutions

08:13 Collaborative Carbon Measurement Initiative

09:49 Collective Action for Regulatory Change

15:08 Ensuring Robust Carbon Footprint Standards

20:38 Creating a Carbon Accounting Register

25:51 Global Sustainability Updates: Knowledge Sharing

27:47 UK Carbon Reporting Consultation Feedback

33:28 Open Carbon Data Collaboration

35:33 Granular Data for Carbon Reduction

41:06 Advocating Open Source for Emission Data

45:00 Transparent Collaboration in Safe Spaces

46:21 Carbon Accounting: Art and Science

50:44 Radical Collaboration Across Professions