## 1 Introduction  
Uncertainty and high cost of typical commercial forest carbon offset protocols are unresolved [1; 2; 3; 4; 5; 6], impeding widespread adoption and expansion of forest conservation projects. The main endeavor of commercial forest carbon offset trading is to assist landowners with the conservation and restoration of forests based on the net carbon sequestration and carbon credit sales for a project [7; 8] while verifiably reducing net emissions. While forest restoration is recognized as a viable, economic, and readily deployable nature-based commercial solution to mitigate climate change [9; 10; 11; 12; 13; 14], forest loss continues at a rate of \(\sim\)10 million hectares annually from 2015-2020 [15], outpacing restorative efforts. In contrast, the forest landscape conserved by carbon protocols and trading is astonishingly small, \(\sim\)0.03% of the available land for restoration of \(\sim\)0.9 billion hectares [12; 15], evidence that existing methods underpinning forest carbon are not economically or ecologically viable. Forest carbon sequestration credits, typically derived from sparse forest mensuration (6- or 12-year timber inventory) [16; 17; 18] surveys for above-ground carbon and use of multiple, carbon denominated growth models [18; 19; 20], by default, exclude direct measurement of GHG's, limiting innovative commercial applications. In contrast, direct, hourly, in situ measurement of forest greenhouse gas (GHG) fluxes, via eddy covariance and soil accumulation chambers are widely used and accepted forest research methods [21; 22]. Such methods result in net ecosystem exchange (NEE) [22; 23; 24], integrating vertical gross fluxes between the forest, soils, and the atmosphere [25; 26; 27; 28; 29]. The NEE approach, reported in 600+ forest carbon and GHG studies [30], provides the foundation for commercial applications across small and large landscapes [1; 31; 32], and three-gas forest products (CO2, CH4, N2O), integrating gas flux sources (tower and soil accumulation chambers) with pricing guidelines to establish commercial products. Prices for tCH4 and tN2O emission reductions and abatement costs are not well established [7]. However, the social cost of GHGs represents, in theory, the monetary value of the net harm to society linked to the emission of one ton of a GHG each year and is used here to value social cost linked offsets [33]. Emissions linked to their social cost and corresponding offset revenue potential, now and in the future, are fundamental to the realization of Green New Deal policies [34] mandating emission reductions, but lacking specificity of the role of forests and GHG pricing in green policies [35; 36; 37]. The expense and operational challenges of measuring multiple GHGs are justified given their high global warming potential (e.g., CH4 (28-36x); N2O (265-298x), 100-year lifetime) relative to CO2 [33], the availability of \(\sim\)4 billion forested hectares globally, the high value of GHG data for fundamental ecosystem studies and model validation [38], and as innovative GHG forest products. In this study, we analyze the Howland Forest GHG flux measurement record (tower and soil accumulation chamber) to determine the net multi-gas budget for the period studied. The GHG data are monetized using social cost pricing factors for each gas, demonstrating a new GHG forest product (GHG-SCF). We then analyze annual NEE reported as gC m\({}^{-2}\) y\({}^{-1}\), or equivalent units, for two adjacent Howland Forest CO2 flux towers, quantifying differences between the California Air Resources Board [16] and the Climate Action Reserve (CARB-CAR) [39] data [40; 41]; Howland is the only site where both methods have been used contemporaneously. The CARB-CAR third-party validation process, a critical link in the carbon offset supply chain, is evaluated for error sources and non-adherence to regulatory provisions, including assessment of independent verification methods for CARB-CAR forest carbon offsets.