Contemporary and projected biogenic fluxes of methane and nitrous oxide in North American terrestrial ecosystems.

Accurately estimating biogenic methane (CH₄) and nitrous oxide (N₂0) fluxes in terrestrial ecosystems is critical for resolving global budgets of these greenhouse gases (GHGs) and continuing to mitigate climate warming. Here, we assess contemporary biogenic CH₄ and N₂0 budgets and probable climate-change-related impacts on CH₄ and N₂0 emissions in terrestrial North America. Multi-approach estimations show that, during 1990-2010, biogenic CH₄ emissions ranged from 0.159 to 0.502 petagrams of carbon dioxide (C0₂) equivalents per year (Pg CO₂eq yr^-1 where 1 Pg = 1 x 10¹⁵ g) and N₂0 emissions ranged from 0.802 to 1.016 Pg C0₂eq yr^-1, which offset 47-166% of ter-restrial C0₂ sequestration (0.915-2.040 Pg C0₂eq yr^-1 as indicated elsewhere in this Special Issue). According to two future climate scenarios, CH₄ and N₂0 emissions are projected to continue increasing by 137-151% and 157-227%, respectively, by the end of this century, as compared with levels during 2000-2010. Strategies to miti-gate climate change must account for non-C0₂ GHG emissions, given their substantial warming potentials. INSET: In a nutshell:. [ABSTRACT FROM AUTHOR]