Fig. 2: MACC of global NH3 emissions.
From: Halving global ammonia emissions with cost-effective measures
a, MACC of global NH3 emissions by option, the x axis stands for the value of cumulative NH3 mitigation and the y axis is the marginal abatement cost of the mitigation option in dollars per kilogram of NH3 mitigated. Note that the values do not include the financial value of N saved by reduced NH3 emissions of the measures listed; each dot on the MACCs represents a different mitigation option, and all options are ranked according to their unit costs, with the least costly on the left. Options labelled in green represent NH3-targeted options, whereas options with orange borders are behavioural options; the remaining options are non-technological options and/or co-benefit options. Detailed option classification and description could be found in Supplementary Tables 3–5. b, NH3 mitigation potential and costs categorized by NH3-targeted versus co-benefit options and technological versus non-technological options. c, Global and regional NH3 mitigation potential and cumulative cost. 60% represent the overall NH3 mitigation potential globally under the current baseline. The red dashed line represents the global average abatement cost (dollars per kilogram of NH3 abated), which is calculated by dividing the global total mitigation cost by the total NH3 reduction. d, The enlarged version of regional MACC in c for better visibility. LCP, low-crude protein; 4R, right time, right type, right rate and right place of fertilization; EENF, enhanced efficiency nitrogen fertilizer; SCR, selective catalytic reduction.
