Bottom-Up Estimates of Coal Mine Methane Emissions in China: A Gridded Inventory, Emission Factors, and Trends

China has large but uncertain coal mine methane (CMM) emissions. Inverse modeling (top-down) analyses of atmospheric methane observations can help improve the emission estimates but require reliable emission patterns as prior information. To serve this urgent need, we developed a high-resolution (0.25° × 0.25°) methane emission inventory for China’s coal mining using a recent publicly available database of more than 10000 coal mines in China for 2011. This number of coal mines is 25 and 2.5 times, respectively, more than the number available in the EDGAR v4.2 and EDGAR v4.3.2 gridded global inventories, which have been extensively used in past inverse analyses. Our inventory shows large differences with the EDGAR v4.2 as well as its more recent version, EDGAR v4.3.2. Our results suggest that China’s CMM emissions have been decreasing since 2012 on the basis of coal mining activities and assuming time-invariant emission factors but that regional trends differ greatly. Use of our inventory as prior information in future inverse modeling analyses can help better quantify CMM emissions as well as more confidently guide the future mitigation of coal to gas in China

Brain areas with increased ReHo in anisometropic amblyopia individuals (<i>P<0.01</i>, 130 voxels, Alphasim corrected <i>P_alpha</i> = 0.01).

<p>Abbreviations: PostCG = postcentral gyrus, PretCG = precentral gyrus, PCL = paracentral lobule, INS/PUT = insula and putamen, STG = superior temporal gyrus, FG = fusiform gyrus, MOG = middle occipital gyrus.</p><p>L: left, R: right.</p

White matter region with increased FA in adult strabismus.

<p>White matter region with higher FA in strabismus patients was found in the right inferior frontal gyrus (Z = +6).</p

Brain areas with decreased ReHo in anisometropic amblyopia individuals (<i>P<0.01</i>, 130 voxels, Alphasim corrected <i>P_alpha</i> = 0.01).

<p>Abbreviations: Pcun = precuneus, IFG = inferior frontal gyrus, MPFC = media prefrontal cortex, Cereb = cerebellum.</p><p>L: left, R: right.</p

Demographic characteristics of the participants with anisometropic amblyopia.

<p>Demographic characteristics of the participants with anisometropic amblyopia.</p

The anatomical distribution of the altered normalized ReHo in anisometropic amblyopia visualized by individuals Caret v5.61 software (<i>P<0.01</i>, 130 voxels, Alphasim corrected <i>P_alpha</i> = 0.01).

<p>Abbreviations: Pcun = precuneus, IFG = inferior frontal gyrus, MPFC = media prefrontal cortex, Cereb = cerebellum; PostCG = postcentral gyrus, PretCG = precentral gyrus, PCL = paracentral lobule, STG = superior temporal gyrus, FG = fusiform gyrus, MOG = middle occipital gyrus.</p

Plot of the normalized ReHo values in the brain areas in which ReHo values were significantly different between the subjects with normal vision and anisometropic amblyopia individuals(A).

<p>Correlation between the mean fitted ReHo indices and visual acuities in the patients with anisometropic amblyopia (P<0.05)(B). Abbreviations: same with <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0043373#pone-0043373-g001" target="_blank">Figure 1</a>.</p

Locations of white matter regions with FA changes in adult strabismus.

<p>There are several white matter regions with significantly lower FA in adult strabismus than that in normal controls by voxel-based analysis of DTI. These regions include the right middle occipital gyrus and right supramarginal gyrus. Region with increased FA in strabismus was found in the right inferior frontal gyrus.</p

White matter regions with reduced volumes in adult strabismus.

<p>Strabismus patients showed smaller white matter in several regions, including the right middle occipital gyrus (Z = +5), right occipital lobe/cuneus (Z = +33), right supramarginal gyrus (Z = +31), right cingulate gyrus (Z = +29), right frontal lobe/sub-gyral (Z = +44), right inferior temporal gyrus (Z = −25), left parahippocampa gyrus (Z = −24), left cingulate gyrus (Z = +37), left occipital lobe/cuneus (Z = +9), left middle frontal gyrus (Z = +30), left inferior parietal lobule (Z = 30), and left postcentral gyrus (Z = +55, Z = +49).</p

Clinical Characteristics.

a<p>Two sample t-test.</p>b<p>Pearson Chi-square test.</p