A novel concept and approach to engineering carbon nanodots (CNDs) were explored to overcome the limited light absorption of CNDs in low-energy spectral regions. In this work, we constructed a novel type of supra-CND by the assembly of surface charge-confined CNDs through possible electrostatic interactions and hydrogen bonding. The resulting supra-CNDs are the first to feature a strong, well-defined absorption band in the visible to near-infrared (NIR) range and to exhibit effective NIR photothermal conversion performance with high photothermal conversion efficiency in excess of 50%.

Increases in atmospheric carbon dioxide (CO2) concentrations is the main driver of global warming due to fossil fuel combustion. Satellite observations provide continuous global CO2 retrieval products, that reveal the nonuniform distributions of atmospheric CO2 concentrations. However, climate simulation studies are almost based on a globally uniform mean or latitudinally resolved CO2 concentrations assumption. In this study, we reconstructed the historical global monthly distributions of atmospheric CO2 concentrations with 1° resolution from 1850 to 2013 which are based on the historical monthly and latitudinally resolved CO2 concentrations accounting longitudinal features retrieved from fossil-fuel CO2 emissions from Carbon Dioxide Information Analysis Center. And the spatial distributions of nonuniform CO2 under Shared Socio-economic Pathways and Representative Concentration Pathways scenarios were generated based on the spatial, seasonal and interannual scales of the current CO2 concentrations from 2015 to 2150. Including the heterogenous CO2 distributions could enhance the realism of global climate modeling, to better anticipate the potential socio-economic implications, adaptation practices, and mitigation of climate change.

Biological nitrogen fixation (BNF) is the largest nitrogen (N) input pathway in natural terrestrial ecosystems at present, fueling the drawdown of atmospheric CO 2 in vegetation and soil on decadal to century time scales. Here, we use a global land-surface model (CABLE) with three different approaches for estimating the responses of BNF to CO 2 , climate, and N deposition through Year 2100, particularly the linear versus nonlinear dependence of BNF on C investment and the temperature dependence of BNF. From 1900 to 2100, the cumulative rise in BNF varied from 1.6 to 3.0 Pg N, translating to an increase in terrestrial carbon (C) storage between 33 and 68 Pg C. This range reflects the different approaches used to model BNF (i.e., C-limited vs. resource optimization approaches), indicating major uncertainties in C-climate-N interactions in Earth system model forecasts. The differences among different approaches were most significant at high or low latitudes. At high latitudes, accounting for temperature dependence of BNF resulted in 53% and 79% additional BNF increases and 14% and 21% additional land C accumulation in evergreen needle leaf forest and tundra, respectively, from 1901 to 2100. At low latitudes, resource optimization approaches using linear dependence of BNF on C investment estimated more rapid increase in BNF and therefore greater C accumulation than the C-limited approach using nonlinear dependence. The difference in the estimated additional C accumulation due to varying BNF was as much as 24% for deciduous broadleaf forest. Our findings highlight the need for more field measurements of BNF, particularly at high latitudes to better constrain the projected BNF under future conditions, and also the fundamental importance of BNF in determining the pattern, response, and magnitude of terrestrial C accumulation through 2100.