Structural decline in China’s CO2 emissions through transitions in industry and energy systems

Abstract

China is the top CO2-emitting nation, with emissions making up nearly a third (29.5%) of the global total in 2015 1. For this reason, international efforts to stabilize the Earth's climate depend heavily upon the trajectory of Chinese emissions, and the country's recent pledge to reduce its annual emissions before 2030 has been widely celebrated 2,3. Now, it is becoming clear that China may have already fulfilled this commitment: estimates made by various organizations indicate that-after more than decade of rapid growth-China's annual CO2 emissions have decreased year-on-year over the period 2013-2016. Although undoubtedly a watershed event, the peak of Chinese emissions prompts important questions about what factors are driving the current decrease, their relative importance, and whether or not the decline can be sustained or even accelerated. In particular, if China's emissions are have fallen primarily as a result of slowing economic activity, as happened in the U.S. during the global financial crisis 4 , renewed economic growth could reverse the decrease 5,6 .

Weakened growth of cropland‐N2O emissions in China associated with nationwide policy interventions

“…We applied the Logarithmic Mean Divisia Index (LMDI; Ang, ; Guan et al, ) to attribute N 2 O emission trends to different driving factors. The LMDI was chosen because of its path independence, consistency in aggregation, and ability to handle zero values (Ang, ).…”

“…The detailed methodology of LMDI can be found in Ang (). According to previous modeling studies (Guan et al, ), we decomposed cropland‐N 2 O emissions into a combination of different drivers: total sowing area ( A k , ha), the share of nine different crops to total sowing area ( m jk , %) also known as crop mix, N application rate ( R jk , kg N ha −1 year −1 ), and the emission intensity ( e jk , %) per crop type and region:where region k = 1–8 correspond to China, the Northwest, the Northeast Plain, the North China Plain, the lower reach of Yangtze River basin, the Southwest, the Northwest, and Qinghai‐Tibet Plateau; A jk is the sowing area of crop j in cropping region k ; N jk and E jk are N‐fertilizer application amount and croplands‐N 2 O emission of crop j in cropping region k , respectively. It should be noted that e jk is defined as cropland‐N 2 O emission per unit of N jk , which is different from the EF defined in the 2006 IPCC Guidelines, and represents the gross emission intensity at a given N application level.…”

“…We applied the Logarithmic Mean Divisia Index (LMDI; Ang, 2015;Guan et al, 2018) to attribute N 2 O emission trends to different driving factors.…”

“…The detailed methodology of LMDI can be found in Ang (2015). According to previous modeling studies (Guan et al, 2018), we decomposed cropland-N 2 O emissions into a combination of different drivers: total sowing area (A k , ha), the share of nine different crops to total sowing area (m jk , %) also known as crop mix, N application rate (R jk , kg N ha −1 year −1 ), and the emission intensity (e jk , %) per crop type and region:…”

2D Metal–Organic Framework Derived CuCo Alloy Nanoparticles Encapsulated by Nitrogen‐Doped Carbonaceous Nanoleaves for Efficient Bifunctional Oxygen Electrocatalyst and Zinc–Air Batteries

“…[1][2][3][4][5][6][7][8] Precious-metal-based electrocatalysts have shown high activities for the oxygen evolution reaction (OER) and oxygen reduction reaction(ORR).However,t heir poor stability and high cost limit the commercializationo fm etal-air batteries. [1][2][3][4][5][6][7][8] Precious-metal-based electrocatalysts have shown high activities for the oxygen evolution reaction (OER) and oxygen reduction reaction(ORR).However,t heir poor stability and high cost limit the commercializationo fm etal-air batteries.…”