Monday, June 29, 2020

Good News For Arctic Ice: China's Black Carbon Emissions Decreasing

We've been harping on how devastating the stuff can be for a very long time.* Here's a post from January 2020 that quickly makes our case:
IMO 2020 Low-Sulfur Rules May Result In More Black Carbon Emissions in the Arctic
This could be very not good.
Spreading black carbon on the polar ice caps was one of the geoengineering proposals during the Global Cooling scare of the 1970's. It's also one of the concerns associated with China's coal-fired power plants. (mostly soot, larger diameter than what emerges from VLSFO combustion)
The stuff lands on the ice and reduces the albedo. It also directly absorbs infrared.
Very not good.....
From the Japan Agency for Marine-Earth Science and Technology (JAMSTEC, also one of our big four sources for ENSO info)

Major Reduction in Black Carbon Emissions from China Over the Past Decade – A revision of the emission inputs to IPCC climate models is needed
1. Key Points ♦Highly accurate observations of air pollution on Fukue Island, western Japan, have revealed a rapid reduction in black carbon emissions from China by as much as 40% over the past decade.
♦The fine particulate (PM2.5) emissions reduction measures in China are considered to have driven the reduction in black carbon emissions.
♦In the Sixth IPCC Assessment Report, which is to be published in 2021, the effects of black carbon emissions on climate are assessed assuming that these emissions increased until 2014; however, this should be revised in the seventh assessment.

Dr. Yugo Kanaya of the Earth Surface System Research Center (ESS) in the Research Institute for Global Change (RIGC) at the Japan Agency for Marine–Earth Science and Technology (JAMSTEC) and colleagues have worked jointly with Kobe University and the National Institute for Environmental Studies to conduct long-term atmospheric observations on Fukue Island in Nagasaki Prefecture, Japan. Their efforts have revealed a substantial reduction, by as much as 40%, in black carbon (BC) emissions from China over the past decade. Black carbon particles, also known as soot, are emitted into the atmosphere as a result of the incomplete combustion of fossil fuels and biomass. As BC contributes to global warming as CO2, it is important to understand changes in BC emissions and to assess their effects on the global climate.

Black carbon emissions have been estimated based on socioeconomic statistics, but the range of uncertainty remained wide, at 0.5–2 times the median value. Additionally, there has been no consensus on whether or not emissions from China, considered to account for as much as 30% of global emissions, were increasing or decreasing. Therefore, in the study summarized here, atmospheric BC concentrations on Fukue Island, where air pollution from China tends to arrive via the prevailing westerlies, were monitored continuously for more than 10 years, from 2009 to 2019, and based on these trends, the emissions and changes therein of BC were estimated. As a result, the uncertainty in BC emissions from China was narrowed to ±27%, and a substantial reduction in emissions – by as much as 40% over the past decade – was discovered. In the Sixth Intergovernmental Panel on Climate Change (IPCC) Assessment Report (IPCC AR6), which is currently being compiled for publication in 2021, the effects of BC emissions from China on the climate are assessed based on the assumption that these emissions increased until 2014. However, the results of this research clearly show for the first time that the trend is in the opposite direction. The reason for this declining trend is thought to be that policies aimed at reducing the atmospheric particulate matter <2 .5="" in="" m="" size="" sub="">2.5
) in China have also curbed BC emissions, which are a component of PM2.5. This means that the effect of BC on global climate change is, in fact, lower than the assessment in the forthcoming IPCC AR6. It is hoped that these results will be of use for improving simulations in the seventh IPCC assessment cycle, and that they will also be applied in the creation of inventories for short-lived climate forcer (SLCF) emissions, due to be considered therein.
This research was conducted as part of the Environment Research and Technology Development Fund (ERTDF) of the Ministry of the Environment of Japan (Grant No. 2-1803) and the Arctic Challenge for Sustainability (ArCS) Project. The findings were published in Atmospheric Chemistry and Physics on June 5, 2020 (JST).....
*A very long time. Here's a post from 2007:
NASA Examines Arctic Sea Ice Changes Leading to Record Low in 2007
...The findings appear in the latest issue of the Proceedings of the National Academy of Sciences. It is authored by Makiko Sato, James Hansen and others from NASA's Goddard Institute for Space Studies (GISS) and Columbia University, New York; Oleg Dubovik, Brent Holben and Mian Chin of NASA's Goddard Space Flight Center, Greenbelt, Md.; and Tica Novakov, Lawrence Berkeley National Laboratory, Berkeley, Calif.
And many more in between those bookends