Sustainable Development and Technological Impact on CO2 Reducing Conditions in Romania

Abstract

Ozone and methane are chemically active climate-forcing agents affected by climate-chemistry interactions in the atmosphere. Key chemical reactions and processes affecting ozone and methane are presented. It is shown that climate-chemistry interactions have a significant impact on the two compounds. Ozone, which is a secondary compound in the atmosphere, produced and broken down mainly in the troposphere and stratosphre through chemical reactions involving atomic oxygen (O), NOx compounds (NO, NO 2 ), CO, hydrogen radicals (OH, HO 2 ), volatile organic compounds (VOC) and chlorine (Cl, ClO) and bromine (Br, BrO). Ozone is broken down through changes in the atmospheric distribution of the afore mentioned compounds. Methane is a primary compound emitted from different sources (wetlands, rice production, livestock, mining, oil and gas production and landfills).Methane is broken down by the hydroxyl radical (OH). OH is significantly affected by methane emissions, defined by the feedback factor, OPEN ACCESSAtmosphere 2014, 5 519 currently estimated to be in the range 1.3 to 1.5, and increasing with increasing methane emission. Ozone and methane changes are affected by NOx emissions. While ozone in general increase with increases in NOx emission, methane is reduced, due to increases in OH. Several processes where current and future changes have implications for climate-chemistry interactions are identified. It is also shown that climatic changes through dynamic processes could have significant impact on the atmospheric chemical distribution of ozone and methane, as we can see through the impact of Quasi Biennial Oscillation (QBO). Modeling studies indicate that increases in ozone could be more pronounced toward the end of this century. Thawing permafrost could lead to important positive feedbacks in the climate system. Large amounts of organic material are stored in the upper layers of the permafrost in the yedoma deposits in Siberia, where 2 to 5% of the deposits could be organic material. During thawing of permafrost, parts of the organic material that is deposited could be converted to methane. Furthermore, methane stored in deposits under shallow waters in the Arctic have the potential to be released in a future warmer climate with enhanced climate impact on methane, ozone and stratospheric water vapor. Studies performed by several groups show that the transport sectors have the potential for significant impacts on climate-chemistry interactions. There are large uncertainties connected to ozone and methane changes from the transport sector, and to methane release and climate impact during permafrost thawing.

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

“…With a lifetime of approximately a decade in the atmosphere, methane is well mixed globally and therefore has a significant influence on background ozone levels. Methane is a distinct win-win possibility for air quality and climate in that reductions in methane emissions would decrease ozone, including baseline ozone, and thereby lessen adverse impacts on vegetation and human health, but also benefit climate by reducing two greenhouse gases simultaneously (Fry et al, 2012;Shindell et al, 2012;Isaksen et al, 2014). A model study investigated the air quality (O 3 ) and climate benefits of methane reductions and found that O 3 reductions were relatively linear with respect to reduc- Figure 43.…”

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

“…With a lifetime of approximately a decade in the atmosphere, methane is well mixed globally and therefore has a significant influence on background ozone levels. Methane is a distinct win-win possibility for air quality and climate in that reductions in methane emissions would decrease ozone, including baseline ozone, and thereby lessen adverse impacts on vegetation and human health, but also benefit climate by reducing two greenhouse gases simultaneously (Fry et al, 2012;Shindell et al, 2012;Isaksen et al, 2014). A model study investigated the air quality (O 3 ) and climate benefits of methane reductions and found that O 3 reductions were relatively linear with respect to reduc- Figure 43.…”

Atmospheric methane evolution the last 40 years

“…Increasing atmospheric CH 4 would accelerate near-S. B. Dalsøren et al: Atmospheric methane evolution the last 40 years term warming, due to its strong climate impact on a 20-year time frame (Myhre et al, 2013). Enhanced CH 4 levels would also increase the ozone levels in surface air (Fiore et al, 2008(Fiore et al, , 2012West and Fiore, 2005;Isaksen et al, 2014), and thereby worsen air pollution impacts on vegetation, crops, and human health.…”