Heat waves in the Arctic may strongly impact environment and local communities. Recently several indices have been proposed for monitoring environmental changes in the Arctic, but heat waves have not ...been addressed. By applying a structured approach for evaluating occurrences of periods with exceptionally high temperatures, this study demonstrates that in the last decades there was an increase of heat wave occurrences over the terrestrial Arctic. The increase is mainly over the Canadian Arctic Archipelago and Greenland that are surrounded by ocean undergoing a sea-ice melting trend, while the Eurasian Arctic shows no significant change in heat wave occurrence. Since 2002 the probability of experiencing heat waves in the Arctic has been similar or even higher than in the middle and low latitudes and heat waves have already started to increasingly threaten local vegetation, ecology, human health and economy.
•The EDGAR dataset provides decades-long time series of GHG emissions for all world countries.•The EDGAR V5.0 updates CO2 emissions data to 2018 and non-CO2 to 2015.•EDGAR shows an overall upward ...trend for global GHG emissions.•A detailed overview of emission trends and features is provided by gas, by activity sector and by geographical areas.
Over the last three decades, socio-economic, demographic and technological transitions have been witnessed throughout the world, modifying both sectorial and geographical distributions of greenhouse gas (GHG) emissions. Understanding these trends is central to the design of current and future climate change mitigation policies, requiring up-to-date methodologically robust emission inventories such as the Emissions Database for Global Atmospheric Research (EDGAR), the European Commission’s in-house, independent global emission inventory. EDGAR is a key tool to track the evolution of GHG emissions and contributes to quantifying the global carbon budget, providing independent and systematically calculated emissions for all countries.
According to the results of the EDGAR v.5.0 release, total anthropogenic global greenhouse gas emissions (excluding land use, land use change and forestry) were estimated at 49.1 Gt CO2eq in 2015, 50 % higher than in 1990, despite a monotonic decrease in GHG emissions per unit of economic output. Between 1990 and 2015, emissions from developed countries fell by 9%, while emissions from low to medium income countries increased by 130%, predominantly from 2000 onwards. The 27 Member States of the European Union and the United Kingdom led the pathway for emission reductions in industrialised economies whilst, in developing countries, the rise in emissions was driven by higher emissions in China, India, Brazil and nations in the South-East Asian region. This diversity of patterns shows how different patterns for GHG emissions are and the need for identifying regionally tailored emission reduction measures.
Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current ...technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.
An aerosol model (M7) designed to be coupled to general circulation models (GCM) and chemistry transport models (CTM) is described. In M7 the aerosol population is divided into two types of ...particles: mixed, or water‐soluble particles, and insoluble particles. The particles are represented by seven classes, using a “pseudomodal” approach. Four classes are for the mixed particles representing nucleation, Aitken, accumulation, and coarse mode, and three are for the insoluble (Aitken, accumulation, and coarse mode). The components considered are mineral dust, black carbon (BC) and primary organic carbon (OC), sulfate, and sea salt. The aerosol dynamic processes in M7 include nucleation, coagulation, and condensation of sulfuric acid. Mixed particles are formed from insoluble particles by coagulation and condensation. The integration scheme is computationally very efficient. The model has been tested against the analytical solution and a sectional model for the formation of SO4/BC mixed particles, evaluating the mixing by condensation and coagulation. Furthermore, M7 has been run in free tropospheric conditions and compared to aircraft observations. M7 has proven to be accurate and fast enough to be included in a GCM or CTM.
Background: Tropospheric ozone and black carbon (BC), a component of fine paniculate matter (PM < 2.5 urn in aerodynamic diameter; PM₂.₅), are associated with premature mortality and they disrupt ...global and regional climate. Objectives: We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20-40 years. Methods: We simulated the impacts of mitigation measures on outdoor concentrations of PM₂.₅ and ozone using two composition-climate models, and calculated associated changes in premature PM₂.₅-and ozone-related deaths using epidemiologically derived concentration-response functions. Results: We estimated that, for PM₂.₅ and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23-34% and 7-17% and avoid 0.6-4.4 and 0.04-0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM₂.₅ relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration-response function. Conclusions: In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution.
Throughout the world, ambient fine particulate matter (PM2.5) is the environmental factor that poses the greatest risk to health and most European citizens continue to be exposed to PM2.5 levels well ...above World Health Organization guidelines. Here we present a comprehensive PM2.5 modelling-based source allocation assessment in 708 urban areas in Europe. The results show that urban cores, together with their commuting zones, contribute an average of 22% to urban PM2.5 concentrations levels. The residential sector is the highest source sector in 56% of cities. Its average contribution to PM2.5 formation is 27%, with a cluster of cities in Northern Italy and Eastern Europe contributing to more than 50%. Industry, agriculture and road transport show average contributions of 18%, 17% and 14%, respectively. Most emissions from residential sectors are anthropogenic primary PM2.5 which includes a condensable fraction. Furthermore, anthropogenic primary PM2.5 represents the precursor with the highest contribution in most cities (72%), contributing an average of 35% to urban PM2.5 levels. Emissions of anthropogenic primary PM2.5 by the residential sector are almost entirely (with exceptions of few countries) due to biomass burning. These results suggest that the residential sector should be a key target of any policy to improve air quality and that climate policies promoting biomass as a climate-neutral fuel could have a detrimental effect on air quality. A more integrated approach to climate and air quality policy design is desirable.
Aerosols are formed, evolve, and are eventually removed within the general circulation of the atmosphere. The characteristic time of many of the microphysical aerosol processes is days up to several ...weeks, hence longer than the residence time of the aerosol within a typical atmospheric compartment (e.g. the marine boundary layer, the free troposphere, etc.). Hence, to understand aerosol properties, one cannot confine the discussion to such compartments, but one needs to view aerosol microphysical phenomena within the context of atmospheric dynamics that connects those compartments. This paper attempts to present an integrated microphysical and dynamical picture of the global tropospheric aerosol system. It does so by reviewing the microphysical processes and those elements of the general circulation that determine the size distribution and chemical composition of the aerosol, and by implementing both types of processes in a diagnostic model, in a 3-D global Chemical Transport Model, and in a General Circulation Model. Initial results are presented regarding the formation, transformation, and cycling of aerosols within the global troposphere.
In a series of simulations with the global ECHAM5-HAM aerosol-climate model, the response to changes in anthropogenic emissions is analyzed. Traditionally, additivity is assumed in the assessment of ...the aerosol climate impact, as the underlying bulk aerosol models are largely constrained to linearity. The microphysical aerosol module HAM establishes degrees of freedom for nonlinear responses of the aerosol system. In this study’s results, aerosol column mass burdens respond nonlinearly to changes in anthropogenic emissions, manifested in alterations of the aerosol lifetimes. Specific emission changes induce modifications of aerosol cycles with unaltered emissions, indicating a microphysical coupling of the aerosol cycles. Anthropogenic carbonaceous emissions disproportionately contribute to the accumulation mode numbers close to the source regions. In contrast, anthropogenic sulfuric emissions less than proportionally contribute to the accumulation mode numbers close to the source regions and disproportionately contribute in remote regions. The additivity of the aerosol system is analyzed by comparing the changes from a simulation with emission changes for several compounds with the sum of changes of single simulations, in each of which one of the emission changes was introduced. Close to the anthropogenic source regions, deviations from additivity are found at up to 30% and 15% for the accumulation mode number burden and aerosol optical thickness, respectively. These results challenge the traditional approach of assessing the climate impact of aerosols separately for each component and demand for integrated assessments and emission strategies.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Production of sea spray aerosol in the surf zone Leeuw, Gerrit; Neele, Filip P.; Hill, Martin ...
Journal of Geophysical Research, Washington, DC,
27 December 2000, Letnik:
105, Številka:
D24
Journal Article
Recenzirano
A quantitative source function for sea spray aerosol produced by waves breaking in the surf zone was determined from data collected with optical particle counters at both sides of the surf zone at ...two locations on the Californian coast. Three optical particle counters were used to measure profiles at the base of a pier; a fourth instrument was used at the end of the pier. Careful calibration and intercomparisons of the instruments were made to avoid systematic errors. Aerosol concentrations measured downwind from the surf, in wind speeds of up to 9 m s−1, were 1–2 orders of magnitude higher than those upwind. Surf aerosol concentration gradients and plume heights vary with particle size and with wind speed. The derived surf aerosol source functions are compared with current estimates for the open ocean, taking into account the different proportions of the ocean surface covered by whitecaps. Application of a simple transport model indicates that surf‐produced sea spray contributes significantly to the aerosol concentrations at fetches up to at least 25 km. This has implications for, for example, heterogeneous chemistry and electro‐optical propagation.
The ongoing shrinkage of the Arctic sea ice cover is likely linked to the global temperature rise, the pronounced warming in the Arctic, and possibly weather anomalies in the midlatitudes. By ...evaluating independent components of global atmospheric energy anomalies in winters from 1980 to 2015, the study finds the link between the sea ice melting in the Arctic and the combination of only three well-known atmospheric oscillation patterns approximating observed spatial variations of near-surface temperature trends in winter. The three patterns are the North Atlantic Oscillation (NAO), Scandinavian blocking (SB), and El Niño–Southern Oscillation (ENSO). The first two are directly related to the ongoing sea ice cover shrinkage in the Barents Sea and the hemispheric increase of near-surface temperature. By independent dynamical processes they connect the sea ice melting and related atmospheric perturbations in the Arctic either with the negative phase of the NAO or the negative trend of atmospheric temperatures over the tropical Pacific. The study further shows that the ongoing sea ice melting may often imply the formation of large-scale circulation patterns bringing the recent trend of colder winters in densely populated areas like Europe and North America.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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