Eloise Ann Marais | |
---|---|
Alma mater | Harvard University Rhodes University University of KwaZulu-Natal |
Scientific career | |
Institutions | Harvard University University College London |
Thesis | Non-methane volatile organic compounds in Africa: a view from space (2014) |
Eloise Ann Marais is a South African chemist who is a professor at University College London. She leads the UCL Atmospheric Composition and Air Quality group, which develop complex models to understand human influence on air quality.
Marais is from South Africa. [1] She studied chemistry and applied chemistry at the University of KwaZulu-Natal for her undergraduate degree, [1] before moving to Rhodes University for an MSc in physical and analytical chemistry.[ citation needed ] She was awarded an International Fulbright Science and Technology Award and completed her doctorate at Harvard University.[ citation needed ] Her doctoral research used satellite observations and chemical transport models to quantify air pollutant precursor emissions of volatile organic compounds across Africa. Marais spent two years at Harvard as a postdoctoral researcher. She joined the University of Birmingham in 2016, where she developed tools for air monitoring in urban environments.[ citation needed ] and established the Atmospheric Composition and Air Quality research group.
In 2018, Marais joined Leicester as an associate professor. [2] She spent two years in Leicester before moving to University College London, where she studied the impact of fossil fuel emissions on human health. [3] Her research has shown that fossil fuel emissions accounted for 18% of deaths around the world in 2018, and that regions with the highest concentrations of fossil fuels in the air had the highest rates of mortality. [3]
Marais was awarded a European Research Council grant to understand the understudied upper troposphere using multi-modal data. [1] There are uncertainties in the composition of the upper troposphere, and limited understanding of how it influences climate and air quality. She has studied how space tourism impacts the climate. [4] She ran a 10-year simulation to understand how rocket emissions compared with traditional sources of carbon dioxide, finding space tourism undermined environmental efforts on planet Earth. [4] Her research showed that a SpaceX launch emitted one hundred times more carbon dioxide than a traditional transatlantic flight, [5] [6] and that these pollutants could destroy the ozone if injected into the stratospheric ozone layer. [4] [7] She showed that this could persist for two or more years. [8]
Marais has ongoing projects to measures the atmosphere above Central London, develop inventories and derive new data sets from satellite observations. [9] She worked as a researcher in residence with the Connected Places Catapult, where she developed tools to better understand the city environment. [10] She has used Multi-Axis Differential Optical Absorption Spectroscopy to evaluate the presence of nitrogen dioxide and formaldehyde. [11] Marias was supported by the Department for Environment, Food and Rural Affairs to understand air pollution above Leicester. In 2024 she was promoted to Professor at University College London.[ citation needed ]
The scientific community has been investigating the causes of climate change for decades. After thousands of studies, it came to a consensus, where it is "unequivocal that human influence has warmed the atmosphere, ocean and land since pre-industrial times." This consensus is supported by around 200 scientific organizations worldwide, The dominant role in this climate change has been played by the direct emissions of carbon dioxide from the burning of fossil fuels. Indirect CO2 emissions from land use change, and the emissions of methane, nitrous oxide and other greenhouse gases play major supporting roles.
The stratosphere is the second-lowest layer of the atmosphere of Earth, located above the troposphere and below the mesosphere. The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher and the cooler layers lower. The increase of temperature with altitude is a result of the absorption of the Sun's ultraviolet (UV) radiation by the ozone layer, where ozone is exothermically photolyzed into oxygen in a cyclical fashion. This temperature inversion is in contrast to the troposphere, where temperature decreases with altitude, and between the troposphere and stratosphere is the tropopause border that demarcates the beginning of the temperature inversion.
A fossil fuel is a carbon compound- or hydrocarbon-containing material such as coal, oil, and natural gas, formed naturally in the Earth's crust from the remains of prehistoric organisms, a process that occurs within geological formations. Reservoirs of such compound mixtures can be extracted and burned as a fuel for human consumption to provide heat for direct use, to power heat engines that can propel vehicles, or to generate electricity via steam turbine generators. Some fossil fuels are further refined into derivatives such as kerosene, gasoline and diesel.
Environmental science is an interdisciplinary academic field that integrates physics, biology, meteorology, mathematics and geography to the study of the environment, and the solution of environmental problems. Environmental science emerged from the fields of natural history and medicine during the Enlightenment. Today it provides an integrated, quantitative, and interdisciplinary approach to the study of environmental systems.
The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface, known collectively as air, with variable quantities of suspended aerosols and particulates, all retained by Earth's gravity. The atmosphere serves as a protective buffer between the Earth's surface and outer space, shields the surface from most meteoroids and ultraviolet solar radiation, keeps it warm and reduces diurnal temperature variation through heat retention, redistributes heat and moisture among different regions via air currents, and provides the chemical and climate conditions allowing life to exist and evolve on Earth.
Ground-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface. The troposphere extends from the ground up to a variable height of approximately 14 kilometers above sea level. Ozone is least concentrated in the ground layer (or planetary boundary layer) of the troposphere. Ground-level or tropospheric ozone is created by chemical reactions between NOx gases (oxides of nitrogen produced by combustion) and volatile organic compounds (VOCs). The combination of these chemicals in the presence of sunlight form ozone. Its concentration increases as height above sea level increases, with a maximum concentration at the tropopause. About 90% of total ozone in the atmosphere is in the stratosphere, and 10% is in the troposphere. Although tropospheric ozone is less concentrated than stratospheric ozone, it is of concern because of its health effects. Ozone in the troposphere is considered a greenhouse gas, and may contribute to global warming.
Indoor air quality (IAQ) is the air quality within buildings and structures. Poor indoor air quality due to indoor air pollution is known to affect the health, comfort, and well-being of building occupants. It has also been linked to sick building syndrome, respiratory issues, reduced productivity, and impaired learning in schools. Common pollutants of indoor air include: secondhand tobacco smoke, air pollutants from indoor combustion, radon, molds and other allergens, carbon monoxide, volatile organic compounds, legionella and other bacteria, asbestos fibers, carbon dioxide, ozone and particulates.
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.
Drew Shindell is a physicist and a climate specialist and professor at Duke University's Nicholas School of the Environment. He is listed as an ISI Highly Cited Researcher. He was a chapter lead of the Intergovernmental Panel on Climate Change (IPCC) October 8, 2018 Special Report on Global Warming of 1.5 °C as well as on the Intergovernmental Panel on Climate Change's Fifth Assessment Report in 2013. He has testified on climate issues before both houses of the US Congress, at the request of both parties. His research concerns natural and human drivers of climate change, linkages between air quality and climate change, and the interface between climate change science and policy. He has been an author on more than 200 peer-reviewed publications and received awards from Scientific American, NASA, the EPA, and the NSF.
In atmospheric chemistry, NOx is shorthand for nitric oxide and nitrogen dioxide, the nitrogen oxides that are most relevant for air pollution. These gases contribute to the formation of smog and acid rain, as well as affecting tropospheric ozone.
Air pollution is the contamination of air due to the presence of substances called pollutants in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. It is also the contamination of the indoor or outdoor environment either by chemical, physical, or biological agents that alters the natural features of the atmosphere. There are many different types of air pollutants, such as gases, particulates and biological molecules. Air pollution can cause diseases, allergies, and even death to humans; it can also cause harm to other living organisms such as animals and crops, and may damage the natural environment or built environment. Air pollution can be caused by both human activities and natural phenomena.
The United States produced 5.2 billion metric tons of carbon dioxide equivalent greenhouse gas (GHG) emissions in 2020, the second largest in the world after greenhouse gas emissions by China and among the countries with the highest greenhouse gas emissions per person. In 2019 China is estimated to have emitted 27% of world GHG, followed by the United States with 11%, then India with 6.6%. In total the United States has emitted a quarter of world GHG, more than any other country. Annual emissions are over 15 tons per person and, amongst the top eight emitters, is the highest country by greenhouse gas emissions per person.
Tropospheric ozone depletion events are phenomena that reduce the concentration of ozone in the earth's troposphere. Ozone (O3) is a trace gas which has been of concern because of its unique dual role in different layers of the lower atmosphere. Apart from absorbing UV-B radiation and converting solar energy into heat in the stratosphere, ozone in the troposphere provides greenhouse effect and controls the oxidation capacity of the atmosphere.
Air quality laws govern the emission of air pollutants into the atmosphere. A specialized subset of air quality laws regulate the quality of air inside buildings. Air quality laws are often designed specifically to protect human health by limiting or eliminating airborne pollutant concentrations. Other initiatives are designed to address broader ecological problems, such as limitations on chemicals that affect the ozone layer, and emissions trading programs to address acid rain or climate change. Regulatory efforts include identifying and categorising air pollutants, setting limits on acceptable emissions levels, and dictating necessary or appropriate mitigation technologies.
Air Pollution in Mexico City has been of concern to the city's population and health officials for decades. In the 20th century, Mexico City's population rapidly increased as industrialization brought thousands of migrants from all over the world. Such a rapid and unexpected growth led to the UN declaring Mexico City as the most polluted city in the world in 1992. This was partly due to Mexico City's high altitude, which causes its oxygen levels to be 25% lower. Carbon-based fuels also do not combust completely. Other factors include the proliferation of vehicles, rapid industrial growth, and the population boom. The Mexican government has several active plans to reduce emission levels which require citizen participation, vehicular restrictions, increase of green areas, and expanded bicycle accessibility.
Barbara J. Finlayson-Pitts is a Canadian-American atmospheric chemist. She is a professor in the chemistry department at the University of California, Irvine and is the Director of AirUCI Institute. Finlayson-Pitts and James N. Pitts, Jr. are the authors of Chemistry of the Upper and Lower Atmosphere: Theory, Experiments, and Applications (1999). She has been a member of the National Academy of Sciences since 2006 and is the laureate for the 2017 Garvan–Olin Medal. In 2016 she co-chaired the National Academy of Science report "The Future of Atmospheric Chemistry Research"
Akkihebbal Ramaiah (Ravi) Ravishankara ForMemRS FAAAS FRSC is a scientist specializing in Chemistry and Atmospheric Sciences, and University Distinguished Professor in the Departments of Chemistry and Atmospheric Sciences at Colorado State University, Fort Collins.
Johannes "Jos" Lelieveld is a Dutch atmospheric chemist. Since 2000, he has been a Scientific Member of the Max Planck Society and director of the Atmospheric Chemistry Department at the Max Planck Institute for Chemistry in Mainz. He is also professor at the University of Mainz and at the Cyprus Institute in Nicosia.
Nadine Unger is a Professor of Atmospheric Chemistry at the University of Exeter. She has studied the role of human activities and forests on the Earth's climate.
Particulate pollution is pollution of an environment that consists of particles suspended in some medium. There are three primary forms: atmospheric particulate matter, marine debris, and space debris. Some particles are released directly from a specific source, while others form in chemical reactions in the atmosphere. Particulate pollution can be derived from either natural sources or anthropogenic processes.
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