Env 107 Lecture 9: Air & Climate PDF

LECTURE 8 AIR & CLIMATE What is Air Pollution? Air pollution occurs when harmful or excessive quantities of substances are introduced into Earth's atmosphere. These substances include –Gases: sulfuroxides, nitrogenoxides, carbonmonoxide, hydrocarbons etc. –Particulate matter: smoke, dust, f...

LECTURE 8 AIR & CLIMATE What is Air Pollution? Air pollution occurs when harmful or excessive quantities of substances are introduced into Earth's atmosphere. These substances include –Gases: sulfuroxides, nitrogenoxides, carbonmonoxide, hydrocarbons etc. –Particulate matter: smoke, dust, fumes, aerosols –Radioactive materials and many others Air pollution is a mixture of solid particles, liquid particles and gases are suspended in the air. Air pollution kills an estimated seven million people worldwide every year. WHO data shows that 9 out of 10 people breathe air containing high levels of pollutants. Source: https://www.who.int/health-topics/air-pollution#tab=tab_1  Sources of Air Pollution? Sources of air pollution are grouped into two major categories based on location: Stationary sources -Those that have a relatively fixed location Mobile sources -Move from place to place while emitting pollutants -These include automobiles, trucks, buses, ships and trains Stationary sources Point sources: emit pollutants from one or more controllable sites e.g. smoke stacks of power plants. Fugitivesources: Pollutants that is dispersed by the wind. e.g. burning for agricultural purposes, dirt roads, surface mines and other exposed areas from which particulates may be removed by wind. Area sources: Well-defined areas within which have several sources of air pollutants e.g. small urban communities and areas of intense industrialization within urban complexes. Sources of Air Pollution Based on Origin A. Natural natural gas emission, discharge during storm, pollens, microorganisms etc. B. Manmade Transportation-motor vehicle, aircraft, railway engines etc. Industrial mainly petroleum, steel, paper industries, power plants mining operations. Agriculture-Pesticides, herbicides, agricultural burning etc. Other-Solid waste, forest fires, nuclear explosion  Primary Pollutants Primary pollutants: emitted directly from the sources Typical pollutants included under this category are: Particulate matter such as ash, smoke, dust, fumes, mist and spray Inorganic gases such as sulfur dioxide, hydrogen sulfide, nitric oxide, ammonia, carbon monoxide, carbondioxide and hydrogen fluoride Aromatic hydrocarbons Radio active compounds  Secondary Pollutants Secondary pollutants: formed in the atmosphere by chemical interactions among primary pollutants and normal atmospheric constituents. Pollutants included in this category are: –Sulfur trioxide –Nitrogen dioxide –Tropospheric Ozone –Aldehydes –Ketones –Various sulfate and nitrate salts What else causes air pollution? Certain gases in the atmosphere can cause air pollution. For example, Ozone Ozone can be both good and bad for our environment. It all depends where it is in Earth’s atmosphere. Good Zone: Ozone high up in our atmosphere is a good thing. It helps block harmful energy from the Sun, called radiation. Bad Ozone: when ozone is closer to the ground, it can be really bad for our health. Ground level ozone is created when sunlight reacts with certain chemicals that come from sources of burning fossil fuels, such as factories or car exhaust. Source: https://climatekids.nasa.gov/air-pollution/ How does air pollution affect Earth’s climate? some air pollutant reflect sunlight while others absorb sunlight. It depends on the color of the particle. Dark colour particles—a dark particle in the atmosphere—absorb the Sun's heat. Hence, increase the temperature. Whitecolour particles-light-colored particles that reflect the Sun’s light and heat away from Earth can make the global temperature cooler. Source: https://climatekids.nasa.gov/air-pollution/ How does air pollution affect Human health?  Indoor Air Pollution Human kind faces the most prolonged and worst exposure to pollution within the four walls of home. Indoor air pollution can have an astonishing variety of sources incl. cooking gas, heaters, fire places, wood or coal burning stoves, cigarette smoking, household products like detergents, waxes, polishes, air fresheners, pesticides, glues, paints, hair sprays, oven cleaners, permanent press fabrics, synthetic fibers and cleaning activities like dusting and vacuum cleaning. And whatever pollutes the outside air eventually becomes indoor pollution as well, especially in older leaky buildings Bangladesh perspective Source of Air pollution in Bangladesh ✓Mass industrialization, urbanization, and infrastructure construction cause air pollution in dry season. ✓Industrial emissions, vehicle emissions, and waste burning are other major causes of air pollution. ✓Substances of 10 micrometre in size or smaller (gas and solid) are known as particulate matters PM10. These substances are severe health hazards. PM10 is emitted from brick kilns, cement, steel and ceramic factories. Each brick kiln emits 83 tons, steel re-rolling mill 17 tons, cement factory 130 tons, and ceramic factory emits 20 tons of PM10 annually. ✓Around 72% of national household use solid fuel, which contribute to air pollution, according to State of Global Air 2019. https://www.dhakatribune.com/bangladesh/2019/11/07/what-is-bangladesh-doing-to-combat-air-pollution Legal and policy initiatives Bangladesh Environmental Conservation Act, 1995 (ECA, 1995) and Environment Conservation Rules 1997 (ECR, 1997): Mandatory requirement of prior environment clearance for certain category of project for conservation and improvement of environment and control and mitigation of pollution of the environment. Standards are described under ECR, 1997 ECA & ECR amendment 2002; ECR amendment 2003, ECA & ECR amendment 2010: Restriction on polluting automobiles, sale and production of environmental harmful items. The Vehicle Act, 1927; The Motor Vehicles Ordinance, 1983 The Bengal Motor Vehicle Rules, 1940 : To regulate vehicular exhaust emissions. Legal and policy initiatives ✓The Brick Production and Brick Kiln Building (Control) Act, 2013 was amended in 2019. ✓The DoE says 71.64% brick kiln use technology that reduce emissions. ✓DoE made a GIS database to monitor all the brick kilns in the country. ✓The Clean Air Act has yet to be passed in parliament. ✓The DoE will also make it mandatory to set up an Air Treatment Plant for large industrial units. So far, 16 air quality observation stations have been set up nationwide, with only 11 functioning.  How to stop air pollution? ❑ More uses of public transport ❑ Walking ❑ Bicycles ❑ Clean energy ❑ complete ban of old vehicles ❑ Public awareness ❑ Need to increase plantations ❑ replacing a technological process that doesn’t pollute the air. ❑ prevention of escape of toxic substances into the air Climate Change Weather and Climate Weather is what’s happening now or over some short time period—this hour, today, this week—in the atmosphere near the ground: its temperature, pressure, cloudiness, precipitation, winds etc. Climate is the average weather and usually refers to average weather conditions over long periods, at least seasons, but more often years or decades. WHAT IS CLIMATE CHANGE? ◼ Climate is the average weather at a given point and time of year, over a long period. ◼ We expect the weather to change a lot from day to day, but we expect the climate to remain relatively constant. ◼ If the climate doesn’t remain constant, we call it climate change. ◼ The key question is what is a significant change – and this depends upon the underlying level of climate variability ◼ Crucial to understand difference between climate change and climate variability… How Global Warming Works? The Greenhouse Effect Major Greenhouse Gases ❖The green house causes resulting in un-natural global warming result from anthropogenic sources and include: ✓Carbon dioxide ✓CFC’s ✓Methane ✓Nitrous oxides ✓Ozone Other Gases 2% Source: IPCC (2014) EXIT based on global emissions from 2010. Details about the sources included in these estimates can be found in the Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Please go through IPCC Sixth assessment report for more update Source: IPCC (2014); EXIT based on global emissions from 2010. Details about the sources included in these estimates can be found in the Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Please go through IPCC Sixth assessment report for more update The rise in average global temperature is directly linked to the rise in the concentration of CO2 / GHGs in the atmosphere WMO: 2016 highest CO2 WMO: 2016 warmest year on record, concentration in atmosphere in 1.1°C above pre-industrial levels 800,000 years with 403.3 ppm Source: NOAA 2017, Atmospheric CO2 at Manau Loa Observatory, Hawai. Source: WMO 2017: WMO Statement on the State of the Global Climate in 2016. What’s the difference between “global warming” and “climate change”? Difference GLOBAL WARMING CLIMATE CHANGE is the increase of the Earth’s average is a broader term that refers to long-term surface temperature due to a build-up of changes in climate, including average greenhouse gases in the atmosphere. temperature and precipitation. Effects of Global Warming Rising Sea Level Effects of global warming includes: Changes in climate Rise in Sea Level Glacier retreats and Ice Cap melting Changes in the Biosphere Habitat Damage and Species Affected Increased Temperature Changes in Water Supply WHAT’S THE PROOF THAT GLOBAL WARMING IS TAKING PLACE? Portage Glacier Alaska 1914 2004 Rising tides. Some scientists predict that a warmer climate will trigger more violent storms, which will cause increased rates of coastal erosion. Cape Hatteras in North Carolina in the USA. Low-lying Bangladesh is prone to coastal flooding caused by storm surges, which have killed many people in recent years. Experts say if the sea level goes up by 1 metre, Bangladesh will lose 17.5% of its land.  BANGLADESH THE WORST SUFFERER Bangladesh-most vulnerable countries of the world. Negligible gas emissions - worst victim. Why Bangladesh is vulnerable due to Climate Change? Bangladesh is one of the most vulnerable countries because of its…….. 1. Flat and low-lying topography (of the total land area, 79% has less than 1m elevation) 2. High population density 3. Reliance of many livelihoods on climate sensitive sectors, particularly agriculture and fisheries ❖ Socioeconomic conditions ❖ Poor infrastructure Past climate change scenarios and related impacts in Bangladesh ❖ Temperature (since 1960) Increase in 0.24°C per decade during the hot season of March to May and 0.19°C per decade during the cool season of December to February ❖ Rainfall (from 1958-2007) Increase in annual and pre-monsoon rainfall as 5.53 and 2.47 mm/year, respectively ❖Cyclone Between 1985-2009 an increased frequency of cyclonic storms (5.48 annually) was experienced in the Bay of Bengal. ❖Sea level Sea level has risen (1.5-5.6mm/year) along the Bangladeshi coast over the past 60 years. N.B. Need to update with recent references Future climate change scenarios and related impacts in Bangladesh ❖ Temperature ✓ 3 – 3.5°C increase in temperature by 2100 ❖ Rainfall ✓ 20% increase in rainfall in the north; 5 – 10% increase in rainfall for the rest of the country by 2100 ❖Sea level rise ✓ By 2030 – 14cm ✓ By 2050 - 32 cm ✓ By 2100 – 88cm to 1m ❖Extreme Temperature and Drought ✓North and North-western regions of the country will suffer from Extreme Temperature and drought Climate Change Impacts ❖Cyclone/storm surge: increased frequency, intensity, increasing salinity ❖Floods: increased frequency, magnitudes ❖Droughts: Spreading over time and space ❖Erratic rainfall: Intensive rain in short time ❖Temperature: extremes increasing ❖Riverbank and coastal erosion: increasing ❖Water logging and permanent inundation due to Sea Level Rise (SLR) N.B. Need to update with recent references  Drought Cyclone Storm surge, salinity Hazards Bangladesh faces Flood Water logging Bank Erosion Bank erosion Adjusting to Climate Change ❖ Two separate options for addressing climate change: mitigation and adaptation. ❖ Mitigation is defined as any anthropogenic interventions that can either reduce the greenhouse gas emissions or enhance their sinks (sequestration). ❖ Adaptation: Learn to live with climate change because there is warming in the pipeline from greenhouse gases already emitted. Adaptation for Drought ❖ Cultivation of rice with minor irrigation: rice grown in drought-prone areas ❖ Digging of small ponds for water reservoir ❖ Digging of mini pond in a crop land ❖ Less water consuming trees ❖ More vegetation ❖ Homestead Garden ❖ Crop Diversification ❖................................ ❖ ………………………………. Adaptation for Flash Flood in Haor areas ❖ Crop diversification ❖ Swamp vegetation plantation ❖ Canal re-excavation ❖ …………………………….. ❖ …………………………….. Adaptation for Coastal Areas ❖ Cyclone shelter centre ❖ Climate smart house design ❖ Salt tolerant crops ❖ Afforestation to protect the Chars and river bank ❖ ………………….. Be energy – efficient!  Biomass Solar Wind Institutional Initiatives ❖ Bangladesh Rice Research Institute (BRRI) ✓ Should conduct research to develop salinity-tolerant rice species ❖ Bangladesh Agricultural Research Council (BARC) ✓ Research for other agricultural crops ❖ The Bangladesh Forest Research Institute (BFRI) ✓ Identify mangrove plantation technique ❖ The Department of Agricultural Extension (DAE), Ministry of Agriculture (MoA) ✓ Should be involved to disseminate new species and their cultivation techniques. NAPA 2009 Measures ❖NAPA undertook some short-term and medium-term projects on Adaptation. How to mainstream adaptation to climate change into various sectoral policies of the government. Other specific measures are as follows: ✓ Adaptation to coastal crop agriculture ✓ Adaptation to coastal fisheries ✓ Adaptation to flash floods ✓ Adaptation to floods ✓ Adaptation to natural hazards Reading material Chapter 21 Thank you