Environmental Science CH 15 (EXAM 3)

La Niña

During intervening La Niña years, hot, dry weather is often present. Resulting high sea surface temperatures cause hurricanes to be more violent. Notes: ~La Nina ~Right now in La Niña, droughts,

Atmospheric Gases

Earliest atmosphere likely consisted of mostly lightweight hydrogen and helium • Over billions of years, most of those diffused into space • Volcanic emission added carbon, nitrogen, oxygen, sulfur, and other elements to the atmosphere • Almost all molecular oxygen that we breathe was produced by photosynthesis in blue-green bacteria, algae, and green plants (~volcanic emission — natural occurrence ~i.e. dust, pollutant particles: aerosols) The atmosphere today is composed of: •Nitrogen gas •Oxygen gas •Water vapor (varies between zero and 4%) •Aerosols-minute, suspended particles & droplets

Flooding, Storms and Disease

Melting of the glacial ice caps in Greenland and Antarctica could raise global sea levels 100 meters • This would many flood coastal areas where 1/3 of the world's population live. Insurance companies have $2 trillion in insured properties along U.S. coastlines at risk from flooding or severe storms. • At least 87,000 homes in the U.S. within 150m (500 feet) of a shoreline are in danger of coastal erosion or flooding in next 50 years

Should We Focus on Methane Instead?

Methane is a more powerful absorber of heat energy than carbon dioxide. Reducing methane emissions from landfills, rice paddies, oil wells and coal mines could reduce warming. Reducing the number of ruminants could help also. (Clone set burning fossil fuel; releases to atmosphere prior to burning is harmful to the environment)

Ice Cores

collected from glaciers, have revolutionized our understanding of climate history. • Air bubbles trapped in ice can be analyzed for atmospheric composition. • Reveals information about past atmospheric conditions. • We can reconstruct past temperature patterns. • Vostok ice core gives us a record back 420,000 years.

Carbon Dioxide

emissions have doubled from 1970 to 2015 • fossil-fuel burning is the major human caused source of carbon dioxide.

Climate

long term patterns of temperature and precipitation

Weather

physical conditions in the atmosphere (humidity, temperature, air pressure, wind and precipitation) over short time scales

Implement Emissions Trading

to promote cost-effective emissions reductions

The 4 Zones of the Atmosphere

troposphere, stratosphere, mesosphere, thermosphere

Hurricanes

(Atlantic) • Katrina in 2005 caused most devastation primarily due to storm surge. Type of Cyclonic Storms

Alternative Practices Can Be Important

(Greenhouse gases can be captured and stored) Carbon capture and storage is beginning to be practiced. • Some companies, like Norway's Statoil, are pumping carbon dioxide into an aquifer beneath the seafloor via a gas well. (Injecting CO2 increases pressure on oil reserves and enhances oil recovery) • The carbon is sequestered, the company avoids carbon taxes on emissions and the increased pressure on oil reserves enhances oil recovery.

Thermosphere

(Heated layer) • Begins at 80 km • Region of highly ionized (electrically charged) gases and high temperatures (heated by steady flow of high- energy solar and cosmic radiation) • Lower thermosphere has ions which are struck by high energy radiation resulting in the Aurora borealis (northern lights)

Typhoons

(Western Pacific) Type of Cyclonic Storms

Anthropogenic Climate Change

(~anthropogenic — Human activities ~changing the planet in a way it might not change back ~climate change is not a new concept) Many scientists believe that anthropogenic climate change is the most important environmental issue of our time. • Not a new concept; 1895 Svante Arrhenius predicted CO2 released by coal burning could cause global warming • At the time it seemed theoretical only and real impacts seemed unlikely The earliest data came from an observatory on Mauna Loa volcano in 1957; built in a remote location to capture data on air chemistry in an undisturbed pristine environment. • Early measurements showed CO2 concentrations were increasing 0.5 % per year • Currently carbon dioxide levels are rising at over 2 ppm per year. • Levels have risen from 315 ppm in 1958 to over 400 ppm in 2017.

Convection Currents

(~differences in pressure causes localized weather patterns) Releasing latent heat causes air to rise, cool, and lose more water vapor as precipitation. Warm air close to equator vs. cold air at poles also produces pressure differences that cause weather. • vertical convection currents

Ocean Currents Modify Weather

(~mixing of deep ocean water, replacing surface water sediments) Warm and cold ocean currents strongly influence climate conditions on land. • Surface ocean currents result from wind pushing on ocean surface and the Coriolis effect • As surface water moves, deep water wells up to replace it causing deeper ocean currents. • Ocean circulation is also driven by differences in water density due to temperature and saltiness of water • Huge circling gyres carry water north and south redistributing heat from low latitudes to high altitudes

Many People Rely on Seasonal Rains

(~positive and neg for monsoons In general rely on it) Monsoon • Most prevalent in subtropical and tropical areas. • Tilt of earth's axis changes location where the sun is most intense over the course of the year. Places where the sun shines most directly have evaporation and convection currents which bring thunderstorms. • Seasonal rains support tropical forests and fill large rivers such as Ganges and Amazon. • Supports life, but flooding can also take it away.

4 Steps For Combating Climate Change

1. Implement emissions trading 2. Technology sharing 3. Reducing deforestation 4. Helping poorer countries respond to climate change

Historical Climate Changes

A historical climate change that had destabilizing effects on human populations was the Little Ice Age that began in the 1400's. Temperatures dropped, crops failed, fish migrations changed, and shipping lanes were blocked with ice Ice cores show drastic changes may have occurred over short periods (abruptly) of time (years or decades rather than centuries). • During last interglacial period (135,000-115,000 YA), temperatures flipped suddenly from warm to cold and vice versa over decades rather than centuries

Low Pressure

Air is rising

High Pressure

Air sinking

Absorbed vs Reflected Solar Energy

Albedo: reflectivity of surfaces ~higher albedo more reflection, tend to be white in color

Observations of Climate Change

Average global temperature climbed 0.6°C (1°F) in last century. • Sixteen of the warmest years in the past 150 have occurred since 1998. • Poles are warming fastest (4°C, 7°F) over past 50 years. • Permafrost is melting in Alaska and Canada and houses, pipelines, sewage systems, and transmission lines are being damaged as the ground sinks beneath them. • Beetle infestations due to warmer winters are killing millions of hectares of pine and spruce across western North America • Arctic Sea ice is half as thick as it was 30 years ago, and the ocean area covered by ice has decreased by 1 million km2 in 30 yr. • Polar bears are dying as they attempt to find pack ice (which is declining) on which to hunt. • Antarctic ice shelves are disappearing. • Penguins have declined 50% in last 50 yrs. • Glaciers are retreating all over the world. • Sea-level is rising at about 1 mm per year. • The oceans are absorbing and storing more heat. • Oceans are absorbing some of the extra CO2 but that is acidifying the ocean and damaging corals. • Growing seasons are lengthening in Northern hemisphere. Some animals are breeding earlier or extending their range, others are disappearing. • Droughts are more frequent and widespread and storms more severe. • Animal breeding and migratory schedules are changing. • Some species are declining or going extinct due to warming temperatures and loss of habitat.

Stabilization Wedges Could Work Now

By utilizing Wedge Analysis the problem of climate stabilization can be broken down into smaller, bite- sized pieces. To stabilize carbon emissions we would need to cut 7 GT (gigatons) over the next 50 years. Doubling vehicle efficiency, and halving the miles we drive would save up to 1.5 GT. Installing energy efficient appliances, lighting and insulating building could save another 2 GT. Capturing and storing carbon emissions from power plants and gas wells could save another GT.

Important Greenhouse Gases

Carbon Dioxide Methane Nitrous Oxide CO2 is the Most Important Greenhouse Gas The relative effects of each greenhouse gas can be seenbyconvertingthemtoCO2 Equivalents.

An Option for Controlling Emissions

Carbon Trading

Carbon Trading

Carbon Trading: legal limits on emissions are set and countries that want to emit more must purchase emissions credits from others. • This approach is favored under Kyoto. By 2016, Global trade had grown to 140 billion tons worth $53 billion. But markets have failed, thus far, to set a price high enough to encourage much change.

Natural Climate Variability

Climates shift on scales of decades, centuries or millennia. •Ice cores (~past carbon dioxide patterns ~analyzed for atmosphere gas content)

Multi-Decade Oscillations

Climatologists have observed many decade-scale oscillations - • Pacific Decadal Oscillation • North Atlantic Oscillation, or NAO

Frontal Systems Create Local Weather

Cold Front and Warm Front

Conservation and Renewable Energy Offer the Best Solutions

Denmark gets 40% of its electricity from windmills, and plans to increase that to 50% by 2030 Individual cities like Copenhagen, Helsinki and Toronto have pledged to reduce carbon emissions by 20% by 2010. (Many have met or exceed their targets) Current U.S. emissions are about 9 percent higher than in 1990, but have declined slightly since 2008, largely because of a decline in coal use. Benefits: Conservation efforts save energy costs and shifting to renewable energy frees us from dependence on foreign oil.

ENSO Effects on North America

During an El Niño year, the northern jet stream pulls moist air from the Pacific over the U.S. • Intense storms and heavy rains from California to the Midwestern states

latent heat.

Energy stored in water vapor as latent heat • When water vapor condenses, heat energy is released (580 calories of heat/gram water). • Heat and water move from warmer areas near the equator towards cooler areas at poles. Heat redistribution prevents extreme temperature fluctuation.

Notes on Solar Energy

Intensity of sun rays on how they strike the earth ~trailhead on at the equators ~less intense as the angle hits the earth surface, lowest angle at the pole, aka coldest

Energy and the Greenhouse Effect

Most solar energy reaching the Earth is near infrared (high intensity, short wavelength). • Energy re-emitted by the earth is mainly far infrared radiation (lower intensity, long wavelength, heat) • Longer wavelengths are absorbed in the lower atmosphere, trapping heat close to the earth's surface. • Greenhouse Effect

Convection and Atmospheric Pressure

Much of solar energy absorbed by the Earth is used to evaporate water. • latent heat

The El Niño Southern Oscillation (ENSO)

Occurs when warm surface waters in Pacific Ocean move back and forth between Indonesia and South America. Most years, the pool is held in western Pacific by steady equatorial trade winds. Surface waters driven westward by trade winds allow upwelling of cold, nutrient rich waters off west coast of South America benefiting fisheries. Every three-five years the Indonesian low collapses and the mass of warm surface water surges back east Notes: ~from SA to Indonesia ~cold water rises to top, mixes, warmer water blows off, nutrients at bottom have resurfaced, fishing is benefited by this ~every 3-5 years it does not happen

Absorbed Solar Energy

Of the solar energy that reaches the outer atmosphere: • About one-quarter is reflected by clouds and the atmosphere. • Another quarter is absorbed by carbon dioxide, water vapor, methane, ozone and a few other gases. • About half reaches the earth's surface. • Some of this solar energy is reflected back by portions of earth's surface covered with water, snow, ice and sand.

Regional Initiatives Are Emerging

The U.K., New Zealand, Germany and many other countries are working to reduce carbon emissions voluntarily. The United Kingdom has rolled back its CO2 emissions to 1990 levels and is aiming for a 60% reduction by 2050. New Zealand has pledged to be the first Carbon Neutral country

Winds

The movement of air from high to low pressure areas

Ocean/Atmosphere Cycle

There are also decades long oscillations in the oceans and atmosphere The ocean and the atmosphere have regular patterns of flow or currents, but these may shift from time to time. Winds and rains may change because of these shifts. El Niño or ENSO (El Nino Southern Oscillation) is an example of such a shift.

Northern Lights

above the earths surface, high energy charged areas

Types of Cyclonic Storms

all cyclonic storms just depends where it happens (hurricanes, typhoon, tornadoes)

Intergovernmental Panel on Climate Change or IPCC

an international group of scientists and governmental representatives from 130 countries formed to review the scientific evidence for climate change. • The 2013-2014 report stated that there is a 99% probability that some observed climate changes are the result of human activities. • The report projects warming of 1 to 6°C by 2100 with the best estimate being 2 to 4°C (3 to 8°F) •For perspective, there has only been a 5°C rise since the last ice age 20,000 years ago. Notes: ~some observed climate change is due to human activities ~Make general assessments of all climate change research at regular intervals of time ~need both natural and anthropogenic causes of warming included for models of climate change to be in most agreement of observed data

At Mid-Latitudes

angle of sun is lower; heating less intense

North Atlantic Oscillation (NAO)

another oscillation that occurs between Canada and Europe.

Cold Front

boundary formed when cooler air pushes away warmer air • Cold air is denser, tends to hug the ground and pushes warm air up. • The warm air is cooled which triggers strong thunderstorms.

Warm Front

boundary formed when warm air slides over cooler air • Warm air is less dense and slides over cool air • A long wedge-shaped band of clouds is formed • Can bring days of drizzle.

Tropopause

boundary that limits mixing between the troposphere and upper zones as air ceases to rise since it is no longer warmer than its surroundings (the limit, forms boundary between troposphere here and stratosphere)

Helping Poorer Countries Respond to Climate Change

by honoring pledges for development assistance to adapt to climate change (Sustainable)

Greenhouse Gases

gases in the atmosphere, especially carbon dioxide, water vapor, nitrous oxides, methane and other substances that retain heat. • Burning fossil fuels releases extra carbon dioxide. • Deforestation destroys carbon sinks. Notes: ~certain gases when become too consented, negative impact, cause global warming ~come from agriculture, commercial/residential processes, industry, electricity (burning of fossil fuels), transportation (gasoline) ~most of the gas emotions are carbon dioxide, then methane, then nitrous oxide ~methane produces more heat, even in smaller amounts that carbon dioxide, can be more harmful

Troposphere

immediately adjacent to the earth's surface • Ranges in depth from 18 km over the equator to 8 km over the poles. • Air is in constant motion • Air absorbs energy from the sun-warmed earth's surface and moisture evaporating from oceans • Convection currents (warm air circulates in vertical and horizontal currents) redistribute heat and moisture around the globe. • Air temperature drops rapidly with increasing distance from the earth. (Majority of evaporations occurs over oceans) • Tropopause

Carbon Neutral

reducing green house gas emissions to zero. New Zealand has pledged to be the first Carbon Neutral country-reducing green house gas emissions to zero by 2025

Methane

ruminants and rice paddies are sources • Absorbs more energy than CO2.

Monsoon

seasonal reversal of wind patterns caused by differential heating and cooling rates of oceans and continents

Weather

short-lived, local patterns of temperature and precipitation due to circulation of the troposphere (layer immediately adjacent to earth's surface)

At Poles

sun shines low on the horizon much of year; little heat is available for heating land

Near Equator

sun shines straight overhead; solar heating is intense

Tornadoes

swirling funnel clouds that form over land • Generated by "supercell" frontal systems where strong dry cold fronts collide with warm humid air • Greater air temperature differences in the spring, thus more tornadoes Type of Cyclonic Storms

Nitrous Oxide

vehicle engines, agriculture processes are major sources. • Highly effective at capturing heat energy.

Pacific Decadal Oscillation

very large pool of warm water moving back and forth across the North Pacific every 30 years.

Reducing Deforestation

which is a quick and highly cost- effective way to reduce emissions (Don't cut the trees, keep CO2 inside of them)

Technology Sharing

with less developed countries that would double research investment in clean-energy technology

Energy Balance

~5% reflected rom earth 25% reflected from cloud, 25% absorbed 45% absorbed by earth ~absorbed energy warms air, contributes to convention currents before going back into space, evaporates water,

The purpose of ice core drilling is to analyze trapped ancient bubbles of atmosphere for ________ and _______

~co2 and oxygen isotopes (tiny bubble are oxygen that is trapped)

What can you do?

~fuel-efficient vesicle ~carpooling ~weatherization ~driving behavior ~appliance efficiency ~heating, AC equipment

Gyres

~water movement cycles within world's oceans 5 main gyres ~Indian, North Pacific, South Pacific, North Atlantic, South Atlantic ~Pass equators go counterclockwise

Greenhouse Effect

• A natural phenomena where the atmosphere transmits sunlight while trapping heat. • This process supports life as we know it. • Greenhouse Gases

Rain

• Air cools as it rises, and water condenses as air cools. • Pressure decreases as air rises causing cooling. • Condensation nuclei (tiny particles) must also be present to have precipitation; form a surface on which water molecules can begin to coalesce

vertical convection currents

• Air near surface warms and becomes less dense than the air above it; rises above cool air creating vertical convection currents (rising or sinking air currents that stir the atmosphere and transport heat from one area to another).

Global Warming will be Expensive

• At present, reducing greenhouse gas emissions would cost 5% of world GDP according to Stern report. • If we delay, it could cost as much as 20% of world GDP. • Energy production will need to be 80% decarbonized by 2050 to stabilize climate. • Those in richer countries will be able to blunt the effects of climate change. • Those in poorer countries will suffer the most; at least 200 million people will become refugees of floods or victims of drought.

Atmospheric Circulation

• Atmosphericcirculation carries heat and moisture from warm humid places to cool drier places • Pressuredifferencesarean important cause of wind • Thereisalwayssomeplace where high pressure (sinking) air and another with low pressure (rising) air • Airmovesfromhightolow pressure creating "wind" Notes: ~second law of thermodynamics high to low concentration (entropy) ~counter clockwise in southern hemisphere ~northern hemisphere, clockwise ~easterlies at poles ~outerside, convection currents, high to low pressure

Stratosphere

• From tropopause up to about 50 km (31 miles) • Has almost no water vapor, but 1000X more ozone than the troposphere

Jet Streams

• Hurricane force winds at the top of the trophosphere that circle the earth • Follow an undulating path approximately where the Hadley and Ferrell cells meet • Affect weather patterns (~outer current)

Energy is Redistributed Around the Globe

• Incoming solar energy that passes all the way through our atmosphere is absorbed by the ground surface or by water • Incoming solar energy is unevenly distributed around the globe (~all other resources are unevenly distributed) • equator • mid-latitudes • poles

The Zones of the Atmosphere

• Layersofthe atmosphere vary in temperature and composition • Our weather happens in the troposphere • Stratospheric zone is important for blocking UV solar energy (Extends to 87 miles above earths surface)

Mesosphere

• Middle Layer where the temperature diminishes again.

Paris Climate Agreement (2015)

• Most important international agreement since the Kyoto Protocol • The 195 countries in attendance at the Paris meeting agreed on a number of major points: •Holding the global average temperature increase to well below 2°C (above pre-industrial levels) is necessary; Below 1.5°C should be the target. •Reduction plans submitted thus far are not sufficient to keep warming below 2°C, so plans must be revised every five years. •Zero carbon emissions •Voluntary emissions reductions goals by participating countries •Climate finance is necessary •Advanced economies agreed to strive toward donations of $100 billion per year to a "green carbon fund" to support low-carbon development in emerging economies The Paris accord required ratification by at least 55 countries, accounting for 55 percent of global emissions, to come into force. Remarkably, this goal was achieved within a year. • U.S. signed on in April 2016; Obama committed the U.S. to contributing 3 billion to the green carbon fund • Trump withdrew the US in 2019

Atmosphere

• Of all the planets in the solar system, only Earth has an atmosphere that makes life possible • Retains solar heat, protects us from deadly radiation in space, and distributes water around the globe • Consists of gas molecules held near the earth's surface by gravity and extending upward about 500 km (~310 miles)

Ozone

• Ozone is a pollutant near the earth's surface but serves important function in stratosphere: • Ozone absorbs ultraviolet light, which warms upper part of stratosphere. • Ozone protects all life on Earth since UV radiation damages living tissues. • Ozone is being depleted by pollutants including Freon (used as refrigerant) and bromine (used in pesticides). (UV—skin cancer CFC caused hole in ozone, still there, slowed it, the hole allows the UV to penetrate the earth to a greater extent)

Effects of Global Warming

• People will experience more extreme weather including droughts, floods, heat waves and hurricanes. • These could have disastrous economic and human costs. • Estimates project a sea level rise of 1 to 2 meters. • This could flood low-lying coastal cities like New Orleans, Miami, Boston, New York and London and Mumbai. ~projected sea level rises

Summer Monsoons in India

• Summer monsoon air flows over the Indian subcontinent • Warming air rises over the plains of central India in summer, creating a low- pressure cell that brings in warm, wet oceanic air • As moist air rises over the Western Ghats or Himalayas, it cools and heavy rain results • These monsoon rains flood the rivers, bringing needed water for agriculture but also causing human suffering

Computer Models Provide Evidence of Human-Caused Climate Change

• Traditional controlled experiments on the climate are impossible, but complex computer models can be used to simulate climate based on known natural fluctuations and human inputs. • If a computer model can accurately predict past climate, this is an indication of its effectiveness at predicting future climate. • When the models are run without human inputs the predictions don't match historical climate records. • When they are run with the human inputs, they do predict historical climate records.

Envisioning Solutions Kyoto Protocol (1997)

• Was not successful in in terms of reducing overall global emissions. • However, many countries, mostly in Europe, met or exceeded their target reduction of 5 to 10 percent below 1990 emissions by 2012. • China and India were both exempt from this agreement due to poverty and were allowed to expand economic development and improve standard of living. • The legislatures of both Australia and the U.S. declined to ratify the agreement.

Parts of the Atmosphere

• Weather • Climate

The Coriolis Effect

•As air warms at the equator, rises, and moves northward, it sinks and rises in several intermediate bands, forming circulation cells. • Winds and currents appear to move clockwise in Northern Hemisphere (Gulf Stream) and counterclockwise in the Southern Hemisphere (Humboldt Current). • This curving pattern results from the fact that the earth rotates in an eastward direction as winds move above it. • Surface flows do not move straight north and south but are deflected due to Coriolis effect. Notes: ~tilt of the earth and rotation that cause the differences in the patterns of the winds ~causes clock wise and counter clock wise movements

Cyclonic Storms

•When water vapor is abundant, the latent heat released by condensation intensifies convection currents and draws up more warm air and water vapor. •The storms swirl in a direction dictated by the Coriolis effect and are called cyclonic storms •Storm cell will exist if temperature differences exist.