MB&B Exam 2

Oceans cover

Oceans cover

71% of Earth’s surface

Ocean bottom habitats

Sandy, muddy, rocky

Diverse ocean habitats

coral reef, kelp forest, deep sea hydrothermal vent, open ocean

Food Webs

complex layers of relationships that consist of multiple food chains; food relationships between these organisms exist all at once since different species often have different sources of food

Phytoplankton

Photosynthetic, live in the upper sunlit layer of oceans, and produce half of the oxygen in Earth’s atmosphere. They are eukaryotic organisms

Diatoms

they are eukaryotes, most of them are single-celled organisms, they also conduct photosynthesis, and they have an enclosed cell wall made out of silica

Dinoflagellates

eukaryotic organisms and many of them are photosynthetic

Coccolithophores

unicellular phytoplankton, and they’re eukaryotes

Prochlorococcus

tiny photosynthetic bacterium; probably the most abundant photosynthetic organism on the planet, and one of the world’s most plentiful species; makes 20% of the world’s atmospheric oxygen; part of base of ocean food chain; completely unknown until 40 years ago

Zooplankton

they are small multicellular, eukaryotic organisms that eat phytoplankton

Bacterium SAR11

Completely unknown until 35 yrs ago; Smallest free-living cell known; smallest genome of any cell (~1354 protein-coding genes); accounts for 25% of microbial cells in the ocean; combined weight exceeds that of all fish in oceans; 1028 of them in the oceans: among the most successful organisms on Earth

Archae

Single-celled prokaryotes; different lipids in membranes; extremely abundant in oceans; generate methane in cow gut, in human navel; can live in extreme environments: hot springs, deep sea hydrothermal vents, Great Salt Lake

Ocean Acidification

dissolving carbon dioxide (CO2) in the ocean increases the hydrogen ion concentration and decreases the pH, acidifying the ocean

pH

measure of the concentration of hydrogen ions: H+; acidic solutions has a high concentration of H+; base solutions have a low concentration of H+; basic solution, like bleach, has low pH; acidic solution, like lemon juice, has high pH

common sources of CO2

burning of coal, oil, and gas

Anthropogenic CO2

45% stays in atmosphere; 30% in oceans

Pre-Industrial Ocean Acidification vs Now

8.25 (1751) - 8.15 (1996); Since pH is a logarithmic scale, like the Richter scale for earthquakes, this decline represents a 30% increase in acidity

Rate of Acidification

This rate [of acidification] is 100 times faster than any changes in ocean acidity in the last 20 million years, making it unlikely that marine life can somehow adapt to the changes

Effects of Acidification on Humans

drop of 0.1 pH units in human blood pH can result in seizures, heart arrhythmia, or even coma

Effects of Acidification on Marine Organisms

respiration: ocean acidification slows down many marine organisms respiration, and slowing this down also slows down their metabolism; calcification: building of shells or skeletons; photosynthesis; reproduction; bleaching of coral reefs; killed 14% of world’s coral reefs in a decade

Bleaching of Coral Reefs

when corals lose photosynthetic algae growing on reef which gives it color and produces all oxygen; can be temporary

Pteropod

Shells contain calcium and are sensitive to acidification. These are >50% of the diet of young salmon in the ocean

Ocean Dead Zones

Regions where O2 levels are so low that fish, shrimp, and other animals can’t survive

The Mississippi Basin

41% of the US drains into the Mississippi River and the Gulf of Mexico; 22 million tons of fertilizer are used by US farmers (2015); Nitrogen and phosphorus runs off into streams and ultimately the Gulf

Algae Bloom

Occurs when nutrient-rich water (usually from fertilizer run-off) prompts overpopulation of algae and phytoplankton

Hypoxia

occurs when bacteria consume oxygen while decomposing dead algal cells; not enough oxygen left to support life of fish or shrimp: get a Dead Zone

Gulf of Mexico Dead Zone

Has doubled in size in last 25 years, partly because of conversion of forests and wetlands into farms; bad because it produces: 72% of US-harvested shrimp; 66% harvested oysters; 16% commercial fish; to reduce the size, nitrogen runoff needs to be reduced by 30%

The Black Sea Dead Zone

After the collapse of the Soviet Union, fertilizers became too expensive to use and fishing again became a major industry

US Energy Independence and Security Act of 2007

wanted to produce more biofuel (corn-based ethanol); 25% of US corn croplands are used for ethanol production, but corn production heavily dependent on nitrogen fertilizer; increased nitrogen by 15%l fertilizer use leads to more nitrogen flow into Gulf of Mexico

Midwest Agribusiness

$100 billion in total produce sales; political forces behind nitrogen use in crops

Overfishing

35% of fish stocks assessed worldwide were overfished; ecological issue that disrupts foodchains (if tuna is removed, smaller fish proliferate); 500 mil ppl employed worldwide in fishing; fish is bigger source of protein for ppl than beef

Newfoundland Cod Industry

Ppl had been fishing for cod since 16th century

development of sophisticated fishing technology (boats w longer ranges; better navigation systems; larger nets; sonar tech to locate fish)

got to the point that there was so much overfishing that surviving fish left behind couldn’t reproduce fast enough so that catch went down to 1%

govt ignored scientific recommendation

lots of cultural precedence, jobs in it, and investors in it

only when it went to 1% did govt declare moratorium on fishing

after overfishing, severely reduced, small fish proliferate, survival of eggs declines bc small fish eat eggs; hard for population to recover (hasn’t recovered 25 yrs later)

Solutions to Overfishing

Protected areas where fishing is fairly limited: only 7% is protected that way—>should be 30%

Encourage sustainable fishing: seafood advisory that tells you which fish are in trouble and which aren’t

Swordfish Recovery

Late 1990s: US Government places large area of N. Atlantic off limits; population then increases in N. Atlantic

Plastic Mass

8 Gt v 4Gt (living biomass); there are 86 million tons in oceans, much of which is slow to degrade; 5 trillion pieces are on surface of oceans

Macroplastics

harm animals that ingest them or are entangled in them

Microplastics

ingested by filter feeders and enter food chain

Effects of Plastic

can impair the development, reproduction, and survival of organisms

The Great Pacific Garbage Patch

Estimated 1.8 trillion pieces of plastic

Hantavirus

RNA viruses with 3 strands of RNA

Four Corners Disease

disease that originated where Utah, Colorado, Arizona, New Mexico come together; outbreak followed abnormal weather and a population explosion of deer mice

Reservoir Species

resistant, but if they come into contact w non-resistant animals, can lead to an epidemic that appears “new” in humans

Deer Mouse

hantavirus reservoir species that contained anti-hantavirus antibodies that matched viral RNA of hantavirus in humans

Bushmeat Theory

Around 1921 near Congo, SIV was transmitted to a human whose blood somehow mixed with chimpanzee blood so it became HIV and led to 60 million infections

Simian Immunodeficiency Virus

SIV; found in primates in SubSaharan Africa

Bats

potential Ebola reservoir species; no one has yet been able to purify a live Ebola virus; index case was a 2-year-old boy in Meliandou, Guinea who used to play at a tree that was hollowed out and had a huge bat colony in it

SARS CoV-1

outbreak in 2002-2004; likely animal reservoir is bats but spread to humans via civets and other animals

MERS-COV

Cause of Middle East Respiratory Syndrome; believed to originate from bats; virus transmitted to humans from camels via unclear mechanisms; transmission from human to human is limited

SARS-COV-2

contains single strand of RNA ~30,000 nucleotides in length

Laos bats host closest known relatives of virus behind COVID

spike protein contains a receptor binding domain (RBD) which comes in physical contact w the receptor

discovery raises fears that there are numerous coronaviruses with the potential to infect ppl

still unclear how entered human population, whether it came directly from bats or via another intermediate animal

Index Case

first case to be described in medical literature

Effects of Deforestation

when you cut down rain forests and displace animals, more contact between animals and ppl occurs and more diseases will break out in epidemics; when trees are cut down and decay or burn, they release CO2

Cattle Ranching

70% of Amazon rainforest cutting is for

Amazon Rainforest

called “lung of the world”

Effects of Livestock

cows produce tons of methane—which as 25x problematic on climate change than CO2; livestock contributes 14.5% of anthropogenic greenhouse gas emissions (including dairy, egg production)

Effects of Logging

development project in Amazon like highways have positive short-term economic effect but negative long-term effect on deforestation; spillover of diseases affect the poor the most; cheaper to prevent than to suffer consequences

Canine Distemper Virus

infected tigers and lions in the Serengeti; usually found in dogs who had not been vaccinated against them

Effects of Climate Change on Malaria

1. can spread as range of mosquito can expand; mosquitoes can breed faster at higher temps and need water sources to host life cycle; WHO estimates that temperature increases predicted by IPCC will increase number of ppl at risk by several hundred million

Mercedes Pascual

2. selected region in West Africa and did complicated math analysis that said that small temp increase can lead to large increase in malaria cases; confirmed by another study on spread of malaria to higher altitudes in Ethiopia and Colombia; in warmer years, malaria would spread

Lyme Disease

tick that carries it moved northward to Canada because of warming trends

Cholera

disease acquired by ingesting contaminated water or seafood; colonizes gut; highly contagious; storms and floods can lead to contamination of drinking water; within 3-4 hrs of onset of symptoms, a healthy person may become severely dehydrated and if not treated, can die

How climate change increases intensity of hurricanes

accumulation of CO2 and other greenhouse gases in atmosphere traps heat; 90% of additional heat trapped by greenhouse gases ends up stored in the ocean; ocean temperature rises; hurricanes draw their energy from heat stored in the ocean; warmer oceans mean more intense and longer storms

Storm surge

an abnormal rise of water generated by a storm; greatest threat to life and property from a hurricane; sea levels rising 3mm/year (glaciers melting at both poles, water expands as it warms); higher seas means these reach farther inland

Hurricane Mitch

1998; killed 11,000 people immediately; also killed more due to diseases like cholera, malaria, and dengue

Climate change and human rights

negative impacts of climate change are disproportionately borne by persons and communities who have contributed little to climate change (ie. Pacific island nations)

Climate change and intergenerational justice

the carbon we emit today will have enormous effect on future people

Angela Merkel

German chancellor from 2005-2021; had PhD in Physical Chemistry

China

president has degree in chemical engineering; 80% of elite leadership has degrees in the natural sciences or engineering

Weather

what happens in a certain place at a certain time; day-to-day range

Climate

long-term average of weather over 20-30 years

How We Use Climate

determine residential & commercial building codes, energy demand we plan for, how big water reservoirs should be

Baseline Temperature

measured from base period

1 degree Celcius

Global Warming temperature is almost at

Arctic

warms 4x faster than tropics bc as ice melts, it reveals darker ocean underneath and makes earth more warm and melts more ice; sea ice reflects more than 50% of incoming sunlight; open ocean only reflects 6% of incoming sunlight

Global Warming

• is the increase in avg temperature of the planet that results from enhanced greenhouse effect

• there was relative stability between 1800s-1950s, but rate of warming since 1970s has been accelerating; it’s getting warmer at a faster rate

Intergovernmental Panel on Climate Change

• international intergovernmental group that coordinates thousands of scientists to produce massive reports every 5-7 years

  • 1st report: physical processes underlying warming

  • 2nd report: impacts and adaptation and vulnerability

  • 3rd report: what can we do to reduce emissions?

Disaster risk

Composed of exposure, vulnerability, and weather/climate events

exposure

the people and valuable assets like infrastructure that are at risked for the event; increasing bc we have 8 billion ppl; human population has been following an exponential curve over past 100 years; there are more ppl living in the general area of Asia than outside of it, so, greater exposure; most tropical cyclones go to this area as well; China and other developed countries have billions of dollars toward infrastructure that is rigid and not easy to move; settled civilizations; but most of our cities have yet to be built, so we have a choice as to what we could build

Vulnerability

how prepared we are for weather and climate events; we can evaluate it by looking at state of infrastructure; in the US, an association for civil engineers evaluated the US and gave them C-, bc many of the infrastructure is outdated and vulnerable

Hurricane Matthew

hit Florida in 2016 (27 deaths, 10 billion damages, widespread devastation); hit Haiti, which had a cholera outbreak so there was less attention paid to infrastructure (546 deaths, 200,000 homes, 1.4 mil ppl in need of humanitarian aid, cholera turned into epidemic)

Asthma

exacerbated and amplified by climate change bc as planet warms, existing pollution will be heated and transformed into smog that triggers it in ppl; Puerto Ricans, Black women and children more likely to die from it: attributable to the fact that communities of color are more likely to be located in polluted areas next to highways, factories, and in places that are more vulnerable to extreme weather and climate change

Extreme Weather Events

changing in location, timing, frequency, magnitude, duration

Heat Waves

kill more than other natural disasters bc we have a concrete threshold above which our bodies can’t function; policy infrastructure not meant to deal with it; these emergencies are not eligible for FEMA assistance bc policy is based on economic damages only, not protecting human life

2022 Europe Heat Wave

• data from 1936 to present showed >73,000 deaths; more women than men died; partly bc women live longer, so more elderly women were killed

Wet Bulb Temperature

temperature when sweat can’t evaporate; usually 35 degrees Celcius; if air is 100% saturated, 100% humid, then it is the same as temp of air on a regular thermometer

Urban Heat Island Effect

heat creates pollution, which increases risk of other illnesses - eg a fatal heart attack doubles when extreme heat overlaps w poor air quality

Effects of Heat Waves in Oceans

we’re losing reefs because of this; rate of change in ocean chemistry is faster than any time we’ve observed in past 50 million years

Wildfires

increasing due to longer fire seasons, hotter high temperatures, drier fuels, increasing ignitions from higher populations; contributed to CO2 emissions

Flooding

as you increase temperature by 1 degree C, air can hold abt 7% more humidity; rain clouds store more moisture bc theres more moisture in atmosphere from the ocean, so there’s heavier rainfall; is problem bc of infrastructure in urban and rural areas; even after flooding, you can still have problems w mold growing and spreading diseases

Effects of Heat Waves on Hurricanes

heating planet intensifies hydrological cycle bc of warming oceans —> precipitation rates increasing; storms are getting harder to predict bc it used to be ramping up over several days, but now they intensify quickly; storms move more slowly, getting bigger, moving northward, and sea level is increasing storm surge

John Holdren

said that we have 3 choices: mitigation, adaptation, or suffering; the more mitigation we do, the less adaptation will be required, the less suffering there will be

Mitigation

(first choice): reducing causes of climate change (our carbon dioxide emissions)

• substitute w clean energy

• store more carbon

• reduce energy demand

• retiring coal plants

Adaptation

(second choice): painting services white to reflect sunlight and keep buildings cool, moving houses and buildings above water level; build buffers incorporated within community

Suffering

(3rd choice) people most vulnerable to climate impacts are already where ppl are hungry, thirsty, and in poverty

Joseph Fourier

French mathematician and scientist in 1820s who went to Egypt with Napolean and wondered why he was hot in black clothing while white-garbed Egyptians were less affected by heat

figured out how to calculate the temperature of any object if he knew how much it was heated by the sun and how reflective it was

but if so, Earth should be frozen, so he speculated that there’s a thin layer of air acting like a blanket trapping heat around earth’s surface called greenhouse effect

Eunice Foote

• in 1850s, used glass jars with different gasess to show that CO2 absorbed energy and heated up than other gasses

• hypothesized if atmospheric CO2 were higher, planet would be warmer

John Tyndall

• in 1850s identified which specific gases had vibrational or rotational absorption capacities in the infrared spectrum, ie which gases could absorb the heat produced by the earth

• concluded correctly that water vapor is the strongest absorber of infrared energy or heat in earth’s atmosphere

• identified CO2 and methane as important gases and connected them to coal mining

Greenhouse Effect

• when light (shortwave radiation) from sun reaches the Earth and is absorbed by the surface, heating it up

• traps earth’s energy in lower atmosphere

• Earth then radiates longer wavelengths (heat) back to outer space, trying to keep the system in balance

• some of the heat (infrared thermal radiation) is trapped at the Earth’s surface by natural greenhouse gases

• as humans add more CO2 to the atmosphere, we’re trapping more heat, adding an extra layer of heat

CO2

• makes up .04% of our atmosphere

• has more vibrational and rotational force that is able to bounce back more heat

• heat being trapped by molecules is really most concentrated at the surface of the earth

• there is 200x as much of it in the atmosphere as methane, making this the biggest greenhouse gas

Svante Arrhenius

• in 1890s calculated by hand that doubling CO2 would increase temps by greater than 4 degrees Celcius

  • thought it’d take 3,000 yrs to get there and did not foresee industrial revolution

• calculated correctly that the Arctic would warm much faster than rest of the world

Keeling Curve

• imposed wiggle on upward trend that is the seasonal CO2 breathing of the planet

• showed that in context, CO2 is on exponential curve since 1950s

• we’re producing CO2 from coal, oil, gas