Earths Climate Flashcards

Troposphere

Where sulfur, pollution, and aerosols go Cools the planet briefly

Where all of the weather happens

Atmosphere

Current CO2 is 420 (double from the industrial revolution of 280 ppm)

Oceans

Phytoplankton hang out in the top part of the ocean to perform Photosynthesis

Phytoplankton are at the bottom of the ocean food chain

Ocean snow bringing CO2 into sediment

Hydrosphere

Water systems

Salt and fresh water

Cryosphere

Ice caps and ocean ice

North hemisphere (formed in the late Cenozoic era)

South hemisphere (formed in the mid Cenozoic era)

Geosphere

rock and earths systems

Silicate weathering

Limestone (CaCO3)

Quartz (SiO2)

Biosphere

living systems (ecosystems)

Photosynthesis vs cellular respiration

Climate Observations: Globally

2024 & 2023 were some of the hottest years globally

“pause” of temperature rise from 1940-1980 arousal pollution

The majority of CO2 was emitted mid the 1970s

1-1.5 Celsius warming since preindustrial times

Climate observations: Cryosphere

Decrease in sea ice from ice not staying frozen

Arctic is melting faster than the Antarctic

However, 2023 & 2024 shows sea ice swiftly disappearing

Contributes to sea level rise

Climate observations: Sea level rise

Most of the rise is form thermal expansion (it literally getting physically bigger)

ice melting contributes to a change in sea salinity

Climate observations: Atmosphere

CO2 is rising swiftly

Milanovich cycles

Roughly 100,000 years long

Tilt

Eccentricity

Precession

Changes how much solar radiation earth receives

Shift recently in temperatures DO NOT line up with the Milinkovich cycles because we are “supposed” to be going into a cooler climate if so (BUT THATS NOT HAPPENING)

Paleoclimate

Climate in the past

Using proxies such as

tree rings (now to 2000 years)

Ice cores (now to 800,000 years)

Marine sediments (now to hundreds of millions of years)

Tree Rings

Ice cores

marine sediments

Isotopic fractionation

measured in ice cores and marine sediments

Hotter temperatures can evaporate “heavier elements” which go back into precipitation

Deuterium- heavy hydrogen

(shows in ice cores more when temp was high)

O18- heavy oxygen

(In ice more when temp is high)

(in ocean sediments when more when temps are low)

C13- Heavy carbon

(biosphere prefers lighter C12)

(low C13 in air shows more fossile fuels contribution)

Late holocene

Last 2000 years

Recent human and earth history

CO2 spiked

Holocene

Last 12,000 years

Coming out of the last glacial period with more climate stability

Agriculture invented 10,000 years

CO2 was stable

Plastiocene

Last 2.58 million years

Ice ages and very variable climate

When temp is low, CO2 is low

Cold water dissolves more CO2 (think like a warm flat soda)

albedo loop

Cenozoic

Last 66 million years

Started 15 Celsius hotter but started a downward temp trend due to silicate weathering

The silicate weathering is from the uplift of the Himalayas made from Africa bumping into India

PETM due to large volcanic eruptions spewing CO2 & blubbering basalt (carbon-rich sediments leading to temp rise) End permian

End cretaceous asteroid crashes into earth and releases aerosols (colder temps)

The circumpolar current is made from the Drake passage (south America and Antarctica) being opened. it’s a cold current keeping Antarctica frozen

Ocean currents

Downwelling- colder, saltier water

Upwelling- hotter, lighter water

This contributes to the ocean carbon cycle

Snowball earth

Volcanic silicate weathering around the equator causing a cooling in that area via more rain

Cools into ice and ice reflects light back into space via Albedo effect

Brought back to life via CO2 volcanic activity

Energy budget

How much radiation earth takes in and how does the atmosphere interact with it

Ozone grabs UV light

Most of sunlight makes it to us

70% of light stays trapped via greenhouse gasses and warms the planet

Positive climate feedbacks

Amplified over time

Ice-Albedo reflecting light back into space making earth colder

Water vapor and methane causing more warming causing trapped material to repeat the process

Negative climate feedbacks

Dampens overtime

Ocean Gas exchange

Silicate weathering

Climate sensitivity

Total amount of warming via radiative forcings (energy from the sun) + other relevent feedbacks

Equilibrium Climate Sensitivity is from CO2 doubling causing a raise in temp

Terrestrial Carbon cycle

Fast processes (stays and leaves fairly fast)

Biological processes

Slow processes (stays and leaves fairly slow)

Silicate weathering

silicates + H2O + CO2 → dissolved ions → rivers → oceans → sequestered in ocean sediments/rocks)

Carbon Cycle in Oceans

Ocean acidification

Ocean Atmosphere exchange

Calcifies role

Anthropogenic Carbon

We know because of

Economic data (countries physically telling us)

Carbon isotopes (fossil fuels have a low C13)

Atmospheric Oxygen concentration (less oxygen in the air)

Summary

Humans put so much CO2 into the atmosphere

CO2 has doubled since pre-industrial PPMS

Greenhouse effect