Earth System Science
Hydrosphere
Total liquid sphere of the Earth
Atmosphere-
Layer of gasses surrounding the earth
Lithosphere
Outermost, solid, layer of Earth
Biosphere
Encompasses all living things on Earth
Weather v Climate
Weather
State of the atmosphere at any place and time
Climate
Average/typical conditions of atmosphere and how conditions change over time
Weather adds up to climate
Frequency of intense rainstorms
Average annual temperatures over 30 years
El Niño and La Niña
Climate Change
Ice Ages
SI Units
Temperatures : C
Precipitation: mm
Pressure: hPa
Streamflow: m3/s
What is parts per million (ppm)
Pie charts: abundance as a percent
Percent = ppm
Changes in very small abundances
How do we visualize climate
For a single location
Climate graph
Maps
What is an anomaly
Anomaly = observation - mean
Climate Change
Greenhouse Effect and Greenhouse Gases
Fossil carbon has an isotopic signature
Temperature is warming as predicted
Does 5 degrees C matter?
What to do?
CO2 is a green house gas that traps heat in the atmosphere
Weak greenhouse gas
Greenhouse effect
Sun produces solar radiation
Hits the earths surface
Earth radiates heat
Atmosphere gasses absorb the heat
Greenhouse gasses
Water Vapor
Carbon dioxide
Methane
Nitrous oxide
Other man made compounds
How much have we really changed the atmosphere
CO2 has risen from 315 ppm in 1958to 407 ppm in 2018
How do we know that the CO2 is ours
Fossil fuel burning has changed the isotopic C composition of the atmosphere: Our carbon leaves a chemical signature
Fossil fuel has changed the isotopic C composition of the atmosphere
Climate has always changed
Yes but it changing more in recent years
Maybe it is the sun
Number 1 contributor is CO2 not the sun
Didn't it stop warming
No just slowed down for a little bit
Can we predict what will happen to the climate system in 100 years
The biggest think that we are unsure about with climate in the future is what we are going to do about it.
Does 5 degrees c matter
5x the variation of the entire Holocene (last 10k years)
Some change as from last ice to Holocene, but warmer and 20x faster
Falling harvests
Sea level rise
Water shortages and extreme flooding
Extinction of coral reefs and 1.5 C and many other species
Continued extreme wildfire
Other unpredictable risks to the climate system
What are we going to do about ir
Nothing - business as usual
Mitigate - reduce the cause (greenhouse gases)
Build Resilience - invest in infrastructure, emergency support, community-building
Adapt - change the way we live to suit warmer climate