Lesson1 Flashcards
How much have average global temperatures incresaed since 1880?
2.2°F (1.4°C)
The average temp is 15°C
Where has it been worst?
The Arctic.
It has increased 4°C (7.2°F)
What has human activity since 1850 triggered?
a Greenhouse effect
What normally happens when the Sun warms the Earth?
Infrared Radiation is emitted, mostly back out into Space.
What are the major Greenhouse Gases?
Carbon Dioxide (CO2)
Methane (CH4)
Nitrous Oxide (N20)
(smaller: F Gases)
What do the Greenhouse gases do?
They absorb some of the radiation.
What does this absorbtion do?
It raises the temperature of the planet.
What is the weight of Greenhouse Gases currently emitted by humans each year?
51 billion tons
What is the limit of how much more temperature increase to avoid the severest effects of climate change?
1.5 to 2 degrees Celsius
What must we do to avoid the catastrophic effects?
Reduce emmission of Greenhouse Gases to net zero in a few decades (2050).
[What percentage of the Earth’s population live north of the Equator?]
90%
Can Greenhouse Gases occur naturally?
To some extent.
Before 1750, however, it was in equilibrium.
Which is the most prevalent Greenhouse Gas?
CO2
How is CO2 created?
Burning of fossil fuels.
Deforestation.
How is methane (CH4) created?
Livestock.
Fossil fuel production.
Breakdown of waste in landfills.
How is Nitrous Oxide (N2O) created?
Waste from animal agriculture.
Nitrogen fertilzers to increase
crop yields.
What are F-Gases?
Like HydroFluorocarbons (HFCs)
found in refrigerants.
Which of the Greenhouse Gases have a higher warming potential?
Methane
Nitrous Oxide
F-Gases
What is another important
characteristic of
these gases?
How long they stay in the
atmosphere.
How long do each of the gases
stay in the atmosphere?
Methane - 12 years
N2O - 121 years
How are these differences accounted for?
In CO2 equivalents.(CO2e)
How is this done?
They are measured by their 100-year warming potential compared to CO2.
Using this measure, what is the 100-year impact of a ton of methane?
Methane: 28X CO2.
What is the 100-year impact of a ton of nitrous oxide?
N2O: 265x CO2.
What is the 100-year impact of a ton of F-gases (HFCs)?
HFCs: 138x CO2
Given the quantity and staying power, how much do each account for?
CO2 - 75% (38B)
Methane - 17%
N2O - 6%
HFCs - 2%
What is the IPCC?
https://www.ipcc.ch/
Intergovernmental
Panel on
Climate Change
Who does the IPCC serve?
The UN Framework
Convention on
Climate Change.
What is their latest report?
The 6th Assessment Report
https://www.ipcc.ch/ar6-syr/
What is their most fundamental finding?
Humans are influencing Climate Change.
Where is most of the heat increase being retained?
the Oceans
What percentage of heat stored on the planet is in the oceans?
90%
What do warming oceans do?
Warm the atmosphere.
Increase the sea level: thermosteric expansion
How much of current sea level increase is due to thermosteric expansion?
about half
What percentage of glaciers are in retreat?
95%
How detailed have forecasts of Climate Change become?
Within 50 miles.
What else are the models getting better at?
Looking at the connection between weather events and Climate Change
What time of day is warming faster than the other?
Nights
What is the TropoPause?
The place between the Troposphere (where we live) and the Stratosphere.
What has happened to the Tropopause?
Its height has increased.
What has happened to the Stratosphere?
It cooled because of ozone depletion (caused by CFCs) but has stopped.
Do clouds reflect heat back out into space?
Not really.
Wrong color.
Wrong altitude.
What is a tipping point?
A place in a natural cycle where there is so much change, you can’t go back.
What is the Atlantic Meridional Overturning Circulation (AMOC)?
A large system of ocean currents carrying water from the Tropics north.
What does AMOC include?
The Gulf Stream moves heat north. This is why Europe has mild weather.
What has happened to the Gulf Stream?
It has slowed making Europe colder.
What tipping point could there be with the thawing Permafrost?
It contains much organic matter which could rot and turn into methane.
What are Methane Cathrates?
Methane trapped in water crystals on the ocean floor.
What tipping point could we have with Methane Cathrates?
They can explode (one did in Siberia) releasing much Methane.
What are the 2 primary conclusions of the UN report?
- Climate Change is happening now
- The primary driver is the burning of fossil fuels.(Oil, coal, natural gas)
What are oil, coal and gas?
Stored carbon from millions of years is released over just 200 years.
