Issues of recent Interest

List the 5 spheres?

• Atmosphere

• Biosphere

• Hydrosphere

• Cryosphere

• Lithosphere

Atmosphere

The gaseous envelope close to Earth where humans live, containing nitrogen, oxygen, and trace gases/greenhouse gases

Biosphere

The sphere where all living organisms and their interactions are located.

Hydrosphere

All water on Earth.

Cryosphere

All frozen water on Earth.

Lithosphere

The solid surface, land, and soil of Earth.

What happens if one sphere heats up/changes?

Changes affect all the other spheres.

List the layers of the atmosphere

1. Exosphere

2. Thermosphere

3. Mesosphere

4. Stratosphere

5. Troposphere

Troposphere

Lowest layer of the atmosphere (10-15 km) where weather and climate occur.

Why does temp increase with height?

Temperature increases with height because the ozone up there absorbs ultraviolet radiation.

Stratosphere

• 50 km from troposphere

• temperature increases

• Aircraft pass through.

Mesosphere

• 85 km up

• coldest layer reaching 90 degrees Celsius

• where most meteors burn up.

Thermosphere

• 500-1000 km up

• absorbs high energy from solar radiation,

• where the International Space Station orbits.

Exosphere

outermost layer that gradually phases out into space with low density where molecules escape Earth's gravity.

What causes the ozone hole versus global warming?

The ozone hole is a stratospheric ultraviolet problem, whereas global warming is a tropospheric heat-trapping problem.

Ozone hole

Stratospheric problem due to ultraviolet radiation.

Global warming

Tropospheric problem when heat is trapped close to Earth's surface because of greenhouse gases.

Define Global Warming?

An abnormal, sustained increase in the average atmospheric temperature at Earth's surface caused by human activity.

What are the percentages of Nitrogen and Oxygen in atmospheric composition?

• Nitrogen: 78%

• Oxygen: 21%

What are the percentages of minor gases in atmospheric composition?

• Argon: 1%

• Water vapour: 0.4%

• Carbon dioxide: 0.04%

• Neon: 0.0018%

• Other: 0.04%

List the trace gasses

• Carbon Dioxide

• Methane

• Nitrous Oxide

• Ozone

what are trace gasses?

atmospheric gases that make up less than 1% of a planet's volume.

What is Carbon Dioxide (CO2)?

The primary greenhouse gas that increases due to fossil fuel combustion, with a current concentration of 420 ppm.

What is Methane (CH4)?

A gas with 28-36 times the warming potential of CO2 over 100 years. Its sources include wetlands, agriculture, fossil fuel extraction, and thawing permafrost.

What is Nitrous Oxide (N2O)?

A long-lived GHG gas with 265-298 times the warming potential of CO2 over 100 years. Sources include agricultural practices, industrial processes, & fossil fuel combustion.

What does Ozone (O3) do?

• Absorbs UV radiation in the stratosphere, protecting Earth's life.

• Acts as a GHG gas in the troposphere, contributing to warming and air pollution.

What is the average surface atmospheric temperature of Earth?

59 F/ 15 C

How do we know the temperature of Earth is increasing?

Sunlight passes through atmospheric layers, Earth absorbs this light and re-radiates it as heat, and some heat is trapped by the atmosphere while some returns to space (100% energy in = 100% energy out originally).

Why is more energy being trapped on Earth now?

Because of greenhouse gases, more energy is being absorbed and not sent back out to space, which causes warming.

What is the role of human activity in climate change?

• Urbanization,

• deforestation,

• burning fossil fuels enhance natural effects, leading to more trapped heat and warmer temperatures.

Natural vs Enhanced

• The effect of human activity = more heat trapped & warmer temps

• All climate variables are linked together in some way — temperature, rainfall, wind & humidity.

What causes Natural Variation like seasons?

Earth rotating around the sun (taking a year) changes the amount of sun the side of Earth facing the sun normally gets

What causes night and day?

Earth rotating around its own axis.

The further away from the sun, the ______ it is.

cooler

How do volcanic eruptions change our climate?

Ash plumes go high in the atmosphere creating a blanket effect that blocks sunlight, reflecting solar radiation and the heat Earth would have gotten back into outer space.

What additional issue is caused by sulfur from volcanic eruptions?

Acid rain

What are anthropogenic problems?

Human-induced problems.

What is the rising trend in mean temperature for the Caribbean?

0.1 degrees celcius per decade.

How have warm days changed in the Caribbean since the 1960s?

steadily increased by 22 days.

How have warm nights changed in the Caribbean since the 1960s?

steadily increased by 21 days.

How have cold nights and days changed in the Caribbean since the 1960s?

They have decreased, with 14 fewer cold nights and days.

What is happening to sea levels in the Caribbean?

Sea levels are rising

What is happening to tropical diseases in the Caribbean?

They are increasing, with Dengue as an example.

How are atmospheric parameters and their interactions projected for the future?

They are expressed in the form of equations involving 9 time and 3-dimensional spaces, which are solved using computer models because they are too complex and time-consuming to solve by hand.

What is a "scenario" in climate modeling?

Assumptions made by scientists about whether emissions will remain the same, increase, or decrease based on technology and population.

What do climate models project for hot days by the 2090s?

30% to 98% of days annually will be considered "hot" by the 2090s.

What do climate models project for cool days by the 2080s?

Only 2% of days will be considered "cool" by the 2080s.