Climate change ( A1 ) midterm

Assignment questions/Ai

Which is the best definition of climate?

The average weather conditions over a longe period.

Which of the following is a FALSE statement about the change in global mean sea level that is occurring?

Melting sea ice contributes to the rise in global mean sea level. 

Which of the following is a TRUE statement about the change in global mean sea level that is occurring?

There are seasonal trends to mean sea level; rising sea levels can lead to increased coastal erosion and flooding; thermal expansion of seawater as it warms is a factor of rising sea levels; and sea levels can be measured with satellites. 

Which of the following is the best evidence of climate change?

In the past century, sea levels have risen by around 17 cm.

Definition of evidence of climate change

Increased frequency of extreme weather events, rising global temperatures, and shrinking ice sheets are the best evidence of climate change. These indicators highlight significant shifts in the Earth's climate system, impacting ecosystems and human activities.

Which of the following is TRUE about the chemical composition of the atmosphere?

Nitrogen is the most abundant gas, making up about 78% of the atmosphere

What are the chemical composition of the atmosphere?

The atmosphere consists primarily of nitrogen (78%), oxygen (21%), and trace amounts of other gases such as argon, carbon dioxide, and neon.

Which of the following is FALSE about thermal radiation?

Thermal radiation is only emitted by objects that are visible to the human eye.

What is thermal radiation?

Thermal radiation is the emission of electromagnetic waves from all matter that has a temperature greater than absolute zero. It includes infrared radiation and does not require a medium to propagate. Radiation emitted increases with system temperature. Solar and terrestrial radiation both contain infrared radiation. Gases do not behave like black bodies.

What are black bodies, and how are they different from thermal radiation?

Black bodies are idealized physical bodies that absorb all incident electromagnetic radiation, regardless of frequency or angle of incidence. They emit thermal radiation in a characteristic spectrum that depends only on their temperature, unlike thermal radiation from other materials, which may reflect or transmit some frequencies.

What’s electromagnetic radiation in climate change?

Electromagnetic radiation in climate change refers to the spectrum of energy emitted by the sun and the Earth, which includes visible light, infrared, and ultraviolet radiation. This radiation plays a crucial role in regulating the Earth's temperature and climate patterns.

What is the difference between solar infrared and terrestrial radiation?

Solar infrared radiation has a shorter wavelength than terrestrial radiation, as it comes directly from the sun, while terrestrial radiation is emitted by the Earth and has a longer wavelength, being primarily in the infrared spectrum.

What are the similarities between solar infrared and terrestrial radiation?

Both types of radiation are electromagnetic waves and play significant roles in the Earth's energy balance. They both contribute to the greenhouse effect and influence climate patterns.

Which statement BEST describes the requirement for the Earth to be in energy balance?

The total incoming solar energy must equal the total outgoing terrestrial radiation

Which of the following is FALSE when the Earth is in energy balance?

The amount of energy stored in the Earth's oceans equals the amount of energy radiated by the oceans.

Which statement best describes the planetary albedo?

It is the fraction of solar energy reflected by the Earth back into space and varies based on surface composition and cloud cover.

What is the energy balance of the earth?

The condition where the total energy received from the sun equals the total energy radiated back into space, maintaining a stable climate.

Why is the planetary effective temperature much lower than what we observe on the surface?

The effective temperature does not account for the greenhouse effect, which warms the Earth's surface and leads to a higher average temperature than the effective temperature calculated from solar energy alone.

The Earth is currently

Not in energy balance, terrestrial radiation is being partially blocked

How does adding greenhouse gases warm the Earth?

Greenhouse gases absorb and re-radiate infrared radiation, trapping heat within the Earth's atmosphere and contributing to the greenhouse effect, which raises surface temperatures.

What is the greenhouse gas effect?

The greenhouse gas effect is the process by which greenhouse gases in the Earth's atmosphere trap heat by absorbing and re-emitting infrared radiation, leading to an increase in the planet's surface temperature.