GEO217 Climate Change and Sustainability

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Questions and Answers

What distinguishes weather from climate?

Climate is the average of meteorological parameters over a long time. (correct)

Climate refers to short-term fluctuations.

Weather does not involve extreme events.

Weather is influenced by human activities.

Which factor does NOT contribute to climate variability?

Daily temperature changes (correct)

Natural variations in earth's orbit

Changes in solar intensity

Volcanic eruptions (correct)

What are considered external forcings that can change the climate system?

Individual weather events

Long-duration droughts

Periodic solar activity (correct)

Day-to-day weather patterns

How do greenhouse gases affect Earth's temperature?

They trap heat within the atmosphere. Signup and view all the answers

What happens when the concentration of greenhouse gases is too high?

Too much heat is trapped, raising temperatures. Signup and view all the answers

Which statement best describes the climate system?

It involves complex interactions among multiple components. Signup and view all the answers

What have human activities contributed to the atmosphere since the Industrial Revolution?

Substantial increases in greenhouse gases Signup and view all the answers

Which of the following best exemplifies a natural variation affecting climate?

Variations in Earth's orbit over thousands of years Signup and view all the answers

What percentage of CO2 emissions is attributed to electricity production, transportation, and industrial processes combined?

80% Signup and view all the answers

At what rate has the Earth's surface and oceans warmed since 1957?

0.13 °C per decade Signup and view all the answers

What phenomenon is associated with the increase in the frequency and intensity of storms as the atmosphere warms?

Changes in the global water cycle Signup and view all the answers

What contribution do melting glaciers and snowpacks make to rising sea levels?

They contribute alongside the thermal expansion of water Signup and view all the answers

What percentage of actively publishing climate scientists agree that humans are causing global warming?

97% Signup and view all the answers

Which of the following is NOT an impact of climate change mentioned?

Increased biodiversity Signup and view all the answers

What percentage of emitted CO2 do oceans absorb, leading to acidification?

25% Signup and view all the answers

Which area is experiencing an increase in annual precipitation as a result of climate change?

Kerala, India Signup and view all the answers

What percentage of solar radiation that hits the atmosphere is reflected back into space?

30% Signup and view all the answers

Which gas is considered the most abundant greenhouse gas in the atmosphere?

Water Vapor Signup and view all the answers

What is the Global Warming Potential (GWP) of Carbon Dioxide (CO2)?

1 Signup and view all the answers

How long does Methane (CH4) remain in the atmosphere on average?

A decade Signup and view all the answers

Which greenhouse gas has the highest Global Warming Potential per molecule?

Sulfur Hexafluoride (SF6) Signup and view all the answers

What is the estimated GWP of Nitrous Oxide (N2O) over a 100-year timescale?

273 Signup and view all the answers

Which gas accounted for 82% of all human-caused greenhouse gas emissions?

Carbon Dioxide (CO2) Signup and view all the answers

What phenomenon contributes to the positive feedback loop associated with water vapor in the atmosphere?

Increased warmth leads to more evaporation Signup and view all the answers

Study Notes

Climate Change and Sustainability

GEO217 course on climate change and sustainability
Course instructors: Mohamed Mahmoud, PhD, and Tarek Abdel Shafy, PhD
Contact information provided for instructors

Understanding the Climate System

Weather: Day-to-day changes in meteorological parameters (e.g., rainfall, temperature, pressure) at a specific location. Often described by extreme events like heat waves, downpours, and cold spells.
Climate: The average weather over a long time period (30-50 years) in a region.

Climate Variability

Climate variability: The way aspects of climate (like temperature and precipitation) differ from an average. Driven by natural factors like changes in the circulation of air and ocean currents, volcanic eruptions, and other factors.

Climate System

Climate system: A complex interactive system encompassing the atmosphere, land surface, snow, ice, oceans, other water bodies, and living things.

What is Climate Change?

Climate change: A change in climate directly or indirectly attributed to human activity altering the global atmosphere's composition, in addition to natural climate variability over comparable time periods.
Long-term changes in climate, happening over decades, centuries, or longer.
Caused by increasing greenhouse gases produced by burning fossil fuels (e.g., coal, oil, and natural gas).

What Causes Climate Change?

Climate change: Driven by imbalances in Earth's energy balance—how much energy from the sun enters the Earth's system versus how much is released back into space.
This imbalance can be likened to people gaining weight due to an excess of calories in comparison to calories burned.

How Can Climate Be Changed?

External forcings: Factors that alter the climate system, such as natural variations (e.g., changes in Earth's orbit, solar intensity), volcanic eruptions (altering aerosols blocking sunlight, and altering carbon dioxide concentrations), and human activities (e.g. burning fossil fuels).
These external forces drive changes in climate over time.

Greenhouse Gases

Greenhouse gases (GHGs): Gases that trap the sun's energy, thus preventing it from escaping back into space and impacting the Earth's temperature.
Added to the atmosphere in significant quantities due to human activities since the Industrial Revolution.
Acting like a blanket or windshield to trap heat, leading to rising temperatures outside the range of natural variation.
Key greenhouse gases: Water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), Chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6)

Carbon Dioxide (CO2)

Carbon Dioxide (CO2): The most significant human-caused GHG.
Major source of CO2 emissions: the combustion of fossil fuels (coal, oil, and natural gas) for electricity production, transportation, and industrial processes.
CO2 emission from these three activities accounts for more than 80% of the CO2 released into the atmosphere.
Dominates the warming effect among human-caused GHG emissions to date: 82%

Examples of Greenhouse Gases

Water vapor: The most abundant greenhouse gas, its concentration increases with warming.
Carbon dioxide (CO2): Has a global warming potential (GWP) of 1. Remains in the atmosphere for a long time (thousands of years).
Methane (CH4): Estimated GWP of 27–30 over 100 years. Short atmospheric lifetime (approximately a decade) but higher energy absorption than CO2 leading to a higher GWP.
Nitrous Oxide (N2O): High GWP of 273 times that of CO2 over 100 years and long atmospheric lifetime (more than 100 years)
Other strong GHGs: Chlorofluorocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, perfluorocarbons, and sulfur hexafluoride (high global warming potential and often thousands or tens of thousands times higher than CO2).

Impacts of Climate Change

Warming temperatures: Earth's surface and oceans have warmed at a rate of .13°C per decade since 1957—twice as fast as the previous century.
Changes in the global water cycle: Significant geographic changes in total annual precipitation (some areas experiencing severe drought or increased rainfall).
Declining glaciers and snowpack: Nearly all glaciers are shrinking in area, volume, and mass.
Sea level rise: Warmer water expands, and melting glaciers contribute to rising seas.
Ocean acidification: Oceans absorb significant CO2, leading to acidification.

Global Average Surface Temperature

2021 was the sixth-warmest year on record.
Averaged across land and ocean, the 2021 surface temperature was 0.84°C warmer than the twentieth-century average (13.9°C) and 1.04°C warmer than the pre-industrial period (1880–1900).

Is Climate Change Real?

The vast majority of actively publishing climate scientists (approximately 97%) agree that humans are causing global warming and climate change and urgent action is needed to mitigate its impacts.

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Description

This quiz covers key concepts from the GEO217 course on climate change and sustainability. It includes definitions and explanations of weather, climate variability, and the climate system. Test your understanding of how these elements interact and influence our environment.