The Human Impact

Question 1

What was the CO2 concentration pre-industrial and what is it now?

Answer 1

The CO2 concentration was 280 ppm pre-industrial and is now 420 ppm in 2024.

Question 2

How much has the CO2 concentration increased in the last 200 years?

Answer 2

There has been a 50% increase in CO2 concentration in the last 200 years.

Question 3

What effect does CO2 and H2O have on radiation?

Answer 3

CO2 and H2O let incoming shortwave radiation in but trap outgoing longwave radiation, re-radiating it back to the Earth.

Question 4

What evidence is there for climate change?

Answer 4

Evidence includes extreme heat waves, increasing wildfires, and melting glaciers.

Question 5

What is the Keeling Curve?

Answer 5

The Keeling Curve shows the overall trend of increasing CO2 ppm since 1958.

Question 6

What does HadCRUT5 measure?

Answer 6

HadCRUT5 measures global average temperature change.

Question 7

How much has the world temperature increased since 1850?

Answer 7

The world temperature has increased by over 1.5°C since 1850.

Question 8

What is the impact of a 1°C increase in air temperature?

Answer 8

A 1°C increase in air temperature means it can store 7% more water.

Question 9

How do ocean temperature changes compare to land?

Answer 9

Oceans heat up much less than land, with changes 3-4 times lower than temperature increases.

Question 10

What has happened to Arctic sea ice since 1979?

Answer 10

The amount of Arctic sea ice has decreased significantly, with the Arctic becoming 13.3% smaller every decade.

Question 11

What is the ice albedo positive feedback loop?

Answer 11

Ice reflects a lot of incoming insolation, but if it melts, darker ground absorbs more insolation, increasing temperatures.

Question 12

How much have sea levels risen since pre-industrial levels?

Answer 12

Sea levels have risen by 30 cm since pre-industrial levels.

Question 13

What are the main causes of sea level rise?

Answer 13

Melting terrestrial ice and thermal expansion of water as it heats up.

Question 14

What was the hottest decade in the 20th century?

Answer 14

The 1990s was the hottest decade in the 20th century.

Question 15

What did the 1997 Kyoto Protocol aim to achieve?

Answer 15

It aimed to reduce greenhouse gas emissions to 5.2% below 1990 levels over the period 2008-2012.

Question 16

What percentage of greenhouse gas emissions is CO2?

Answer 16

76% of emissions are CO2.

Question 17

What is the atmospheric lifetime of methane?

Answer 17

Methane has an atmospheric lifetime of 9-15 years.

Question 18

What is the primary greenhouse gas contributing to climate change?

Answer 18

Carbon dioxide (CO2) is the primary greenhouse gas.

Question 19

How much CO2 is released by human activities annually?

Answer 19

Human activities currently release over 50 gigatons of CO2 into the atmosphere every year.

Question 20

What percentage of global greenhouse gas emissions does the food industry account for?

Answer 20

The food industry accounts for roughly a quarter of total global greenhouse gas emissions.

Question 21

What is the impact of urban areas on local climates?

Answer 21

Urban areas modify temperature, precipitation, humidity, and wind.

Question 22

What is an urban heat island?

Answer 22

An urban heat island is a localized area that experiences higher temperatures than surrounding rural areas.

Question 23

How much more rainfall occurs in London compared to surrounding areas?

Answer 23

Up to 25% more rainfall occurs in London compared to surrounding areas.

Question 24

What effect do tall buildings have on wind in urban areas?

Answer 24

Tall buildings can channel wind and create an ‘urban canyon’ effect, increasing local wind speeds.

Question 25

What happens during a temperature inversion in cities?

Answer 25

Pollution gets trapped in a city, creating thick smog.

Question 26

What is the effect of the Venturi Effect on local wind speeds?

Answer 26

Local speeds are higher due to the Venturi Effect, creating turbulence and abrupt changes in wind direction and speed, increasing the frequency of turbulent winds.

Question 27

How do urban areas compare to rural areas in terms of average wind speeds?

Answer 27

Urban areas experience slower average wind speeds compared to rural areas, which may see higher velocity winds.

Question 28

What happens to pollution in the presence of strong prevailing winds?

Answer 28

Strong prevailing winds can blow pollution to the side, creating a pollution plume.

Question 29

What are pollution domes and when do they occur?

Answer 29

Pollution domes occur during a temperature inversion, trapping pollution in a city and creating thick smog.

Question 30

What is smog and how does it form?

Answer 30

Smog occurs when particulate matter mixes with fog under a temperature inversion.

Question 31

How does increased heat affect smog formation?

Answer 31

Increased heat enhances photochemical reactions, increasing airborne particles and contributing to smog and cloud formation.

Question 32

How much less sunlight does London receive compared to the surrounding countryside?

Answer 32

London receives approximately 279 fewer hours of sunlight than the surrounding countryside due to clouds and smog.

Question 33

What is photochemical smog?

Answer 33

Photochemical smog is formed through a chemical reaction involving sunlight, nitrogen oxides, and volatile organic compounds (VOCs), resulting in airborne particles and ground-level ozone.

Question 34

What pollutants contribute to photochemical smog?

Answer 34

Pollutants such as nitrogen oxides, sulphur oxides, and hydrocarbons are released by fossil fuels.

Question 35

How does UV light affect pollutants in the atmosphere?

Answer 35

UV light causes pollutants to break down into harmful chemicals, such as ozone, which forms photochemical smog.

Question 36

What are some pollution reduction policies?

Answer 36

Pollution reduction policies include clean air acts, vehicle control in urban areas (e.g., congestion charge in London), public transport improvements, and more environmentally friendly or electric public transport.