Scientific basis of climate change

Question 1

Present a short definition of climate change

Answer 1

Question 2

Present a short definition of global warming

Answer 2

Question 3

What are examples of recent local events that point towards unusual climate patterns?

Answer 3

Hurricane in the Alps 2018
Glaciers in the Alps are vanishing
Venice under water 2019
Emilia-Romagna under water 2023

Question 4

What are three main points about the scientific basis of climate change?

Answer 4

Question 5

Name at least three evidences that global warming is unequivocal

Answer 5

:)

Question 6

How much has the global temperature risen by since 1880?

Answer 6

Earth’s average temperature has risen by
approximately 1.0 ^C since 1880, and it is
projected to rise even more.

Question 7

What can small changes in average temperature of the planet cause?

Answer 7

Large and potentially dangerous
shifts in climate and weather

Question 8

How big of a decrease in ice and snow have we seen from 1979-2012?

Answer 8

-3.5/4.1% decrease in Arctic sea
ice extent per decade in 1979-2012

Question 9

How much have the sea levels risen by from 1901-2010?

Answer 9

19 cm

Question 10

Explain short and precisely how the greenhouse effect works

Answer 10

• The greenhouse effect refers to the process by which certain gases in Earth’s atmosphere trap and retain heat from the sun, leading to a warming of the planet.
• These gases, such as carbon dioxide and methane, act like the glass walls of a greenhouse, allowing sunlight in but preventing some of the heat from escaping back into space.
• The increased concentration of these greenhouse gases due to human activities, such as burning fossil fuels, intensifies the greenhouse effect, contributing to global warming and climate change.

Question 11

Define the green house effect in one sentence

Answer 11

The greenhouse effect is a natural process that helps regulate the Earth’s temperature and make it habitable

Question 12

What are greenhouse gasses?

Answer 12

• Certain gases in the Earth’s atmosphere, such as carbon dioxide (CO2), Nitrous oxide, and methane (CH4)
• These gases, both natural and anthropogenic, can absorb and emit radiation emitted by the Earth’s surface, the atmosphere, and by clouds causing the warming greenhouse effect.

Question 13

Talk about this picture :)

Answer 13

GHG’s come from pretty much everything we do. Energy production produce a large share.

Question 14

How and on which sources is the global energy supply distributed?

Answer 14

Much of our energy supply is based on coal, gas, and oil

Question 15

How much do we pollute today compared to earlier?

Answer 15

We are at a high point in terms of pollution and CO2 emissions, polluting more than we have done in previous years

Question 16

Who were the top 6 emitters in 2018 and how much of the emissions did they cover?

Answer 16

China 28%, United States 15%, EU28 9%, India 7%, Russia 5%, and Japan 3%. In total, the six countries covered 67% of global emissions

Question 17

Explain the difference between stock and flow when we talk about the greenhouse effect

Answer 17

Stock: the stock refers to the total amount or quantity of greenhouse gases present in the atmosphere at a given time. It represents the cumulative effect of past emissions and can be thought of as the “stockpile” of greenhouse gases in the atmosphere.

Flow: Flow refers to the rate at which greenhouse gases are being emitted into or removed from the atmosphere over a specific period. It represents the ongoing or continuous movement of greenhouse gases. Flow is typically expressed as a rate, such as metric tons per year.

Emissions from human activities, such as the burning of fossil fuels for energy, industrial processes, and deforestation, contribute to the flow of greenhouse gases into the atmosphere. On the other hand, natural processes like photosynthesis in plants and the absorption of carbon dioxide by oceans act as sinks, removing greenhouse gases from the atmosphere.

While the stock represents the total amount of greenhouse gases present in the atmosphere, the flow determines the rate at which these gases are being added or removed, which directly influences the overall concentration and impact of the greenhouse effect.

Climate change is caused by the stock
of atmospheric greenhouse gases, not
by the flow of our annual emissions. There is a linear relationship between stock of GHG and temperature.

Question 18

How has the amount of greenhouse gasses in the atmosphere developed in the last 150 years?

Answer 18

Greenhouse gases in the atmosphere
have been constantly rising in the last
150 years (stock)

Question 19

What are three competing explanations of global warming and how likely is each of them?

Answer 19

Question 20

What is the IPCC?

Answer 20

• a scientific body established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) and endorsed by the United Nations General Assembly
• Its mission is to provide comprehensive scientific assessments about the risk of climate change caused by human activity, its potential environmental and socio-economic
  consequences, and possible options for adapting to these consequences or mitigating the effects.
• Thousands of scientists and other experts contribute on a voluntary basis writing reports, which are reviewed by representatives of more than 120 governments.

Question 21

How has the conclusion on wether climate change is anthropogenic developed since the 90’s?

Answer 21

The conclusions of the Intergovernmental Panel on Climate Change have become more and more certain over time, today pointing to a 99-100% probability that climate change is anthropogenic.

Question 22

What scenarios do the IPCC predict in terms of tempereature increases if we do business as usual vs. strict mitigation?

Answer 22

Business as usual: 4.7 degrees celsius relative to pre-industrial levels

Strict mitigation: 1.5 degrees celsius relative to pre-industrial levels

Question 23

What scenarios do the IPCC predict in terms of tempereature increases if we do business as usual vs. strict mitigation?

Answer 23

Business as usual: 4.7 degrees celsius relative to pre-industrial levels

Strict mitigation: 1.5 degrees celsius relative to pre-industrial levels

Question 24

What are the likely impacts on the earth system in year 2100 if we go with business-as-usual?

Answer 24

There will be modifications in the geography of the planet: coastlines will be different

Extreme weather: increase risks from heat
stress, storms and extreme precipitation, floods, landslides, drought, water scarcity, and storm surges.

Ocean acidification

Loss of biodiversity, extinction of large a large fraction of species

Marine ecosystems

Terrestrial ecosystems

Question 25

What is ocean acidification and what are the consequences of it?

Answer 25

Ocean acidification is a decrease in the pH-value of seawater due to the uptake of anthropogenic carbon.

It threatens organisms that incorporate
calcium carbonate (CaCO3) into their shells
and skeletons (molluscs, mussels, oysters,
coral reefs,…)

Question 26

How long will the climatic impacts of releasing CO2 to the atmosphere last?

Answer 26

Releasing CO2 to the atmosphere today will have climatic impacts that last longer than the age of human civilization so far

Question 27

What is the carbon budget approach?

Answer 27

The carbon budget approach includes estimating the total amount of greenhouse gases that can be emitted over a given timeframe to limit global temperature rise to a desired level

Takes into account the cumulative nature of greenhouse gases in the atmosphere and the long-term implications of emissions