Greenhouse gases Flashcards
What is a greenhouse gas (GHG)?
A natural process that warms up the Earth’s surface
Describe how GHG warm the Earth’s surface?
When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by GHG.
The absorbed energy warms the atmosphere and the surface of the Earth.
What are the main GHG?
Water vapor, CO2, methane, nitrous oxide and ozone
What is radiative forcing?
The change in the average net radiation at the top of the troposphere (lower atmosphere) that occurs because of a change in overall climate system.
What is the primary source of increased CO2 levels?
- Burning fossil fuels
- Land-use change
How much CO2 has increased since pre-industrial times?
> 40%
Main sources of methane?
1 - Human sources:
Ruminants, fossil fuel extraction/use, rice paddy agriculture and landfills/waste
2 - Natural sources:
Wetlands and biomass burning
How much has methane increased since pre-industrial times?
By 2.5 times
Where is nitrous oxide (N20) concentrated latitudinally?
Lower concentration at lower latitudes and is lower at higher latitudes in the S. Hemisphere.
What is the Ruddiman hypothesis?
Humans began affecting climate thousands of years ago, rather than just since industrialisation
How much has Global surface temperatures risen since 1850-1900?
> 1C
Where is warming most pronounced?
Warming in the artic is stronger than in other area of the world and is stronger over land than over the oceans
What are RCPs?
4 main pathways used by climate modelers to develop long-term and near-term climate projections
What is Transient Climate Response (TCR)?
The temperature increase at the instant that atmospheric CO2 has doubled.
What is Equilibrium Climate Sensitivity (ECS)?
The long-term temperature increase after the TCR point, as the climate continues to warm over time in response to doubled CO2.
What is the Montreal Protocol?
An international treaty designed to protect the ozone layer
What is the IPCC?
Intergovernmental Panel on Climate Change - Leading international body for the assessment of climate change
What is the UNFCCC?
United Nations Framework Convention on Climate Change - aims to stabalise GHG concentrations in the atmosphere
What was the Kyoto Protocol?
The Worlds first GHG emissions reduction treaty.
What is the Paris Agreement?
International treaty with aims to limit global warming to 2 (preferably 1.5C)
By how much have emissions in the UK fallen between 1990 and 2020?
49%
What happened to UK emissions in 2021?
CO2 emissions rose by 6.3% from 2021 and total GHG emissions increased by 4.7%
