Current state and observed changes in climate:
Regionale Unterschiede in der Erwärmung:
Observed precipitation changes:
Observed changes:
Observed changes in extremes:
Current state of climate:
- the last five years were the five warmest on record globally and on average over 1.1°C warmer than during pre-industrial times
- 2019 was the second warmest year
- 2010-2019 was the warmest decade
- globally already many extensive impacts of climate change in physical, chemical and biological systems are detectable and verifyable
Natural and anthropogenic drivers in the climate system:
- External drivers
- plate tectonics
- orbital parameters
- solar activity
- volcanism
- Internal climate variability
- Anthropogenic drivers
- greenhouse gas emissions
- land use change
Germany under Climate Change:
Natural greenhouse effect:
- radiation equilibrium temperature without atmosphere: -18°C
- real average temperature: +15°C
- anthropogenic effect on top
Drivers:
Development of important GHG:
Natural and anthropogenic forcing:
It‘s getting hot in here…!
does the future look like?
Example 1: Ice-albedo-feedback
Heat wave 2019:
- Temperature records:
- Germany 42,6°C (2 K above old one)
- almost everywhere in Europe
Excursus: probability density of extremes
Example 3:
Correlation between temperature and CO2
Example 2: Biogeochemical feedback mechanisms
Feedbacks and timescales:
Tipping points, 1.5°C is the right target!
Risks and impacts:
Important global tipping points in the climate system:
Further severe, long-term consequences:
- Loss of biodiversity and mass extinction of species
- Strong increase of extremes
- Sea level rise
- Mass migration
- High adaptation and mitigation costs
- many other ecological, social and economic consequences in all areas of society
