Ocean-Climate system - 17 Flashcards
How reliable are model predictions for climate change?
- Assumptions are made
- Simplified versions of reality
- Quantitative results are less reliable than qualitative results
How will global warming cause sea level rise?
- Melting of ice sheets and glaciers
- Thermal expansion
How much will global sea level rise in the 21st century?
Around 50 cm (5mm/yr)
What affect will sea level rise have?
- Extensive coastal flooding
- Barrier island erosion
- Salt marshes and mangrove disappearance (impact on commercial fishing industry)
Give an example of a species that has disappeared due to warming ocean temperatures …
Winter Flounder in New England … reduced survivability of eggs and larvae due to warmer temperatures
How much of a reduction in the northerly flow of the Gulf stream has been recorded?
30% reduction … precursor for the switching off of the thermohaline conveyer belt?
How much excess heat is absorbed by the oceans?
70-80%
How much of our emissions are being absorbed by the oceans?
1/3 (IPCC)
How much will calcification reduce by is we hit 700ppm of CO2?
Reduction by 30%
How many people would be displaced by rising sea level?
1 billion
How are organisms responding to rising sea level temperature?
- Migration to cooler waters … e.g. squid, jellyfish
- phytoplankton population decreasing … in turn causes die off of sea bird populations
What impact does acidifying water have on organisms?
- Shell formation of pteropods and formanifera disturbed
- Reduction of carbonate to produce coral reefs
What can we do to solve these issues?
- Geoengineering?
- New policy?
- International agreements?