Global Climate Change

and Ocean Current

YSCN0029 Climate Change

through Earth History

Presented by: Jacky Poon,

Candy Cheung, Connie Yu,

Vannessa Poon,.

Is the Planet Warming?10 warmest year records since 1990: 1998, 2002 & 2003 (joint), 2001, 1997, 1995,1990 &1999 (joint), 1991 & 2000 (joint).

Analyses of over 400 proxy climate series (from trees, corals, ice cores and historical records) showed that 20th century was the warmest century.

The Inter-governmental Panel on Climate Change (IPCC) in its most recent report stated:“most of the observed warming over the last 20 years is likely to have been due to the increase in greenhouse gas concentrations.”

The warming leads to changes in ocean current and in the world.

Uneven distribution of sun’s energy

Current movements

Deep water wave

Coriolis Effect

Relationship between Atlantic Thermohaline Circulation and Global Warming

Significant slowing of the ocean circulation that transfers warm water to the North Atlantic Ocean

The southern hemisphere would become warmer and the northern hemisphere would become colder

Why?

Result of Global Warming:

Higher temperatures under global warming

Increasing the precipitation, melting nearby sea ice, mountain glaciers and the Greenland ice sheet

Add fresh water to the northern oceans

The influx of fresh water reduce the surface salinity and density

Dense water then sinks and slowly travels through the deep water southward into the Southern Hemisphere

Lead to the significant slowing of the thermohaline circulation

The North Atlantic Sink

Impacts of ocean current slow downDistinct regional variability

Bitter winters as Little Ice Age 17th-19th centuries

possibly related to changes in the strength of North Atlantic thermohaline circulation

10,000 years ago, a period called ‘Younger Dryas’ caused European temperature dropped >10C

The Day After Tomorrow?

Solution

The Framework Convention on Climate Change (UNFCCC)

International Cooperation : Kyoto Protocol; USA rejectedProduce less green house gases, eg CO2 , MethaneChina`s responsibility