Projections of Future Changes in Climate   Oceans
Temperature, Circulation & pH

The global ocean will continue to warm during the 21st century. Heat will penetrate from the surface to the deep ocean and affect ocean circulation.

The strongest ocean warming is projected for the surface in tropical and Northern Hemisphere subtropical regions. At greater depth the warming will be most pronounced in the Southern Ocean.

The IPCC projects that the Atlantic Meridional Overturning Circulation (AMOC) will weaken over the 21st century. The meridional overturning circulation is another term for the Earths thermohaline circulation and refers to ocean circulation driven by differences in water density due to heat (thermo) and salt content (haline). The AMOC is an important mechanism for bringing heat to polar regions. If it slows down this heat transfer would slow down.

Ocean acidification is also projected to increase over the 21st century. Below is a graph showing projections from RCP 2.6 and RCP 8.5.

The IPCC stresses that continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.