As carbon concentrations in the atmosphere increase, so do concentrations in the ocean, with resultant acidification as a natural chemical process.

(a) Current (early 2000s) and (b) climate-shifted distributions of the small yellow croaker Larimichthys polyactis (Sciaenidae). The climate-shifted distribution was predicted by a dynamic bioclimate envelope model described by Cheung et al. (2008), under a hypothetical increase in average global ocean temperature of 2.5°C. Boundaries of Exclusive Economic Zones are delineated by the dashed lines.

Distribution of the world's blue carbon sinks (seagrasses).

Thermohaline circulation is a 3-dimensional flow involving surface and deep ocean waters, which is driven by differences in water temperature and salinity. (Image source: NOAA/NCDC).

The Southern Oceans are recognised as an important carbon sink currently taking up approximately 15% of anthropogenic CO2. Models predict that as the atmospheric concentration of CO2 increases, so should the ocean’s absorbtive capacity. This seems to be happening in most areas, but not so in the Southern Ocean, which is observed to have a declining ability to absorb CO2.

Trends in number of reported disasters. Much of the increase in the number of hazardous events reported is probably due to significant improvements in information access and also to population growth, but the number of floods and cyclones reported is still rising compared to earthquakes. Is global warming affecting the frequency of natural hazards?

The capacity of ocean's blue carbon sinks (tons of carbon per hectare per year).

An important role played by the ocean is the storage and exchange of CO2 with the atmosphere, and its diffusion toward deeper layers. At high latitudes, dense waters sink, transferring carbon to the deep ocean. Warming of the ocean surface inhibits this sinking process and therefore reduces the efficiency of CO2 transport and storage. Furthermore, as water warms up, the solubility of CO2 declines, therefore less gas can be stored in the sea water...

The carbon captured by living organisms in oceans is stored in the form of sediments from mangroves, salt marshes and seagrasses. Benefiting from the excellent conditions available to support plant growth, vegetated coastal habitats rank amongst the most productive habitats in the world, comparable in production to the most productive agricultural crops. Blue carbon sinks are strongly autotrophic, which means that these ecosystems fix CO2 as orga...

All transport accounts for approximately 13.5% of the total emissions, while deforestation accounts for approximately 18%. However, estimates of the loss of marine carbon-binding ecosystems have previously not been included.

45% of green carbon stored in natural terrestrial ecosystems and the remaining 55% is captured by living organisms in oceans and ocean's blue carbon sinks.

The worlds most productive fishing grounds are confined to major hotspots in around 7.5% of the ocean surface, where over half of the fish are caught.

Although coastal ecosystems are already among the most valuable on the planet, the current estimates of the economic value for some of the oceans blue carbon sinks are surprisingly low. How should human perception of these important ecosystems change as we learn of the vast benefits of maintaining healthy coasts and oceans?

Projected growth in energy demand in coming decades.

Combustion sources of black carbon. Black carbon is thought to be the second largest contributor to global warming, next to brown carbon (the gases). Thus, reducing black carbon emission represents one of the most efficient ways for mitigating global warming that we know today.

The capacity of ocean's blue carbon sinks (total annual blue carbon sink burial rates).

Comparative vulnerability of national economies to climate impacts on fisheries. Vulnerability of national economies of potential climate change impacts on fisheries (which integrates exposure, sensitivity and adaptive capacity) under IPCC scenario B2 (local development, lower emissions).

Carbon cycling in the world’s oceans. The flow of carbon dioxide across the air-sea interface is a function of CO2 solubility in sea water (Solubility Pump). The amount of CO2 dissolved in sea water is mainly influenced by physico-chemical conditions (sea water temperature, salinity, total alkalinity) and biological processes, e.g. primary production. The solubility pump and the biological pump enhance the uptake of CO2 by the surface ocean influ...

Arctic sea-ice reductions have significant impacts on climate, wildlife and communities. The opening of open water across the Arctic ocean will have unknown consequences in terms of changes in water circulation and redistribution of species from the Atlantic and Pacific oceans. As sea ice coverage declines, albedo diminishes and more radiation is absorbed by the sea water, in a feed-back process that enhances warming and melting sea ice.

Distribution of the world's coral reefs. Oceans blue carbon sinks, along with coral reefs and kelp communities, all fulfil very important functions in the coastal zone while providing opportunities for jobs and coastal prosperity.