Seasonal variation in the extent of ice and snow cover is greatest in the Northern Hemisphere. Imagine the Earth with white caps on the top and bottom. The top cap increases by a factor of six from [..]
Three-quarters of all poor people still live in rural areas. They are heavily reliant on natural resources for their livelihoods: soil, water, forests and fisheries underpin commercial and subsistence [..]
Primary ocean productivity, as measured in grammes of carbon per square meter, from remote sensing imagery outlines the areas with rich marine life. These areas are characterised by an abundance of [..]
The continental shelves, ridges and sea mounts are the most productive areas in terms of biodiversity, and is of highest importance for economic activities. It is also here that natural resources [..]
The World’s most productive fishing grounds are confined to major hotspots, less than 10% of the World oceans. The maps shows annual catch (tonnes per km2) for the World’s oceans. Notice the strong [..]
The two main reasons for sea-level rise are thermal expansion of ocean waters as they warm, and increase in the ocean mass, principally from land-based sources of ice (glaciers and ice caps, and the [..]
All across the planet, the number and severity of outbreaks and infestations of invasive species (i.e. species purposefully or accidentally introduced in non-native environments) is growing, and [..]
Atmospheric concentration of CO2 is steadily rising, and oceans directly assimilate CO2. As ocean concentration of CO2 increases, the oceans automatically become more acidic. This, in turn, may have [..]
The global conveyor belt thermohaline circulation is driven primarily by the formation and sinking of deep water (from around 1500m to the Antarctic bottom water overlying the bottom of the ocean) in [..]
Glaciers and ice caps reached their Holocene (the past 10 000 years) maximum extent in most mountain ranges throughout the world towards the end of the Little Ice Age, between the 17th and mid-19th [..]
Snow and the various forms of ice - the cryosphere - play different roles within the climate system. The two continental ice sheets of Antarctica and Greenland actively influence the global climate [..]
Coastal and island tide-gauge data show that sea level rose by just under 20 cm between 1870 and 2001, with an average rise of 1.7 mm per year during the 20th century and with an increase in the rate [..]
The most recent geological history, in the last hundred thousand years, has been characterised by cycles of glaciations, or ice ages. The historic temperatures, through these times, have been low, and [..]
These projections of biodiversity loss from 2000 to 2050 were produced by the GLOBIO consortium for UNEP's Global Environment Outlook 4. Across the GEO scenarios and regions, global biodiversity [..]
In the Arctic, winter sea ice extends over an area of approximately 15 million km2 at its peak in March and up to 7 million km2 in September, at the end of the summer melt season. Corresponding [..]
