Graphics Library >> global

Region: global

Ice-albedo feedback process
In spring, the ice is snow-covered and there is very little open water. Most sunlight is reflected, but some is absorbed. This absorbed sunlight leads to melting, which in turn reduces the ice albedo and increases the am...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in sea level, 1870-2006
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 of rise over this pe...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Schematic diagram of glacier, permafrost and forest limits as a function of mean annual air temperature and average annual precipitation
Glaciers and ice caps form around the world where snow deposited during the cold/humid season does not entirely melt during warm/dry times. This seasonal snow gradually becomes denser and transforms into perennial firn (...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Ice sheets, schematic illustration for Greenland and Antarctica
The ice cover in Greenland and Antarctica has two components – thick, grounded, inland ice that rests on a more or less solid bed, and thinner floating ice shelves and glacier tongues. An ice sheet is actually a giant gl...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Projected sea-level rise for the 21st century
The projected range of global averaged sea-level rise from the IPCC 2001 Assessment Report for the period 1990 to 2100 is shown by the lines and shading. The updated AR4 IPCC projections made are shown by the bars plotte...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
World ocean thermohaline circulation
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 the Norwegian Sea. W...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Effects of sea-level rise on water resources of small islands and low-lying coastal areas
The water resources of small islands and low-lying coastal areas are very susceptible to sea-level rise. This figure illustrates the direct impacts on the water resources sector, as well as the plethora of higher-order i...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Monthly average sea ice extent globally and in both hemispheres
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 numbers for the Southern O...
01 Oct 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Overview on glacier changes since the end of the Little Ice Age
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 century. Over the past...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Projected winter temperature changes in the Arctic
The changes in cold-season mean temperatures over Arctic land regions are broken into three latitudinal bands for each region, as shown on the small map (which has an outer rim of 50° N). Error bars represent standard de...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Population, area and economy affected by a 1 m sea level rise (global and regional estimates, based on today's situation)
Even for today’s socio-economic conditions, both regionally and globally, large numbers of people and significant economic activity are exposed to sea-level rise. The densely populated megadeltas are especially vulnerabl...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in Arctic sea ice extent in March (maximum) and September (minimum) in the time period of 1979–2008
For the Northern Hemisphere (primarily the Arctic), observations using remote sensing technologies have been used to measure the extent and the to assess the development. Despite considerable year-to-year variability, si...
18 Apr 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
The Cryosphere, world map
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 over time scales of mi...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Sea ice concentration change over the 21st century as projected by climate models
The data are taken from climate model experiments of 12 (out of 24) different models that were conducted for the IPCC Assessment Report 4 using the SRES A1B greenhouse gas emission scenario. Plots on the right show chang...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Mountain permafrost patterns and temperature gradients
Steep terrain and strong variability in surface temperatures are typical of mountain permafrost. The cross section in the foreground shows the complex distribution of subsurface temperatures characteristic of mountains, ...
01 Jun 2007 - by Stephan Gruber, University of Zürich. Hugo Ahlenius, UNEP/GRID-Arednal
Glaciers monitored through the World Glacier Monitoring Service
Worldwide collection of information about ongoing glacier changes was initiated in 1894 with the foundation of the International Glacier Commission at the 6th International Geological Congress in Zurich, Switzerland. Tod...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Monthly average sea ice extent globally and in both hemispheres (radial)
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 numbers for the Southern O...
01 Oct 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Regional changes in Arctic and Antarctic sea ice
There are major regional differences for the Arctic sea ice, with the strongest decline in ice extent observed for the Greenland Sea (10.6 per cent per decade). The smallest decreases of annual mean sea ice extent were f...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Developing countries with environmental strategies
While many countries have shown indifference to environmental commitments made at Rio, the summit significantly helped legitimise environmental issues in political agendas worldwide: over 50 countries currently have nati...
29 Nov 2007 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Water Availability Trends
Water availability in developing countries (with and without arid climates) has declined by about 65 percent since the 1960s and continues to do so. Forecast indicate that water will become very scarce by 2020.
29 Nov 2007 - by Philippe Rekacewicz, UNEP/GRID-Arendal