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Walnut forest in the Jalal-Abad province (Kyrgyzstan)
The walnut forest is remnants of Central Asia Tertiary era subtropical forests. They are located primarily in the northern slopes of the Ferghana and Chatkal ranges of the Tien Shan and on the southern slopes of the Giss...
16 Mar 2006 - by Viktor Novikov, UNEP/GRID-Arendal
Environment and Security Initiative : Today`s priorities and future challenges
The pilot phase of the initiative in 2003 assessed environmental threats in Central Asia and South –Eastern Europe, two regions where environmental concerns have clear security implications. The Southern Caucasus joined ...
16 Mar 2006 - by Viktor Novikov and Philippe Rekacewicz, UNEP/GRID-Arendal
Water withdrawal and availability in Aral Sea basin
Agriculture is a mainstay of Central Asia’s economy. With the economic crisis following independence it has become even more important. Agriculture being almost entirely dependent upon irrigation, access to water is of s...
16 Mar 2006 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Topography and hydrography of the Ferghana Valley
To date there are three main groups of issues that are relevant to environmental and security issues in the region. These are access to and quality if natural resources (primarily water and land but also forest and more...
03 Oct 2006 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Gross National Income (GNI) kyrgyzstan, Tajikistan and Uzbekistan
The rationale of the common soviet market and economic system has disappeared, forcing Central Asian states to find their own position in the global market without the support of a redistributive economy. Their geographi...
16 Mar 2006 - by Viktor Novikov, UNEP/GRID-Arendal
Trends in regional average surface temperature in the Ferghana Valley area
An important factor when looking at the region in terms of environment and security is the impact of climate change in Central Asia in general, and Ferghana Valley in particular. By modifying people’s livelihood, climate...
16 Mar 2006 - by Viktor Novikov, UNEP/GRID-Arendal
Population distribution in the Ferghana valley
Given the importance of agriculture for the whole Ferghana basin, natural resources such as land and water have historically been amongst the most important factor in this regions development. The size of the population ...
16 Mar 2006 - by Dominique del Pietro and Diana Rizzolio
Water issues in the Ferghana Valley
Water is a basic production resource for agriculture. Competition for scarce water resources has been recognized as a potential source of international conflict. In the case of the Ferghana Valley, despite the very local...
16 Mar 2006 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Industrial pollution and waste hotspots in the Ferghana Valley
Mercury mining, uranium mining, chemical and textile industries, oil facilities and processing plants which contribute to the contamination of the soil with highly toxic heavy metals are recognized as environmental chall...
16 Mar 2006 - by Philippe Rekacewicz, UNEP/GRID-Arendal
Arctic map, political
The Arctic is extremely diverse in terms of landscapes, varying from pack and drift ice to rugged shores, flat coastal plains, rolling hills and mountains surpassing 6000 metres above sea level (Denali, 6,194 m asl, in s...
16 Sep 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Projected changes in the Arctic climate, 2090 - with shipping routes
The averages of the scenarios in the Arctic Climate Impact Assessment (ACIA) are presented in this figure, for the year 2090, with the surface temperatures over land, the size of the polar ice cap, and the outer limits o...
16 Sep 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic conservation area (CAFF), political map
The Conservation of Arctic Flora and Fauna is a working group under the Arctic Council, for the countries of Russia, Denmark, USA, Canada, Sweden, Iceland, Norway and Finland and indigenous peoples. Monitoring, assessmen...
16 Sep 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic conservation area (CAFF), topographic map
The Conservation of Arctic Flora and Fauna is a working group under the Arctic Council, for the countries of Russia, Denmark, USA, Canada, Sweden, Iceland, Norway and Finland and indigenous peoples. Monitoring, assessmen...
16 Sep 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Re-infestation by 'Aedes aegypti'
Climate change affect the health of the population, not only through heat waves and waterborne diseases, but also as a result of the expansion of geographical areas conducive to the transmission of vector-borne diseases ...
16 Sep 2006 - by Nieves López Izquierdo, Assosciate Consultant UNEP/GRID-Arendal
Uganda: quantifying the importance of environment and natural resources
Estimations calculate that the environment and natural resources sector should contribute USD 791 million to the Uganda GDP, excluding benefits like ecosystem services. In the formal figures, only USD 405 million is reco...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Economic impacts of Gorilla tourism in Uganda
Gorilla tourism in Uganda is primarily taking place in the Mgabinga Gorilla National Park and Bwindi Impenetrable National Park, and represents one of the main destinations for wildlife tourism in the country. Estimation...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Rainfall variability and economic growth in Zimbabwe
In Zimbabwe, trends in economic growth have been linked to rainfall variability, which can be attributed to sensitivity in the agricultural sector. Improved water resources management is critical to the stability and sec...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Pro-poor growth, absolute and relative definition
Pro-poor growth is a term used for primarily national policies to stimulate economic growth for the benefit of poor people (primarily in the economic sense of poverty). Pro-poor growth can be defined as absolute, where t...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Catches in the Mauritania Exclusive Economic Zone (EEZ) 1950-2002
Marine fisheries represent a significant, but finite, natural resource for coastal countries. The majority of the catches in some of the areas of the coast are not primarily by the coastal countries, but rather as in thi...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Export of fisheries products in Africa
For some African countries, particularly in West-Africa and to lesser extent also countries along the Indian Ocean, fisheries contribute significantly to exports. Remarkable is also that the fish sector is important for ...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Water, irrigated cropland percentage by region
Irrigated land currently produces 40% of the world’s food on 17% of the world’s land. A broadening of irrigation and more effective rain fed agriculture will be necessary to meet the need for increasing agricultural outp...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Household income by source, Masvingo province, Zimbabwe
A study of households (rich and poor) in the Masvingo Province in southeastern Zimbabwe provides a good example of how agricultural income complements wild income and how it compares with other income sources such as wag...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Employment in the travel and tourism industry in Africa
About 6.3 million people work in the travel and tourism industry in Africa, where tourism is highly dependent on natural and cultural environment. However, since travel & tourism touches all sectors of the economy, its r...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Number of people in the mining sector in selected countries in Sub-Saharan Africa
There is 1.5 million small-scale miners estimated to work within whole SADC region. Main countries for small-scale mining activities are Tanzania miners and Zimbabwe, where more people are involved in the small-scale, ra...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Water requirements for food production 1960-2050
The requirements for water in agriculture in developing countries will need to increase in order to meet the Millennium Development Goal 1, target 2 'Halve, between 1990 and 2015, the proportion of people who suffer from...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
The composition and levels of wealth per capita for low-income countries
In low-income countries, the natural section represents a quarter of the total wealth, this represents the land that is managed either by household, individual or communally, and the potential for generating income. Phys...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Government revenues from diamond exports in Sierra Leone
The government of Sierra Leone saw a total of USD 5.2 million (2004) in revenues from diamond related activities. This comes in the form of mining, dealer and export license fees and from export taxes. To feed some of th...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
EU fishing agreements to West and Central African countries
Fisheries activities by European Union countries in the seas of West Africa contribute EUR 120 million annually in government revenues. A part of the contribution is set for “targeted actions” to promote local resource m...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Contribution of forest to GDP, and ratio of forest exports out of total exports, for selected countries
Forestry provides more than 8% of the GDP in some of the poorest countries. In most of the developing country production is consumed domestically, but for some countries forestry contributes significantly to total export...
02 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Oil and gas development in the Mackenzie valley
The Mackenzie Valley in Arctic Canada, Northwest Territories, represents one of the main sites for development of fuels extraction in North America. Activities, including the development of pipelines, impact indigenous p...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Protected areas and wilderness
Wilderness areas in the Arctic, representing vast expanses of tundra and taiga that sees very little human disturbance and stress have been determined by an analysis prepared by the UN Environment Programme World Conserv...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Ecoregions prioritised for conservation, in the Arctic (WWF Global 200)
Ecoregions represent large areas with geographically characteristic fauna, flora and climate - both marine and terrestrial. This graphic presents the ecoregion definitions identified by the World Wildlife Fund and associ...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Barents Sea vulnerability index
Areas that are vulnerable to pollution from oil and chemical spills where identified using a multiple index in a geographical analysis. Factors, including shoreline sensitivity, corals, benthic conditions, sea birds, mar...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Major wilderness areas in the Arctic
The Arctic covers around 33.5 million km2 and holds the largest continuous expanses of unfragmented wilderness in the world, outside of Antarctica. Indeed, seven of the ten largest wilderness areas in the world outside A...
01 Oct 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Pathways of contaminants to the Arctic
Many POPs (persistent organic pollutants), heavy metals and other contaminants from emissions further south are accumulated in Arctic food chains and ultimately in indigenous peoples. This process is often referred to as...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Shift in climatic zones, Arctic scenario
The scenarios from the Arctic Climate Impact Assessment (ACIA) project that temperatures will increase dramatically in the Arctic, more than in many other parts of the world. This leads to effects, such as the decrease o...
01 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Protected areas in the terrestrial priority ecoregions in the Arctic
Certain areas have been identified as priority ecoregions for conservation (WWF Global 200) due to their unique biodiversity characteristics. Significant parts of these regions are without any protection, as identified b...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic development scenarios, human impact in 2050
Human activities influence the environment and reduce the value of forests, tundra and plains in terms of original biodiversity and habitat. Primarily larger mammals are hit by the fragmentation caused by roads and pipel...
01 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Barents Sea ecoregion conservation priority areas and oil and gas infrastructure
The Barents Sea ecoregion - the part of the World Ocean north of the Nordic countries and Northwest Russia, has a unique environment with major sea bird colonies, rich benthic and plankton fauna and many major sea mammal...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Temperature increase in the Arctic, 2090 scenario
The averages of the scenarios in the Arctic Climate Impact Assessment (ACIA) are presented in this figure, for the year 2090. The Arctic is a place where the effects of climate change are already very visible, and scenar...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Barents Sea - Oil free zones
Proposal from the World Wildlife Fund for Nature (WWF) for permanent petroleum-free zones in the Barents Sea. Areas covered with ice for parts of the year are also included in the proposed zones. The map has been drawn u...
01 Nov 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic transportation routes - roads, shipping and pipelines
Land infrastructure represents a fragmentation of the natural ecosystems, splitting up expanses of tundra and taiga - and creates a disturbance in the form of traffic. In addition, it promotes development of side roads, ...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Demography of indigenous peoples of the Arctic based on linguistic groups
Language not only communicates, it defines culture, nature, history, humanity, and ancestry. The indigenous languages of the Arctic have been formed and shaped in close contact with their environment. They are a valuable...
01 May 2010 - by Hugo Ahlenius, UNEP/GRID-Arendal
Demography of indigenous peoples of the Arctic based on linguistic groups
Areas show colours according to the original languages of the respective indigenous peoples, even if they do not speak their languages today. Notes: Overlapping populations are not shown. The map does not claim to show e...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Fossil fuel resources and oil and gas production in the Arctic
The Arctic has been opened up for increased exploration of petroleum, gas and mining activities. The Barents Sea, the Mackenzie Valley in Canada and the Alaskan North Slope, are the areas of chief interest at the moment....
06 Dec 2006 - by Philippe Rekacewicz & Hugo Ahlenius UNEP/GRID-Arendal
Protected areas in the Arctic
The Arctic is a unique region in the world, with very little human activity and vast expanses of tundra and taiga that presents ecological values. This graphics presents the areas that currently are protected for conserv...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
Protected areas in the Barents ecoregion
The Barents Sea ecoregion - the part of the World Ocean north of the Nordic countries and Northwest Russia, has a unique environment with major sea bird colonies, rich benthic and plankton fauna and many major sea mammal...
06 Dec 2006 - by Hugo Ahlenius, UNEP/GRID-Arendal
World economy cartogram
To highlight the distribution of wealth and power in the world of today, this cartogram sizes the countries according to their relative financial status, here presented through gross domestic product (gdp) per capita, of...
13 Feb 2007 - by Philippe Rekacewicz, UNEP/GRID-Arendal, Vladimir S. Tikunov
p08-09-hazards
No data.
13 Feb 2007 - by Bounford.com and UNEP/GRID-Arendal
Mass balance reference glaciers in nine mountain ranges
Thirty reference glaciers with almost continuous mass balance measurements since 1975 show an average annual mass loss of 0.58 m water equivalent for the past decade (1996–2005), which is more than twice the loss rat...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Time series of freeze-up and break-up dates from selected Northern Hemisphere lakes and rivers, 1846–1995
Limited by the availability of detailed observations, most historical evaluations of changes in freshwater ice have focused on relatively simple characteristics, such as the timing of autumn freeze up and spring break up...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Overview of world glaciers and ice caps
By far the largest area of glaciers and ice fields are found in Canada (about 201 000 km2), followed by Alaska (about 75 000 km2) with about 700 km2 in the rest of the USA. Glaciers and ice fields are concentrated in th...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Mass balance of Maliy Aktru Glacier, Russian Altai
Measurements on this valley-type glacier in the North Chuyskiy Range show a slightly negative annual mass balance trend culminating in an ice loss of about 4 m water equivalent over the period 1964–2005.
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Northern Hemisphere snow-cover extent anomalies 1966-2005
Data from satellite monitoring from 1966 to 2005 show that mean monthly snow-cover extent in the Northern Hemisphere is decreasing at a rate of 1.3 per cent per decade. For the calendar year of 2006 average snow-cover ex...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Projected temperatures in the 21th century
Projected Arctic annual land temperature increases for the first half of the 21st century relative to the average temperature for 1980–99. The average of the IPCC models (the blue line) shows an increase of 3ºC by 2050. ...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Temperatures over previous centuries from various proxy records
Evidence from tree rings and other temperature proxies suggests that during the previous 500 years global temperatures were 1.0ºC cooler than those of the 20th century during a period roughly from 1300 to 1870 – known as...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Antarctica, showing rates of surface-elevation change derived from satellite radar-altimeter measurements
The figure shows rates at which the ice-sheet mass was estimated to be changing based on radar-altimeter data (black), mass-budget calculations (red), and satellite gravity measurements (blue). Rectangles depict the time...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in permafrost temperatures and active-layer thickness, Northern Tien Shan mountains
Mountain permafrost in Central Asia occupies approximately 3.5 million square kilometers and makes up about 15 per cent of the total permafrost area in the Northern Hemisphere. The climatic variations during the 20th ce...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
The Cryosphere, components and world maps
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 Oct 2008 - by Hugo Ahlenius, UNEP/GRID-Arendal
Albedo of basic thick sea ice surface types
The albedo for different surface conditions on the sea ice range widely, from roughly 85 per cent of radiation reflected for snow-covered ice to 7 per cent for open water. These two surfaces cover the range from the larg...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Change in the age of ice on the Arctic Ocean, comparing September ice ages in 1988, 1990, 2001 and 2005
The age of sea ice in the Arctic is changing, and not only the extent and concentrations. Studies show that in recent years there is a higher proportion of younger ice to older ice than was observed in the late 1980s. Th...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Melting ice on Mount Kilimanjaro, East Africa
Close to 50 per cent of the glaciers in Africa, on the Rwenzori Mountains, Mount Kenya and Kilimanjaro have disappeared, while larger glaciers – particularly on Kilimanjaro – have been fragmented. Changes in glacier area...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Projected reduction in snow 2080-2100
Using one specific climate change model (ECHAM5) and the SRES A2 emission scenario (run 2) the projected loss of snow amounts to decreases of 60–80 per cent in monthly maximum snow water equivalent over most middle latit...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
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
Shrinking of Fedchenko Glacier in the Pamirs of Tajikistan
Significant loss of glaciers in Central Asia began around the 1930s, and become more dramatic in the second half of the 20th century and continue into the 21st century. Glacier area was reduced in the Tien Shan and in th...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in spring snow cover duration for the Northern Hemisphere, 1970-2004
Examination of regional trends in spring snow-cover duration from 1969–2003 using NOAA snow-cover data shows the western United States to be among the regions with the strongest decreases. This supports results from stud...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Glacier shrinking on Cumberland Peninsula, Baffin Island, Canadian Arctic
A new glacier inventory based on satellite data shows that the glacier cover reduced by about 22 per cent between the Little Ice Age (LIA) maximum extent and 2000. Changes in glacier area and volume are being used as ind...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in Arctic temperature, 1880-2006
A history of Arctic land temperature anomalies from 1880 through 2006 is shown in this figure. The zero line represents the average temperature for 1961–1990. In the late 1800s the Arctic was relatively cold, although t...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Water towers of Asia - glaciers, water and population in the greater Himalayas-Hindu Kush-Tien Shan-Tibet region
The Himalayas–Hindu Kush, Kunlun Shan, Pamir and Tien Shan mountain ranges function as water towers, providing water to people through much of Asia. The glacier-fed rivers originating from the Himalaya mountain ranges su...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Glacier front variations in the European Alps
Large Alpine glaciers have retreated continuously since the mid- 19th century, whereas steep mid-sized glaciers reacted with readvances in the 1890s, 1920s and between the 1970s and 1980s due to the somewhat cooler and w...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Trends in Antarctic tourism
Antarctic annual sea-ice extent is projected to decrease by 25 per cent by 2100, and this will bring easier access to the Antarctic continent by ship. This is likely to affect not only research, which is a main activity ...
01 Nov 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Northern Sea Route and the Northwest Passage compared with currently used shipping routes
Climate models project that summer sea ice in the Arctic Basin will retreat further and further away from most Arctic landmasses, opening new shipping routes and extending the navigation season in the Northern Sea Route ...
01 Oct 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
Annual snowfall pattern for a typical mountain environment, Columbine Pass, Colorado 1971-2000
Mountain snow cover typically develops in the autumn and grows to a maximum depth in early spring. As day length and sun angles increase, so do air temperatures, causing snow cover to warm and begin to melt. Snow cover ...
01 Oct 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
Mean snow-cover extent in the Northern Hemisphere 1966-2006
Snow occurs predominantly on the northern continents, on the sea ice of the Arctic Ocean and on Antarctica. On the Northern Hemisphere continents, snow covers a maximum mean area of 45.2 million km2, typically in January...
01 Oct 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Shrinking Lewis Glacier, Mount Kenya
The tropical Lewis Glacier retreated by more than 800 m between 1893 and 2004 and lost almost 16 m water equivalent of its thickness between 1979 and 1996. Located on Mount Kenya, this is one of few locations in Africa w...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic sea ice minimum extent in September 1982 and 2005
The red line indicates the median minimum extent of the ice cover for the period 1979–2000. This figure compares the Arctic sea-ice extent in September for the years 1982 (the record maximum since 1979) and 2005 (the rec...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Ratio of existing ski areas in the Alps with natural snow-reliability under current conditions and warmer conditions
Winter tourism is a significant part of the economy of Alpine countries and the most important source of income in many regions. In Austria, winter tourism revenue makes up 4.5 per cent of GNP and half of the total incom...
01 Jun 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
Population size of Peary caribou in the Canadian Arctic islands
In northwestern North America, recent warming has led to a dramatic increase in the number of days of above freezing temperatures during the migration period for the caribou (Rangifier tarandus). Thawing and subsequent r...
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
Glacier changes on Nevado de Santa Isabel, Colombia
With spectacular mountain peak glaciers melting away, the NEvado de Santa Isabel area in Colombia becomes less attractive to tourists. In addition, the local forestry and agricultural fertility suffer may suffer from red...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Formation of lakes and glacier lake outburst floods (GLOFs) by Medvezhi Glacier, Pamirs
The increasing number of glacial and moraine lakes in Central Asian mountains is a matter of great concern. One of the surging glaciers that poses a potential threat is the 15 km long Medvezhi (Bear) Glacier in the Pamir...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Arctic temperature anomaly patterns
Natural climate variability is organized into spatial patterns of high and low pressure regions, represented by the Arctic Oscillation (also called the Northern Annular Mode) and North Pacific patterns in the Northern...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Cryosphere - winter seasons, Northern and Southern Hemispheres
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 summer to winter, whil...
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
Permafrost extent in the Northern Hemisphere
Permafrost zones occupy up to 24 per cent of the exposed land area of the Northern Hemisphere. Permafrost is also common within the vast continental shelves of the Arctic Ocean. This subsea permafrost formed during the l...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Time series of freeze-up and break-up dates from selected Northern Hemisphere lakes and rivers, 1846–1995
Limited by the availability of detailed observations, most historical evaluations of changes in freshwater ice have focused on relatively simple characteristics, such as the timing of autumn freeze up and spring break up...
01 May 2010 - by Hugo Ahlenius, UNEP/GRID-Arendal
Example of enhanced water levels produced from river ice, Liard River, Canada
The lower curve shows the correspondence between river flow and water levels under open-water conditions. The much greater maximum water levels possible under ice-jam conditions are illustrated by the upper curve. The t...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Greenland, showing rates of surface-elevation change between the late 1990s and 2003
Mass-balance estimates for Greenland show thickening at high elevations since the early 1990s at rates that increased to about 4 cm per year after 2000, consistent with expectations of increasing snowfall in a warming cl...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal
Antarctica, topographic map
Antarctic is the fifth largest continent of the world at 14 million square kilometres and is covered by a permanent continental ice sheet. The ice is distributed in two major ice sheets, the East Antarctic and the West A...
01 Jun 2007 - by Hugo Ahlenius, UNEP/GRID-Arendal