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Trends in vegetation biomass, Ellsmere Island 1995-2007 Trends in vegetation biomass, Ellsmere Island 1995-2007
Data from many sources and at several scales suggest that recent climate change is already affecting terrestrial Arctic ecosystems. Comparisons of historical and contemporary aerial photographs provide evidence that Arctic vegetation has already undergone significant shifts in recent decades, foreshadowing changes that are likely to come. In a repeated measurement study conducted on Ellesmere Island, Nunavut, Canada, over a period of 13 years, t...
17 Mar 2010 - by Hugo Ahlenius, GRID-Arendal & CAFF
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Arctic sea ice food web - schematic illustration Arctic sea ice food web - schematic illustration
Sea ice represents a unique ecosystem in the Arctic, providing habitat to specialized iceassociated species that include microorganisms, fish, birds, and marine mammals. Individual species use sea ice in different ways depending on their biological needs. Ice algae form the base of the food web. Some algae stay attached to the bottom of the ice, some fall into the water column, and some fall to the bottom of the sea, and so provide food for speci...
17 Mar 2010 - by Hugo Ahlenius, GRID-Arendal & CAFF
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How the comb-jelly (Mnemiopsis leidyi) is spreading through European seas (invasive species) How the comb-jelly (Mnemiopsis leidyi) is spreading through European seas (invasive species)
The most threatening event for the Caspian ecosystem was the arrival of the North American comb jelly (Mnemiopsis leidyi). It was brought accidentally to the Caspian in the ballast water of oil tankers. Invasive and alien species can exploit ecological niches that are not currently occupied, and spread rapidly, out-competing indigenous species.
21 May 2010 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Red king crab native and invasive distribution Red king crab native and invasive distribution
The red king crab is native to the Okhotsk and Japan Seas, the Bering Sea, and the northern Pacific Ocean, where it is an important economic resource. In Alaskan waters, red king crabs have historically been the second most valuable species to fishermen after salmon, although since the 1980s overharvesting has led to the closure of some areas to fishing. The king crab also has an invasive distribution in the Barents Sea. Since its introduction in...
13 Oct 2010 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Marine mammals in the Arctic Marine mammals in the Arctic
Seven species of marine mammals live in the Arctic year-round – the bowhead whale, beluga whale, narwhal, ringed seal, beaded seal, walrus, and polar bear - and many more migrate to the Arctic seasonally. Many marine mammals aggregate in specific areas across the Arctic, for example to feed, or for whelping, pupping or moulting. A common feature of marine mammals in the Arctic is that they are associated with sea ice, although the ecological rela...
13 Oct 2010 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Index of biodiversity potential in Central America Index of biodiversity potential in Central America
Biodiversity is vitally important to human well-being as it provides ecosystem services on which humans depend. For many species that are sensitive to even small variations in climate, their primary threat is climate change. Variations in climate affect different species of flora and fauna differently, producing, in some cases, a disruption in food chains and/or in reproductive patterns. It is therefore necessary to reduce or control greenhouse g...
22 Nov 2010 - by Nieves López Izquierdo, Associate Consultant UNEP/GRID-Arendal
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Expected impacts of climate change in 2050 Expected impacts of climate change in 2050
It is expected that by 2050 there will be threats to ecosystem services in the Andes and Mexico, in the Central American and Caribbean sub-regions, and in southeastern Brazil, while there will be negative effects on fishing in the Pacific coastal areas of Peru and Chile. The decrease in precipitation will have adverse effects on agricultural yields in several regions and countries throughout the continent. Particularly noteworthy within Latin Ame...
22 Nov 2010 - by Nieves López Izquierdo, Associate Consultant UNEP/GRID-Arendal
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Ecosystems in Northwest Russia Ecosystems in Northwest Russia
The map shows the range of fourteen different ecosystem types across Russia. The Barents region is in the Arctic and covers the area of Western Russia and the northern areas of Finland, Sweden and Norway. (Please note that the The Barents Euro-Arctic Council has expanded the membership since 1998)
04 Oct 2005 - by Philippe Rekacewicz, UNEP/GRID-Arendal
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Harmful effects of ecosystem changes on human health Harmful effects of ecosystem changes on human health
No data
28 Mar 2006 - by Bounford.com and UNEP/GRID-Arendal
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Sea level rise and assessment of the state of the marine environment Sea level rise and assessment of the state of the marine environment
A significant sea level rise is one of the major anticipated consequences of climate change. This will cause some low-lying coastal areas to become completely submerged, while others will increasingly face short-lived high-water levels. These anticipated changes could have a major impact on the lives of coastal populations. The small island developing states (SIDS) will be especially vulnerable to the effects of sea level rise, and to changes in ...
01 Oct 2009 - by Philippe Rekacewicz
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Freshwater use by sector at the beginning of the 2000s Freshwater use by sector at the beginning of the 2000s
The agricultural sector is by far the biggest user of freshwater. Analysis indicates that: - In the United States, agriculture accounts for some 49% of total freshwater use, with 80% of this volume being used for irrigation (Shiklomanov, 1999). - In Africa and Asia, an estimated 85-90% of all freshwater used is for agriculture (Shiklomanov, 1999). - According to estimates for the year 2000, agriculture accounted for 67% of the world’s total fr...
26 Jan 2009 - by Philippe Rekacewicz (Le Monde diplomatique)
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Tigris and Euphrates rivers fragmentation Tigris and Euphrates rivers fragmentation
It has been predicted that access to water will create conflict between countries. In Africa, central Asia, west Asia and the Americas, some countries are already arguing fiercely over access to rivers and inland seas, and confrontations could arise as water shortages grow (Gleick, 2000). Countries currently or potentially involved in international disputes over access to river water and aquifers include: - Turkey, Syria and Iraq (the Tigris and...
26 Jan 2009 - by Philippe Rekacewicz
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Cereal productivity in sub-Saharan Africa under a projected Intergovernamental Panel on Climate Change (IPCC) scenario Cereal productivity in sub-Saharan Africa under a projected Intergovernamental Panel on Climate Change (IPCC) scenario
A majority of the population in sub-Saharan African lives in rural areas, where income and employment depend almost entirely on rain-fed agriculture. This population is today at high risk. Sub-Saharan Africa already has a highly variable and unpredictable climate and is acutely vulnerable to floods and droughts. A third of the people in the region live in drought-prone areas, and floods are a recurrent threat in several countries. With climate ch...
26 Jan 2009 - by Philippe Rekacewicz
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Human actions leading to coastal degradation Human actions leading to coastal degradation
Physical alteration and the destruction of habitats are now considered one of the most significant threats to coastal areas. Half of the world’s wetlands, and even more of its mangrove forests, have been lost over the past century to physical alterations, the major causes being accelerating social and economic development and poor-planning (UNEP, 2002). There are currently about one billion people living in coastal urban areas. It is estimated t...
26 Jan 2009 - by Philippe Rekacewicz (Le Monde diplomatique), February 2006
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Coastal populations and shoreline degradation Coastal populations and shoreline degradation
Unsurprisingly, the coastal areas with the greatest population densities are also those with the most shoreline degradation. The areas surrounding the Black Sea, the Mediterranean and southern Asia have the highest proportion of altered land, while the coastal zones of the Arctic, northeast Pacific, south Pacific, West and Central Africa, East Africa, the Red Sea/Gulf of Aden, and Kuwait have the highest proportions of least modified land. In o...
01 Oct 2009 - by Phillippe Rekacewicz, February 2006
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Lake Chad: almost gone Lake Chad: almost gone
Straddling the borders of Chad, Niger and Cameroon in West Africa, Lake Chad has been a source of freshwater for irrigation projects in each of these countries. Maps drawn from a series of satellite images show a dramatic decrease in the size of the lake over the past 30 years. Since 1963, the lake has shrunk to nearly a twentieth of its original size, due both to climatic changes and to high demands for agricultural water. Since 1963, the surfac...
06 Nov 2009 - by Philippe Rekacewicz (Le Monde diplomatique), February 2006
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Global waterstress and scarcity Global waterstress and scarcity
Water scarcity occurs when the amount of water withdrawn from lakes, rivers or groundwater is so great that water supplies are no longer adequate to satisfy all human or ecosystem requirements, resulting in increased competition between water users and other demands.
26 Jan 2009 - by Philippe Rekacewicz (Le Monde diplomatique), February 2006
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Species Turnover Species Turnover
Change in the initial species richness in 2005 relative to 2001-2005 average (high-range climate change scenario). Studies predict species invasion will be profound in the Arctic and Southern Oceans. Among others these changes could result in a significant turnover of species of more than 60% of present biodiversity. This has the potential to disrupt a range of marine ecosystem services including food provisioning.
06 Oct 2009 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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South Africa biomes South Africa biomes
South Africa is blessed with a rich abundance of biodiversity and a wide range of ecosystems and biomes. Among them are the wetland ecosystems, which occupy approximately seven per cent of South Africa’s total land area. Wetlands are regarded as one of the most productive ecosystems because of all the ecosystem services they provide. But the country’s wetlands are under pressure from both natural and human threats and approximately sixty per cen...
21 Jun 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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Pressures on the South African coast Pressures on the South African coast
Population growth puts pressure on coastal ecosystems. Increased population means growing demand for land for housing and infrastructure, increased use of living resources for food, and more use of available freshwater resources. The negative environmental impacts of the shipping industry also harm the coastal ecosystem. Impacts from shipping include oil spills and the discharge of ballast water and waste into the sea, which affect the quality of...
21 Jun 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
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