HomeAboutActivitiesMapsPhotosPublicationsNews
 
Home >> Pressure

Tag: Pressure

El Niño-Southern Oscillation (ENSO) Phenomenon El Niño-Southern Oscillation (ENSO) Phenomenon
El Niño describes 'the warm phase of a naturally occurring sea surface temperature oscillation in the tropical Pacific Ocean', and southern oscillation refers to 'a seesaw shift in surface air pressure at Darwin, Australia and the South Pacific Island of Tahiti'. This graphic explains the El Niño-Southern Oscillation Phenomenon, showing the differences between a normal year and an El Niño year.
17 May 2005 - by Delphine Digout, UNEP/GRID-Arendal
4
ENSO impact on Southern Africa ENSO impact on Southern Africa
El Niño describes 'the warm phase of a naturally occurring sea surface temperature oscillation in the tropical Pacific Ocean', southern oscillation refers to 'a seesaw shift in surface air pressure at Darwin, Australia and the South Pacific Island of Tahiti' amd La Nina refers to the cooling phase of the same temperature oscillation that causes El Nino. This graphic shows how the El Nino phenomenon changed weather conditions in southern Africa in...
17 May 2005 - by Delphine Digout, UNEP/GRID-Arendal
2
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
4
Fishing yield Fishing yield
Three-quarters of the world’s fish stocks are currently exploited to the maximum extent, if not in excess (FAO, 2000). This exploitation has had the following impacts: - A growing variety of fishery products are being exploited. Commercial fishermen are targeting progressively smaller species at lower levels of the food chain because the main predator species are being depleted. - Most of the world’s main fishing areas are close to full exploit...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
4
Benefits of marine and coastal ecosystems to human wellbeing Benefits of marine and coastal ecosystems to human wellbeing
Besides the well-known economic value of fisheries, there are several other activities generating significant revenues in coastal and marine areas. Tourism has become one of the world’s fastest growing industries, providing a significant proportion of the GDPs of many developing countries. Small island states are particularly reliant on coastal and marine tourism. In the Caribbean, for example, the industry accounts for a quarter of the total eco...
26 Jan 2009 - by Phillippe Rekacewicz, February 2006
3
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
3
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
5
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
4
Biodiversity threats Biodiversity threats
South Africa is recognised as the third most megadiverse country in the world. The abundance of biodiversity found within its borders covers an estimated ten per cent of the world’s plant species, seven per cent of all bird, six per cent of all mammal, and five per cent of all reptile species found on the planet. Due to various causes ranging from unsustainable land use and farming practices, to invasion by alien species and climate change, So...
21 Jun 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
3
Highway threaten Serengeti wildlife Highway threaten Serengeti wildlife
This graph shows proposed commercial roads across the Serengeti and surrounding region in 2010. However, following intense international pressure, the Tanzanian Government announced in 2011 that it will favour an alternative route to the South, outside the park. Some projections suggest that if the road were built, numbers may fall to less than 300,000 (Dobson and Borner, 2010), others that the herd could decline by a third (Holdo et al., 2011), ...
15 Nov 2011 - by Riccardo Pravettoni, UNEP/GRID-Arendal
3
Previous | 1 2