Coastal erosion in the context of "Beach"

Climate change and cities are deeply connected. Cities are one of the greatest contributors and likely best opportunities for addressing climate change. Cities are also one of the most vulnerable parts of the human society to the effects of climate change, and likely one of the most important solutions for reducing the environmental impact of humans. The UN projects that 68% of the world population will live in urban areas by 2050. In the year 2016, 31 mega-cities reported having at least 10 million in their population, 8 of which surpassed 20 million people. However, secondary cities - small to medium size cities (500,000 to 1 million) are rapidly increasing in number and are some of the fastest growing urbanizing areas in the world further contributing to climate change impacts. Cities have a significant influence on construction and transportation—two of the key contributors to global warming emissions. Moreover, because of processes that create climate conflict and climate refugees, city areas are expected to grow during the next several decades, stressing infrastructure and concentrating more impoverished peoples in cities.

High density and urban heat island effect are examples of weather changes that impact cities due to climate change. It also causes exacerbating existing problems such as air pollution, water scarcity, and heat illness in metropolitan areas. Moreover, because most cities have been built on rivers or coastal areas, cities are frequently vulnerable to the subsequent effects of sea level rise, which cause flooding and erosion; these effects are also connected with other urban environmental problems, such as subsidence and aquifer depletion.

Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.

Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion proceeds the fastest on steeply sloping surfaces, and rates may also be sensitive to some climatically controlled properties including amounts of water supplied (e.g., by rain), storminess, wind speed, wave fetch, or atmospheric temperature (especially for some ice-related processes). Feedbacks are also possible between rates of erosion and the amount of eroded material that is already carried by, for example, a river or glacier. The transport of eroded materials from their original location is followed by deposition, which is arrival and emplacement of material at a new location.

A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters. They also support terrestrial animals and provide coastal protection.

Salt marshes have historically been endangered by poorly implemented coastal management practices, with land reclaimed for human uses or polluted by upstream agriculture or other industrial coastal uses. Additionally, sea level rise caused by climate change is endangering other marshes, through erosion and submersion of otherwise tidal marshes. However, recent acknowledgment by both environmentalists and larger society for the importance of saltwater marshes for biodiversity, ecological productivity and other ecosystem services, such as carbon sequestration, have led to an increase in salt marsh restoration and management since the 1980s.

Like other island nations, Antigua and Barbuda faces unique environmental issues created by its proximity to the ocean, and small size. These include pressures on drinking water resources, natural ecosystems, and deforestation more generally.

Existing issues on the island are further made worse by climate change, where, not unlike other island nations affected by climate change, sea level rise and increased weather variability, create increased pressures on the communities on the islands and the land, through processes like coastal erosion and saltwater intrusion.

Denudation is the geological process in which moving water, ice, wind, and waves erode the Earth's surface, leading to a reduction in elevation and in relief of landforms and landscapes. Although the terms erosion and denudation are used interchangeably, erosion is the transport of soil and rocks from one location to another, and denudation is the sum of processes, including erosion, that result in the lowering of Earth's surface. Endogenous processes such as volcanoes, earthquakes, and tectonic uplift can expose continental crust to the exogenous processes of weathering, erosion, and mass wasting. The effects of denudation have been recorded for millennia but the mechanics behind it have been debated for the past 200 years and have only begun to be understood in the past few decades.

Land loss is the term typically used to refer to the conversion of coastal land to open water by natural processes and human activities. The term land loss includes coastal erosion. It is a much broader term than coastal erosion because land loss also includes land converted to open water around the edges of estuaries and interior bays and lakes and by subsidence of coastal plain wetlands. The most important causes of land loss in coastal plains are erosion, inadequate sediment supply to beaches and wetlands, subsidence, and global sea level rise. The mixture of processes responsible for most of the land loss will vary according to the specific part of a coastal plain being examined. The definition of land loss does not include the loss of coastal lands to agricultural use, urbanization, or other development.