Effects Of Global Warming

Flooding Bangladesh

One of the poorest nations in the world is projected to lose 17.5% of its land if sea level rises about 40 inches (1 m). Tens of thousands of people are likely to be displaced, and the country’s agricultural system will be adversely affected. Coastal flooding will threaten animals, plants, and fresh water supplies. The current danger posed by storm surges when cyclones hit Bangladesh is likely to increase.

Disappearing Islands

The Majuro Atoll in the Pacific Marshall Islands is projected to lose 80% of its land with a 20-inch (0.5m) rise in sea level. Many of the islands will simply disappear under the rising seas. A similar fate awaits other islands throughout the South Pacific and Indian Oceans, including many in the Maldives and French Polynesia. Coral reefs, which protect many of these islands, will be submerged, subjecting the local peoples to heightened storm surges and disrupted coastal ecosystems. Tourism and local agriculture will be severely challenged. 
Urban Flooding

Thirteen of the world’s fifteen largest cities are on coastal plains. Many smaller cities, such as Alexandria, Egypt’s ancient center of learning, also face a severe risk of inundation with a 39-inch (1m) rise in sea level. Parts of San Jose and Long Beach, California, are about three feet below sea level and New Orleans is about eight feet below sea level today. Cities at risk cover a wide range of economic circumstances, yet many will require extensive infrastructure development to minimize the potential impacts of flooding, particularly from storm surge.
Adapting to Rising Seas

Rising sea level requires many different local responses. Urban areas on the U.S. coastline could be surrounded by rising sea water. Cities may require extensive infrastructure development to assure fresh water supplies, secure transportation, and protect people from flooding and storm surge.
Sea walls can be built to protect cities and roads from rising seas. More robust building construction may also be required to withstand the increasingly intense storms that are likely to result from global warming. Fresh water supply is a concern as sea water penetrates ground water aquifers, which become brackish and less usable further inland.

Regional Challenges

The United States could lose 10,000 square miles of dry land if sea level rises two feet (0.6m). But the impacts of rising sea level vary from one region to another. These maps identify areas along the U.S. Gulf and Atlantic Coasts that are vulnerable to a 5–10 feet (1.5–3m) rise in sea level. The U.S. Pacific Coast is far less vulnerable to coastal flooding because the land rises more abruptly from the sea.

Ecological Tradeoffs

sea walls is an effective way to protect roads and cities from rising sea level. Sea walls literally prevent sea water from encroaching inland and provide a buffer against storm surges.
Unfortunately, sea walls disrupt coastal ecosystems. The abrupt transition between sea water and concrete eliminates the beaches and tidal areas that support life along the coasts. This may be particularly problematic in barrier island ecosystems, such as along the southeastern coast of the United States.
The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of sea level rise on nature.

Disappearing Wetlands

Coastal wetlands are especially vulnerable because they are within a few feet of sea level. In the United States, a sea level rise of one foot (0.3m) could eliminate 17–43% of today’s wetlands, with more than half the loss in Louisiana. As sea level rises, new wetlands will form further inland, but the total area will probably be reduced. In developed areas, dikes and other structures will prevent new wetlands from forming.
Coral Bleaching

Corals weakened by a variety of stresses are susceptible to “bleaching.” This occurs when the microscopic algae that give corals their brilliant color die. In 1997 and 1998, a large El Niño event contributed to bleaching in tropical corals around the world. Over the next century, warming of the oceans, in combination with other stressors such as sea level rise and water pollution, could lead to an increase in bleaching events.

 Coral Bleaching
The algae in this coral died giving it a bleached appearance. (Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce)
Coastal Erosion

Over the past century, approximately 70% of the world’s shorelines have been retreating due to sea level rise and increased erosion. Over the next century, increased erosion is likely as sea level rises. Erosion will increase along different types of unprotected shoreline, including the low-lying barrier dunes of the southern U.S. Atlantic Coast and the soft cliff coasts of California.
Climate models project rising sea level during the 21st century due to greenhouse warming. Sea level is not expected to rise as much as shown here by the year 2100, but it will likely be rising for centuries to come, especially as polar ice melts. Much of eastern Maryland is low-lying, leaving vast areas vulnerable to flooding.

  Water Resources

The 1930s Dust Bowl was a relatively minor drought by prehistoric standards, yet tens of thousands of people were displaced. Today, farms and cities in the western United States could face a similar water shortage. This region relies heavily on the Colorado River for fresh water. The river, which is fed by the mountain snows, is overtaxed during dryer periods. Decreasing snow pack in the high mountains threatens to create severe water shortages throughout the southwestern U.S., and reduce the ability to generate hydroelectric power during the warmer summers.

Disappearing Glaciers

Glaciers are complex, and a short-lived advance or retreat of one or a few glaciers could have many causes. But almost all of the mountain glaciers on Earth have shrunk over the last century. The temperature increase needed to explain the rate of glacier disappearance agrees with warming estimated from thermometers.

Will Melting Ice Trigger an Ice Age?

Not likely. But, remember the Younger Dryas? Melting polar ice may have poured fresh water into the North Atlantic and interrupted the deep ocean circulation pattern, which may have sent the Northern Hemisphere into a 1,000-year cold period. Today, fresh water flow into the Arctic Ocean from Siberia’s four great rivers has increased, and oceanographers observe a slight decrease in the salinity of the North Atlantic. Although climate models do not project that these trends will lead to anything like an ice age, some indicate that over the next few hundred years deep ocean currents may be disrupted, which would affect regional temperature and precipitation patterns over North America and Europe.
The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of climate change on traditional cultures.

Disappearing Ice Packs

Wildlife in the arctic regions will be seriously affected as warmer temperatures affect the ocean ice cover. Polar bears rely on sea ice to hunt seals, which use the ice for rearing their young. The native peoples also rely on the ice to hunt these species and walruses. Observations of walrus in 1996-99 showed them to be thin and in poor condition, partly due to receding sea ice.

Livestock Farming

Over the past several thousand years, traditional livestock farmers in Africa have developed a variety of ways to cope with large climate variations. These coping mechanisms include keeping diverse species of livestock, moving temporarily to more lush grasslands, maintaining economic diversity, and distributing drought-induced hunger across the stronger members of the community. Coping with climate changes over the next century will be increasingly difficult as human populations increase and available grazing land decreases.

Limited Resources

Many indigenous peoples live in harsh climatic environments to which they have adapted. However, when climate changes occur rapidly, populations with limited resources can be the first to suffer from famine and disease. Adaptation techniques include altering crop mixes and water infrastructure to deal with drought, and improving public healthcare systems to reduce the harm caused by climate-related disease outbreaks.
The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of climate changes on health and disease.
Infectious Diseases

Cold winter weather reduces the spread of infectious diseases by killing infectious organisms and carrier species, such as mosquitoes. Warmer, wetter weather could increase the spread of malaria, dengue fever, and yellow fever. The possible increase in flooding and damage to water and sewage infrastructure can further encourage the spread of disease.

Increased Air Pollution

Three out of four of the world’s highest-density cities are in rapidly developing countries, where vehicle pollution is high. In Central Europe alone, 21,000 deaths are tied to air pollution each year. The concentration of photochemical pollutants, such as ozone, tends to increase with warmer temperatures. Ozone damages lung tissue and is especially harmful to people with asthma and other lung conditions.

Hotter Summers & Warmer Winters

A 1995 heat wave killed more than 500 people in the Chicago area, and heat intensity is likely to rise in the future. Statistical studies estimate that a temperature rise of 2°F could double or triple the number of heat-related deaths in Atlanta, in part because the heat index will increase exponentially as temperature rises. But warmer weather may save lives in the winter by reducing hypothermia and driving-related fatalities.
The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of climate change on agriculture.

American Crops

Agriculture in the United States is relatively well positioned to adapt to climate change, due in part to the advanced technologies available to U.S. farmers. The overall system is regionally diverse and has already adapted to a wide range of growing conditions. On the whole, U.S. crop production could increase, unless warming becomes great or the frequency of extreme weather increases.
Isolated Arid Regions

Peoples most at risk of famine live in agriculturally isolated, arid or semi-arid regions, such as sub-Saharan Africa and Latin America. African agriculture was already unable to keep pace with population growth during the last decades of the 20th century. And climate models generally predict that mid-continental summer soil moisture will tend to be lower with greenhouse warming.

CO2 Fertilization

Because plants require CO2, rising levels may actually help plant growth. However, the increased plant growth requires adequate water supply and other fertilization, such as nitrates. Experiments in which crops are grown in CO2-rich air show that the CO2 fertilization effect could become small after a few years.

The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of climate change on ecosystems.

American Ecosystems

Earlier spring – A study observing 36 species in the central U.S. documented advances in flowering dates by an average of 7.3 days from 1936 to 1998.
Northward Shift – A study projecting responses to a doubling of atmospheric CO2 found that tree habitats in the eastern U.S. may migrate northward more than 50 miles on average. However, the ability of trees to shift might be limited in regions where forests are only found in isolated patches.

Shifting Penguin Populations

Adélie penguin populations decreased 22% during the last 25 years, while Chinstrap penguins increased by 400%. The two species depend on different habitats for survival: Adélies inhabit the winter ice pack, whereas Chinstraps remain in close association with open water. A 7°–9°F rise in midwinter temperatures on the western Antarctic Peninsula during the past 50 years, and associated receding sea-ice pack, is reflected in their changing populations.

Tiger Losses

It is estimated that only about 3,000 – 4,500 Bengal tigers remain in the wild. The number in Bangladesh is projected to decrease as a result of rising sea levels. For tigers and the many other species that inhabit the forested wetlands of Bangladesh, migration to higher ground probably would be blocked by human habitation of adjacent lands.