In 2007, the science of climate change achieved an unfortunate milestone: the Intergovernmental Panel on Climate Change reached a consensus position that human-induced global warming is already causing physical and biological impacts worldwide. The most recent scientific work demonstrates that changes in the climate system are occurring in the patterns that scientists had predicted, but the observed changes are happening earlier and faster than expected—again, unfortunate. Although serious reductions in manmade greenhouse gas emissions must be undertaken to reduce the extent of future impacts, climate change is already here and some impacts are clearly unavoidable. It is imperative, therefore, that we take stock of current and projected impacts so that we may begin to prepare for a future unlike the past we have known.
The wetlands provide services that are significant to the quality of life in the region, help sustain the national economy, and help protect life and property from climate extremes. Fisheries, recreation, and tourism, all thrive in the regions alongside urban development, agriculture, shipping, and the oil and gas industries. However, some regions of the world are experiencing some of the highest wetland loss rates, largely because of engineered modifications to regional watersheds and coastal landscapes. Such modifications increase the vulnerability of these wetlands to future climate variability and change. Sustainable restoration of wetlands requires planning for a more extreme future climate by returning critical water resources in the coastal landscapes to levels that existed before humans began modifying these regions three centuries ago. Wetlands support economic and ecological productivity as well as quality of life in many ways. Wetlands provide food, refuge, and nurseries for fish and shellfish, and they support the region’s large commercial and recreational fishing industries.
Wetlands provide stopover habitat for an estimated 75 percent of the waterfowl migrating along the Flyways. Wetland soils and vegetation naturally store water, filter sediment and pollutants from fresh water supplies, and help stabilize shorelines by reducing erosion and storm surges associated with rising sea levels.
Degradation of coastal wetlands through land development and water management reduces the capacity of wetlands to provide significant ecosystem services that reduce the risks of living and working in coastal landscapes. For example, extensive coastal wetland landscapes, especially forested ecosystems, can reduce storm surge and wind energy during tropical storms and cyclones, minimizing hurricane damage to life and property. In part because of recent hurricanes, local, state, and federal agencies have renewed their emphasis on coastal wetland restoration in the Gulf Coast region. However, such programs may fail without effective planning for future climate change, including accelerated sea-level rise and the potential intensification and increased frequency of hurricanes.
Human activities intended to reduce damage to life and property from climate extremes have unintentionally increased the vulnerability of coastal areas to climate change by altering the natural hydrologic functions of wetlands. For coastal wetlands to be sustained in a changing climate, therefore, restoration planning must account for the consequences of both climate change and human engineering of the environment.
Global climate change is expected to affect air and water temperatures, ocean and atmosphere circulation, sea-level rise, the intensity of hurricanes, and the timing, frequency, and magnitude of precipitation. Under natural conditions, coastal wetlands adjust to rising seas and changes in local storm patterns, but climate changes and human activities that alter natural conditions disrupt wetland hydrology, biogeochemical cycling, and other processes that sustain wetlands. The combined effects of water engineering, land development, natural subsidence, and climate change will have tremendous consequences for coastal wetlands in the coming decades.
Recent evidence suggests that human-induced global warming has already increased both the intensity and frequency of hurricanes in the North Atlantic, including the Gulf of Mexico . A recent analysis of Atlantic basin hurricane activity by Goldenberg and others indicated a five-fold increase in hurricanes affecting the Caribbean when comparing 1995–2000 to the previous 24 years. Hurricanes exhibit multi-decadal patterns that appear to be associated with variations in tropical sea-surface temperature patterns and vertical wind shear, and the Atlantic basin is in a period of high-level hurricane activity that could persist for10–40 years, irrespective of global warming . Moreover, several oceancoupled global circulation models project that the intensity of hurricanes will increase as the climate warms during the next 100 years.
The frequency and magnitude of the El Niño/Southern Oscillation (ENSO) also has a strong effect on ecological conditions in coastal areas. During ENSO events, large-scale disruptions to global weather patterns occur in the atmosphere and in the tropical Pacific Ocean. In general, El Niño events (the warm ENSO phase associated with unusually warm waters in the tropical Pacific) are correlated with greatly increased winter precipitation in the Gulf Coast region. During La Niña (the cool ENSO phase), fall and winter along the Gulf Coast are warmer and drier than usual. Hurricanes increase during La Niña events, but are less frequent during El Niño events. El Niño events have occurred more frequently and have persisted longer since the 1970s, a trend that has been linked statistically to global warming, although this linkage remains to be confirmed. Future intensification of El Niño events could alter marine and terrestrial ecosystems in unpredictable ways.
Even if storm intensities remain constant, sea-level rise may contribute to increased shoreline erosion, wetland flooding, and higher storm surges. Rising sea levels will generate higher storm surges even from minor storms. Flood damage will increase as a result of the combined effect of increased storm surges and the decreased storm surge-reduction capacity of altered wetlands.
Climate models project sea-level rise along the Gulf Coast to range from one to three feet in the next century. The position of wetlands relative to the sea surface will remain constant over time only if the combined effects of land subsidence and rising seas can be balanced by elevation gain from wetland soil formation. With regional subsidence projected to range from 8 to 40 inches in the next century, relative sea-level rise—the combination of absolute sea-level rise and land subsidence—over the next 100 years could range from two feet along most of the Gulf Coast to more than six feet in various rewgions.
A key theme emerges from these arguments and suggests that problems caused by human activities are exacerbated by climate change, itself mostly a human-induced phenomenon. Fortunately, manmade problems are amenable to manmade solutions. Climate change cannot be stopped entirely, but it can be limited significantly through national and international action to reduce the amount of greenhouse gases emitted to the atmosphere over the next several decades and thereafter, thus limiting climate change impacts. Managing those impacts requires that we adapt other human activities so that crucial resources, such as Gulf Coast wetlands or public emergency systems, continue to function effectively.
Qualifications
Bachelors of Environmental Sciences (2010)
Fatima Jinnah Women University
CGPA 3.8 out of 4.00
SILVER MEDALIST
Freshman of Science-FSc (2006)
F.G Post Graduate College for Women, Rwalapindi
1st Division
Matriculation (2004):
1st Division
Army Public School, Westridge III, Rawalpindi
Researches
Article from articlesbase.com
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