Impact of Global Warming on Ecosystem

Read this article to learn about the impact of global warming on ecosystem.

A warmer global climate could have a number of possible effects. One of the changes is food pro­duction, which could increase in some areas and drop in others.

Archaeological evidence and com­puter models indicate that, in the worst case, cli­mate belts would shift northward by 100-150 Kms (60-90 miles) or upward 150 meter (500 ft.) in alti­tude for each 1°C (1.8°F) rise in global tempera­ture and thus tolerance ranges of plant species (in­cluding crops) can be altered.

Global warming would also cause reductions in water supplies in some areas. Lakes, streams, and aquifers in some areas that have provided water to ecosystems, croplands and cities for centuries would also shrink or dry up altogether, forcing en­tire populations to migrate to areas with adequate water supplies — if they could. We can’t say with much certainty where this might happen.

It is further interesting to note the fact that make up and location of forests would change with changing climate. Forests in temperate and subarctic regions would be forced to move towards the poles or to higher altitudes, leaving more grass­land and shrub land in their place.

Some recent scientific studies suggest that 7-11% of North American’s native plant species could be placed outside their thermal limits for survival by a tem­perature rise of 3°C (5°F). There will be substan­tial loss of biodiversity in many areas of the world too. Large scale forest diebacks would cause many extinction of species that could not migrate to new areas.

According to a number of ecologists, the resulting loss of biodiversity and subsequent re­duction of ecosystem food chain complexity is likely to reduce ecological resilience and the ability of ecosystems to adapt to climate change.

In a warmer world, water in the oceans would expand and lead to a rise in sea level. Even the modest 0.3 meter (1 ft.) rise projected to occur by 2100 would flood coastal regions—where about one-third of the world’s people and economic in­frastructure are concentrated—as well as lowlands and deltas where crops are grown.

It would also destroy coral reefs, move barrier islands farther inland, accelerate coastal erosion, contaminate coastal aquifers with saltwater, and flood tanks storing oil and other hazardous chemicals in coastal areas.

Weather extremes are expected to increase in number and severity. In a warmer world, prolonged heat waves and droughts could become the norm in many areas, taking a huge toll on many humans and ecosystems.

As the upper layers of sea water warm, hurricanes and typhoons would occur more frequently and blow more fiercely. Indeed between September 1989 and September 1994, the world experienced at least 15 weather-related disasters causing financial losses greater than $1 billion.

Global warming also threats to human health. A warmer world would disrupt supplies of food and fresh water displacing millions of people and altering disease patterns in unpredictable ways. Human beings cope with wide extremes in envi­ronmental conditions much better than other spe­cies by combing physiological and behavioural adaptation.

Minor and gradual changes in tempera­ture and humidity evoke both physiological and behavioural responses. Healthy persons have an efficient bodily heat regulatory mechanism that copes with a moderate rise in ambient environ­mental temperature. But frail or ill individuals with lesser physiological resilience will adopted.

In gen­eral, therefore, temperature increase is a greater health hazard in people with disorders of the car­diovascular, respiratory, kidney or immune systems, in infants with immature regulatory systems and in the elderly frail. Thus higher summer tempera­tures in temperate and tropical countries will in­crease the rates of serious illness and death from heat-related causes.

The most direct thermal effect is heat stress, which can lead to heat exhaustion and heatstroke. Heat stress results from a breakdown in the bal­ance between the competing demands of body temperature regulation and control of blood pres­sure.

Since the control of body heat is mainly achieved by the cardio vascular system, heat stress, which necessitates increased blood flow through the skin to enable loss of body heat, readily exac­erbates pre-exiting heart and blood pressure dis­orders. Heat exhaustion, characterised by dizziness, weakness and fatigue is not due to failed bodily- temperature control, but is caused by an imbal­ance in bodily fluids and salts.

It typically occurs after several days of high temperatures and per­spiration. Heatstroke, however, is a serious condi­tions in which the inner body temperature exceeds 41 °C, and in which confusion, stupor and finally unconsciousness occurs. The outcome is often fatal. Heatstroke is typically preceded by falling blood pressure, faintness, dehydration, salt deple­tion and cramps.

Heat waves also disturb psychological balance; tempers flare, crimes of passion increase in fre­quency and riots are more common. In crowded inner urban environments, thermal stresses may be amplified by the heat island effect of living in treeless conglomerations of stone, concrete and asphalt, by the lack of insulation and air condi­tioning in poor housing, and by the lesser access to medical and hospital care.

It is well documented that heat wave-related deaths are concentrated in these inner urban heat traps. Warming with high humidity also increases high rise of fungal skin diseases and yeast diseases (such as candidiasis) Table 4.8.

Climate change also effects the respiratory tract. Seasonal disorders may reflect air pollution in winter months and increased exposure to pol­len, dusts and photochemical smog in summer months, whereas specific weather conditions such as cold fronts and ram may have direct effects.

People with chronic bronchitis and emphysema often experience exacerbations during winter and the incidence of acute bronchitis peaks in winter.

By contrast, asthma and hay fever tend to peak in the summer months and the release of pollen is thought to be responsible. Hot dry summer weather increases the pollen count, whereas sum­mer ram stimulates the release of certain fungi.

Global warming may destabilize ocean and air currents and thus leading to tropical cyclones, floods or droughts, landslides and coastal erosion. This in turn, would increase the incidence of death, injury, stress-related disorders and may adverse health effects associated with social disruption; enforced migration and settlement in urban slums.

The vast east-west oceanic currents of warm wa­ter across the Pacific (‘La Nina’), which periodi­cally reverse and flow west-east as the ‘El Nino’ Southern Oscillation (ENSO), are a major deter­minant of weather and cyclonic activity along the coasts of the Western Pacific and beyond.