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Threat to our common future
COUNTRIES across the globe actively celebrated World Earth Day last week to mark the event when in 1970 about 20 million people in the US took to the streets to demand better environmental quality and to preserve the quality of air, water and soil.
From that day onwards, Earth Day festival became an annual opportunity for masses to demonstrate to those who run the world that they care for nature. However, 2006 promises to be one of the most exciting and active years due to the launch of a sustained, three-year campaign to educate consumers, corporations and governments worldwide on the urgent need to take concrete steps on climate changes.
The term climatic change refers to global changes in temperature, wind patterns, and precipitation. These changes are being driven by a gradual warming of the Earth's atmosphere. The threat of global warming hangs over our planet like a storm cloud. If not checked soon, it could some day cause untold — possibly irreparable — harm to our planet's ecosystem, triggering rising sea level, severe weather changes, threat to our food and water supplies, endangering of thousands of plant and animal species and spread of deadly diseases.
Global warming
One of the major global problems of earth is the threat to a long run increase in the surface temperature of the earth. Carbon dioxide, Methane, CFCs and Nitrous oxides act like a greenhouse, warming the earth's surface. Of all these gases, carbon dioxide is the most important. The rise in earth temperature due to increase in carbon dioxide emission has been speculated since 1800s and its effect have been analysed for almost a century. The main source of its increase is the burning of fossil fuels.
The amount of carbon dioxide in the atmosphere is by convention-expressed in terms of the carbon component. An estimate reveals that about 6 billion tonnes of carbon from burning fossil fuels are emitted into the atmosphere annually. The worst offender in terms of carbon dioxide emission is coal which accounts for about one-third of fossil fuels combustion worldwide. The second major source of emissions is deforestation and other biomass burning accounting for about 265 billion tonnes of carbon dioxide emissions annually. The gas, thus, accounts more than half of the warming.
Presently not a single state has contributed more than a small fraction to the greenhouse gases but it is estimated that by 2025, developing countries contribution to carbon dioxide emission will rise to 6.71 billion. The US is the largest contributor in developed countries list and globally accounting for nearly 20 per cent.
In fact, the US has been slow to embrace significant change in these big issues, citing excuse that the threat is not real, or that dealing with it will not harm the economy. The US government has also refused to sign the Kyoto Protocol which most of the nations have already signed in order to set mandatory caps on carbon dioxide.
Effects of global warming
The potential effects of climatic change by global warming are dramatic. Recent estimates indicate that if the concentration of these gases continue to increase, the earth average temperature will sometime rise by as much as 1.5-4.5C. Besides this, the rate of change of heating is put at 0.30C per decade, which is expected to a lot faster than the previous decades when the climate change was just 0.05C per decade.
An increase in overall temperature is changing weather patterns. Hurricanes and other extreme weather are likely to be more severe and devastating, as witnessed by Hurricanes Katrina and Rita.
Sea level: Global warming is expected to bring about rise in the sea level because of the expansion of seawater, caused by the melting of glaciers. Resultantly, the first effect will increase flooding of many coastal wetlands. Furthermore, this coastal erosion is expected to create shoreline losses of between 10 and 100ft depending on local conditions. It is predicted that lower islands nations like Maldives and Bahamas may even disappear. Studies prophesy that around 18 per cent of Bangladesh could be under water by 2050.
Agriculture: The worst impact is on agriculture, horticulture and ecosystem by climate change. Global warming results in substantial decline in soil moisture due to higher temperature and reduced rainfall besides the increase pest and weed growth promoted by higher carbon dioxide concentration in the areas that are the world's breadbaskets.
Altered rainfall is the most unpredictable effect of greenhouse-related climate change on agriculture. Since with higher global temperature more water will be evaporated from the oceans, average rainfall worldwide is bound to increase. But the rainfall pattern will be disrupted, varying widely among regions and between times.
In the Northern Hemisphere for example, Polar Regions will warm faster than equatorial zones and in the continents the centers will become drier than hemisphere. This varying climate change will drastically affect agriculture dur to crops' inability to withstand changes in temperature. Areas that are already arid like Tunisia, Algeria, Ethiopia and Somalia will dry out further.
Overtime, it is expected that rainfall in Africa and the Middle East will continue to drop. This means less water for people to use for drinking, cleaning, and growing crops, in a region where water is already scarce. As weather patterns change around the world, people who depend on crops for their livelihood will find it increasingly difficult to get good yields. However, agriculture can be adapted to these climate changes through crop development and technical change, which of course needs more time.
Health: Threats to health may also accompany global warming in the form of an increase in diseases carrying vectors, such as mosquitoes that carry disease like malaria, dengue fever, encephalitis and yellow fever, particularly in the regions with high temperature.
Global warming in Pakistan
In a country like Pakistan, the pressures generated as a direct result of climatic change impact multiple sectors including water, agriculture, forests, biodiversity, livestock and coastal zones. These could also lead to fluctuations in crop yields. Not only that, climatic change can also affect human health, animals and many types of eco-systems.
Water is a naturally scarce resource in Pakistan where 92 per cent of the land is covered by arid and semi arid regions. Moreover, the water resources that originate essentially from the rivers of the Indus basin vary seasonally and their geographical distribution is uneven. This water scarcity holds back the development of the country.
Drought, resulting from a notorious and prolonged decrease in rainfall, is a common phenomenon in Pakistan. The last drought, one of the most severe in over 40 years, affected parts of Sindh and Balochistan in 1999-2000 and extended till 2002 in certain areas. The number of affected persons was estimated at 3.3 million and dead in several hundreds with a direct effect on economy and poverty levels.
Similarly, floods pose another direct pressure on water usually caused by monsoon storms occurring in August and September. Since 1947 losses due to floods have been estimates at Rs. 110 billion with number of deaths reaching a cumulative total of 6,500. On the other hand, many wild animals, plants, aquatic species, birds and other forms of flora and fauna are affected and many of these may succumb to water scarcity and get destroyed.
The mangroves forest cover that was until 1970 approximately 260,000 hectares has shrunk to 160,000ha in 1990s and recent survey find the areas restricted to mere 80,000ha leading to increased levels of salinity and extinction of four species peculiar to Indus Delta. This would eventually cause harm to fish and shrimp with extremely negative consequences for the fish industry.
The biodiversity by climatic change in Sindh is at risk, as biotic potential of many species is starting to be diminished and many of them may be lost forever if the environmental devastation is not reversed or properly controlled. The water accord of 1991 provisionally guarantees 10MAF subject to further studies to establish the actual need to maintain the delta eco-system. However, since the accord came into place, the quantity of promised flow has hardly been maintained. Consequently, the scenario led to degradation of fertile land due to sea intrusion.
Besides the issues pertaining to global warming, desertification and biodiversity conservation are associated directly with forest. World over, there is a strong sense of crisis in forestry. Forest goods and services, once thought to be abundant are now scarce. Pakistan suffers far more severe forest scarcities than most countries since its natural forest assets are very small.
According to Forestry Sector Master Plan, forests, scrub and trees on farmlands cover 4.2 million hectares or 4.8 per cent of the country. The deforestation rate has been estimated as 0.2 per cent to 0.5 per cent per annum, which is the world's second highest rate of deforestation. Two recent studies revealed that Pakistan's wood biomass is declining at a rate of 4.6 per cent per year. This directly effects the rural communities whose livelihoods suffer.
Response to greenhouse effect
The consequences of global warming and climate change clearly indicates two things:
— Both developed and developing states have good reason to worry about global warming and towards the future of our earth.
— Global cooperation is an important consideration when addressing global warming issues.
The world now recognises the problem. Governments around the globe are taking action to cap carbon dioxide emissions, set meaningful targets for fuel-efficient cars and offer incentives for green buildings.
Reduction in the emission of greenhouse gases calls for
— Increased energy efficiency in consumption and production.
— Switch over to low or no carbon fuels.
— Using substitutes of CFCs in refrigerants, air conditioners.
— Promote complete combustion in vehicles used for transport through proper maintenance and increase fuel efficiency and CNG in vehicles.
— Reduce methane production from livestock and rice fields.
— Switch over to non-fossil fuel sources of energy such as solar, nuclear and hydro.
Besides these steps, a worldwide cooperation is required to prevent further warming of the globe to reduce emission of the greenhouse gases. The formation of the Intergovernmental Panel of Climate Change (IPCC) in 1988 is an attempt at achieving this global cooperation. The Kyoto protocol is yet another milestone in attempt to reduce global warming. Yet these are only a beginning and more practical steps needed to protect the future of mankind.
The writer <nusrat_khurshedi@yahoo.com> is a freelance contributor
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