Adnan Khandker runs through the basics of climate change concepts to explain what we can do to slow the change, and what societies can do to better adapt themselves

In lay terms, climate change means a change in the earth’s climate – change over a period of decades to centuries and change that can be both natural and human-induced.The United Nations Framework Convention on Climate Change defines climate change as the change in climate that can be attributed directly or indirectly to human activities. It says climate change is ‘a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.’ Such changes have serious implications for the stability of climate on which life on earth is heavily dependent.
   
   The cause
   The energy in the form of visible light from the sun is the driving force for life on earth. The outer atmosphere of the earth reflects back approximately 30 per cent of sunlight and the rest reaches the surface and is reflected back in the form of infrared radiation. The infrared radiation is trapped within the Earth's atmosphere by greenhouse gases such as water vapour, carbon dioxide, ozone, and methane.
   According to scientists, greenhouse gases that act like a blanket around the earth comprise of about 1 per cent of the atmosphere. They function like the glass roof of the back-garden greenhouse, common in cold climates, by trapping heat and keeping the planet some 30 degrees hotter than it would be otherwise. Human activities mainly are making the blanket ‘thicker.’ Emissions of carbon dioxide from the burning of coal, oil, and natural gas alongside the natural levels of these gases are increasing the ‘thickness.’ Additional methane and nitrous oxide produced by farming activities and changes in land use and several long-lived industrial gases that do not occur naturally are further compounding the problem.
   These changes are taking place at an extraordinary rate. If emissions keep rising at existing rates, the atmospheric levels of carbon dioxide will double from pre-industrial levels during the 21st century. Carbon dioxide is to blame for over 60 per cent of the enhanced greenhouse effect. The human race, and more specifically the industrialised West, is using coal, oil, and natural gas at a rate that is faster than the speed at which these fossil fuels were created. This is disrupting the carbon cycle by releasing the carbon stored in the fuels into the atmosphere. Currently, atmospheric levels of carbon dioxide are rising by over 10 per cent every 20 years.
   
   IPCC and UNFCCC
   In the 1960s and 1970s, climatologists and other scientists provided evidence that concentrations of carbon dioxide were increasing in the atmosphere. Yet, it took years for the international community to respond. In 1988, the World Meteorological Organisation and the United Nations Environment Programme created the Intergovernmental Panel on Climate Change, conceived to be the apex scientific body on climate change. In 1990, the panel presented reports that global warming was real and urged that something be done about it. Its findings prompted governments to draft the United Nations Framework Convention on Climate Change. At the 1992 United Nations Conference on Environment and Development, more popularly known as the ‘Earth Summit’, in Rio de Janeiro, the convention was signed.
   According to the convention, the IPCC findings, because they reflect global scientific consensus and are apolitical in character, form a useful counterbalance to the often highly charged political debate over what to do about climate change. IPCC reports are frequently used as the basis for decisions made under the convention, and they played a major role in the negotiations leading to the Kyoto Protocol, a second, more far-reaching international treaty on climate change that entered into force on February 16, 2005.
   
   The evidence
   According to the intergovernmental panel, numerous long-term changes in the climate have been observed, including extreme weather events such as droughts, heavy precipitation, heat waves and tropical cyclones. Trends towards more potent storms and hotter, longer dry periods have been observed and are evaluated in the panel’s fourth assessment report.
   According to climatologists, the Rhine floods of 1996 and 1997, the Chinese floods of 1998, the East European floods of 1998 and 2002, the Mozambique and European floods of 2000, and the monsoon-based flooding of 2004 in Bangladesh, which left 60 per cent of the country under water, are some compelling examples.
   Warmer temperatures result in larger amounts of evaporation and a hotter atmosphere is able to hold more moisture. Therefore, more water is in the atmosphere that can fall as precipitation. Droughts and desertification are worsened as dry regions are bound to lose still more moisture if the weather is hotter. Over most land areas, the incidence of torrential rainfall events has increased. Significantly increased rainfall has been experienced in eastern parts of North and South America, northern Europe and northern and central Asia. There is evidence of an increase in intense tropical cyclone activity in the North Atlantic since about 1970.
   As per the climate change convention, droughts and desertification are worsened as dry regions are bound to lose still more moisture if the weather is hotter. Drying has also taken place in large regions such as the Sahel, the Mediterranean, southern Africa and parts of southern Asia. In Africa’s large catchments basins, total available water has decreased by 40 to 60 per cent, and desertification has been worsened by lower average annual rainfall, runoff, and soil moisture, especially in southern, northern, and western Africa.
   Average Arctic temperatures increased at almost twice the global rate in the past 100 years. Temperatures at the top of the permafrost layer have generally increased since the 1980s by up to three degrees Celsius. In the Russian Arctic, buildings are collapsing because permafrost under their foundations has melted, say the IPCC reports.
   The climate change convention warns that snow cover has declined some 10 per cent in the mid and high latitudes of the Northern Hemisphere since the late 1960s. Mountain glaciers and snow cover have declined in both hemispheres and widespread decreases in glaciers and icecaps have contributed to sea level rise. New data evaluated by the intergovernmental panel shows that losses from the ice sheets of Greenland and Antarctica have very likely contributed to sea level rise from 1993 to 2003. The average global sea level rose at an average rate of 1.8mm per year between 1961 and 2003, but between 1993 and 2003 it rose by 3.1 mm per year.
   Scientists have observed climate-induced changes in at least 420 physical processes and biological species or communities. In the Alps, some plant species have been migrating upward by one to four metres per decade, and some plants previously found only on mountaintops have disappeared.
   
   The effects
   Due to past and present emissions, climate change is unavoidable. According to the UNFCC, the climate does not respond immediately to external changes, but after 150 years of industrialisation, global warming has momentum, and it will continue to affect the earth’s natural systems for hundreds of years even if greenhouse gas emissions are reduced and atmospheric levels stop rising. Even the minimum predicted shifts in climate for the 21st century are likely to be significant and disruptive. Scientific understanding and computer models have improved recently and many projections can now be made with greater certainty. Predictions of future climate impacts show that the consequences could vary from disruptive to catastrophic.
   Current climate models predict a global temperature increase of 1.4-5.8°C by 2100 if nothing is done to reduce emissions. The minimum warming forecast for the next 100 years is more than twice the 0.6°C increase that has occurred since 1900 and that earlier increase is already having marked consequences.
   The intergovernmental panel says a future of more severe storms and floods along the world’s increasingly crowded coastlines is likely, and will be a bad combination even under the minimum scenarios forecast. Furthermore, extra-tropical storm tracks are projected to move pole-ward, with consequent changes in wind, precipitation, and temperature patterns, continuing the pattern observed over the last half century. The panel also points to very likely increases in the amounts of precipitation in high latitudes, as well as likely precipitation decreases in most sub-tropical land regions. Projections also point to continued snow cover contraction, as well as widespread increases in thaw depth over most permafrost regions.
   The seas level has already risen by 10-20cm over pre-industrial records. Sea level rise will continue for centuries due to the time scales associated with climate processes and feedbacks. In its fourth assessment report, the panel states that the contraction of the Greenland ice sheet is projected to continue to contribute to sea level rise after 2100. If this contraction is sustained for centuries, it would lead to the virtually complete elimination of the Greenland ice sheet and a concomitant sea level rise of about 7m.
   Rising sea levels resulting in salt-water intrusion will reduce the quality and quantity of freshwater. This is a major concern, since billions of people already lack access to freshwater. Higher ocean levels already are contaminating underground water sources in Israel and Thailand, in various small island states in the Pacific and Indian Oceans and the Caribbean Sea, and in some of the world’s most productive deltas, such as China’s Yangtze Delta and Vietnam’s Mekong Delta.
   According to the climate change convention, a general reduction is expected in potential crop yields in most tropical and sub-tropical regions although regional and local effects may differ widely. Mid-continental areas such as the US’s grain belt and vast areas of Asia are likely to dry. Where agriculture is dependent exclusively on rain, as in sub-Saharan Africa, yields would decrease significantly even with negligible increases in temperature. Such changes could cause disruptions in food supply in a world that is already afflicted with food shortages and famines.
   Most of the world’s endangered species, some 25 per cent of mammals and 12 per cent of birds, may become extinct over the next few decades as warmer conditions alter the forests, wetlands and rangelands they depend on, and human development blocks them from migrating elsewhere. Higher temperatures are expected to expand the range of some dangerous ‘vector-borne’ diseases, such as malaria, which already kills 1 million people annually, most of them children.
   Environmental damage such as overgrazed rangeland, deforested mountainsides means that nature will be more vulnerable than before to changes in climate. In any case, when climate shifts occurred thousands and tens of thousands of years ago, they generally took place more gradually. Natural systems had both more space and more time to adapt.
   Similarly, the world’s vast human population, much of it poor, is vulnerable to climate stress. Millions live in dangerous places such as on floodplains or in shantytowns on exposed hillsides around the enormous cities of the developing world. Often there is nowhere else for them to go. In the distant past, man and his ancestors migrated in response to changes in habitat. There will be much less room for migration this time around, says the intergovernmental panel.
   As per the climate change convention, global warming almost certainly will be unfair. The industrialised countries of North America and Western Europe, along with a few other states, such as Japan, are responsible for the vast bulk of past and current greenhouse gas emissions. These emissions are a debt unwittingly incurred for the high standards of living enjoyed by a minority of the world’s population. Yet, the developing countries will suffer most from climate change. More importantly, developing countries have fewer resources for coping with the changes like storms, floods, droughts, etc. At the same time, developing states are working for economic development but may find that this already difficult process has become more difficult because of climate change. The poorer nations of the world have done almost nothing to cause global warming yet are most exposed to its effects.
   
   The Bangladesh context
   Bangladesh will be affected in many ways and from all fronts, say experts. The most important change will be brought about by the rise in sea levels along the coastline of Bangladesh. Bangladesh will face catastrophic consequences if the sea levels rise to predicted levels of 88 and 89cm. Ain-un-Nishat of the International Union for Conservation of Nature (IUCN) points out that Bangladesh is on average 10m above the sea level, but the regions near the coast are even lower. ‘Roughly 25 per cent of our country’s landmass will be under water if sea levels rise by 89cm. Such a catastrophe would make roughly 18 million people homeless. For a densely populated country like Bangladesh 18 million refugees on top of a 20 per cent landmass loss would spell disaster,’ says Nishat.
   In addition, he warns, saltwater intrusion could further compound the problem by crippling the agriculture sector. Most of the mangrove forests would also go under water. While these tidal mangroves are generally neglected and heavily exploited for forest produce, the reality is that they are our first and only line of defense against tropical cyclones such as SIDR, which whit Bangladesh on November 15 extracting a death toll of over 3,000 lives. ‘Not only will we lose a lot of cultivatable land but most of the land near the newly created coastline would also be useless. There could be a food crisis resulting from the demise of our agriculture sector,’ adds Ainun.
   In the north, the intensity of flooding is bound to increase. Saleemul Haq, who heads climate change research at the London-based IIED, explains that rising temperatures will exacerbate the melting of the Himalayan snow-caps, which will mean heavier flooding down stream. The large-scale deforestation in the path of this downstream flooding will mean that we have little natural cover against the flooding. Therefore, this will compound the intensity of the flooding.
   ‘More importantly, trend analysis of flooding data shows that massive floods which were once in a decade events will become more frequent. Therefore, the country will have to arm itself to tackle massive floods on a regular basis,’ says Saleemul.
   Cyclones will also take on new facets in their rate of recurrence and increase in impact. Sirajul Islam, associate professor at North South University, argues that with rising sea surface temperatures it is very likely that the intensity and frequency of the storms will increase. ‘There will also be more periods of drought and heavier rainfall,’ adds Sirajul.
   
   The Kyoto Protocol
   The IPCC findings, because they reflect global scientific consensus and are apolitical in character, form a useful counterbalance to the often highly charged political debate over what to do about climate change. IPCC reports are frequently used as the basis for decisions made under the Convention, and they played a major role in the negotiations leading to the Kyoto Protocol, a second, more far-reaching international treaty on climate change that entered into force on 16 February 2005.
   In Kyoto, Japan, on 1997 the Kyoto Protocol was adopted at the third Conference of the Parties to the climate change convention (COP 3) after two and a half years of intense negotiations. The protocol shares the objective and institutions of the convention. It commits developed countries to stabilise GHG emissions. At COP 7 in Marrakesh in 2001, detailed rules for its implementation were adopted and are called the ‘Marrakesh Accords.’
   The Kyoto Protocol is considered to be the most far-reaching agreement on environment and sustainable development ever adopted because it will affect virtually all major sectors of the economy. However, any treaty not only has to be effective in tackling a complicated worldwide problem, it must also be politically acceptable. Most of the world’s countries eventually agreed to the protocol, but some nations, including the United States and Australia, chose not to ratify it. Following ratification by Russia, the Kyoto Protocol entered into force on February 16, 2005.
   According to the climate convention, the protocol requires developed countries to reduce their GHG emissions below levels specified for each of them in the treaty. These targets must be met within a five-year timeframe between 2008 and 2012, and add up to a total cut in GHG emissions of at least 5 per cent against the baseline of 1990. United Nations-based bodies carry out review and enforcement of these commitments. The protocol places a heavier burden on developed nations.
   The protocol developed three innovative mechanisms such as emissions trading, joint implementation and the clean development mechanism to give countries a certain degree of flexibility in meeting their emission reduction targets. These instruments permit parties to earn and trade emissions credits through projects implemented either in other developed countries or in developing countries, which they can use towards meeting their commitments. The protocol argues that these mechanisms help identify lowest-cost opportunities for reducing emissions and attract private sector participation in emission reduction efforts. Developing nations benefit in terms of technology transfer and investment brought about through collaboration with industrialised nations under the CDM.
   
   Things to do
   The intergovernmental panel says most measures are heavily dependent on teamwork and political will and can slow the rate of global warming and help the world cope with the climate shifts that occur. First of all, we must try to reduce GHG emissions by making our systems and processes more efficient. Getting more electricity, transport, and industrial output for less coal, oil, or gasoline is a no-lose situation: more profit, less pollution, less global warming although initial outlays for better equipment and technology can be expensive. Most of the immediate progress that can be made to reduce greenhouse gas emissions involves using fossil fuels more efficiently. The savings realised this way would buy time for the global climate system while alternative energy technologies can be developed and made cost effective. It is hoped that emissions-free sources ultimately will replace fossil fuels as the main category of energy supply.
   At the same time, we must start using existing renewable energy technologies. Solar energy and wind-generated electricity at current levels of efficiency and cost can replace some fossil-fuel use, and are increasingly being used. Greater employment of such technologies can increase their efficiencies of scale and lower their costs. The current contribution of such energy-producing methods to world supplies is less than 2 per cent. Nuclear energy produces virtually no greenhouse gases while new technologies have become available for ‘capturing’ the carbon dioxide emitted by fossil-fuel power plants before it reaches the atmosphere. The carbon dioxide is then stored underground in empty oil or gas reservoirs, unused coal beds, or in the deep ocean.
   ‘Sinks’ is the term used by climatologists for vast swaths of trees and other green vegetation, which ‘drain away’ the most dominant greenhouse gas. We can expand the role of sinks by increasing forests. Trees and other green plants, using only sunlight for energy, take carbon dioxide out of the atmosphere, releasing oxygen and storing carbon in a safe and useful way. Deforestation, which is occurring all over the world, has a doubly damaging effect: it reduces the number of trees that can recover the carbon dioxide produced by human activities, and it releases into the atmosphere the carbon contained in the trees that are cut down. The value of forests for preventing global warming and preserving the earth’s biodiversity, by contrast, are long-term and their rewards apply to everyone generally. In terms of efforts to reduce global warming, a forest in one place is as good as a forest in another. That can give rise to certain practical arrangements and efficiencies.
   Moreover, the climate change convention argues that we must change agricultural methods to resist climate change. Carbon stored in agricultural soils often can be preserved or enhanced by switching to ‘no-tillage’ or ‘low-tillage’ techniques, which slow the rate at which organic soil matter decomposes. In rice fields, emissions of methane, a powerful greenhouse gas, can be suppressed to some extent through tillage practices, water management, and crop rotation. Using nitrogen fertilisers more efficiently can reduce emissions of nitrous oxide, another potent greenhouse gas.
   The most difficult challenge is bringing about change in people’s lifestyles and culture. People don’t necessarily make decisions based on efficiency or the health of the environment. And when thousands and even millions of people make choices that add unnecessarily to the global warming problem, the effects can be considerable. Traditions and habits also may limit the lifestyle choices that are available. Businesses and governments tend not to supply products, services, and policies people don’t want. Lack of demand also slows innovation and technological progress, while heightened interest accelerates it. If customers and citizens, especially in industrialised countries, become strongly interested in combating global warming and are willing to buy products that cut emissions, new processes and technologies could well be invented that would greatly reduce or even solve the problem. Enormous technological breakthroughs in the past have occurred because of such pressures, says the convention.
   It stresses that laws and regulations can have a major impact on greenhouse gas emissions because they affect business behaviour and public habits. Some governments encourage the use of mass transit; some through tax arrangements, road-building programmers, and even subsidies encourage the burning of fossil fuels. One way (admittedly not always popular) of changing behaviour is to make it illegal. Another is to make it more expensive through taxes or penalties.
   Furthermore, adaptation and planning are needed. It is vital for countries and communities to take practical steps to protect themselves from the likely disruption and damage that will result since major effects from climate change now appear inevitable. Prevention calls for superseding human nature and politicians’ instincts. It is difficult to take expensive and painful measures when, in any given place, people don’t know exactly what’s coming, exactly when, and how bad it will be. Few practical precautions against climate change have been taken to date, although the need is urgent. Efforts are at least going forward in the form of assessments and studies. One approach that has proved valuable is to focus on vulnerability rather than on the still-uncertain extent of the danger posed by climate change. It is vital, in other words, to know who is going to need help, whatever climate difficulties arise.
   Flexibility is a valuable tool. It is a sensible way of planning ahead for example, to grow a variety of crops, some of which may be viable in times of climate flux, rather than investing in a single crop that may be felled by a drought or a heat wave. Rational decisions about the safe location of new facilities and infrastructure are a valuable, cost-effective step government and industries can take now and in coming years. It is better to put future electrical-generating plants, train lines, major roads, and hospitals, not to mention houses, in spots where more intense storms and floods won’t damage or destroy them.
   
   The accomplishments and challenges
   IPCC figures show that between 1990 and 2000, the total greenhouse gas emissions of industrialised countries actually declined by 5.6 per cent. But that reflected unusual circumstances. Because of the steep and painful drop in economic output of the countries of Eastern Europe and the former Soviet Union, which were shifting from centrally planned to market economies, emissions in those nations fell by 37 per cent. That more than compensated for an 8.2 per cent increase in emissions among developed countries elsewhere. But now the Eastern European economies are growing again, and their emissions are rising. Worldwide economic progress combined with reduced emissions has yet to be accomplished.
   The good news is that technology already exists that could stabilise and even reduce greenhouse gas levels within a few decades. The problem is that getting such technology in place, installing and paying for more efficient procedures for burning fossil fuels and for using renewable energy sources such as solar power and wind power, is politically and economically difficult, says the UN convention. These require investments up front which some businesses may not be able or willing to pay, especially if they don’t receive credits or loans from governments.
   Economic systems and governments currently aren’t arranged for accomplishing greenhouse gas reductions. The costs of cutting emissions tend to be immediate and specific. They can carry an economic throb. The system has to be adjusted so that the burdens as well as the benefits are fairly distributed.
   The intergovernmental panel points out that there also are competitiveness problems, if laws and regulations around the world aren’t equally demanding, businesses in countries that don’t require greenhouse gas reductions will be able to operate more cheaply and sell their products at lower prices at least in the short term than businesses in countries that require more climate-friendly behaviour. Multinational corporations may shift their factories to places where regulations are less restrictive.
   At the moment what is most needed to take the fight against climate change further is public consensus, which is the only way we can create the political will necessary for our survival.