Global warming: Net losses for developing world
by Chakravarthi Raghavan
Geneva, 19 Feb 2001 -- Increases in global mean temperatures would produce net economic losses in many developing countries for all magnitudes of warming studied, while in the developed countries there will be a mixture of gains and losses, scientific experts and representatives of some 100 countries at a working group of the Intergovernment Panel on Climate Change (IPCC) has agreed in a report.
IPCC scientific experts, at a meeting in Shanghai a few weeks ago concluded that globally averaged surface temperatures have increased by about 0.6 degrees Celsius over the 20th century, and the temperatures are projected under various models to increase by 1.4 to 5.8 degrees Celsius by year 2100 relative to the temperatures in 1990.
At the lower level of projected global warming, some developed regions may have some economic gains and others may lose. But above a 3 degree Celsius rise, there will be economic losses for most countries, Dr.Robert Watson, chairman of the IPCC, told a news conference Monday where a summary for policy-makers approved by IPCC Working Group II was made public. The full report runs into 1,000 pages, and is to be published by outside publishers. A 100-page report, fleshing some of the points in the summary for policy-makers is likely to be available next week.
Asked by an European media person, whether Europe would be a winner by the prospect of global warming, both Watson, and the Chair of the WG-II, Prof James McCarthy, cautioned against a winners and losers approach, and said that in the various scenarios it would be difficult to find any good news, and most people would be adversely affected, with the poor countries and the poor in every country affected most because of the vulnerability to climate change and the difficulties for adaptation.
The Working Group III of the IPCC, which is to assess the options for limiting greenhouse gas emissions and otherwise mitigating climate change and economic losses is meeting in Accra shortly to finalise its report. The IPCC itself is set to meet in September to put together the reports of the three working groups and prepare and present the overall report.
While some leaked information on the draft report of the Working Group III suggest that this group will come up with support for carbon emissions trading and for sequestering of carbon in forests, this will be more a political economy assessment, rather than the science involved in the work of the two other groups.
For the last IPCC assessment, the Working Group III and its attempts to put a statistical value on lives and property in various parts of the world (one European life is 30 times that of an Indian or a Chinese) resulted in considerable criticisms and expressions of outrage.
Watson, who is a World Bank official, said Monday that this time around the Working Group would avoid this trap, and not be making any statistical evaluations of lives and costs, and the mitigation options would be in the nature of assessments of political economy.
McCarthy, and the secretary of the IPCC, Dr.Sunderaman, underlined that the report had been draw up by some 900 scientific experts who have been working on it. The discussions at the Working Group II meetings in Geneva (13-16 February), where government representatives participated, were in terms of drawing up a summary for policy-makers and formulating the scientific message in clear terms.
The Working Group 1 had made a scientific assessment in terms of the global warming in the recent past, and had projected this for the future. They came to the conclusion that over the 20th century, the globally averaged surface temperatures had increased by 0.6 degrees (plus or minus 0.2) and most of these changes have been due to human activity. And, for the range of scenarios developed in the IPCC Special Report on Emission Scenarios, the globally averaged surface air temperature is projected to warm 1.4 to 5.8 degrees Celsius by 2100.
The warming would vary by region, and be accompanied by increases and decreases in precipitation. In addition there would be changes in variability of climate, and changes in frequency and intensity of some extreme climate phenomena. These general features of climate change act on natural and human systems and set the context of the WG-II assessment of impacts, adaptation and vulnerability, McCarthy said. The available literature, he added, has not yet investigated climate change impacts, adaptation and vulnerability associated with the upper end of the projected range of warming.
The WG-II summary for policy makers finds that recent regional climate changes, particularly temperature increases, have already affected many physical and biological systems in many parts of the world. Examples include the shrinkage of glaciers, thawing of permafrost, later freezing and earlier breakups of ice on rivers and lakes, lengthening of mid- to high-latitude growing seasons, poleward and altitudinal shift of plant and animals ranges, declines of some plant and animal populations, earlier flowering of trees, emergence of insects and egg-laying in birds.
In most cases where changes in biological and physical systems were detected via long-term studies (typically of 20 years or more), the direction of change was that expected on basis of known mechanisms. The probability of these changes occurring by chance alone is negligible.
From the collective evidence (of 44 regional studies of over 400 plants and animals), there is high confidence (67-95%) that recent regional changes in temperature have had discernible impact on many physical and biological systems. There is emerging evidence that some social and economic systems have been affected by the recent increasing frequency of floods and droughts in some areas. However, such systems are also affected by changes in socio-economic factors such as demographic shifts and land-use changes. The relative impacts of climatic and socio-economic factors are generally difficult to quantify.
Natural systems, the WG-II summary says, can be especially vulnerable to climate change because of limited adaptive capacity, and some of these systems may undergo significant and irreversible damage. Natural systems at risk include glaciers, coral reefs and atolls, mangroves, boreal and tropical forests, polar and alpine ecosystems, Prairie wetlands and remnant native grasslands.
While some species may increase in abundance or range, climate change will increase existing risks of extinction of some more vulnerable species and loss of bio-diversity. The geographical extent of damage or loss, and the number of systems affected, will increase with the magnitude and rate of climate change.
Many human systems are sensitive to climate change and these include water resources, agriculture (especially food security) and forestry, coastal zones and marine systems (fisheries),human settlements, energy, and industry, insurance and other financial services and human health.
Projected impacts include:
· a general reduction in potential crop yields in most tropical and sub-tropical regions for most projected increases in temperature;
· a general reduction in potential crop yields in most regions in mid-latitudes for increases in annual average temperature of more than a few degrees Celsius;
· decreased water availability for populations in many water scarce regions, particularly in sub-tropics;
· increase in number of people exposed to vector-borne diseases like malaria, and water-borne diseases like cholera and increase in heat stress mortality;
· widespread increase in risk of flooding for many human settlements (tens of millions of inhabitants in settlements studied) from both increased heavy precipitation events and sea level rise;
· increased energy demand for space cooling due to higher summer temperatures.
The beneficial impacts include:
· increased potential crop yields in some regions at mid-latitudes for increases in temperature of less than a few degrees;
· potential increase in global timber supply from appropriately managed forests;
· increased availability of water for populations in some water-scarce regions, for e.g. in some parts of South East Asia;
· reduced winter mortality in mid- and high-latitudes;
· reduced energy demand for space heating due to higher winter temperatures.
The vulnerability of human societies and natural systems to climate extremes is demonstrated by the damage, hardship and death causes by such events as droughts, floods, heat waves, avalanches and windstorms. While there are uncertainties attached to estimates of such changes, some extreme events are projected to increase in frequency and/or severity during the 21st century. The severity of their impacts will also increase in concert with global warming, while the frequency and magnitude of extreme low temperature events is projected to decrease in the future.
Projected climate changes during the 21st century have the potential to lead to future large-scale and possibly irreversible changes in earth systems - with impacts at continental and global scale. But these are very climate- scenario dependent and a full range of plausible scenarios has not yet been evaluated.
Examples of such changes include significant slowing of the ocean circulation transporting warm water to the North Atlantic, large reductions in Greenland and West Antarctic Ice Sheets, accelerated global warming due to carbon cycle feedbacks, and release of terrestrial carbon from permafrost regions and methane from hydrates in coastal sediments.
The likelihood of many changes is not well-known and probably very low. However, their likelihood is expected to increase with the rate, magnitude and duration of climate change.
And if these changes were to occur, their impacts would be widespread and sustained.
Adaptation to climate change is a necessary strategy at all scales to complement climate change mitigation effects. Adaptation often produces benefits as well as forming a basis for coping with future climate change. However, experience demonstrates that there are constraints to achieving the full measure of potential adaptation. Also, maladaptation, such as promoting development in risk-prone locations, can occur due to decisions based on short-term considerations.
The ability of human systems to adapt to and cope with climate change depends on factors such as wealth, technology, education, information, skills, infrastructure, access to resources and management capabilities.
While both developed and developing countries can enhance and/or acquire adaptive capabilities, populations and communities are highly variable in their endowments with these attributes.
And developing countries, particularly the least developed, are generally poorest in this regard. As a result, they have lesser capacity to adapt and are more vulnerable to climate change damages.
The WG-II summary says that benefits and costs have been estimated in monetary units and aggregated to national, regional and global scales. These estimates generally exclude effects of changes in climate variability and extremes, do not account for effects of different rates of change, and only partially account for impacts on goods and services that are not traded in markets.
These omissions are likely to result in under-estimates of economic losses and over-estimates of gains. The estimates of aggregate impacts are also controversial since they treat gains for some as cancelling out losses for others and the weights used to aggregate across individuals are necessarily subjective.
Notwithstanding these limitations, increases in global mean temperatures would produce net economic losses in many developing countries for all magnitudes of warming studied, and the losses would be greater in magnitude the higher the level of warming.
In contrast, increase in global mean temperature of up to a few degrees Celsius (Dr.Watson put it at below 3 degrees), would produce a mixture of economic gains and losses in developed countries.
The projected distribution of economic impacts is such that it would increase the disparity in well-being between developed and developing countries.
But more people are projected to be harmed than benefited by climate change, even for global mean temperature increases of less than a few degrees. The effects are expected to be greatest in developing countries in terms of loss of life and relative effects on investment and economy
In terms of hydrology and water resources, projections are for increases in annual mean streamflow in high latitudes and southeast Asia, and decreases in central Asia, the area around the Mediterranean, southern Africa and Australia. In the mid-latitudes, there is no strong consistency in projections of streamflow.
One-third of the worlds population, approximately 1.7 billion people, presently live in countries that are water- stressed, using more than 20% of their renewable water supply. Population growth and increased water withdrawals are projected to increase this number to around 5 billion by 2025. Projected climate change would further decrease available water in many of these water-stressed countries - for e.g. in central Asia, southern Africa and countries around the Mediterranean sea, but may increase in some others.
Magnitude of floods and frequency may also increase in most regions, while degrading water quality through higher water temperatures and increased load of pollutants from run-off and overflows of waste facilities.
Demand for water is generally increasing due to population growth and economic development. Climate change is unlikely to have a big effect on municipal and industrial demands in general, but may substantially affect irrigation withdrawals.
The greatest vulnerability will be in unmanaged water systems and those currently stressed or poorly and unsustainably managed due to pricing and other policies.
In terms of agriculture and food security, most studies indicate that global mean annual temperature increases of a few degrees Celsius or greater would prompt food prices to increase due to a slowing in expansion of global food supply relative to growth in global food demand.
Some recent aggregated studies have estimated economic impacts on vulnerable populations such as small-holder producers and poor urban consumers. Climate change would lower incomes of vulnerable populations and increase the absolute number of people at risk of hunger. However this is uncertain and needs further research. It is established, though incompletely, that climate change, mainly through increased extremes and temporal/spatial shifts will worsen food security in Africa..
Contrary to the Second Assessment Report (SAR), global timber market studies that include adaptations through land and product management, even without forestry projects to increase capture and storage of carbon, suggest that a small amount of climate change would increase global timber supply and enhance existing market trends towards rising market share in developing countries. Consumers may benefit from lower timber prices, while producers may gain or lose depending on regional changes in timber productivity and potential dieback effects.
In terms of effects on oceans, there will be increases in sea surface temperatures and mean global sea level, decrease in sea ice cover, and changes in salinity, wave conditions and ocean circulations. Many coastal areas will experience increased levels of flooding, accelerated erosion, loss of wetlands and mangroves, and seawater intrusion into fresh water resources.
In terms of human health, there would be a net increase in the geographic range of potential transmission of malaria and dengue-two vector-borne infections - each of which currently impinge on 40-50% of the world population. These and many other infectious diseases would tend to increase in incidence and seasonality. Actual disease occurrence is strongly influenced by local environmental conditions, socio-economic circumstances and public health infrastructure. The adverse health impacts will be greatest in vulnerable lower-income populations, predominantly within tropical/subtropical countries.
The most widespread direct risk to human settlements is from flooding and landslides. Riverine and coastal settlements are particularly at risk. Rapid urbanisation in low-lying coastal areas, in both developing and developed world, is greatly increasing population densities and value of human-made assets exposed to coastal climatic extremes such as tropical cyclones. The mean annual number of people who would be flooded by coastal storm surges increase several fold - by 75 to 200 million, depending on adaptive responses - for mid-range scenarios of 40 cm sea level rise by 2080s relative to scenarios with no sea level rise
The costs of ordinary and extreme weather events have increased rapidly in recent decades and global economic losses from catastrophic events increased from $3.9 billion a year in 1950s to $40 billion a year in the 1990s (all in 1999 nominal dollars) - with one quarter of the rise in losses in developing countries. The insured proportion of losses rose from a negligible level to $9.2 billion a year over the same period.
The costs have risen rapidly despite significant and increasing efforts at fortifying infrastructure and enhancing disaster preparedness. Part of the upward trend is linked to socio-economic factors - population growth, increased wealth, urbanisation in vulnerable areas. But part is linked to climatic factors such as observed changes in precipitation and flooding events.
There is high confidence (67-95%) that climate change and anticipated changes in weather-related events perceived to be linked to climate change would increase actuarial uncertainty in risk assessment, placing upward pressure on insurance premiums and/or could lead to certain risks being reclassified as uninsurable with subsequent withdrawal of coverage. This would trigger increased insurance costs, slow the expansion of financial services into developing countries, reduce availability of insurance for spreading risk and increase demand for government-funded compensation after natural disasters. In the event, the relative roles of public and private entities in providing insurance and risk management resources can be expected to change.
The effects of climate change are expected to be greatest in the developing world, especially in countries reliant on primary production as a major source of income. The adaptive capacity is low in Africa, Asia and Latin America, and in small island states. Vulnerability is also high.
Africa: Grain yields are projected to decrease, diminishing food security. Major rivers are highly sensitive to climate variation. Extension of ranges of infectious disease vectors would adversely affect human health. Desertification will be exacerbated, and increases in droughts, floods and other extreme events would add to stresses. Significant extinctions of plant and animal species are projected.
Coastal settlements along the Gulf of Guinea, Senegal, Gambia, Egypt and East-Southern African coast would be adversely affected by sea-level rise
Asia: Decreases in agricultural productivity and aquaculture, due to thermal and water stress, sea-level rises, floods and droughts, and tropical cyclones would diminish food security. Run-off and water availability may decrease. Human health would be threatened by increased exposure to vector-borne infectious diseases and heat stress. Climate change would increase energy demand, decrease tourism attraction and influence transportation; exacerbate threats to biodiversity, while sea-level rise would put ecological security at risk.
Latin America: Loss and retreat of glaciers would adversely impact run-off and water supply; floods and droughts would become more frequent; increases in tropical cyclones would alter risks to life, property and ecosystems from heavy rain, flooding, storm surges and wind damages. Yields of important crops are projected to decrease in many locations, and subsistence farming in some regions would be threatened. The geographical distribution of vector-borne diseases would expand poleward and to higher elevations.
Small Island States: projected sea level rise of 5mm a year for the next 100 years would cause enhanced coastal erosion, loss of land and property, dislocation of people, increased risk from storm surges, reduced resilience of coastal ecosystems, saltwater intrusion into freshwater resources and high resource costs to respond to and adapt to these changes. Tourism, an important source of income and foreign exchange for many islands, would face severe disruption from climate change and sea-level rise.
Europe: Southern Europe and the European Arctic are more vulnerable. Summer run-off, water availability and soil moisture are likely to decrease in southern Europe, and would widen the difference between the north and drought-prone south. Half of alpine glaciers and large permafrost areas could disappear by end of the century. River flood hazard will increase across much of Europe. There will be some broadly positive effects on agriculture in northern Europe, while productivity will decrease in southern and eastern Europe. There will be an upward and northward shift of biotic zones, and loss of habitats - wetlands, tundra and isolated habitats would threaten some species.
North America: Adaptive capacity high. But some communities e.g. indigenous peoples and those dependent on climate sensitive resources are more vulnerable. Some crops would benefit from modest warming, but effects vary among crops and regions, including declines due to drought in some areas of Canadas prairies and the US Great Plains. But there would be potential increase in food production in areas of Canada, north of current production areas and increased warm-temperate mixed forest production. However benefits for crops would decrease at an increasing rate and possible become a net loss with further warming.
Australia and New Zealand: adaptive capacity of human systems is generally high, but there are groups such as indigenous peoples, with low capacity to adapt and face high vulnerability. The net impact on some temperate crops of climate and CO2. changes may initially be beneficial, but this balance is expected to become negative for some areas and crops with further climate change. Water is likely to be a key issue. -SUNS4839
The above article first appeared in the South-North Development Monitor (SUNS) of which Chakravarthi Raghavan is the Chief Editor.
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