Senin, 01 Juni 2009

Adaptation to global warming

Adaptation to global warming consists of initiatives and measures to reduce the vulnerability of natural and human systems against actual or expected climate change effects. This is in distinction to the mitigation of global warming.

According to the former Chief Scientific Adviser to the UK Government David King, it is very likely that adaptation to global warming is inevitable as "it is unlikely that levels of greenhouse gases can be kept low enough to avoid a projected temperature rise of 2 °C".

Effects of global warming

The projected effects for the environment and for human life are numerous and varied. The main effect is an increasing global average temperature. This causes a variety of secondary effects, namely, changes in patterns of precipitation, rising sea levels, altered patterns of agriculture, increased extreme weather events, the expansion of the range of tropical diseases, the opening of new trade routes.

Potential effects include sea level rise of 110 to 770 mm (0.36 to 2.5 feet) between 1990 and 2100, repercussions to agriculture, possible slowing of the thermohaline circulation, reductions in the ozone layer, increased intensity and frequency of extreme weather events, lowering of ocean pH, and the spread of diseases such as malaria and dengue fever.

A summary of probable effects and recent understanding can be found in the report made for the IPCC Third Assessment Report by Working Group II. The more recent contribution of Working Group II detailing the impacts of global warming for the IPCC Fourth Assessment Report has been summarized for policymakers.

Necessity for adaptation

National Academy of Sciences

One prominent attempt to broach adaptation was a 1991 report by the American National Academy of Sciences, "Policy Implications of Greenhouse Warming." The National Academy report cautioned that agricultural adaptation will be essential in a greenhouse world.

IPCC Working Group II

IPCC Working Group II argues that mitigation and adaptation should be complementary components of a response strategy to global warming. Their report makes the following observations:

1. Adaptation is a necessary strategy at all scales to complement climate change mitigation efforts.
2. Those with the least resources have the least capacity to adapt and are the most vulnerable
3. Adaptation, sustainable development, and enhancement of equity can be mutually reinforcing.

Adaptation is a necessary strategy

Because of the current and projected climate disruption precipitated by high levels of greenhouse gas emissions by the industrialized nations, adaptation is a necessary strategy at all scales to complement climate change mitigation efforts because we cannot be sure that all climate change can be mitigated. And indeed the odds are quite high that in the long run more warming is inevitable, given the geologic evidence of the past's most similar glacial / interglacial cycle which happened about 400,000 years ago. That similarity being determined by degree of the elliptic shape of the Earth's orbit and how close the Sun is when the most land, that is the northern hemisphere, is being warmed by it.

Adaptation has the potential to reduce adverse impacts of climate change and to enhance beneficial impacts, but will incur costs and will not prevent all damages. Extremes, variability, and rates of change are all key features in addressing vulnerability and adaptation to climate change, not simply changes in average climate conditions.

Human and natural systems will to some degree adapt autonomously to climate change. Planned adaptation can supplement autonomous adaptation, though there are more options and greater possibility for offering incentives in the case of adaptation of human systems than in the case of adaptation to protect natural systems.

Disadvantaged nations

The ability of human systems to adapt to and cope with climate change generally depends on such factors as wealth, technology, education, information, skills, infrastructure, access to resources, management capabilities, and sociopolitical will. There is potential for more advantaged and less advantaged countries to enhance and/or acquire adaptive capabilities. Populations and communities are highly variable in their endowments with these attributes, and disadvantaged countries are weakest in this regard. As a result, they have lesser capacity to adapt and are more vulnerable to climate change damages, just as they are more vulnerable to other stresses. This condition is most extreme among the most disadvantaged people.

Mutual reinforcement

Many communities and regions that are vulnerable to climate change are also under pressure from forces such as population growth, resource depletion, and poverty. Policies that lessen pressures on resources, improve management of environmental risks, and increase the welfare of the poorest members of society can simultaneously advance sustainable development and equity, enhance adaptive capacity, and reduce vulnerability to climate and other stresses. Inclusion of climatic risks in the design and implementation of national and international development initiatives such as polar cities can promote equity and development that is more sustainable and that reduces vulnerability to climate change.

National Center for Policy Analysis

A study by the American National Center for Policy Analysis argues that adaptation is more cost-effective than mitigation. Their report makes the following observations:

1. By 2085, the contribution of (unmitigated) warming to the above listed problems is generally smaller than other factors unrelated to climate change.
2. More important, these risks would be lowered much more effectively and economically by reducing current and future vulnerability to climate change rather than through its mitigation.
3. Finally, adaptation would help developing countries cope with major problems now, and through 2085 and beyond, whereas generations would pass before anything less than draconian mitigation would have a discernible effect.

The Kyoto Protocol

Under the Kyoto Protocol, the United States would have agreed to cut greenhouse emissions by about 400 million tons per year by 2012. In 2003 the world net output of anthropogenic carbon dioxide, the chief greenhouse gas, was about 25 billion metric tons annually.

Even with the Kyoto Protocol, global emissions by 2015 will rise to perhaps 9 billion tons, 50 percent higher than today's level. Such nearly-inevitable carbon buildup ought to tell us is that if greenhouse theory is right, a warming world is now unavoidable: at least through the next generation, until a renewable-fuels energy economy can be created.

Institution of Mechanical Engineers

In February 2009, the Institution of Mechanical Engineers (UK) issued a report in which they expressed pessimism about the ability of any international agreement, such as Kyoto Treaty to reduce carbon emissions. While it did not dismiss mitigation policy all together, it stated that they are "realistic enough to recognise that global CO2 emissions are not reducing and our climate is changing so unless we adapt, we are likely to face a difficult future."

Conceptualising Adaptation

Adaptation can be defined as adjustments of a system to reduce vulnerability and to increase the resilience of system to change, in this case in the climate system . Adaptation occurs at a range of inter-linking scales, and can either occur in anticipation of change (anticipatory adaptation), or be a response to those changes (reactive adaptation). Most adaptation being implemented at present is responding to current climate trends and variability, for example increased use of artificial snow-making in the European Alps. Some adaptation measures, however, are anticipating future climate change, such as the construction of the Confederation Bridge in Canada at a higher elevation to take into account the effect of future sea-level rise on ship clearance under the bridge.

Adaptive capacity and vulnerability are important concepts for understanding adaptation; vulnerability can be seen as the context in which adaptation takes place, and adaptive capacity is the ability or potential of a system to respond successfully to climate variability and change, in order to reduce adverse impacts and take advantage of new opportunities. Those societies that can respond to change quickly and successfully have a high adaptive capacity . It is important to note however, that high adaptive capacity does not necessarily translate into successful adaptation. For example the adaptive capacity in W. Europe is high, and the risks of warmer winters increasing the range of livestock diseases was well documented, but many parts of Europe were still badly affected by outbreaks of the Bluetongue virus in livestock in 2007.

Adaptive capacity is driven by factors operating at many different interlinked scales, and it is important to understand the ways in which the different drivers of adaptive capacity interact. Physical constraints are important, but in most cases it is social processes which increase or decrease adaptive capacity; it can be said that adaptive capacity is socially constructed . The social drivers of adaptive capacity are varied but may include broad structures such as economic and political processes, as well as processes which operate at a very local scale, such as access to decision-making and the structure of social networks and relationships within a community. Adaptive capacity at a local scale is constrained by larger scale processes. For example a farmer’s adaptive capacity will not only depend on access to resources (both physical and social) within the community which allow a crop to be grown successfully, but also the effect of macro-scale economic processes on the price received for the crop. . Gender is another factor which is important in determing adaptive capacity constrain adaptive capacity and vulnerability , for example women may have participation in decision-making, or be constrained by lower levels of education .

The social construction of adaptive capacity is very important when thinking about the risks and impacts of a changing climate. It is not just the change in climate which will affect vulnerability and livelihoods, but the way that these changes are negotiated through complex social systems. A 10% decrease in rainfall may be acceptable and manageable to members of a community who have access to improved agricultural techniques, or whose livelihoods are in some way diversified, whereas marginalised members of the community may not be able to cope with these changes. Adaptation can be seen as a social and institutional process that involves reflecting on and responding to current trends and projected changes in climate .

Both temporal and spatial scales are very important in thinking about adaptation, as is the frame of reference taken for looking at adaptation. Much adaptation takes place in relation to short-term climate variability, however this may cause maladaptation to longer-term climatic trends. For example the expansion of irrigation in Egypt into the W. Sinai desert due to a period of higher river flows is a maladaptation when viewed in relation to the longer term projections of drying in the region). Adaptations at one scale can also create externalities at another by reducing the adaptive capacity of other actors. This is often the case when broad assessments of the costs and benefits of adaptation are examined at smaller scales and it is possible to see that whilst the adaptation may benefit some actors, it has a negative effect on others.

It is clear from the literature that people have always adapted to a changing climate and that coping strategies already exist in many communities, for example changing sowing times or adopting new water saving techniques Traditional knowledge and coping strategies must be maintained and strengthened, otherwise adaptive capacity may be weakened as local knowledge of the environment is lost. Strengthening these indigenous techniques and building upon them also makes it more likely that adaptation strategies will be adopted, as it creates more community ownership and involvement in the process . In some cases however this will be not be enough to adapt to new conditions which are outside the range of those previously experienced, and new techniques will be needed.

Criteria for assessing responses

James Titus identifies the following criteria that policy makers should use in assessing responses to global warming:

* Economic Efficiency: Will the initiative yield benefits substantially greater than if the resources were applied elsewhere?
* Flexibility: Is the strategy reasonable for the entire range of possible changes in temperatures, precipitation, and sea level?
* Urgency: Would the strategy be successful if implementation were delayed ten or twenty years?
* Low Cost: Does the strategy require minimal resources?
* Equity: Does the strategy unfairly benefit some at the expense of other regions, generations, or economic classes?
* Institutional feasibility: Is the strategy acceptable to the public? Can it be implemented with existing institutions under existing laws?
* Unique or Critical Resources: Would the strategy decrease the risk of losing unique environmental or cultural resources?
* Health and Safety: Would the proposed strategy increase or decrease the risk of disease or injury?
* Consistency: Does the policy support other national state, community, or private goals?
* Private v. Public Sector: Does the strategy minimize governmental interference with decisions best made by the private sector?

Adaptation mechanisms

Scheraga and Grambsch identify 9 fundamental principles to be considered when designing adaptation policy.

1. The effects of climate change vary by region.
2. The effects of climate change may vary across demographic groups.
3. Climate change poses both risks and opportunities.
4. The effects of climate change must be considered in the context of multiple stressors and factors, which may be as important to the design of adaptive responses as the sensitivity of the change.
5. Adaptation comes at a cost.
6. Adaptive responses vary in effectiveness, as demonstrated by current efforts to cope with climate variability.
7. The systemic nature of climate impacts complicates the development of adaptation policy.
8. Maladaptation can result in negative effects that are as serious as the climate-induced effects that are being avoided.
9. Many opportunities for adaptation make sense whether or not the effects of climate change are realized.

Methods of adaptation

Examples of adaptation include defending against rising sea levels through better flood defenses, and changing patterns of land use like avoiding more vulnerable areas for housing.

Agricultural production

A significant effect of global climate change is the altering of global rainfall patterns, with certain effects on agriculture. Extended drought can cause the failure of small and marginal farms with resultant economic, political and social disruption.

However, such events have previously occurred in human history independent of global climate change. In recent decades, global trade has created distribution networks capable of delivering surplus food to where it is needed, thus reducing local impact. There are also several ways to adapt to and minimize the disruptive effects of rainfall patterns.

Drought tolerant crop varieties

Agriculture of any kind is strongly influenced by the availability of water. Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. Changes in total seasonal precipitation or in its pattern of variability are both important. The occurrence of moisture stress during flowering, pollination, and grain-filling is harmful to most crops and particularly so to corn, soybeans, and wheat. Increased evaporation from the soil and accelerated transpiration in the plants themselves will cause moisture stress. As a result, there will be a need to develop crop varieties with greater drought tolerance.

More spending on irrigation

The demand for water for irrigation is projected to rise in a warmer climate, bringing increased competition between agriculture--already the largest consumer of water resources in semi-arid regions--and urban as well as industrial users. Falling water tables and the resulting increase in the energy needed to pump water will make the practice of irrigation more expensive, particularly when with drier conditions more water will be required per acre.

Rainwater storage

One strategy involves adapting urban areas to increasingly severe storms by increasing rainwater storage (domestic water butts, unpaved gardens etc) and increasing the capacity of stormwater systems (and also separating stormwater from blackwater, so that overflows in peak periods do not contaminate rivers).

According to English Nature, gardeners can help mitigate the effects of climate change by providing habitats for the most threatened species, and/or saving water by changing gardens to use plants which require less.

Weather control

Russian and American scientists have in the past tried to control the weather, for example by seeding clouds with chemicals to try to produce rain when and where it is needed. A new method being developed involves replicating the urban heat island effect, where cities are slightly hotter than the countryside because they are darker and absorb more heat. This creates 28% more rain 20–40 miles downwind from cities compared to upwind. On the timescale of several decades, new weather control techniques may become feasible which would allow control of extreme weather such as hurricanes.

Damming glacial lakes

Glacial Lake Outburst Floods may become a bigger concern due to the retreat of glaciers, leaving behind numerous lakes that are impounded by often weak terminal moraine dams. In the past, the sudden failure of these dams has resulted in localized property damage, injury and deaths. Glacial lakes in danger of bursting can have their moraines replaced with concrete dams (which may also provide hydroelectric power).

Geoengineering

Geoengineering may be part of adaptation to global warming. Geoengineering consists of two separate fields: Some scientists, such as Ken Caldeira and Paul Crutzen, suggest geoengineering techniques, which can be employed to change the climate deliberately and thus control some of the effects of global warming. These include:

* Solar radiation management may be seen as an adaptation to global warming. Techniques such as space sunshade, creating stratospheric sulfur aerosols and painting roofing and paving materials white all fall into this category.
* Greenhouse gas remediation can be regarded as a mitigation of global warming. Techniques may include biomass energy with carbon capture and storage, using lasers to break up CFCs in the atmosphere and iron fertilisation of oceans to stimulate phytoplankton growth.
* Hydrological geoengineering - typically seeking to preserve sea ice or adjust thermohaline circulation by using methods such as diverting rivers to keep warm water away from sea ice, or tethering icebergs to prevent them drifting into warmer waters and melting. This may be seen as an adaptation technique, although by preventing Arctic methane release it may also have mitigation aspects as well.

Assisting disadvantaged nations

In 2000, there was a proposal made at the Sixth Conference of Parties to the UN Framework Convention on Climate Change that called for the creation of an Adaptation Fund of $1 billion per year for developing countries, especially the least developed and small island states, to enable them to combat the consequences of climate change.

Many scientists, policy makers and the IPCC Fourth Assessment Report have agreed that disadvantaged nations, especially in the global south need more attention to the negative impacts of climate change. These regions are highly populated and people have generally lower adaptive capacity. A balance, however, between development and climate change mitigation and adaptation needs to be found.

In the global south, national governments are largely responsible for formulation and implementation of the adaptation plan, from local to the national level. In this context, a contradictory situation exists. National governments attach high priority to development polices and plans not climate change. Development agendas are driven by pre-existing problems such as poverty, malnutrition, food insecurity , availability of drinking water, indebtness, illiteracy, unemployment, local resource conflicts, lower technological development etc. Here, it is important to recognize that if climate change phenomenon is not properly understood and coping strategies such as mitigation and adaptation are not adopted on timely manner, climate change impacts will exacerbate these pre-existing problems.

Hence, there is a need of exploring strategies of integration between the climate change plans and development plans in the global south. This integration should include principles such as social justice and equity, inclusion of marginal population in decision making, women’s participation and promotion of social cohesion. Inclusion of these principles will not only promote mitigation and adaptation to climate change but will also make development more distributive.

Adaptation measures by country

Numerous countries have held inquiries into, planned or started adaptation measures including Australia.

From http://en.wikipedia.org/

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