Climate change adaptation

Cities, states, and provinces often have considerable responsibility in land use planning, public health, and disaster management. Some have begun to take steps to adapt to threats intensified by climate change, such as flooding, bushfires, heatwaves, and rising sea levels.[27]

Projects to deal with heat include:

• Incentivizing lighter-colored roofs to reduce the heat island effect[28]
• Adding air conditioning in public schools[29]
• Changing to heat tolerant tree varieties[29][30]
• Adding green roofs to deal with rainwater and heat[29]

There is also a wide variety of adaptation options for flooding:[31]

• Installing protective and/ or resilient technologies and materials in properties that are prone to flooding[32]
• Rainwater storage to deal with more frequent flooding rainfall – Changing to water-permeable pavements, adding water-buffering vegetation, adding underground storage tanks, subsidizing household rain barrels[29]
• Reducing paved areas to deal with rainwater and heat[33]
• Requiring waterfront properties to have higher foundations[28]
• Raising pumps at wastewater treatment plants[28]
• Surveying local vulnerabilities, raising public awareness, and making climate change-specific planning tools like future flood maps[28][34][35]
• Installing devices to prevent seawater from backflowing into storm drains[28]
• Installing better flood defenses, such as sea walls and increased pumping capacity[36]
• Buying out homeowners in flood-prone areas[37]
• Raising street level to prevent flooding[36]

Dealing with more frequent drenching rains may required increasing the capacity of stormwater systems, and separating stormwater from blackwater, so that overflows in peak periods do not contaminate rivers. One example is the SMART Tunnel in Kuala Lumpur.

New York City produced a comprehensive report for its Rebuilding and Resiliency initiative after Hurricane Sandy. Its efforts include not only making buildings less prone to flooding, but taking steps to reduce the future recurrence of specific problems encountered during and after the storm: weeks-long fuel shortages even in unaffected areas due to legal and transportation problems, flooded health care facilities, insurance premium increases, damage to electricity and steam generation in addition to distribution networks, and flooding of subway and roadway tunnels.[38]

Adaptive capacity is the ability of a system (human, natural or managed) to adjust to climate change (including climate variability and extremes) to moderate potential damages, to take advantage of opportunities, or to cope with consequences.[39] As a property, adaptive capacity is distinct from adaptation itself.[40] Those societies that can respond to change quickly and successfully have a high adaptive capacity.[41] High adaptive capacity does not necessarily translate into successful adaptation. For example, adaptive capacity in Western Europe is generally considered to be high,[42] and the risks of warmer winters increasing the range of livestock diseases is well documented, but many parts of Europe were still badly affected by outbreaks of the Bluetongue virus in livestock in 2007.

Unmitigated climate change (i.e., future climate change without efforts to limit greenhouse gas emissions) would, in the long term, be likely to exceed the capacity of natural, managed and human systems to adapt.[43]

It has been found that efforts to enhance adaptive capacity can help to reduce vulnerability to climate change.[44] In many instances, activities to promote sustainable development can also act to enhance people's adaptive capacity to climate change. These activities can include:[45]

• Improving access to resources
• Reducing poverty
• Lowering inequities of resources and wealth among groups
• Improving education and information
• Improving infrastructure
• Improving institutional capacity and efficiency
• Promoting local indigenous practices, knowledge, and experiences

Others have suggested that certain forms of gender inequity should be addressed at the same time;[46] for example women may have participation in decision-making, or be constrained by lower levels of education.[47]

Researchers at the Overseas Development Institute found that development interventions to increase adaptive capacity have tended not to result in increased agency for local people.[48] They argue that this should play a more prominent part in future intervention planning because agency is a central factor in all other aspects of adaptive capacity. Asset holdings and the ability to convert these resources through institutional and market processes are central to agency.[49]

A significant effect of global climate change is the altering of global rainfall patterns, with certain effects on agriculture.[50] Rainfed agriculture constitutes 80% of global agriculture.[51] Many of the 852 million poor people in the world live in parts of Asia and Africa that depend on rainfall to cultivate food crops. Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. Extended drought can cause the failure of small and marginal farms with resultant economic, political and social disruption, more so than this currently occurs.

Agriculture of any kind is strongly influenced by the availability of water. 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.

Adaptive ideas include:

• Taking advantage of global transportation systems to delivering surplus food to where it is needed[50] (though this does not help subsistence farmers unless aid is given).
• Developing crop varieties with greater drought tolerance.[52]
• Rainwater storage. For example, according to the International Water Management Institute, using small planting basins to 'harvest' water in Zimbabwe has been shown to boost maize yields, whether rainfall is abundant or scarce. And in Niger, they have led to three or fourfold increases in millet yields.[53]
• Falling back from crops to wild edible fruits, roots and leaves. Promoting the growth of forests can provide these backup food supplies, and also provide watershed conservation, carbon sequestration, and aesthetic value.

Reforestation, Lake Tahoe area

Reforestation is one of the ways to stop desertification fueled by anthropogenic climate change and non sustainable land use. One of the most important projects is the Great Green Wall that should stop the expansion of Sahara desert to the south. By 2018 only 15% of it is accomplished, but there are already many positive effects, which include: "Over 12 million acres (5 million hectares) of degraded land has been restored in Nigeria; roughly 30 million acres of drought-resistant trees have been planted across Senegal; and a whopping 37 million acres of land has been restored in Ethiopia – just to name a few of the states involved." "Many groundwater wells [were] refilled with drinking water, rural towns with additional food supplies, and new sources of work and income for villagers, thanks to the need for tree maintenance."[54][55][56]

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. Other strategies will be needed to make the most efficient use of water resources. For example, the International Water Management Institute has suggested five strategies that could help Asia feed its growing population in light of climate change. These are:

• Modernising existing irrigation schemes to suit modern methods of farming
• Supporting farmers' efforts to find their own water supplies, by tapping into groundwater in a sustainable way
• Looking beyond conventional "Participatory Irrigation Management" schemes, by engaging the private sector
• Expanding capacity and knowledge
• Investing outside the irrigation sector[57]

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. China has implemented a cloud seeding machine that is controlled through remote sensing technologies.[58] The World Meteorological Organization (WMO) through its Commission for Atmospheric Sciences (CAS) opined in 2007: "Purposeful augmentation of precipitation, reduction of hail damage, dispersion of fog and other types of cloud and storm modifications by cloud seeding are developing technologies which are still striving to achieve a sound scientific foundation and which have to be adapted to enormously varied natural conditions."[59]

Beach nourishment in progress in Barcelona.

Adaptation options to sea level rise can be broadly classified into retreat, accommodate and protect. Retreating involves moving people and infrastructure to less exposed areas and preventing further development in areas at risk. This type of adaptation is potentially disruptive, as displacement of people may lead to tensions. Accommodation options make societies more flexible to sea level rise. Examples are the cultivation of food crops that tolerate a high salt content in the soil and making new building standards which require building to be built higher and incur less damage in the case a flood does occur. Finally, areas can be protected by the construction of dams, dikes and by improving natural defenses.[60][61] In the United States, the Environmental Protection Agency supports the development and maintenance of water supply infrastructure nationwide, especially in coastal cities, and more coastal cities and countries are actively implementing this approach.[62] Besides, storm surges and flooding can be instantaneous and devastating to cities, and some coastal areas have begun investing in storm water valves to cope with more frequent and severe flooding during high tides.[63]

An overview of Imja Tsho showing lake outlet channel, ponds, ablation valley

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).[64]

Migration can be seen as adaptation: people may be able to generate more income, diversify livelihoods, and spread climate risk.[65] This contrasts with two other frames around migration and environmental change: migration as a human's right issue and migration as a security issue. In the human right's frame, normative implications include setting up protection frameworks for migrants, whereas increased border security may be an implication of framing migration as a national security issue.[66]

Would-be migrants often need access to social and financial capital, such as support networks in the chosen destination and the funds or physical resources to be able to move. Migration is frequently the last adaptive response households will take when confronted with environmental factors that threaten their livelihoods, and mostly resorted to when other mechanisms to cope have proven unsuccessful.[67]

Migration events are multi-causal, with the environment being just a factor amongst many. Many discussions around migration are based on projections, while relatively few use current migration data.[68] Migration related to sudden events like hurricanes, heavy rains, floods, and landslides is often short-distance, involuntary, and temporary. Slow-impact events, such as droughts and slowly rising temperatures, have more mixed effects. People may lose the means to migrate, leading to a net decrease in migration. The migration that does take place is seen as voluntary and economically motivated.[69]

Focusing on climate change as the issue may frame the debate around migration in terms of projections, causing the research to be speculative. Migration as tool for climate change adaptation is projected to be a more pressing issue in the decade to come.[70] In Africa, specifically, migrant social networks can help to build social capital to increase the social resilience in the communities of origin and trigger innovations across regions by the transfer of knowledge, technology, remittances and other resources.[71]

In Africa, Mozambique and Zimbabwe are clear examples of adaptation strategies because they have implemented relocation policies that have reduced the exposure of populations and migrants to disaster. Tools can be put in place that limit forced displacement after a disaster; promote employment programs, even if only temporary, for internally displaced people or establish funding plans to ensure their security; to minimize the vulnerability of populations from risk areas. This can limit the displacement caused by environmental shocks and better channel the positive spillovers (money transfers, experiences, etc.) from the migration to the origin countries/communities.[72]

Relocation from the effects of climate change has been brought to light more and more over the years from the constant increasing effects of climate change in the world. Coastal homes in the U.S. are in danger from climate change, this is leading residents to relocate to areas that are less affected.[73] Flooding in coastal areas and drought have been the main reasons for relocation.[73]

Insurance spreads the financial impact of flooding and other extreme weather events.[74] Although it can be preferable to take a proactive approach to eliminate the cause of the risk, reactive post-harm compensation can be used as a last resort.[75] Access to reinsurance may be a form of increasing the resiliency of cities.[76] Where there are failures in the private insurance market, the public sector can subsidize premiums.[77] A study identified key equity issues for policy considerations:[78]

• Transferring risk to the public purse does not reduce overall risk
• Governments can spread the cost of losses across time rather than space
• Governments can force home-owners in low risk areas to cross-subsidize the insurance premiums of those in high risk areas
• Cross-subsidization is increasingly difficult for private sector insurers operating in a competitive market
• Governments can tax people to pay for tomorrow's disaster.

Government-subsidized insurance, such as the U.S. National Flood Insurance Program, is criticized for providing a perverse incentive to develop properties in hazardous areas, thereby increasing overall risk.[79] It is also suggested that insurance can undermine other efforts to increase adaptation, for instance through property level protection and resilience.[80] This behavioral effect may be countered with appropriate land-use policies that limit new construction where current or future climate risks are perceived and/or encourage the adoption of resilient building codes to mitigate potential damages.[81]

A rather new activity in the domain of climatology applied to adaptation is the development and implementation of climate services that "provide climate information to help individuals and organizations to make climate smart decisions".[82] Most recognized applications of climate services are in domains like agriculture, energy, disaster risk reduction, health and water.[83] In Europe a large framework called C3S for supplying climate services has been implemented by the European Union Copernicus programme.[84]

The state of California enacted the first comprehensive state-level climate action plan with its 2009 "California Climate Adaptation Strategy."[90][91] California's electrical grid has been impacted by the increased fire risks associated with climate change. In the 2019 "red flag" warning about the possibility of wildfires declared in some areas of California, the electricity company Pacific Gas and Electric (PG&E) was required to shut down power to prevent inflammation of trees that touch the electricity lines. Millions were impacted.[92][93]

Within the state of Florida four counties (Broward, Miami-Dade, Monroe, Palm Beach) have created the Southeast Florida Regional Climate Change Compact in order to coordinate adaptation and mitigation strategies to cope with the impact of climate change on the region.[94] The Commonwealth of Massachusetts has issued grants to coastal cities and towns for adaptation activities such as fortification against flooding and preventing coastal erosion.[95]

New York State is requiring climate change be taken into account in certain infrastructure permitting, zoning, and open space programs; and is mapping sea level rise along its coast.[96] After Hurricane Sandy, New York and New Jersey accelerated voluntary government buy-back of homes in flood-prone areas. New York City announced in 2013 it planned to spend between $10 and $20 billion on local flood protection, reduction of the heat island effect with reflective and green roofs, flood-hardening of hospitals and public housing, resiliency in food supply, and beach enhancement; rezoned to allow private property owners to move critical features to upper stories; and required electrical utilities to harden infrastructure against flooding.[97][98]

In 2019, a $19.1 billion "disaster relief bill" was approved by the Senate. The bill should help the victims of extreme weather that was partly fueled by climate change.[99]

In Mesoamerica, climate change is one of the main threats to rural Central American farmers, as the region is plagued with frequent droughts, cyclones and the El Niño- Southern-Oscillation.[100] Although there is a wide variety of adaption strategies, these can vary dramatically from country to country. Many of the adjustments that have been made are primarily agricultural or related to water supply. Some of these adaptive strategies include restoration of degraded lands, rearrangement of land uses across territories, livelihood diversification, changes to sowing dates or water harvest, and even migration.[100] The lack of available resources in Mesoamerica continues to pose as a barrier to more substantial adaptations, so the changes made are incremental.[100]

Climate change threatens to undermine decades of development gains in Europe and put at risk efforts to eradicate poverty.[101] In 2013, the European Union adopted the 'EU Adaptation Strategy', which had three key objectives: (1) promoting action by member states, which includes providing funding, (2) promoting adaptation in climate-sensitive sectors and (3) research.[102]

In 2008, the German Federal Cabinet adopted the 'German Strategy for Adaptation to Climate Change'[103] that sets out a framework for adaptation in Germany. Priorities are to collaborate with the Federal States of Germany in assessing the risks of climate change, identifying action areas and defining appropriate goals and measures. In 2011, the Federal Cabinet adopted the 'Adaptation Action Plan'[104] that is accompanied by other items such as research programs, adaptation assessments and systematic observations.[105]

In 2009 the Greenland Climate Research Centre was set up in the capital of Greenland, Nuuk.[106] Traditional knowledge is important for weather and animal migration, as well as for adaptive capacity building in areas such as the recognition of approaching hazards and survival skills.[107]

The Asia-Pacific climate change adaptation information platform (AP-PLAT) was launched in 2019. It aims to provide Asia and Pacific countries with data on climate change and convert it to adaptation and resilience measures.[108]

In 2018, the New York WILD film festival gave the "Best Short Film" award to a 12-minute documentary, titled Adaptation Bangladesh: Sea Level Rise. The film explores the way in which Bangladeshi farmers are preventing their farms from flooding by building floating gardens made of water hyacinth and bamboo.[109]

An Ice Stupa designed by Sonam Wangchuk brings glacial water to farmers in the Himalayan Desert of Ladakh, India.[110]

A research project conducted between 2014 and 2018 in the five districts (Puri, Khordha, Jagatsinghpur, Kendrapara and Bhadrak) of Mahanadi Delta, Odisha and two districts (North and South 24 Parganas) of Indian Bengal Delta (includes the Indian Sundarbans), West Bengal provides evidence on the kinds of adaptations practiced by the delta dwellers. In the Mahanadi delta, the top three practiced adaptations were changing the amount of fertiliser used in the farm, the use of loans, and planting of trees around the homes. In the Indian Bengal Delta, the top three adaptations were changing the amount of fertiliser used in the farm, making changes to irrigation practices, and use of loans. Migration as an adaptation option is practiced in both these deltas but is not considered as a successful adaptation.[111]

In the Indian Sundarbans of West Bengal, farmers are cultivating salt-tolerant rice varieties which have been revived to combat the increasing issue of soil salinity. Other agricultural adaptations include mixed farming, diversifying crops, rain water harvesting, drip irrigation, use of neem-based pesticide, and ridge and farrow land shaping techniques where “the furrows help with drainage and the less-saline ridges can be used to grow vegetables.” These have helped farmers to grow a second crop of vegetables besides the monsoon paddy crop.[112]

In Puri district of Odisha, water logging is a hazard that affects people yearly. In the Totashi village, many women are turning the "water logging in their fields to their advantage" by cultivating vegetables in the waterlogged fields and boosting their family income and nutrition.[113]

Africa will be one of the regions most impacted by the adverse effects of climate change.[114] Reasons for Africa's vulnerability are diverse and include low levels of adaptive capacity, poor diffusion of technologies and information relevant to supporting adaptation, and high dependence on agro-ecosystems for livelihoods.[115] Many countries across Africa are classified as Least-Developed Countries (LDCs) with poor socio-economic conditions, and by implication are faced with particular challenges in responding to the impacts of climate change.[116]  

Pronounced risks identified for Africa in the IPCC's Fifth Assessment Report relate to ecosystems, water availability and agricultural systems, with implications for food security.[114] In relation to agricultural systems, heavy reliance on rain-fed subsistence farming and low adoption of climate smart agricultural practices contribute to the sector's high levels of vulnerability. The situation is compounded by poor reliability of, and access to, climate data and information to support adaptation actions.[117] Climate change is likely to further exacerbate water-stressed catchments across Africa - for example the Rufiji basin in Tanzania[118] - owing to diversity of land uses, and complex sociopolitical challenges.

To reduce the impacts of climate change on African countries, adaption measures are required at multiple scales - ranging from local to national and regional levels.[119] The first generation of adaptation projects in Africa can be largely characterised as small-scale in nature, focused on targeted investments in agriculture and diffusion of technologies to support adaptive decision-making.[120] More recently, programming efforts have re-oriented towards larger and more coordinated efforts, tackling issues that spanning multiple sectors.

At the regional level, regional policies and actions in support of adaptation across Africa are still in their infancy. The IPCC's Fifth Assessment Report (AR5) highlights examples of various regional climate change action plans, including those developed by the Southern African Development Community (SADC) and Lake Victoria Basin Committee.[114] At the national level, many early adaptation initiatives were coordinated through National Adaptation Programmes of Action (NAPAs) or National Climate Change Response Strategies (NCCRS). Implementation has been slow however, with mixed success in delivery.[121] Integration of climate change with wider economic and development planning remains limited but growing.[122][114]

At the subnational level, many provincial and municipal authorities are also developing their own strategies, for example the Western Cape Climate Change Response Strategy.[123] Yet, levels of technical capacity and resources available to implement plans are generally low. There has been considerable attention across Africa given to implementing community-based adaptation projects. There is broad agreement that support to local-level adaptation is best achieved by starting with existing local adaptive capacity, and engaging with indigenous knowledge and practices.[124]

The IPCC highlights a number of successful approaches to promote effective adaptation in Africa, outlining five common principles.[114] These include:

1. Enhancing support for autonomous forms of adaptation;
2. Increasing attention to the cultural, ethical, and rights considerations of adaptation (especially through active participation of women, youth, and poor and vulnerable people in adaptation activities);
3. Combining “soft path” options and flexible and iterative learning approaches with technological and infrastructural approaches (including integration of scientific, local, and indigenous knowledge in developing adaptation strategies)
4. Focusing on enhancing resilience and implementing low-regrets adaptation options; and
5. Building adaptive management and encouraging process of social and institutional learning into adaptation activities.

Key adaptations in northern Africa relate to increased risk of water scarcity (resulting from a combination of climate change affecting water availability and increasing demand). Reduced water availability, in turn, interacts with increasing temperatures to create need for adaptation among rainfed wheat production[125][126] and changing disease risk (for example from leishmaniasis.[127][128]  Most government actions for adaptation centre on water supply side, for example through desalination, inter-basin transfers and dam construction.[129]  Migration has also been observed to act as an adaptation for individuals and households in northern Africa.[130] Like many regions, however, examples of adaptation action (as opposed to intentions to act, or vulnerability assessments) from north Africa are limited - a systematic review published in 2011 showed that only 1 out of 87 examples of reported adaptations came from North Africa.[131]

Water availability is a particular risk in Western Africa, with extreme events such as drought leading to humanitarian crises associated with periodic famines, food insecurity, population displacement, migration and conflict and insecurity. Adaptation strategies can be environmental, cultural/agronomic and economic.[132]

Adaptation strategies are evident in the agriculture sector, some of which are developed or promoted by formal research or experimental stations.[133] Indigenous agricultural adaptations observed in northern Ghana are crop-related, soil-related or involve cultural practices.[133][134] Livestock-based agricultural adaptations include indigenous strategies such as adjusting quantities of feed to feed livestock, storing enough feed during the abundant period to be fed to livestock during the lean season, treating wounds with solution of certain barks of trees, and keeping local breeds which are already adapted to the climate of northern Ghana;[135] and livestock production technologies to include breeding, health, feed/nutrition and housing.[136]

The choice and adoption of adaptation strategies is variously contingent on demographic factors such as the household size, age, gender and education of the household head; economic factors such as income source; farm size; knowledge of adaptation options; and expectation of future prospects.[137]

In Eastern Africa adaptation options are varied, including improving use of climate information, actions in the agriculture and livestock sector, and in the water sector.

Making better use of climate and weather data, weather forecasts, and other management tools enables timely information and preparedness of people in the sectors such as agriculture that depend on weather outcomes.  This means mastering hydro-meteorological information and early warning systems.[138] It has been argued that the indigenous communities possess knowledge on historical climate changes through environmental signs (e.g. appearance and migration of certain birds, butterflies etc.), and thus promoting of indigenous knowledge has been considered an important adaptation strategy.

Adaptation in the agricultural sector[139] includes increased use of manure and crop-specific fertilizer, use of resistant varieties of crops and early maturing crops. Manure, and especially animal manure is thought to retain water and have essential microbes that breakdown nutrients making them available to plants, as compared to synthetic fertilizers that have compounds which when released to the environment due to over-use release greenhouse gases.[140] One major vulnerability of the agriculture sector in Eastern Africa is the dependence on rain-fed agriculture.[141] An adaptation solution is efficient irrigation mechanisms and efficient water storage and use. Drip irrigation has especially been identified as a water-efficient option as it directs the water to the root of the plant with minimal wastage. Countries like Rwanda and Kenya have prioritized developing irrigated areas by gravity water systems from perennial streams and rivers in zones vulnerable to prolonged droughts.[142] During heavy rains, many areas experience flooding resulting from bare grounds due to deforestation and little land cover. Adaptation strategies proposed for this is promoting conservation efforts on land protection, by planting indigenous trees, protecting water catchment areas and managing grazing lands through zoning.[143]

For the livestock sector, adaptation options include managing production through sustainable land and pasture management in the ecosystems. This includes promoting hay and fodder production methods e.g. through irrigation and use of waste treated water, and focusing on investing in hay storage for use during dry seasons. Keeping livestock is considered a livelihood rather than an economic activity. Throughout Eastern Africa Countries especially in the ASALs regions, it is argued that promoting commercialization of livestock is an adaptation option.[144] This involves adopting economic models in livestock feed production, animal traceability, promoting demand for livestock products such as meat, milk and leather and linking to niche markets to enhance businesses and provide disposable income.[145]

In the water sector, options include efficient use of water for households, animals and industrial consumption and protection of water sources. Campaigns such as planting indigenous trees in water catchment areas, controlling human activities near catchment areas especially farming and settlement have been carried out to help protect water resources and avail access to water for communities especially during climatic shocks.

There have been several initiatives at local (site-specific), local, national and regional scales aimed at strengthening to climate change.  Some of these are: The Regional Climate Change Programme (RCCP),[146] SASSCAL,[147] ASSAR,[148] UNDP Climate Change Adaptation,[149] RESILIM,[150][151] FRACTAL.[152] South Africa implemented the Long-Term Adaptation Scenarios Flagship Research Programme (LTAS) from April 2012 to June 2014. This research also produced factsheets and a technical report covering the SADC region entitled "Climate Change Adaptation: Perspectives for the Southern African Development Community (SADC)".[153]

Adaptive policy can occur at the global, national, or local scale, with outcomes dependent on the political will in that area.[154] Scheraga and Grambsch[155] identify nine principles to be considered when designing adaptation policy, including the effects of climate change varying by region, demographics, and effectiveness. Scheraga and Grambsch make it clear that climate change policy is impeded by the high level of variance surrounding climate change impacts as well as the diverse nature of the problems they face. James Titus, project manager for sea level rise at the U.S. Environmental Protection Agency, identifies the following criteria that policy makers should use in assessing responses to global warming: economic efficiency, flexibility, urgency, low cost, equity, institutional feasibility, unique or critical resources, health and safety, consistency, and private versus public sector.[156]

Adaptation can mitigate the adverse impacts of climate change, but it will incur costs and will not prevent all damage.[157] The IPCC points out that many adverse effects of climate change are not changes in the average conditions, but changes in the variation or the extremes of conditions.[158] For example, the average sea level in a port might not be as important as the height of water during a storm surge (which causes flooding); the average rainfall in an area might not be as important as how frequent and severe droughts and extreme precipitation events become.[159] Additionally, effective adaptive policy can be difficult to implement because policymakers are rewarded more for enacting short-term change, rather than long-term planning.[160] Since the impacts of climate change are generally not seen in the short term, policymakers have less incentive to act. Furthermore, climate change is occurring on a global scale, leading to global policy and research efforts such as the Paris Agreement and research through the IPCC, creating a global framework for adapting to and combating climate change.[161] The vast majority of climate change adaptation and mitigation policies are being implemented on a more local scale because different regions must adapt differently and because national and global policies are often more challenging to enact.[162]

Adaptation can either occur in anticipation of change (anticipatory adaptation), or be a response to those changes (reactive adaptation).[163] 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.[47]

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 Western Sinai desert after a period of higher river flows is a maladaptation when viewed in relation to the longer term projections of drying in the region.[164] 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.[163]

People have always adapted to climatic changes and some community coping strategies already exist, for example changing sowing times or adopting new water-saving techniques.[164] 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 local 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.[47] In many cases this will not be enough to adapt to new conditions which are outside the range of those previously experienced, and new techniques will be needed.[41] The incremental adaptations which have been implemented become insufficient as the vulnerabilities and risks of climate change increase, this causes a need for transformational adaptations which are much larger and costlier.[165] Current development efforts are increasingly focusing on community-based climate change adaptation, seeking to enhance local knowledge, participation and ownership of adaptation strategies.[166]

A key and defining feature of international adaptation finance is its premise on the concept of additionality. This reflects the linkages between adaptation finance and other levels of development aid.[172] Many developed countries already provide international aid assistance to developing countries to address challenges such as poverty, malnutrition, food insecurity,[173] availability of drinking water, indebtedness, illiteracy, unemployment, local resource conflicts, and lower technological development. Climate change threatens to exacerbate or stall progress on fixing some of these pre-existing problems, and creates new problems. To avoid existing aid being redirected, additionality refers to the extra costs of adaptation.

The four main definitions of additionality are:[172]

1. Climate finance classified as aid, but additional to (over and above) the 0.7% ODA target;
2. Increase on previous year's Official Development Assistance (ODA) spent on climate change mitigation;
3. Rising ODA levels that include climate change finance but where it is limited to a specified percentage; and
4. Increase in climate finance not connected to ODA.

A criticism of additionality is that it encourages business as usual that does not account for the future risks of climate change. Some advocates have thus proposed integrating climate change adaptation into poverty reduction programs.[174]

From 2010 to 2020, Denmark increased its global warming adaptation aid 33%, from 0.09% of GDP to 0.12% of GDP, but not by additionality. Instead, the aid was subtracted from other foreign assistance funds. Politiken wrote: "Climate assistance is taken from the poorest."[175]

The Intergovernmental Panel on Climate Change (IPCC) Working Group II assesses the scientific literature on adaptation: https://www.ipcc.ch/working-group/wg2/

• Adaptation at Scale in Semi-Arid Regions (ASSAR) project combined interdisciplinary scientific research at regional and thematic levels, capacity building, and stakeholder engagement to improve understanding of the barriers and enablers to effective climate adaptation.
• African Climate Policy Centre (ACCP) goal is to contribute to poverty reduction through successful mitigation and adaptation to climate change in Africa and to improve the capacity of African countries to participate effectively in multilateral climate negotiations.
• African Monsoon Multidisciplinary Analysis 2050 (AMMA-2050) aim to address the challenges of understanding how the monsoon will change in future decades, to 2050, and how this information can be most effectively used to support climate-compatible development in the region.
• Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) builds resilience by supporting collaborative research on climate change adaptation to inform adaptation policy and practice.
• Deltas, Vulnerability and Climate Change: Migration and Adaptation (DECCMA) aims are to evaluate the effectiveness of adaptation options including migration in deltas in Africa and Asia, and to deliver policy support for sustainable, gender-sensitive adaptation.
• Integrating Hydro-Climate Science into Policy Decisions for Climate-Resilient Infrastructure and Livelihoods in East Africa (HyCRISTAL) was aimed to tackle uncertainties that exist around climate change projections for the region, concentrating in particular on what they mean for the availability and management of water.
• Pathways to Resilience In Semi-Arid Economies (PRISE) aims to generates new knowledge about how economic development in semi-arid regions can be made more equitable and resilient to climate change for policy makers
• Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL) initiative aims to put possible solutions to the many challenges of global change to develop and produce scientifically sound findings and sustainable socio-economic benefits for the entire Southern Africa region.
• West African Science Service Center on Climate Change and Adapted Land Use (WASSCAL) is a research-focused Climate Service Centre designed to help tackle this challenge and thereby enhance the resilience of human and environmental systems to climate change and increased variability in West Africa.

Several countries have taken a lead in climate vulnerability assessment and adaptation planning. Their web sites contain reports, strategies, and tools which other countries can customize to their own situation.

• US Global Change Research Program
• Adaptation Clearinghouse of the Georgetown Climate Center

• The United Kingdom's Climate Impacts Programme (UKCIP)
• Australia
• Canada
• The Canadian National Assessment: From Impacts to Adaptation: Canada in a Changing Climate 2007 discusses current and future risks and opportunities that climate change presents to Canada, with a focus on human and managed systems.

In addition to government and United Nations reports, an extensive research literature assesses options for response to global warming. Much of this literature addresses the potential economic costs associated with different strategies.

• The Asian Development Bank has a series of studies on the Economics of Climate Change in the Asia-Pacific region. The studies provide cost analysis of both adaptation and mitigation measures.
• Indigo Development has a page of links to government and research web sites on climate adaptation
• The WEAP (Water Evaluation And Planning system) assists water resources researchers and planners in assessing impacts of and adaptations to climate change.
• The weADAPT platform encourages the collaborative development of tools for adaptation and sharing experiences from adaptation projects
• The UNDP runs the adaptation learning mechanism which provides country case studies of adaptation.
• The UN-CECAR research and development of courses on climate change and adaptation
• The UNFCCC has a database on local adaptation measures and information on the international climate negotiations
• Risks, opportunities, and adaptation to climate change Joel D. Scheraga, Anne E. Grambsch, United States Environmental Protection Agency.
• Ludwig, Fulco, Pavel Kabat, Henk van Schaik and Michael van der Valk (2009) Climate Change Adaptation in the Water Sector, Earthscan, London, 320 pp, ISBN 978-1-84407-652-9.
• Amy Seidl Finding Higher Ground: Adaptation in the Age of Warming Beacon Press (2011) ISBN 978-0-8070-8598-1
• Publications by the Co-operative Programme on Water and Climate (CPWC)
• Henfrey, T. & G. Penha-Lopes, 2015. Permaculture and Climate Change Adaptation. Permanent Publications, East Meon.
• Resilience 2 to 1 – Volunteer multi-disciplinary group of educators, researchers and professionals focused on the issue of resilience for Canada during a changing climate.
• The United Nations Development Programme's Climate Change Adaptation Portal includes studies on climate change adaptation in Africa, Europe and Central Asia, and Asia and the Pacific.
• Adaptation Gap Report 2020. United Nations Environment Programme. 14 January 2021. ISBN 978-92-807-3834-6.