Humans have been adapting to their environments throughout history by developing practices, cultures and livelihoods suited to local conditions – from the Mediterranean siesta to the Vietnamese practice of building homes on stilts to protect against monsoonal rains. However, climate change raises the possibility that existing societies will experience climatic shifts (in temperature, storm frequency, flooding and other factors) that previous experience has not prepared them for. As average global temperatures rise, the impacts of climate change and their associated losses and damage are likely to increase more rapidly and more unpredictably.

Adaptation seeks to reduce the risks posed by climate changes, and to benefit from any associated opportunities where possible. It is one of two main policy responses to climate change, the other being mitigation – reducing greenhouse gas emissions to address the root causes. Both approaches are necessary because, even if emissions are dramatically decreased over the coming decade, further warming is now unavoidable and adaptation will be needed to deal with the climatic changes already set in motion.

Adaptation as a global policy response

The Paris Agreement on climate change contains a global goal on adaptation: “to enhance adaptive capacity and resilience; to reduce vulnerability, with a view to contributing to sustainable development; and ensuring an adequate adaptation response in the context of the goal of holding average global warming well below 2°C and pursuing efforts to hold it below 1.5°C”. In addition, Sustainable Development Goal (SDG) 13 on climate action contains the target to “strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries”, and adaptation and resilience concerns run through other SDGs and their related targets.  

In 2019, a Call for Action to raise ambition on adaptation and resilience was issued at the UN Climate Action Summit. Led by Egypt and the UK, it includes the aim of giving “equal and increased urgency” to the adaptation agenda.

What kinds of adaptation measures are there?

Adaptation measures may be planned in advance or put in place reactively. Low-income countries, and certain populations within them, tend to be more vulnerable to climate risks than developed countries, and some adaptation measures – such as increasing access to education and health facilities – will overlap with existing development programmes. There is also significant overlap between climate change adaptation and disaster risk reduction (DRR) measures and policy frameworks – notably the Sendai Framework on DRR.

However, adaptation goes beyond prevailing approaches to development to include measures to address additional risks specifically caused by climate change – both future risks, which will be altered by a changing climate, and current risks. Actions may include making large-scale infrastructure changes, such as building defences to protect against sea-level rise, and improving the quality of road surfaces to withstand hotter temperatures. It may also include consideration of future risk in current infrastructure design to avoid locking in future exposure and vulnerability. Nature-based approaches can be taken too, such as the preservation and restoration of forests, wetlands and mangroves, the improvement of soil fertility and landscaping for fire management, which also provide other benefits to the natural world.

Adaptation can also include behavioural shifts such as individuals using less water, farmers planting crops that are better suited to the changing climate, and more households and businesses buying flood insurance. Investment in community-based adaptation, and building local knowledge on, for example, climate risk and uncertainty, are also important.

There is increasing recognition of the need for ‘transformative adaptation’, which challenges the assumptions of business-as-usual approaches and considers whole systems in place of more piecemeal approaches to adaptation.

Adaptation requires good governance at different levels, from the local to supra-national approaches, which are required where the impacts of climate change cross borders.

How can adaptation reduce vulnerability?

The Intergovernmental Panel on Climate Change (IPCC) describes vulnerability to climate change as being determined by three factors: exposure to hazards (such as reduced rainfall), sensitivity to those hazards (which might be high, for example, in an economy dominated by rain-fed agriculture), and the capacity to adapt to those hazards (for example, whether farmers have the money or skills to grow more drought-resistant crops). Adaptation measures can help reduce vulnerability – for example by lowering sensitivity or by building adaptive capacity. They can also enable populations to benefit from opportunities caused by climatic changes, such as growing certain crops in areas that were previously unsuitable. This can be supported by taking into account existing inequalities – for example with regard to gender, disability, age and ethnicity – and by ensuring vulnerable and marginalised groups are able to meaningfully participate in adaptation decision-making.

How does investing in adaptation pay off?

Research by the Global Commission on Adaptation found a high rate of return on adaptation investment, with cost–benefit ratios between 2:1 and 10:1, or higher in some cases. It also found that investment of US$1.8 trillion before 2030 could create US$7.1 trillion in benefits, if targeted at five areas: early warning systems, climate-resilient infrastructure, improved dryland agriculture, mangrove protection and making water resources more resilient.

Other research has shown that action taken now to reduce emissions in order to meet the Paris Agreement targets of limiting temperature rise to 2°C and aiming for 1.5°C would reduce the future cost of climate change action and adaptation. In part, this is because borrowing to finance such measures becomes more expensive over time as the increased risk to investments from climate vulnerability causes higher debt repayments.  

Adaptation investment also brings multiple benefits beyond cost-effectiveness – in a ‘triple dividend of resilience’. It is able to reduce future losses and damage, create economic benefits – for example through reducing risk, increasing productivity and promoting innovation, and can bring about a range of social and environmental benefits. These ‘dividends’ can develop regardless of whether or not climate change-related shocks occur.

This Explainer has been updated by Sophie Dicker and Georgina Kyriacou. The preceding version was written by Susannah Fisher, reproduced from What is climate change adaptation? © The Guardian 2012, used under a Creative Commons No Derivative Works licence.

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