Managing Climate Change: Mitigation and Adaptation

Climate change management is divided into two fundamentally different strategies:

Mitigation: reducing the causes of climate change — cutting greenhouse gas emissions so that future warming is less severe.

Adaptation: adjusting human systems to cope with the effects of climate change that are already happening or now unavoidable.

Both are necessary, and this is not a rhetorical claim — it is a logical one:

• Even if all global emissions stopped today, CO₂ already in the atmosphere would continue warming Earth for decades. Populations exposed to current hazards need adaptation now.
• Adaptation without mitigation eventually fails — unchecked warming at 3°C or 4°C above pre-industrial levels will exceed the adaptive capacity of many ecosystems and societies.

	Mitigation	Adaptation
Aim	Reduce future warming	Cope with current and locked-in effects
Timescale of benefit	Decades to centuries	Immediate to medium-term
Example	Building offshore wind farms	Constructing sea walls
Key limitation	Requires global cooperation to be effective	Does not address the root cause

The distinction between these two strategies is tested directly in AQA exams. Know which is which, and be able to classify any given strategy correctly.

The largest single source of global greenhouse gas emissions is the burning of fossil fuels for energy. Replacing fossil fuels with low- or zero-carbon alternatives is the core of mitigation.

Renewable energy produces no CO₂ during operation:

• Wind power: offshore wind is now the cheapest new source of electricity generation in the UK and several other countries. The Hornsea offshore wind farm (North Sea, off Yorkshire) has a capacity of over 1.2 GW, enough to power more than 1 million homes.
• Solar photovoltaic (PV): the cost of solar panels has fallen by over 90% since 2010, making solar competitive globally. Particularly effective in sunnier regions (Middle East, sub-Saharan Africa, southern Europe).
• Hydroelectric: rivers dammed to drive turbines; large-scale (China's Three Gorges Dam, 22.5 GW capacity) and small-scale run-of-river. Geographic constraints limit where it is viable.
• Tidal: the UK's high tidal range makes it theoretically viable; currently limited in scale.
• Geothermal: highly location-specific but where available (Iceland, Kenya, parts of the USA) provides continuous, reliable low-carbon power.

Nuclear power: low-carbon but not renewable; generates radioactive waste requiring long-term storage. Provides ~10% of global electricity. France generates ~70% of its electricity from nuclear — its grid has one of the lowest carbon intensities in Europe.

Carbon capture and storage (CCS): CO₂ is captured from the exhaust gases of power stations or industrial facilities, compressed, and pumped into underground geological formations (depleted oil fields, saline aquifers) for permanent storage. Currently expensive and not yet at scale, but considered essential for decarbonising industries (such as cement and steel) where direct electrification is difficult.

Natural carbon sequestration:

• Afforestation and reforestation: planting trees absorbs CO₂. The Bonn Challenge (2011) aims to restore 350 million hectares of degraded forest globally by 2030.
• Peatland restoration: peat bogs store twice as much carbon as all the world's forests combined. Damaged peatlands become sources of CO₂; restored peatlands become sinks.
• Protecting existing forests: the Amazon, Congo Basin, and Southeast Asian forests store vast amounts of carbon. Halting deforestation is a cheaper and faster mitigation strategy than planting new trees.

International agreements:

Agreement	Year	Key features
Kyoto Protocol	1997	Binding reduction targets for developed nations only; USA never ratified; developing nations did not have binding reduction targets
Paris Agreement	2015	Countries submit their own pledges (NDCs); aim to limit warming to 1.5–2°C; no enforcement mechanism
Glasgow COP26	2021	Updated NDCs; coal phase-down (not phase-out) commitment; reaffirmed climate finance commitments for developing countries

The Paris Agreement was a diplomatic breakthrough — 196 countries committed to climate action for the first time. However, as of the mid-2020s, national pledges — even if fully implemented — still point toward approximately 2.5–3°C of warming by 2100. The gap between pledges and what the science requires is the central challenge.

As temperatures rise and rainfall patterns shift, food and water systems must adapt — whether or not emissions are cut.

Agricultural adaptation:

• Drought-resistant crop varieties: traditional selective breeding and genetic modification produce crops that maintain yields under water stress. Drought-tolerant maize varieties are already deployed across sub-Saharan Africa.
• Changing planting dates: warmer springs in northern latitudes allow earlier sowing. Farmers across northern Europe and Canada are already adjusting seasonal calendars.
• New crop opportunities: wine production has expanded northward — the UK now has around 900 commercial vineyards, producing award-winning still and sparkling wines. Arctic Canada and Siberian Russia may become viable agricultural land as permafrost thaws.
• Irrigation expansion: essential in drying regions but increases pressure on water systems already under stress.

Water supply adaptation:

• Increased reservoir capacity: storing rainfall from increasingly unpredictable storm events for use during dry periods
• Inter-basin water transfer: moving water from water-abundant to water-scarce regions; China's South-North Water Transfer Project (the world's largest water infrastructure project) moves ~10 billion cubic metres per year from southern to northern China
• Desalination: converting seawater to drinking water; energy-intensive but increasingly used in water-scarce coastal cities (Saudi Arabia, Israel, Cape Town)
• Water conservation: greywater recycling, demand management, metering — reducing consumption rather than finding new supply

Sea level is rising. Hundreds of millions of people live within 10 metres of current mean sea level. Coastal protection is among the most urgent and expensive adaptation challenges.

Hard engineering:

• Sea walls: concrete or rock barriers along the shoreline; expensive and require regular maintenance; can cause increased erosion immediately downdrift
• Flood barriers: the Thames Barrier protects central London from tidal surges. In its first full year of operation (1983), it was raised 4 times. In the winter of 2013–14 alone, it was raised 50 times — more in a single season than in its first decade. Over 200 total closures had been recorded by 2020.
• Storm surge barriers: the Netherlands' Maeslantkering barrier closes automatically when storm surge threatens Rotterdam — one of the largest moving structures on Earth

Soft engineering and natural approaches:

• Managed retreat (coastal realignment): deliberately allowing low-lying coastal land to flood, creating new salt marshes and mudflats that naturally absorb wave energy. Cheaper and more sustainable than permanent hard engineering. The Medmerry realignment scheme in West Sussex is the UK's largest managed coastal realignment.
• Mangrove restoration: mangrove forests dissipate storm surge energy and protect shorelines; large-scale replanting programmes are underway in Bangladesh, Vietnam, and Indonesia
• Beach nourishment: pumping sand onto eroding beaches to maintain a natural buffer

The hardest adaptation choice: For some communities and some countries, the eventual answer may be planned relocation. The Maldives government has purchased land in Sri Lanka and India as contingency against complete inundation. Pacific island nations — Tuvalu, Kiribati — face the loss of their entire territory within decades under high-emissions scenarios.

As of the mid-2020s, existing mitigation commitments are not on track to limit warming to 1.5°C. National pledges, if fully implemented, still point toward approximately 2.5–3°C of warming above pre-industrial levels by 2100.

The adaptation gap: Adaptation requires money, technology, and governance capacity. The countries most exposed to climate change — low-lying Pacific island states, semi-arid sub-Saharan Africa, vulnerable coastal LICs — have contributed least to cumulative emissions yet face the largest relative costs.

Climate justice:

• Consumption-based emissions studies consistently find that the wealthiest groups contribute a disproportionately large share of global emissions, while the poorest groups face the greatest risks from food insecurity, displacement, and water stress
• The countries most exposed to climate impacts — low-lying Pacific island states, semi-arid sub-Saharan Africa — have contributed least to cumulative emissions
• International climate agreements have included a target for developed countries to mobilise $100 billion per year to support mitigation and adaptation in developing nations. The Green Climate Fund is one of the mechanisms used to channel this support, but the target has consistently not been fully met.

Extended-answer questions about climate change management frequently reward evaluation of effectiveness and discussion of who bears the costs. An answer that lists strategies without noting that current pledges are insufficient, or without engaging with climate justice, is less likely to reach the highest marks.

1. Confusing mitigation and adaptation

Mitigation = reducing causes (cutting emissions, planting trees, international agreements to limit warming). Adaptation = responding to effects (drought-resistant crops, sea walls, managed retreat). This is tested directly. Misclassifying a strategy — calling a flood wall "mitigation" — is a basic factual error.

2. Claiming international agreements have "solved" climate change

No agreement has prevented warming — current pledges still lead to approximately 2.5–3°C of warming. The Paris Agreement lacks enforcement mechanisms. Critical evaluation of international agreements — noting what they achieve and where they fall short — is expected in higher-mark questions.

3. Saying "we should just plant trees" as a complete solution

Afforestation absorbs carbon, but planting enough trees to offset current global emissions would require an area the size of the United States. Simultaneously, large areas of existing forest are being cleared. Trees are one component of a mitigation strategy; they are not a substitute for cutting emissions.

4. Ignoring climate justice in evaluation questions

Evaluation questions about managing climate change often reward the observation that management burden and climate vulnerability are inversely distributed. LICs that contributed little to emissions face the greatest adaptation costs. Including this kind of observation can strengthen higher-mark evaluation answers.

5. Mixing up carbon capture and natural sequestration

Carbon capture and storage (CCS) is a technological process: capturing CO₂ from power station exhaust gases and pumping it underground. Natural carbon sequestration refers to biological processes: trees, peatlands, and soils absorbing CO₂ naturally. These are distinct strategies with different costs, limitations, and scales. Treat them separately in answers.