Carbon dioxide stays in the atmosphere for a very long time, so today’s warming was caused by emissions released across two centuries, mostly by a small number of countries. The countries facing the worst consequences are largely not those countries. That mismatch is the whole of climate justice.
📚 What you need to know
Responsibility is hard to pin down because it can be measured in at least three ways: current emissions, historical emissions and emissions per person.
The biggest current emitters include China, the USA and India. The biggest cumulative contributors are the USA and the European Union.
Per capita emissions are generally much higher in developed nations, even where their national total is not the largest.
Vulnerability is how badly a country is affected, and it depends on geographical location and economic capacity.
The countries least responsible are often the most vulnerable — small island states such as the Maldives and Kiribati are the standard example.
Climate justice asks who ought to bear the cost; equity asks that costs and benefits be shared fairly.
Many argue that wealthier nations should provide financial support or reparations to help poorer nations adapt.
Three ways to count responsibility
Ask “which country is responsible for climate change” and you will get different answers depending on how you count. All three are legitimate, which is exactly why the politics is so difficult.
Current emissions — how much a country is releasing right now. This favours the argument that today’s large emitters must act, whatever happened historically.
Historical and cumulative emissions — the total a country has added since the Industrial Revolution. Since carbon dioxide persists for centuries, the warming we experience today was largely caused by past emissions from early industrialised nations.
Emissions per person — the national total divided by population. A country with a very large population can have huge total emissions and still be well below the world average per person.
Both charts are true at once. A country with a large population can dominate the total emissions table while sitting below the world average per person — and that is precisely the argument used in international negotiations.
If an exam gives you an emissions graph, check the axis label first. “Total” and “per capita” produce almost opposite rankings, and reading the wrong one will send your whole answer off course.
Vulnerability: who actually gets hurt
Vulnerability describes how badly a country or region is affected by impacts such as rising seas, extreme weather and threats to food security. Two factors decide it.
Geographical location. Low-lying coastal nations, small islands and countries in tropical or arid zones face more flooding, more storms and more temperature extremes simply because of where they are.
Economic capacity. Wealthier countries can invest in defences, warning systems, drought-tolerant agriculture and rebuilding. Poorer countries and those with limited infrastructure often cannot.
Kiribati and the Maldives have contributed a negligible share of global emissions and face the loss of their territory to sea-level rise. No amount of action by them alone would change their situation.
Climate justice and equity
Climate justice is the ethical side of the question: given that the harm is unevenly distributed and the responsibility is unevenly distributed, who should pay to fix it? The usual argument runs that developed countries have both the greater historical responsibility and the greater economic resources, while developing countries are more vulnerable and contributed far less to the problem.
Equity is the principle that the costs and benefits of mitigation and adaptation should be shared fairly. Fairly does not mean equally — an equal split would ignore the fact that some nations built their wealth on the emissions that caused the problem. This is why many argue that wealthier nations should provide financial climate reparations, funding adaptation in countries that are dealing with impacts they did not cause.
The counter-argument matters too. Current emitters point out that warming responds to what is emitted from now on, not only to the past, and that any effective agreement has to include today’s largest emitters regardless of history. A good “evaluate” answer gives both sides.
Measure
What it shows
Who it puts at the top
The argument it supports
Current annual emissions
How much is being released right now
Large industrialised and industrialising economies
Today’s biggest emitters must lead the cuts
Historical cumulative emissions
Everything added since the Industrial Revolution
The USA and the European Union
Early industrialisers caused most of the warming already locked in
Emissions per person
National total divided by population
Wealthy, high-consumption nations
Fair shares should be counted per person, not per country
Vulnerability
Exposure to impacts and ability to cope
Small island states and low-income coastal nations
Support should flow to those least able to adapt
WORKED EXAMPLE
Explain why the countries least responsible for climate change are often the most vulnerable to it. [4]
Point 1 — low responsibility
Many low-income countries have small industrial sectors and low emissions per person, so their contribution to cumulative global emissions is very small.
Point 2 — geographical exposureSeveral are low-lying, coastal or in tropical and arid zones, so they face sea-level rise, storms and drought most directly.Point 3 — limited economic capacityThey lack the resources for flood defences, warning systems and rebuilding, so the same hazard causes far greater damage.Point 4 — named exampleSmall island states such as the Maldives and Kiribati risk becoming uninhabitable despite contributing almost nothing to global emissions.4 / 4Two reasons for vulnerability, one for low responsibility, one example. Clean four marks.
WORKED EXAMPLE
Evaluate the claim that developed countries should pay for climate adaptation in developing countries. [6]
Supporting argument 1
Developed nations hold the largest share of cumulative emissions, so most of the warming already in the system is attributable to them.
Supporting argument 2They also have the greatest economic capacity, and their per capita emissions remain high.Supporting argument 3Vulnerable nations face costs they did not cause and often cannot meet, so equity requires transferring some of that cost.Counter-argument 1Future warming depends on emissions from now on, so agreements that exclude today’s largest emitters will not work.Counter-argument 2Assigning historical blame is complicated by changing borders, unclear early records and the fact that past emitters did not know the consequences.Judgement
On balance, historical responsibility and economic capacity make a strong case for developed nations funding adaptation, but it must sit alongside emission cuts by all major emitters rather than replace them.
6 / 6Six marks needs both sides and a stated conclusion. Never leave an evaluate question hanging.
💡 Exam tip
Name all three ways of measuring responsibility. Answers that use only one look shallow.
Explain vulnerability with both factors: geographical location and economic capacity.
Keep two named examples ready: the Maldives and Kiribati for vulnerability; the USA and EU for cumulative responsibility.
Use the terms climate justice, equity and reparations precisely — they are the assessment vocabulary.
For “evaluate”, give at least one counter-argument and finish with a clear judgement.
Watch the axis on any emissions graph: total and per capita give opposite rankings.
⚠️ Common mix-up
Assuming the biggest current emitter is the biggest historical emitter. They are usually different countries.
Ignoring population size. Total emissions without per capita context is only half the picture.
Treating vulnerability as purely geographical. Wealth and infrastructure matter just as much.
Confusing equity with equality. Equity means a fair share given circumstances, not an identical share.
Mixing up mitigation and adaptation when discussing what the funding is for.
Giving only one side in an evaluate question. No counter-argument means no top band.
Up next: Climate Change Mitigation & Adaptation — having established the causes, impacts and responsibility, sub-topic 6.3 moves on to what can actually be done about it.
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