🗞️ Why in News The United Nations Environment Programme released a Spotlight Report, Limiting Overshoot: Navigating exceedance of 1.5°C and pathways towards return, on September 2, 2026. It assesses that exceedance of 1.5 degrees Celsius is now widely assessed as unavoidable, and warns that some impacts of an overshoot will be irreversible even if temperatures later return below that level.
The Findings
| Finding | Figure |
|---|---|
| Best-case peak warming | About 1.8 degrees Celsius around midcentury, in a range of 1.7 to 2.2 |
| Current policies, median by 2100 | About 2.6 degrees Celsius |
| Current policies, range | 1.9 to 3.6 degrees Celsius |
| Cut required for 1.5C with limited exceedance | 55 per cent below 2019 levels by 2035 |
| When the crossing occurs | Likely within the next few years |
The 55 per cent figure carries a condition that is usually dropped. It is drawn from the Emissions Gap Report 2025, which pairs it with a cut of 35 per cent by 2035 for a 2 degree pathway, both measured against 2019 levels. These are least-cost pathways that assume early and immediate action, so every year of delay raises the cut required in the years that remain. This is the most important structural fact about carbon budgets and the one most often stated without its assumption.
What Overshoot Means, Precisely
Overshoot is not the same as failure. It describes a temperature path that rises above a threshold, peaks, and then declines back below it, typically through large-scale carbon dioxide removal later in the century.
The report’s central warning is about what does not come back. Temperature is reversible in the models. Several of the physical consequences are not.
| System | Why the damage does not reverse with temperature |
|---|---|
| Ice sheets | Greenland and West Antarctic ice loss passes thresholds beyond which retreat continues independently of later cooling |
| Sea level | Thermal expansion and ice loss commit centuries of rise regardless of a later temperature decline |
| Coral reefs | Repeated bleaching at intervals shorter than recovery time destroys the reef structure itself |
| Species and ecosystems | Extinction is definitionally irreversible; range shifts and ecosystem reorganisation do not simply run backwards |
| Amazon dieback | A forest that crosses into savanna does not return when temperatures fall; the report names it among the irreversible tipping risks |
| Permafrost | Thaw releases carbon and methane, which adds warming rather than responding to it |
The reason this is a policy finding and not only a scientific one. If overshoot were fully reversible, delay would be expensive but recoverable, and a strategy of emitting now and removing later would be defensible. Because parts of it are not reversible, the peak temperature itself is a policy target, distinct from the end-of-century temperature. That reframing is the report’s actual contribution.
The Architecture Being Measured Against
The Paris Agreement, 2015, adopted at COP21 and in force from November 4, 2016, sets the goal in Article 2: holding the increase in global average temperature to well below 2 degrees Celsius above pre-industrial levels, while pursuing efforts to limit it to 1.5 degrees Celsius.
The mechanism is the Nationally Determined Contribution. Parties set their own targets, submit them, and revise them upward over time. There is no enforcement provision. The Global Stocktake, which occurs every five years, assesses collective progress rather than individual compliance.
UNEP itself. Established in 1972 following the United Nations Conference on the Human Environment at Stockholm, headquartered at Nairobi, Kenya. It publishes the annual Emissions Gap Report and the Adaptation Gap Report, and hosts the UN Environment Assembly, the world’s highest decision-making body on the environment.
Where India Sits
| Commitment | Content |
|---|---|
| Net zero | 2070, announced at COP26, Glasgow |
| Emissions intensity | Reduce emissions intensity of GDP by 45 per cent by 2030 from 2005 levels |
| Non-fossil capacity | 50 per cent of cumulative electric power installed capacity from non-fossil sources by 2030 |
India’s position in these negotiations rests on two arguments, and both should be named accurately. The first is historical responsibility: the stock of carbon dioxide already in the atmosphere was overwhelmingly emitted by countries that industrialised early, and warming responds to the stock, not to the current flow. The second is per capita emissions, which for India remain well below the global average.
The principle in the text. Common But Differentiated Responsibilities and Respective Capabilities, carried from the UN Framework Convention on Climate Change, 1992, is the treaty language that expresses this. The Paris Agreement retains it with the qualifier “in the light of different national circumstances”, a formulation that softened the firewall between developed and developing country obligations.
The argument an aspirant should be able to make both ways. Adaptation finance and loss-and-damage become more central as overshoot is conceded, because adaptation is what a country does when mitigation has already failed to prevent the impact. But an overshoot framing also risks becoming a licence: if the target can be crossed and recovered, the political pressure to avoid crossing it weakens. Name both. The report’s insistence on irreversibility is precisely an attempt to close that loophole.
UPSC Relevance
GS Paper 3. Conservation, environmental pollution and degradation; climate change; international agreements and their effect on India.
GS Paper 2. Important international institutions, agencies and their structure and mandate; bilateral and global groupings involving India.
A Mains question worth preparing. “An overshoot of 1.5 degrees Celsius is now treated as unavoidable in mainstream climate assessments. Examine the implications of this shift for India’s climate policy and its negotiating position. (250 words)”
Prelims focus. UNEP’s founding year, headquarters and flagship reports; the Paris Agreement’s Article 2 language and entry into force; the Global Stocktake cycle; CBDR-RC and its Paris qualifier; India’s three headline commitments; the meaning of overshoot.
📌 Facts Corner — Knowledgepedia
Prelims, statement-ready facts:
- UNEP released the report Limiting Overshoot on 2 September 2026.
- The report’s full title is Limiting Overshoot: Navigating exceedance of 1.5 degrees Celsius and pathways towards return, and it is a UNEP Spotlight Report rather than a flagship report like the Emissions Gap Report.
- It assesses exceedance of 1.5 degrees Celsius as now widely assessed as unavoidable.
- The best-case scenario sees warming peak at about 1.8 degrees Celsius around midcentury, in a range of 1.7 to 2.2 degrees.
- Under current policies the median projection is about 2.6 degrees Celsius by 2100, ranging 1.9 to 3.6 degrees.
- Limiting warming to 1.5 degrees with limited exceedance requires emissions 55 per cent below 2019 levels by 2035.
- The 55 per cent figure comes from the Emissions Gap Report 2025, is measured against 2019 levels, and is paired with a 35 per cent cut by 2035 for a 2 degree pathway.
- Both are least-cost pathways assuming early and immediate action, so delay raises the required cut.
- UNEP was established in 1972 after the Stockholm Conference on the Human Environment.
- UNEP is headquartered at Nairobi, Kenya, and publishes the Emissions Gap Report and the Adaptation Gap Report.
- The Paris Agreement was adopted at COP21 in 2015 and entered into force on 4 November 2016.
- Paris Agreement Article 2 sets a goal of well below 2 degrees while pursuing efforts to limit warming to 1.5 degrees.
- The Global Stocktake assesses collective progress every five years.
- India’s net zero target year is 2070, announced at COP26 in Glasgow.
- India’s NDC targets a 45 per cent reduction in emissions intensity of GDP by 2030 from 2005 levels.
- India targets 50 per cent of cumulative electric power installed capacity from non-fossil sources by 2030.
Prelims, the traps:
- Overshoot means exceeding a threshold and later returning below it; it is not a permanent stabilisation at the higher level.
- Reversible temperature does not mean reversible impact: ice sheet loss, sea level rise and extinction do not run backwards.
- The Paris goal is well below 2 degrees while pursuing 1.5 degrees; 1.5 degrees alone is not the treaty’s binding formulation.
- The Global Stocktake assesses collective, not individual, progress, and the Paris Agreement has no enforcement provision.
- UNEP is a programme of the United Nations, not a specialised agency, and it is distinct from the IPCC.
Mains, arguments and keywords:
- Frame: because parts of overshoot are irreversible, peak temperature becomes a policy target distinct from end-of-century temperature.
- Keywords: overshoot, carbon dioxide removal, irreversibility, CBDR-RC, historical responsibility, per capita emissions.
- Conceding overshoot moves adaptation and loss-and-damage finance to the centre of the negotiation.
- Counter-argument: an overshoot framing can function as a licence to delay, which is why the irreversibility finding matters politically.
- India’s case rests on the stock of atmospheric carbon, not the current flow, and on per capita emissions below the global average.
Interview, be ready for:
- Probe: “If 1.5 degrees is already lost, why keep the target?” Answer through peak temperature and irreversibility, not through symbolism.
- Probe: “Is India doing enough on climate?” Use the non-fossil capacity target and per capita emissions, and concede the coal question rather than avoiding it.
Sources: UNEP, Limiting Overshoot, UNEP, Emissions Gap Report 2025
Source: UNEP Says 1.5 Degrees Will Be Crossed: What "Overshoot" Actually Means — Ujiyari.com | Free UPSC & State PCS Current Affairs
