UN Charts Course to Manage Global Warming-Limit Breach

Context

• • A new UN Environment Programme (UNEP) report, “Limiting Overshoot: Navigating Exceedance of 1.5°C and Pathways Towards Return”, warns that the world is likely to cross the 1.5°C warming threshold within the next few years.
  • The report does not suggest abandoning the Paris Agreement goal. Instead, it proposes an “overshoot, peak and decline” pathway—first limiting the rise, then bringing global temperatures down.

Key Facts

• • The 1.5°C target refers to limiting long-term global warming compared with the pre-industrial period, not merely crossing the threshold in a single year.
  • 2024 was already the first calendar year in which the global average temperature exceeded 1.5°C above pre-industrial levels.
  • Under the most optimistic scenario involving implementation of current climate commitments and long-term net-zero targets, warming could still peak around 1.8°C.
  • Under current policies, global warming could reach around 2.6°C by 2100, with an estimated range of 1.9–3.6°C.
  • Every additional fraction of a degree and every extra year above 1.5°C increases risks to ecosystems, food security, water resources, human health and economies.

What is “Overshoot”?

Overshoot means temporarily exceeding the 1.5°C threshold, reaching a higher peak and subsequently bringing temperatures down.

Proposed pathway:

1.5°C → Overshoot → Peak → Temperature Decline → Stabilisation

• • UNEP considers this the best remaining option, given the likelihood that 1.5°C will be exceeded.
  • The crucial objective is to keep both the magnitude and duration of overshoot as small as possible.

Why is Overshoot Dangerous?

1. Extreme Weather

• • Higher temperatures increase the intensity of heatwaves, floods, droughts and wildfires.
  • Recent extreme events demonstrate the growing vulnerability of communities and infrastructure.

2. Climate Tipping Points

Longer and higher warming increases the risk of potentially irreversible changes such as:

• • Greenland and West Antarctic ice-sheet destabilisation
  • Amazon rainforest degradation
  • Disruption of Atlantic Meridional Overturning Circulation (AMOC).

3. Food & Water Security

• • Climate stress can reduce agricultural productivity and increase water scarcity.
  • Vulnerable developing countries are likely to face disproportionate losses.

How Can Temperatures Be Brought Down?

1. Rapid Emission Reduction

• • Accelerate transition away from coal, oil and gas.
  • Expand renewable energy, energy efficiency and clean technologies.
  • Reduce short-lived but powerful greenhouse gases such as methane.

2. Carbon Dioxide Removal (CDR)

• • Remove CO₂ from the atmosphere through:
    • Afforestation and ecosystem restoration
    • Bioenergy with Carbon Capture and Storage (BECCS)
    • Direct Air Capture (DAC)
  • However, CDR cannot substitute for rapid emission cuts and remains technologically, economically and environmentally challenging.

3. Adaptation

• • Mitigation alone is no longer sufficient.
  • Countries must simultaneously invest in:
    • Climate-resilient infrastructure
    • Heat-action plans
    • Disaster preparedness
    • Water security
    • Climate-resilient agriculture

Important Analytical Point

Crossing 1.5°C is not a “climate cliff”, but every additional fraction of a degree matters.

Even if temperatures eventually return below 1.5°C, some consequences of the overshoot—such as species loss, glacier retreat and displacement of vulnerable communities—may not be reversible.

Therefore, net-zero should be treated as a milestone, not the final destination; returning below 1.5°C would ultimately require net-negative emissions.

India’s Perspective

• • India faces significant risks from heatwaves, changing monsoon patterns, Himalayan glacier loss, floods and sea-level rise.
  • At the same time, India must balance climate action with energy access, poverty reduction and development needs.
  • Hence, India should emphasise:
    • Renewable energy expansion
    • Energy efficiency
    • Green hydrogen
    • Climate-resilient agriculture
    • Adaptation finance
    • International climate finance and technology transfer

Conclusion

The UNEP report represents a shift from “preventing 1.5°C” to “minimising and reversing the overshoot.” The message is not to surrender but to act faster: the lower the peak and shorter the overshoot, the lower the irreversible damage to people and nature.