Question 1

Global temperature records exclusively measure surface air temperature changes.

Accepted Answer

WMO reports comprehensively assess seven distinct global climate indicators, including ocean heat content, sea-level rise, glacier mass loss, ocean acidification, and sea-ice extent.

Question 2

A transition to La Nina means global warming has stopped or reversed.

Accepted Answer

La Nina only temporarily cools surface temperatures; long-term warming indicators like Ocean Heat Content and atmospheric greenhouse gas concentrations continue to rise steadily regardless of ENSO cycles.

Question 3

Consider the following statements regarding the WMO State of the Global Climate reports:
1. The WMO bases its climate assessments on seven primary Global Climate Indicators, which include Ocean Heat Content and Ocean Acidification.
2. The 2025 dip in the global surface temperature ranking compared to 2024 was primarily driven by a decrease in atmospheric carbon dioxide concentrations.
3. Over 90 percent of the excess heat trapped by greenhouse gases in the Earth system is stored in the oceans.
How many of the above statements are correct?

Accepted Answer

(b) Only two — Statement 1 is correct; the WMO uses 7 key indicators based on GCOS variables. Statement 3 is correct; oceans act as a massive heat sink, absorbing over 90% of excess anthropogenic heat. Statement 2 is incorrect; the 2025 dip in temperature ranking (from 1st to 2nd/3rd) was due to the natural transition from El Nino to La Nina, while CO2 concentrations actually continued to rise to unprecedented record highs.

Question 4

Match the WMO Global Climate Indicator / Initiative (List I) with its defining characteristic (List II):
List I:
A. Global Mean Surface Temperature
B. Ocean Heat Content
C. Glacier Mass Balance
D. Global Greenhouse Gas Watch

List II:
1. Measures the total thermal energy stored in marine environments, acting as a buffer for Earth's energy imbalance.
2. An operational framework providing routine monitoring of atmospheric concentrations and fluxes to support the Paris Agreement.
3. The primary metric cited in media to represent short-term planetary warming, which is highly sensitive to ENSO cycles.
4. Assesses the net gain or loss of continental ice, significantly contributing to global sea-level rise alongside thermal expansion.

Accepted Answer

(a) A-3, B-1, C-4, D-2 — Surface Temperature (A) is the highly publicized metric sensitive to ENSO (3). Ocean Heat Content (B) measures thermal energy storage and buffers the climate (1). Glacier Mass Balance (C) measures ice loss contributing to sea-level rise (4). Global Greenhouse Gas Watch (D) is the WMO's operational monitoring framework for carbon fluxes (2).

Question 5

Assertion (A): Even in a year where the global surface temperature ranking drops slightly, global mean sea levels can continue to rise at a record pace.
Reason (R): Sea-level rise is primarily driven by the accumulation of greenhouse gases in the atmosphere rather than the melting of continental ice.

Accepted Answer

(c) A is true but R is false. — The Assertion is true: sea levels can continue to rise even if surface temperatures dip slightly (e.g., during a La Nina year) because the deep ocean continues to warm and expand, and glaciers continue to melt due to accumulated historical heat. The Reason is false: sea-level rise is primarily driven by the thermal expansion of seawater (due to rising ocean heat content) and the physical melting of continental ice (glaciers and ice sheets), not directly by the gaseous presence of greenhouse gases (which are the root cause, but not the direct physical mechanism of the volume change).

WMO State of the Climate Update for COP30

EU Commission President Visit to India and TTC Meeting