Which of the following activities has contributed maximum to global warming?

Concept

Global warming results from the accumulation of heat-trapping greenhouse gases. The contribution of an activity depends on both the gases it emits and the scale and persistence of those emissions.

Carbon dioxide from burning carbon-based fuels remains in the climate system for a long time, so repeated large-scale combustion raises atmospheric carbon dioxide and strengthens radiative forcing.

Application

Power generation, transport, industry, and buildings burn coal, oil, and natural gas on a very large scale. This direct and widespread carbon dioxide release makes fossil fuel combustion the largest contributor among the listed activities.

Contrast

• Industrial processes add emissions through cement calcination and chemical production, but fuel-burning emissions are accounted for on a broader scale.

• Deforestation releases stored carbon and removes sinks that absorb carbon dioxide; it is important but smaller globally than cumulative fossil-fuel combustion.

• Agriculture emits methane and nitrous oxide through livestock, rice cultivation, manure, and soils; these are major contributors but do not exceed fossil-fuel carbon dioxide in aggregate.

Cross-check

Global carbon budgets and IPCC assessments consistently identify fossil carbon dioxide emissions as the dominant source of anthropogenic carbon dioxide and the largest cumulative contribution to warming.

Result

Fossil fuel combustion has contributed the most to global warming among the listed activities.