Emissions Analysis

Last updated: · PlainEmissions Editorial

Where the world is

The roughly 50-55 GtCO2e of global annual greenhouse-gas emissions break down approximately as follows: energy (including transport, buildings, and industrial fuel combustion) accounts for roughly 70-75%; agriculture for 10-12%; LULUCF for a net contribution that can range from -2 to +5 GtCO2e depending on methodology; industry process emissions (cement, steel, chemistry) for roughly 6-8%; waste for 3-4%; fugitive methane for 3-5% by bottom-up inventory and likely higher by satellite observation. These are global averages — the sector composition varies dramatically across countries.

Why coal is the policy hinge

Coal-fired electricity generation is the single largest source of CO2 emissions globally — roughly 14 GtCO2/year, or about 30% of global energy CO2. Coal also has the highest CO2 emission factor per unit of energy of any major fuel — roughly 80% higher than natural gas and infinitely higher than nuclear or renewables. The policy and economic question of how quickly coal-fired power is retired is the largest single determinant of global emissions trajectory through 2040.

The split by country is concentrated: China operates roughly 1,100 GW of coal-fired generating capacity, India roughly 240 GW, the United States roughly 200 GW (declining), the EU roughly 120 GW (declining), Japan and South Korea roughly 80 GW combined. Decisions in China and India about coal retirement timing dominate the global trajectory.

The structural difference between energy and process emissions

Energy emissions can in principle be eliminated by switching to zero-carbon fuels or electricity from zero-carbon sources. Process emissions cannot — the chemistry of cement-making (calcining limestone) releases CO2 regardless of fuel choice, as does iron-making (reducing iron ore with carbon) and chemicals manufacturing (producing ammonia from natural gas).

This matters because the policy lever for process emissions is structurally different. Carbon capture and storage (CCS), hydrogen-based reduction, or material-substitution research are required — none of which are mature at industrial scale. Process-emission-heavy economies (China, India, Russia, parts of the Middle East) face a harder decarbonization path than fuel-combustion-heavy economies.

Methane as the leverage point

Methane has GWP100 = 27.9 but GWP20 ≈ 80 — meaning methane reduction has very high near-term climate impact per tonne avoided. Methane has a relatively short atmospheric lifetime (about 12 years) so emission reductions translate to atmospheric concentration declines within a decade or two — much faster than CO2. The Global Methane Pledge launched at COP26 commits signatories to a 30% reduction in methane emissions by 2030 from 2020 levels.

Fugitive methane from oil-and-gas operations is the most actionable target: leaks can be detected by satellite, the abatement technology (better seals, fewer flares, no venting) is well-understood, and the cost is often negative (captured gas can be sold). The challenge is regulatory enforcement and operator incentive, not technology. PlainEmissions's fugitive-emissions sector pages surface the satellite-vs-inventory gap for major producing countries.

Source-disagreement patterns we keep seeing

Across the 150+ countries with multi-source data on PlainEmissions, certain patterns recur:

What we don't yet know

The biggest pending question is whether the Paris-Agreement-consistent emissions pathway — roughly 50% reduction by 2030 from 2019 levels — is achievable on the current policy trajectory. PlainEmissions's role is to provide the data substrate for honest reading of where each country actually is. The political and economic question of what to do about it is downstream of getting the numbers right.