In World Energy Outlook 2023 the IEA notes that We are on track to see all fossil fuels peak before 2030.[1]: 18
The IEA presents three scenarios.[1]: 17
The "Stated Policies Scenario (STEPS)" provides an outlook based on the latest policy settings. The share of fossil fuel in global energy supply – stuck for decades around 80% – starts to edge downwards and reaches 73% by 2030.[1]: 18 This undercuts the rationale for any increase in fossil fuel investment.[1]: 19 Renewables are set to contribute 80% of new power capacity to 2030, with solar PV alone accounting for more than half.[1]: 20 The STEPS sees a peak in energy-related CO2 emissions in the mid-2020s but emissions remain high enough to push up global average temperatures to around 2.4 °C in 2100.[1]: 22 Total energy demand continues to increase through to 2050.[1]: 23 Total energy investment remains at about USD 3 trillion per year.[1]: 49
The "Announced Pledges Scenario (APS)" assumes all national energy and climate targets made by governments are met in full and on time. The APS is associated with a temperature rise of 1.7 °C in 2100 (with a 50% probability).[1]: 92 Total energy investment rises to about USD 4 trillion per year after 2030.[1]: 49
The "Net Zero Emissions by 2050 (NZE)" Scenario limits global warming to 1.5 °C.[1]: 17 The share of fossil fuel reaches 62% in 2030.[1]: 101 Methane emissions from fossil fuel supply cuts by 75% in 2030.[1]: 45 Total energy investment rises to almost USD 5 trillion per year after 2030.[1]: 49 Clean energy investment needs to rise everywhere, but the steepest increases are needed in emerging market and developing economies other than China, requiring enhanced international support.[1]: 46 The share of nuclear power remains broadly stable over time in all scenarios, about 9%.[1]: 106
In Dirac representation, the four contravariant gamma matrices are
