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A Key Step for Limiting the Global Temperature Rise to 1.5 Degrees Celsius

The International Energy Agency needs to make that goal the centerpiece of its World Energy Outlook

Huge smokestacks send towering plumes of smoke into the sky.

Coal Creek power station, Underwood, North Dakota.

With less than 90 days until COP26, the annual United Nations climate change conference being held in Glasgow, Scotland this November, pressure is high for nations to limit global temperature rise to 1.5 degrees Celsius.

The 2015 Paris Agreement called for commitments to hold warming to “well below” 2 degrees C and pursue efforts to limit warming to 1.5 degrees C. Since then, advances in climate science have found that the 2 degree C mark is insufficient to stave off the worst impacts of climate change, strengthening the need for an updated 1.5 degrees C target. Temperatures have already risen by 1.2 degrees C above preindustrial levels, resulting in devastating floods, fires and droughts reflected in distressing daily headlines. Every increment of warming beyond 1.5 degrees C will result in increasingly destructive and costly repercussions, particularly for the most vulnerable communities and countries in low-income and small island states.

Now the heat is on the International Energy Agency (IEA), an intergovernmental organization that shapes global energy policy, to convey this to its member governments, businesses and markets by centering a 1.5 degrees C–consistent pathway in its widely-read annual publication, the World Energy Outlook (WEO). 


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Formed in 1974 in the context of a bruising oil crisis, the IEA has become an influential source of data and market analysis with a broadened mandate to ensure affordable, reliable and clean energy. Energy represents the largest source of humanity’s greenhouse gas emissions, with nearly two thirds of emissions linked to the burning of fossil fuels. Rapidly driving down energy emissions is therefore central to holding warming to 1.5 degrees C. 

Although the IEA does not recommend a specific level of acceptable warming, its WEO scenarios provide crucial roadmaps for political and business decisions by outlining the feasibility associated with achieving different policy goals. A landmark shift in international policy focus arrived in 2018 with a sobering report from the Intergovernmental Panel on Climate Change (IPCC)—the United Nations body responsible for assessing climate change science—which revealed that holding warming to 1.5 degrees C would require social and economic changes at a speed and scale for which there is no documented historical precedent.

The question now is how to get there. The latest science shows us that the window to keep 1.5 alive and avoid further catastrophic impacts is closing. This is where the IEA’s upcoming WEO, described as a “Google map” for global energy markets, could be pivotal—if the IEA aligns it with 1.5 degrees C.

Previous WEOs contain a series of scenarios, with the central “Stated Energy Policies Scenario” (STEPS)—the reference case—receiving the most detail and emphasis. STEPS outlines the consequences of no additional climate action: between 2.7 degrees C and 3 degrees C of warming. As the IEA states, showing the insufficiency of existing policies has value. But caution is needed when governments, investment analysts, businesses, and media interpret the reference case as the default guide for decision-making.

Neglecting to align the core WEO scenario with 1.5 degrees C is not the only way that the IEA has been out of touch with the pace of technology change and scientific knowledge. Both the scientific community and civil society have criticized the IEA’s modeling for its underlying bias in favor of the fossil fuel-based status quo. Moreover, the agency significantly underestimates the growth of renewables, which risks hindering renewable energy transitions. The campaign to #FixtheWEO also calls for replacing the central scenario to account for the imperative of staying below 1.5 degrees C.

Although the IEA shows signs of moving in the right direction, international consensus on 1.5 degrees C as the de facto target is not a foregone conclusion. In May, at the request of the U.K. COP presidency, the IEA released its first comprehensive study of how to transition to a net zero energy system by 2050 and give the world a chance of limiting global temperature rise to 1.5 degrees C. This marked a sea change in the IEA’s messaging. Instead of calling for more oil and gas investment, the IEA concluded there is “no need for investment in new fossil fuel supply.” However, countries including Japan, Brazil and Australia have disputed the findings, which clash with their own fossil fuel expansion plans. But illuminating the gaps between countries’ Paris Agreement commitments and policy action is exactly what the world needs before COP26.

Because the WEO is used by policy makers and investors alike to guide trillions in energy investment, the scenarios it prioritizes could become a self-fulfilling prophecy—either toward a 1.5 degrees C aligned future or worsening climate crisis. In an open letter to Fatih Birol, the executive director of the IEA, 60 leaders in policy, investment, academia, and civil society argued that the reference case “represents an insufficient level and pace of transformation” and “charts a dangerous course.” Christiana Figueres, the former executive secretary of the U.N. Framework Convention on Climate Change (UNFCCC), joined in, calling a 1.5 degrees C–aligned WEO a “golden key” to “open the portal to policy development and capital deployment.”

Holding warming to 1.5 degrees C poses significant economic and technical challenges, but the alternative would be a less habitable planet. With global energy growth outpacing decarbonization, achieving a livable future will require a guiding blueprint that supports policy coherence with IPCC 1.5 degrees C recommendations and guides investment toward a stable climate.

Placing a 1.5 degrees C-centered scenario at the heart of the WEO would model the market pathways needed to allow countries, companies and communities to cooperate toward this goal. As negotiatorsprepareto devise the future of climate action at COP26, the IEA is positioned to foreground this pathway in the WEO 2021 during what could be a turning point for this decisive decade.

This is an opinion and analysis article; the views expressed by the author or authors are not necessarily those of Scientific American.