waterfall
By Cully Cavness, Co-Founder, President and COO
A decade ago, at the UN’s COP21, 196 countries came together with great optimism and fanfare to adopt the landmark Paris Climate Agreement, committing to global cooperation to limit planetary warming to well below 2oC above pre-industrial levels, with the aim of keeping it to no more than 1.5oC by 2100.
In the years since its adoption, the world has made little headway on achieving this goal. Faced with mounting costs and major social and political headwinds to the transition to a low-carbon economy, a number of countries have backtracked on their commitments. The result has been a rapidly warming planet - especially when viewed in the context of geologic or biologic history. After average global temperature surpassed 1.5°C in 2024, making it the warmest year on record, global surface air temperature hit 1.75oC in January 2025 despite a La Nina cycle that scientists had expected to slow rising temperatures.
Today, the pathways to reaching a 1.5oC or 2oC world are narrowing. The scenarios developed by the UN Intergovernmental Panel on Climate Change (IPCC) that describe how we may get there, ambitious to begin with, are now looking ever more unrealistic and infeasible. At this point, without major technological breakthroughs, it will be nearly impossible to achieve the Paris Agreement’s goal or anything close to it.
The good news is we now have a new tool in our arsenal in the fight against climate change – artificial intelligence (AI). The rapid development and growth of AI can enable the transformative innovations we need to ultimately achieve the elusive goal to mitigate global warming. But before we discuss how AI can advance these breakthroughs, let’s dig into the IPCC scenarios to understand what will be needed to meet our global climate goal.
What are the IPCC Scenarios?
How much emissions rise and how much the world warms are in large part dependent on the technological, economic and policy choices we make now and in the decades to come. Of course, nobody has a crystal ball that allows perfect prediction, so scientists, businesses, and governments have come to rely on scenario analysis as a tool for better understanding potential outcomes.
To assess how the climate may change by the end of the century, the IPCC has developed a set of five scenarios called Shared Socioeconomic Pathways (SSPs) to describe a range of different possible futures that may come to pass. They are based on different assumptions about societal, economic, geopolitical, and technological developments through the end of the century. These scenarios consider factors such as the rates of population growth, economic growth, and urbanization, the levels of trade, the quantity and sources of energy that we will utilize, the levels of education people achieve, the agricultural systems that we will have, the responses that we take to address climate change, and the level of global cooperation between countries.
The five SSPs are:
SSP1 (Sustainability - Taking the Green Road): A sustainable, low-carbon world focused on social equity and environmental protection.
SSP2 (Middle of the Road): A middle-of-the-road pathway with moderate environmental and economic trends.
SSP3 (Regional Rivalry - A Rocky Road): A fragmented, regionalized world with slow economic growth, high inequality, and little global cooperation.
SSP4 (Inequality - A Road Divided): A fragmented world marked by high inequality, where technological and climate solutions are concentrated in wealthy regions, while others lag behind.
SSP5 (Fossil-Fueled Development - Taking the Highway): A world focused on rapid economic growth with high fossil fuel dependence and limited attention to environmental sustainability, resulting in high emissions.
The SSP scenarios are combined with Representative Concentration Pathways (RCPs), which describe the resulting climate impacts in terms of radiative forcing levels and temperature rise. For example, SSP1-1.9 is a 1.5oC scenario in which the world aims to limit global temperature rise to 1.5°C by stabilizing radiative forcing, a measure of the change in the Earth's energy balance caused by factors like changes in greenhouse gas concentrations that can warm or cool the planet, at 1.9 watts per square meter (W/m²) by the end of the century. SSP1-2.6 is a 2oC scenario with a slightly higher level of radiative forcing at 2.6 W/m².
Why 1.5oC and 2oC Pathways Will be Difficult to Achieve
Limiting global warming to below 2°C is crucial because it significantly reduces the risks and impacts of climate change on ecosystems, economies, and society, but achievement of this goal faces major challenges. Analysis of the key assumptions in the IPCC scenarios sheds light on the nature of the challenges.
1. Growth is Reoriented Towards Human Well-Being and Lower Material Consumption
Of the five IPCC scenarios, only one – SSP1 – provides a narrative where limiting warming to below 2oC is achievable. It assumes that there will be strong, sustained climate policies and rapid technological advancements, as well as significant changes in human behavior, with a focus on “inclusive development that respects perceived environmental boundaries” where the “emphasis on economic growth shifts toward a broader emphasis on human well-being” and “consumption is oriented toward low material growth and lower resource and energy intensity.”
Unfortunately, the correlation between human development and energy use historically has been extremely high, as people seek greater material comfort as countries move up the development curve. This makes it less likely that consumption and energy use will decline as the world develops. Human nature often also leans toward self-interest, driving people to desire material wealth, security, and a higher quality of life as economies grow. This aspect of human nature is at odds with the scenario’s narrative that the global population will collectively reject consumption and accept human well-being as the new marker of progress and prosperity.
2. Rapid Decarbonization Across Sectors
To achieve the Paris Climate Goal, significant decarbonization must take place across all sectors of the global economy, including energy, transportation, agriculture, and industry – and in just a few decades. Emissions need to be reduced by 45% by 2030 and reach net zero by 2050 to limit warming to 1.5oC, with near-zero emissions in the electricity sector, widespread use of renewable energy, and the widespread electrification of transport.
To put this level of decarbonization in context, during the peak of the global Covid lockdown, when aviation decreased by 75%, surface transport by 50%, power generation by 15%, and industry by about 35%, we were only able to reduce global emissions by somewhere between 8% and 17%, and emissions increased again as soon as economic activity resumed.
Additionally, in order to transition the energy system, we need to drastically reduce the use of fossil fuels and shift to clean energy sources, which will require massive investments in renewable energy technologies and infrastructure. Depending on the integrated assessment model (IAM) used to generate the IPCC SSP1-1.9 scenario, renewable energy would need to reach anywhere from 50-70% of primary energy and as high as 80% of electricity generation by mid-century. This would require an unprecedented change to our energy system, as the global energy mix in 2022 remained over 80% fossil fuel.
The IEA estimates that to reach net zero emissions by 2050, annual clean energy investment worldwide will need to more than triple by 2030 to around $4 trillion while IRENA estimates that it is more like $5.7 trillion. In reality, decarbonization is progressing at a much slower rate and necessary investments are lagging. Although investments are rising, the IEA reported that in 2024, only $2 trillion of investments were made in clean energy technologies and infrastructure. Beyond cost, renewable energy technologies like solar and wind are also still limited by grid integration challenges and energy storage limitations. In addition, sectors like aviation and heavy industry are still heavily dependent on fossil fuels, with viable green alternative fuels still in their infancy. Unless we achieve breakthroughs in energy storage, hydrogen fuel technology, or carbon capture and storage, such rapid decarbonization does not appear feasible within the projected timeframes.
3. Massive Scale-Up of Carbon Capture and Storage (CCS) and Carbon Dioxide Removal (CDR)
However, both CCS and technological CDR solutions are still not widely deployed due to their high costs, technical complexity, and lack of sufficient infrastructure. Today, while there are a growing number of CCS projects under development, only a handful of CCS projects are operational worldwide and those can only avoid approximately 50 million metric tons per annum. The scale of carbon dioxide removal needed to remain within 1.5oC is approximately 10 billion tons per annum by 2050. Today, we are removing a fraction of that – around 2 giga tons (Gt) a year – but almost all of this comes from conventional, nature-based CDR methods like reforestation while novel CDR technologies, which we will need as well, contribute only 0.0013 Gt of removal, or less than 0.1% of total CDR per year.
Scaling up these technologies at the required level would necessitate not only massive investments in infrastructure but also overcoming significant political, regulatory, and public acceptance barriers as well as the development of massive supply chains to support them. Without breakthroughs in CCS and CDR technologies that reduce the cost and barriers to deployment, their widespread adoption seems unlikely.
4. Widespread Adoption of Electric Vehicles (EVs) and Clean Mobility
The transportation sector makes up the largest share of U.S. greenhouse gas emissions and the second-largest source globally, with road transportation accounting for approximately three-quarters of global transportation emissions. To reduce transport emissions, there is an assumption that electric vehicles (EVs) will quickly dominate the transportation sector, replacing internal combustion engine vehicles. However, despite the growing popularity of EVs, a number of challenges remain:
Battery Technology: Although the price of EVs has come down significantly and adoption is rising in many places, the mass adoption of EVs is contingent on breakthroughs in battery technology. Skeptics argue that current lithium-ion batteries remain expensive and take a long time to charge. More efficient, affordable, and durable battery technologies, such as solid-state batteries, are needed to drive widespread adoption of EVs.
Infrastructure and Supply Chain Issues: There needs to be a vast expansion of charging infrastructure to support the mass adoption of EVs. Moreover, the supply of raw materials, such as lithium, cobalt, and nickel, required for battery production is limited and remains a key risk for supply chain bottlenecks.
Consumer Behavior: Even with the improvements in EV technology and pricing, consumer behavior will play a critical role. Convincing people to adopt EVs involves overcoming not just technological barriers but also cultural and economic ones.
These challenges suggest that the swift transition to EVs and clean mobility envisioned in the SSPs is unlikely without significant technological advancements in batteries, infrastructure, and supply chain logistics.
5. Global Economic Transformation and Policy Coordination
Scenarios projected to achieve the Paris Climate Goal assume extraordinary and far-reaching changes to global energy systems, industries, and policies, and require change at a rapid pace and massive scale. This kind of ubiquitous industrial reform would require a high level of global cooperation and coordinated global governance to enforce climate policies. This international collaboration would include agreements on carbon pricing, subsidies for clean technologies, international trade deals, and stringent regulations on emissions.
However, unified global coordination is increasingly challenging in today’s geopolitical climate, where competition for resources and national economic interests are often seen by world leaders as greater priorities. There is growing social and political resistance to climate policies in many places, especially in countries with struggling economies or strong fossil fuel industries.
Global economic transformation also requires large-scale investments in green technologies, but not all countries have the financial resources or technological capacity to make such investments. Given the slow progress in even wealthy, developed countries, the assumption that developing economies will rapidly transition to clean energy and sustainable practices is unrealistic without major financial support or breakthroughs in clean technologies that can be deployed at lower costs. In fact, we see the opposite happening today – significant growth in coal-fired power generation in countries like China and India to meet rising power demand, rather than a reduction in fossil fuel use. In 2024, China initiated the construction of 94.5 gigawatts (GW) of new coal-fired power capacity, the highest level since 2015 while India added almost 4 GW of coal-fired power capacity.
Given the realities of the current geopolitical environment, we are much closer to an SSP2 middle-of-the-road world, in which there is modest economic growth and we transition to cleaner energy sources but at a moderate level that is insufficient to limit warming to below 2oC. In this scenario, fossil fuels continue to play a significant role in the energy mix, accounting for around 55-65% in 2050, though there is growth in renewable energy sources like solar, wind, and hydro. If regional rivalries emerge, pushing us to an SSP3 scenario, progress on renewables will be even slower, and fossil fuels would remain at between 65-75% of the energy mix in 2050. These scenarios would result in global warming of approximately 2.7-3.6oC.
Can AI solve the Climate Challenge?
The IPCC scenarios highlight the central role that technological innovation must play in achieving a sustainable and low-emission future. We need advancements in a number of areas – from energy storage, electric grid innovation, nuclear fusion and fission, energy efficiency, CCS, CDR, alternative fuels and energy sources, and breakthroughs in transportation and industrial technologies – to make progress toward global climate goals. AI can help us make advancements in all of these areas – we will highlight how in our next blog.
