Accelerating the Renewable Energy Revolution to Get Back to the Holocene

The UN's Paris Agreement goal of keeping global warming between 1.5 and 2°C is dangerously obsolete and needs to be replaced by a commitment to restore Earth's climate. We now know that continued use of fossil fuels associated with 1.5–2°C scenarios would result in hundreds of millions of pollution deaths and likely trigger multiple tipping elements in the Earth system. Unexpected advances in renewable power production and storage have radically expanded our climate response capacity. The cost of renewable technologies has plummeted at least 30‐year faster than projected, and renewables now dominate energy investment and growth. This renewable revolution creates an opportunity and responsibility to raise our climate ambitions. Rather than aiming for climate mitigation—making things less bad—we should commit to climate restoration—a rapid return to Holocene‐like climate conditions where we know humanity and life on Earth can thrive. Based on observed and projected energy system trends, we estimate that the global economy could reach zero emissions by 2040 and potentially return atmospheric CO2 to pre‐industrial levels by 2100–2150. However, this would require an intense and sustained rollout of renewable energy and negative emissions technologies on very large scales. We describe these clean electrification scenarios and outline technical and socioeconomic strategies that would increase the likelihood of restoring a Holocene‐like climate in the next 100 years. We invite researchers, policymakers, regulators, educators, and citizens in all countries to share and promote this positive message of climate restoration for human wellbeing and planetary stability.

• Goals of 1.5-2°C are not safe given current understanding of ecosystem climate sensitivity and high social costs of fossil fuel pollution • Climate restoration-rapidly reestablishing Holocene-like conditions-has not been fully considered because of socioeconomic obstacles • Strategic financing and prioritization of clean electrification could create pathways back to the Holocene within a century

Supporting Information:
Supporting Information may be found in the online version of this article.
If we take the scientific and economic analysis seriously, the only acceptable goal is to restore a Holocene-like climate as quickly as possible.
Unfortunately, many climate scenarios depict a dark future where even 2°C of warming is out of reach because of technological, political, and economic obstacles (Bradshaw et al., 2021;Breyer et al., 2022;Rogelj et al., 2023;Xiao et al., 2021).Global temperature is currently ∼1.2°C above pre-industrial, and to have a 2 out of 3 chance of staying below 1.5°C by the end of the century, we have a remaining carbon budget of ∼200 ± 220 gigatons of CO 2 equivalent (IPCC, 2022).This is roughly zero to 10 years of global emissions at current levels.Staying below 1.5°C would require both an abrupt decline in emissions and sustained negative emissions through the end of the century to make up for atmospheric overshoot.Is that even possible?
Our analysis shows that rapid defossilization in line with a sub-1.5°Cfuture is possible through clean electrification of all sectors of the economy and renewable-powered CO 2 recapture.The development and deployment of renewable energy technologies are more than 30 years ahead of projections (Figure 1), making clean electrification of the entire economy possible and macroeconomically profitable (Bogdanov et al., 2021;Breyer et al., 2022;Jacobson et al., 2022;Way et al., 2022).This renewable energy revolution has eliminated tradeoffs between economic development and climate mitigation, rendering obsolete many of the techno-economic assumptions in integrated assessment models and fundamentally changing the terms of debates about climate, pollution, and sustainable development (Breyer et al., 2023;Fuller et al., 2022;San-Akca et al., 2020;Way et al., 2022).
In this new world of low-cost renewable energy, we must raise our climate ambitions dramatically.Rather than aiming for climate mitigation-i.e., making things less bad-we should commit to climate restoration-i.e., a rapid return to Holocene-like climate conditions.If we simultaneously supercharge the rollout of renewables and implement negative emissions technologies on a very large scale, we could reach zero emissions by 2040 (Breyer et al., 2022;Victoria et al., 2021;Way et al., 2022) and potentially return atmospheric CO 2 to pre-industrial levels by 2100-2150 (Figure 2).In the following paragraphs, we aim to justify this bold position and call for a planetary commitment to get back to the Holocene.

The Problems With 1.5°C
Since the 2018 IPCC special report, the goal of limiting global warming to 1.5°C above the pre-industrial mean annual surface temperature has been variously criticized as unrealistically ambitious, irresponsibly inadequate, and simply arbitrary.While the attainability debate rages (Breyer et al., 2022;Jacobson et al., 2017;Rogelj et al., 2023), there is agreement that 1.5°C or more of warming entails enormous danger for human society and the broader Earth system (Armstrong McKay et al., 2022;Bradshaw et al., 2021;IPCC, 2021;Ripple et al., 2023;Ritchie et al., 2021).Ice sheets in Greenland and Antarctica have been in a state of persistent annual mass loss since the year 2000 (Bell & Seroussi, 2020;King et al., 2020;Wunderling et al., 2021), suggesting that restoring a climate of less than 0.5°C above pre-industrial is necessary to stabilize or reverse sea level rise.Though projections of sea level rise remain uncertain, recent empirical observations are tracking the most extreme model estimates, indicating that up to 9 m of sea level rise is possible in the coming centuries from currently destabilized ice sheets (Aschwanden et al., 2021;Boers & Rypdal, 2021;Heinze et al., 2021;King et al., 2020;Slater et al., 2020).This could disrupt global ocean circulation within decades and displace hundreds of millions of people within a century and more than a billion within two centuries (DeConto et al., 2021;Ditlevsen & Ditlevsen, 2023;IPCC, 2019;Kulp & Strauss, 2019).Additional tipping points are expected to be triggered in marine environments before or near 1.5°C, including loss of tropical coral reefs, deoxygenation of coastal and deep waters, and collapse of fisheries (Armstrong McKay et al., 2022;Goreau & Hayes, 2021;Gunn et al., 2023;Heinze et al., 2021).On land, a 1.5°C+ future would cause substantial weakening of the terrestrial carbon sink, disruption of the water cycle, and large-scale destabilization of food and water systems (Abbott et al., 2019(Abbott et al., , 2022;;Calzadilla et al., 2013;Duffy et al., 2021;Fernández-Martínez et al., 2023;Schleussner et al., 2018).These changes would directly and indirectly threaten human society and biosphere integrity by eroding the stabilizing feedbacks in the Earth system that currently insulate us from the most costly and dangerous consequences of human climate disruption (Bradshaw et al., 2021;Díaz et al., 2019;Kloenne et al., 2023).
Another danger with 1.5°C+ targets is that they involve atmospheric CO 2 overshoot followed by carbon recapture.Climate scenarios are often referred to by the amount of warming above pre-industrial in the year 2100.However, the risks of activating tipping elements in major Earth systems can be best understood as a function 10.1029/2023EF003639 3 of 14 of the amount of warming above Holocene-like conditions multiplied by the duration of the warmth.Analogous to a speeding vehicle, the chance of a serious accident depends not only on the maximum speed, but on the amount of time in exceedance of the speed limit.Many Earth systems such as ice sheets, permafrost, thermohaline circulation, and distribution of vegetation respond after initial time lags but once in motion have immense inertia (Abbott et al., 2022;Armstrong McKay et al., 2022;Boers & Rypdal, 2021;Ritchie et al., 2021).Even for scenarios with long-term equilibrium temperatures within the Paris Agreement range, temporary overshoot beyond 1.5°C increases the risk of triggering tipping elements by ∼70% compared with non-overshoot scenarios (Wunderling et al., 2023).In this light, a gigaton of CO 2 prevented in 2023 provides much more value than a gigaton removed in 2100 after it has spent decades altering the climate (Groom & Venmans, 2023).Calculating a new metric of gigaton-years demonstrates the extreme climate risk imposed by procrastinating emissions reductions (Figure 2c).Additionally, negative emissions technologies are far less developed and far more costly than renewables (Figure 1d), with some proposed methods producing local pollution or requiring large amounts of land and water (Breyer et al., 2020;Creutzig et al., 2019;Grant et al., 2021;Keiner et al., 2023).Compared to rapid defossilization now, the "wait and cram" approach incurs an order of magnitude more gigaton-years, recapture costs, societal damages, and consequent risks of setting off irreversible changes to Earth's socioecological systems (Figure 2; Figure S2 in Supporting Information S1).
The default plan of accepting a 1.5°C+ world would impose an immense burden on young people and future generations by allowing continued fossil fuel pollution beyond the end of the century (Figure 2a).While emissions are  usually expressed on a net basis-thereby hiding continued fossil fuel burning-all of the Shared Socio-economic Pathway scenarios allow gross emissions above 10 Gt CO 2 /year through 2250 except SSP1-1.9 and SSP1-2.6, which eliminate emissions by 2100 and 2200, respectively (Gidden et al., 2019;Meinshausen et al., 2020;Rogelj et al., 2018).Though decoupling a portion of these emissions from local air pollution may be achievable in the future, current trends are going in the opposite direction, with air pollution deaths rising faster than greenhouse gas emissions, 66% and 46% rises, respectively since 2000 (Fuller et al., 2022;IPCC, 2021;Vohra et al., 2021).
Based on current health and economic coefficients (Errigo et al., 2020;Fuller et al., 2022;Vohra et al., 2021), we estimate that the planned fossil fuel burning in these 1.5°C+ scenarios could cause 0.11-5.3 billion premature deaths and impose US$0.23-6.8quadrillion in pollution and recapture costs through 2250, compared with clean electrification by 2040 (Figure 2; Table S1 in Supporting Information S1; ranges represent scenario differences and estimate uncertainty).Air pollution damages have long been underestimated even in discussions of the social cost of carbon (Errigo et al., 2020;Galimova et al., 2022;Jacobson et al., 2022;Shindell et al., 2021;Vohra et al., 2021).However, air pollution accounts for a much larger economic toll than carbon recapture in our assessment, representing a mean of 81% of total costs (cross-scenario range of 54%-92%; Figure 2d and Figure S2 in Supporting Information S1).Notably, our analysis does not include loss of ecosystem services and costs of adaptation and mitigation due to weather extremes, crop and property damage, biodiversity collapse, and other climate consequences, which range from ∼1% percent to 20% of global GDP (Auffhammer, 2018;Diaz & Moore, 2017;Dietz et al., 2021).
In this light, continued creation of fossil fuel infrastructure is both deeply irresponsible and morally unacceptable, given that cheaper, safer, and more effective renewable technologies are proven at continental scales and rapidly improving (Bogdanov et al., 2021;Breyer et al., 2022;Jacobson et al., 2022).Rather than assuming it is the best possible future, 1.5°C should be considered a socioecological catastrophe-a global failure of understanding, ethics, and implementation.The dominant climate policy question of "how much fossil fuel can we afford to burn" needs to be replaced with "what is the safest and fastest way back to the Holocene?"

The Renewable Revolution Brings the Holocene Back Into Reach
The plummeting cost of renewable technologies has reshaped global energy, creating an opportunity for faster defossilization than previously thought possible (Breyer et al., 2022;IEA, 2023b;Lovins et al., 2019;Victoria et al., 2021;Way et al., 2022).The levelized cost of solar PV and wind power has declined by 91% and 71% respectively since 2009 (Figure 1).Renewables are now the cheapest form of electricity available in human history (Bogdanov et al., 2021), with another 50% cost decrease projected by 2030 (Vartiainen et al., 2020;Way et al., 2022).Energy storage has progressed even faster.Lithium-ion battery costs have dropped 95% since 2009 (Figure 1a) and are projected to decline another 90% by 2040 (Way et al., 2022;Ziegler & Trancik, 2021).Since 2019, utility-scale batteries have been the cheapest way of meeting daily peak power demand (Figure 1a), reducing short-term production-consumption asynchronies and allowing even faster rollout of renewables.
Beyond electricity, advances in materials and manufacturing now allow direct and indirect electrification of every sector of the global economy (Bogdanov et al., 2021;Breyer et al., 2022;Brown et al., 2018).Transportation, heating, chemical production, fertilizer synthesis, steelmaking, and energy-intensive industry all have technologically and economically viable pathways to full defossilization (Supporting Information).Renewable energy can now supply grid-stable energy for every sector of the economy year-round on every continent through a combination of transmission, demand management, sector coupling, slight overproduction, and energy storageprimarily batteries and pumped-hydro (Bogdanov et al., 2021;Breyer et al., 2022;Jacobson et al., 2022;Victoria et al., 2021).
Though not all industry projections and academic debates have caught up with the renewable revolution (Breyer et al., 2022;Jacobson et al., 2017;Victoria et al., 2021), global energy markets have already responded.Renewable energy constituted 83% of all new power production capacity installed in 2022 and is projected to constitute 95% of growth through 2025 (IEA, 2021;IRENA, 2022IRENA, , 2023;;Jacobson et al., 2022).Countries and regions as diverse as Vietnam, Denmark, Uruguay, and South Dakota have achieved high levels of renewables, affordably and quickly.For example, the state of South Australia went from 1% to 70% renewable electricity in 15 years and is on track to reach 100% in 2025.Oil and gas investment in future production has dropped by more than half since 2013, and for the first time, all of the International Energy Association's projections show declines in fossil fuel extraction and use (IEA, 2022a, 2023b).While this does not mean that defossilization will occur fast enough to meet the targets we propose in this paper, it heralds a fundamental departure from the extreme warming scenarios that used to be considered "business as usual" (Hausfather & Peters, 2020;Lovins et al., 2019;Way et al., 2022).
The socioeconomic implications of the renewable revolution are hard to overstate.It has long been believed that an economy-wide energy transition would incur major costs and require socioeconomic tradeoffs (Bradshaw et al., 2021;Smil, 2022).However, the most recent and comprehensive assessment of energy futures found that a rapid transition to a renewable economy results in $5-12 trillion in financial savings through 2070 compared to business as usual, based on energy system costs alone (Way et al., 2022).These estimates increase to $31-775 trillion in savings with the inclusion of environmental and human health co-benefits from pollution reduction and climate stabilization (Way et al., 2022).Because renewable power production has undercut fossil fuels so dramatically, the faster the deployment, the larger the savings, including early retirement of fossil fuel infrastructure (IEA, 2022b;Lovins et al., 2019;Way et al., 2022).
The rapid rollout of renewables is being accompanied by substantial declines in per-unit environmental impact.For example, off-river pumped hydro is providing storage without degrading aquatic ecosystems, and improvements in battery chemistry have eliminated or reduced metals that are ecologically and societally damaging, with more than half of all lithium-ion batteries expected to be nickel and cobalt free within 2 years (Blakers et al., 2021;IEA, 2023a;Yang et al., 2021).Likewise, agrivoltaic, rooftop, canal-top, and floating solar deployments are substantially reducing the land requirements of clean electrification.These advances are enabling a simultaneous decrease in emissions and increase in access to electricity in lower-and middle-income countries (Galimova et al., 2022;Katul, 2023;Ram, Bogdanov, et al., 2022).Indeed, the greatest benefits of renewable energy are concentrated in communities currently suffering the worst environmental injustice (Errigo et al., 2020;Fuller et al., 2022;Jacobson et al., 2022;Shindell et al., 2021).More broadly, the local production of fuel-free electricity could have major geopolitical and sustainable development benefits, including reducing energy-related conflicts (Hosseini, 2022;San-Akca et al., 2020;Vakulchuk et al., 2020).

Better Targets, Clearer Thinking
Despite the radical expansion of our mitigation capacity and improved scientific understanding of climate change consequences, much of the discourse around climate solutions remains incremental (Rogelj et al., 2023;UNEP, 2021).Because political discourse and climate scenarios have not responded as quickly as energy markets to the renewable revolution, emissions targets are playing catch-up rather than motivating and guiding progress (Lovins et al., 2019).More importantly, targets that propose only climate mitigation rather than climate restoration (i.e., a return to a Holocene-like climate) fundamentally miss the mark.Drawing a parallel from air pollution abatement, we now know there is no safe level of air pollution: the amount of damage depends on the concentration and duration of exposure (Errigo et al., 2020;Fuller et al., 2022).Threshold-based targets can produce perverse incentives that slow progress after an arbitrary limit defined as "safe" is reached.A better approach is to set trend-based commitments that will motivate progress and sustain pressure until the issue is resolved.There is no safe level of climate disruption, and our goal must be to get back to the Holocene.
After updating climate targets to aim for a rapid return to the Holocene, the next steps will be to build enough clean machines and retire enough dirty ones to hit the targets.The industrial plants, vehicles, and furnaces that we have already manufactured and installed will very likely take us beyond 2.0°C if not retired early, particularly when combined with ecosystem feedbacks (IPCC, 2022;Koven et al., 2021;Tong et al., 2019).Even if large-scale carbon recapture technologies materialize, local air pollution from these fossil fuel devices would continue to impose unacceptable damage to human health and wellbeing (Errigo et al., 2020;Fuller et al., 2022;Vohra et al., 2021).It is far less costly and risky to accelerate the rollout of renewables, prohibit new dirty power, and retire existing dirty infrastructure early (Groom & Venmans, 2023;Shindell et al., 2021;Way et al., 2022).
Updating and coupling integrated assessment models with energy system models could move us from generic discussions of emissions accounting to development of actionable national and regional clean energy implementation plans (Bogdanov et al., 2021;Lovins et al., 2019;Victoria et al., 2021).Currently, overestimates of future renewable energy prices sometimes exceed the observed values by an order of magnitude (Figure 1b), leading to pessimistic (and grossly unrealistic) projections of a much slower transition to clean energy than is likely even without coordinated encouragement (Way et al., 2022).This in turn contributes to an unwarranted focus on techno-economic scenarios that depend on less mature and more costly technologies such as next generation nuclear and negative emissions.Updated global-scale energy system models and improved estimates of the social cost of carbon are needed to illuminate the most efficient and equitable path to climate restoration (Aldy et al., 2021;Groom & Venmans, 2023;Kaufman et al., 2020;Lovins et al., 2019).

Financial Framing and Legislative Lubrication
The cost of clean electrification depends largely on interest rates, because cost-negative clean energy infrastructure requires upfront spending (Blakers et al., 2021;Hrnčić et al., 2021;Victoria et al., 2020;Way et al., 2022).
Global leaders in renewable energy penetration (EU, China, Germany, U.S.A, India, and Japan, in order of percent renewable electricity) have accelerated uptake by offering a combination of discounted financing and grants for manufacturers and installers.Because renewable production and storage cost less to build and operate than the fossil alternatives they replace, low or no-interest loans can be highly profitable at the national level through their impact on energy prices, job creation, national security, public health, and climate stability (Fofrich et al., 2020;Hrnčić et al., 2021;Ram, Osorio-Aravena, et al., 2022;Shindell et al., 2021;Victoria et al., 2020;Way et al., 2022).Ensuring access to low-cost financing is particularly important for renewable projects in lowand middle-income countries, which currently receive less than 8% of clean energy investment though they suffer 92% of pollution-related deaths (IEA, 2022b; IEA/IFC, 2023; Landrigan et al., 2017;Ram, Bogdanov, et al., 2022;Songwe et al., 2022).
However, historical changes in energy have depended on more than just economics (Stokes, 2020;York & Bell, 2019).Important concerns have been raised about supply chains, policy barriers, and public opposition (Bradshaw et al., 2021;Lowe & Drummond, 2022;Rogelj et al., 2023;Stokes, 2020;York & Bell, 2019).Given the incredibly high stakes of Earth system failures and loss of human life if emissions remain higher for longer (i.e., more gigaton-years), the world needs a global surge of policy and public support for the renewable revolution.Recent global disruptions provide surprising insights into how we can supercharge defossilization even during geopolitical crises.Despite fears that COVID-19 and Russia's invasion of Ukraine would slow the energy transition, absolute and relative growth in renewable energy has accelerated since 2020 (Hosseini, 2022).While renewable energy costs rose in 2022 (Figure 1a), they rose more slowly than fossil fuel energy costs and resumed their decline in 2023, widening renewables' advantage (IEA, 2022b).The abrupt disruption of fossil fuel imports caused by the Russia-Ukraine crisis rewarded early adopters of fuel-free renewables and solidified support for energy independence in Europe and beyond (Hosseini, 2022).Indeed, increased demand and financing from the European Union's REPowerEU initiative and the United States' Inflation Reduction Act are both diversifying supply chains for renewable technologies and accelerating defossilization globally (Bistline et al., 2023;Norman, 2023).Expanding policy initiatives and culturally competent outreach efforts about the benefits of our clean energy future could sustain solidarity and strengthen cultural norms that we need to establish a sustainable civilization (Abbott et al., 2021;Chapin et al., 2022;Leiserowitz et al., 2022).
Growing financial and cultural commitment to clean energy has kicked off a manufacturing renaissance.The cumulative global capacity of wind and solar has doubled every 3.7 and 1.9 years, respectively since 2000.Shoring up supply chains and financing large renewable manufacturing facilities could maintain these growth rates at surprisingly low cost (Lowe & Drummond, 2022;Verlinden, 2020;Victoria et al., 2021;Way et al., 2022).Renewable energy gigafactories are being built around the world, including in India's Gujarat province and China's Shaanxi province at an estimated cost of $9 and $6.7 billion, respectively.These facilities will respectively produce ∼20 and 100 GW of solar panels annually.As few as 60 such facilities could meet total global energy demand with renewables by 2035-2040 (Bogdanov et al., 2021).This would simultaneously yield enormous societal and environmental benefits, including the creation of more than 120 million jobs globally (Bogdanov et al., 2021;Ram, Osorio-Aravena, et al., 2022;Way et al., 2022).
Finally, in addition to innovative financial, industrial, and cultural commitment, we need frictionless coordination between national and local levels.Power production and distribution have been treated as regulated monopolies in many jurisdictions, creating opponents to competing technologies such as distributed generation and storage of renewable power (Stokes, 2020;York & Bell, 2019).Moreover, strategic and coordinated approaches to siting of renewable infrastructure is critical not only for ensuring political support, but also for reducing impacts on vulnerable human communities and the biodiversity and ecosystem services on which we depend (Carley & Konisky, 2020;Errigo et al., 2020;Rockström et al., 2023).Encouragingly, with proper siting, a majority of 10.1029/2023EF003639 8 of 14 negative social and environmental impacts of renewable infrastructure deployment can be mitigated, for example, a 70% reduction in impacts in the U.S. (TNC, 2023).Legislation that allows efficient collaboration among renewable business interests, communities, and governments is needed to ensure that local laws and regulations accelerate responsible deployment rather than postpone the energy transition (Hosseini, 2022;Jenkins et al., 2022;Stokes, 2020).

Fixing Carbon Recapture
Even with an extremely rapid rollout of renewables, negative emissions technologies will be required to get back to the Holocene within the next 100 years (Figure 2a).Low-cost renewable energy is already bringing down the projected cost of direct air carbon capture (Breyer et al., 2022;Creutzig et al., 2019), but CO 2 sequestration is not yet on a learning curve (Way et al., 2022).For renewables, government investment in basic research and guaranteed demand via feed-in tariff laws led to explosive innovation and cost degression (Kavlak et al., 2018;Stokes, 2020;Way et al., 2022).Creating an international market for negative emissions of $10 billion or more annually would jumpstart innovation in a field that is currently experiencing cost increases and backsliding (Breyer et al., 2020;CDR.fyi, 2023;Rubin et al., 2015).Existing multilateral institutions like the World Bank Group and the International Monetary Fund could create and manage this global CO 2 removal fund, with financing from wealthy countries proportional to their contribution to cumulative historic CO 2 emissions.A combination of competitive bids and feed-in tariffs could greatly expand the currently tiny carbon recapture market ($2 billion in all-time transactions), leading to enormous dividends by accelerating the creation and deployment of lower-cost carbon capture over the next 20 years (Breyer et al., 2022;CDR.fyi, 2023).Nature-based carbon sequestration should be prioritized both because of its large potential (up to 11.5 Gt of CO 2 annually through 2050) and substantial cobenefits, including preservation of threatened cultures and the reversal of the ongoing decline of life on Earth (Abbott et al., 2022;Chapin & Díaz, 2020;Seddon, 2022).In any case, the development of cheaper negative emissions technologies must not be used as a justification for continued emissions.Unlike the SSPs, which often choose either rapid emissions reductions or CO 2 removal, a return to the Holocene requires both (e.g., CE1, Figure 2).
Finally, as members of the climate science and climate stabilization communities, we need to be informed and clear communicators.In our conversations and professional interactions, we often encounter "doomerism" about the prospects of change in the energy system (Hausfather & Peters, 2020;Smil, 2022).Pessimistic personal views are understandable given the decades of setbacks and missed climate targets.However, jaded perspectives can have negative consequences for both research and public opinion (Lovins et al., 2019).For example, socioeconomic scenarios that achieve 1.5°C or better are sometimes left out of model intercomparisons (McGuire et al., 2018) because of modelers' beliefs that such scenarios are not realistic and therefore not worth the computational investment.Yet it is the worst-case climate scenarios that are becoming less likely with every passing year (Hausfather & Peters, 2020;Jacobson et al., 2022;Lovins et al., 2019).In engineering terms, renewable electrification of the global economy can be achieved much more quickly than policy discourse suggests, perhaps by 2035, and certainly before 2050 (Breyer et al., 2021;Jacobson et al., 2022;Lowe & Drummond, 2022;Way et al., 2022).We invite climate researchers, policymakers, regulators, educators, and citizens of all countries to share this message and insist on climate restoration for human wellbeing and planetary stability.

Figure 1 .
Figure 1.Observed and projected costs of energy production, storage, and CO 2 recapture.(a) The 2009-2023 levelized cost of energy (LCOE), which includes manufacturing, installation, operation, and decommissioning costs per unit of produced power (megawatt hours).Lines are smoothed conditional means (n = 26).2023 values are based on the first half of the year.(b) Projected LCOE for solar photovoltaic (PV) and onshore wind production from studies published in 2015-2020 (n = 35).Boxplots show the distribution of estimates for each period (quartiles, median, and points beyond 1.5-times the interquartile range), and horizontal lines show the LCOE of onshore wind and solar PV observed in 2021.(c) Projected capital expense of lithium-ion battery cells from studies published in 2015-2020 (n = 17), with the observed 2021 capital expense shown by the horizontal line.(d) Projected CO 2 recapture cost (mean ± SE) in 2050 for Afforestation (AR), Soil carbon sequestration (SCS), Biochar soil amendments, Bioenergy carbon capture and storage (BECCS), Direct air carbon capture and storage (DACCS), and Enhanced weathering (EW) (n = 13).Data sources listed in the Supporting Information and data.

Figure 2 .
Figure2.Six common climate scenarios (Shared Socio-economic Pathway scenarios) compared with two clean electrification scenarios from this study (see Supporting Information for details).The two clean electrification scenarios follow the same emissions trajectory, achieving zero emissions by 2040 by replacing all fossil fuels with solar PV and wind, but they follow different negative emissions pathways.CE1 and CE2 use projected negative emissions from SSP5-8.5 and SSP1-1.9,respectively, until atmospheric CO 2 reaches the pre-industrial target of 275 ppm (allowing for oceanic CO 2 degassing).(a) Observed and projected atmospheric CO 2 partial pressure, gross CO 2 emissions, and CO 2 removal (i.e., negative emissions) for the eight scenarios.The vertical dotted lines indicate when atmospheric concentration of CO 2 returns to 275 ppm.(b) Excess deaths associated with fossil fuel air pollution for each scenario and period.(c) Gt-years are the Gt of CO 2 in the atmosphere above pre-industrial multiplied by number of years spent in the atmosphere.This new metric integrates both the magnitude and duration of climate forcing.(d) Economic damages from fossil fuel use split into pollution costs (human health and economic damages) and recapture costs.These estimates do not include climate change adaptation or mitigation costs such as infrastructure damage or the loss of ecosystem services.