CAMBRIDGE – Negotiations on geoengineering technologies ended in deadlock at the United Nations Environment Assembly in Nairobi, Kenya, last week, when a Swiss-backed proposal to commission an expert UN panel on the subject was withdrawn amid disagreements over language. This is a shame, because the world needs open debate about novel ways to reduce climate risks.

Specifics aside, the impasse stemmed from a dispute within the environmental community about growing scientific interest in solar geoengineering – the possibility of deliberately reflecting a small amount of sunlight back into space to help combat climate change. Some environmental and civil-society groups, convinced that solar geoengineering will be harmful or misused, oppose further research, policy analysis, and debate about the issue. Others, including some large environmental groups, support cautious research.

By reflecting sunlight away from the Earth – perhaps by injecting aerosols into the stratosphere – solar geoengineering could partly offset the energy imbalance caused by accumulating greenhouse gases. Research using most major climate models suggests that solar geoengineering might reduce important climate risks such as changes in water availability, extreme precipitation, sea level, and temperature. But any version of this technology carries risks of its own, including air pollution, damage to the ozone layer, and unanticipated climate changes.

Yet research on solar geoengineering is highly controversial. This has limited research funding to a few tiny programs around the world, although a larger number of climate scientists are beginning to work on this topic using existing funds for climate research.

Why the controversy? Many fear, with good reason, that fossil-fuel interests will exploit solar geoengineering to oppose emissions cuts. But most researchers are not driven by such interests. The vast majority of those researching solar geoengineering or advocating for its inclusion in climate-policy debates also support much stronger action to reduce emissions. Still, it’s very likely that Big Fossil – from multinational energy companies to coal-dependent regions – will eventually use discussion of geoengineering to fight emissions restrictions.

But that risk is not a sufficient reason to abandon or suppress research on solar geoengineering. Environmentalists have spent decades fighting Big Fossil’s opposition to climate protection. And although progress to date has been insufficient, there have been some successes. The world now spends over $300 billion per year on low-carbon energy, and young people are bringing new political energy to the fight for a safer climate.

Open discussion of solar geoengineering would not weaken the commitment of environmental advocates, because they know emissions must be cut to zero to achieve a stable climate. At worst, such a debate could make some in the broad, disengaged middle of the climate battle less interested in near-term emissions cuts. But even this is not certain; there is empirical evidence that public awareness of geoengineering increases interest in cutting emissions.

It is sensible to focus on cutting emissions, and reasonable to worry that discussing solar geoengineering could distract from that fight. But it’s wrong to indulge a monomania whereby emissions cuts become the sole objective of climate policy.

Vital as it is, eliminating emissions simply stops adding to the burden of carbon dioxide in the atmosphere. The CO₂ from the fossil-fuel era, and the resulting climate changes, will persist. We need adaptation that increases resilience to climate threats. But adaptation by itself is no solution. Neither is solar geoengineering. And nor is removing CO₂ from the atmosphere – another emerging set of technologies that were considered in the Swiss-backed proposal in Nairobi.

As the American writer H.L. Mencken put it, “there is always a well-known solution to every human problem – neat, plausible, and wrong.” Complex problems like climate change rarely have a single solution.

My hope is that emissions cuts, solar geoengineering, and carbon removal can work together to reduce the human and environmental effects of climate change beyond what is possible with emissions cuts alone.

Are these hopes justified? The geoengineering research community is small and dominated by a narrow group of members, most of whom are (like me) white, male, and based in Europe or America. Groupthink is a distinct possibility. We may simply be wrong. It would be reckless to deploy solar geoengineering based only on hope and early research.

Instead, an international, open-access research program could, within a decade, dramatically improve understanding of the risks and efficacy of solar geoengineering. Such a program would cost a small share of the sum currently spent on climate science, and far less than 0.1% of outlays to cut emissions. A wise program would reduce groupthink by increasing the diversity of researchers, and by establishing a deliberate tension between research teams developing specific scenarios for deployment and others tasked with critically examining how these scenarios could go wrong.

Governance is the toughest challenge for geoengineering. A global research program should therefore be coupled with greatly expanded international discussion about these technologies and their governance. Such a debate was unfortunately cut short in Nairobi last week.

Although my generation will not use solar geoengineering, it seems plausible that before the middle of this century, a dramatic climate catastrophe will prompt some governments to consider doing so. By foregoing debate and research on geoengineering now, political leaders may be hoping to eliminate the risks of its future misuse. But their stance may actually increase this danger.

Humans rarely make good decisions by choosing ignorance over knowledge, or by preferring closed-door politics to open debate. Rather than keeping future generations in the dark on solar geoengineering, we should shed as much light on it as we can.

MONTEVIDEO – In a recent special report, the Intergovernmental Panel on Climate Change (IPCC) argues that addressing climate change will require fundamental changes to the way we manage forests and farmland. The data are new, but the underlying conclusion isn’t: for over a decade, scientists, environmentalists, and civil-society organizations have been warning that our prevailing – and deeply unjust – model of production and consumption lies at the root of the climate crisis. Protecting the planet on which our survival depends will require nothing short than system change

The world – and the developed countries, in particular – has built an economic system focused on capital accumulation, which privileges corporate profits over the wellbeing of people and the environment, entrenching injustice and rewarding its perpetrators. This process has been unfolding for centuries, but has accelerated in recent decades, as a select few have acquired an ever-larger share of total wealth and political influence. Today, just 100 corporations produce 71% of greenhouse-gas (GHG) emissions. The wealthiest 10% of people are responsible for around 50% of GHG emissions, while the poorest 50% produce 10% of emissions.

Unwilling to stand up to those who are destroying our planet, political leaders have latched onto technological solutions, including geoengineering approaches that promise to suck already-emitted carbon out of the atmosphere. Even the IPCC included assumptions about such technologies in many of its modeled pathways for keeping global temperatures from rising more than 1.5 °C above pre-industrial levels.

But geoengineering technologies are unproven, unsafe, and unrealistic. Consider bio-energy with carbon capture and storage (BECCS), the leading proposed path to “net-negative” emissions. BECCS entails growing certain crops as biomass, burning the plant material for energy, capturing the CO₂ emitted during combustion, and storing it underground.

That sounds promising until one recognizes that growing biomass on the necessary scale would require an estimated three billion hectares – twice the Earth’s currently cultivated land. Any attempt to implement BECCS would thus be impossible without mass deforestation and soil degradation in the tropical belt of the Southern Hemisphere, where most fast-growing biomass is produced. Land grabs are virtually guaranteed. Moreover, as agricultural land was transformed to produce biomass, food prices could rise, fueling hunger and malnutrition. And the destruction of vital ecosystems would eliminate the livelihoods of local communities and indigenous peoples.

Hyping BECCS and other misleading promises – such as Reducing Emissions from Deforestation and Forest Degradation (REDD+) initiatives and carbon-trading schemes – is expedient for rich countries, corporations, and elites, because the technology charade enables them to continue profiting from the climate crisis they have created. But, by distracting from real imperatives, it allows the crisis to deepen and disproportionately affect those who have contributed the least.

It is time for those who caused the climate crisis to take responsibility for addressing it. To this end, developed-country governments must take the lead in drastically cutting emissions at source by pursuing a comprehensive transformation of their energy, transport, food and economic systems.

Essential steps include ending investment in fossil fuels; transforming our energy systems towards community and public renewable energy systems; abandoning destructive practices like industrial agriculture and logging; community management of biodiversity and water resources; and reorganizing urban life to support sustainability. Neoliberal trade and investment agreements that prioritize the interests of business over environmental sustainability and human rights must be reversed to allow for these solutions.

At the same time, developed-country governments must provide large-scale public financing to support the much-needed transformation in the developing world. To succeed, the transition must be just and ensure the rights of workers, peasants, women, migrants, and indigenous peoples. Here, public and community ownership is crucial.

Social movements in the Global South are already providing models of this approach. For example, La Via Campesina – an international movement comprising peasants, smallholder farmers, agricultural workers, rural women and youth, indigenous people, and others – has shown how peasant agriculture and agroecology can cool the planet, feed its inhabitants, nurture its soil, support its forests, safeguard seed diversity, and protect water basins.

Moreover, community forest management helps to safeguard the forests, protecting the livelihoods of those who depend on them and preserving biodiversity. (As it stands, only 8% of the world’s forests are in the hands of communities.)

With strong political will and the right policies, we can systemically tackle climate change and related crises, including biodiversity loss, water scarcity, hunger, and rising inequality. If, however, we keep indulging the fantasy that some “silver bullet” solution will rescue us, progress will be impossible.

SUVA – Geoengineering will save us from the climate crisis, its champions insist. By using technology either to remove carbon dioxide from the atmosphere or to deflect some solar radiation away from the Earth, they claim, we can undo the damage wrought by humanity’s failure to reduce greenhouse-gas (GHG) emissions. But while it certainly sounds like a convenient solution, there is no proof that it will work – and no telling what the side effects could be. In the view of Pacific islanders, it barely merits discussion.

Proponents of geoengineering are right about one thing: we are facing a climate emergency that demands radical and urgent action. The Intergovernmental Panel on Climate Change (IPCC) made that starkly apparent in October 2018, and reinforced the point last month, with its report on climate change and land.

Some major economies – including Canada, Ireland, the United Kingdom – as well as regions and cities have now officially recognized the scale of the crisis. The question is whether this will translate into a commitment to take the necessary action.

That certainly did not happen at last year’s UN Climate Change Conference in Katowice, Poland. Instead, leaders stuck to weak commitments that effectively allow for the continuation of business as usual – an outcome that was driven by countries in which fossil-fuel industries have tremendous political and economic clout. In most cases, they were the same countries that promote geoengineering solutions.

For Pacific islanders, who are on the frontlines of a climate crisis to which they have barely contributed, this persistently selfish and short-sighted approach has gone from disappointing to frustrating to infuriating. The 14 sovereign Pacific island countries account for only about 0.02% of total global GHG emissions. Yet, with many either possessing low-lying islands or composed entirely of low-lying atolls, they are extremely vulnerable to the effects of climate change, beginning with rising sea levels.

But Pacific islanders know better than to succumb to the siren song of geoengineering. In fact, they have been used as guinea pigs for the testing of powerful and risky technologies before, including nuclear weapons in the 1940s and 1950s, and are still suffering the consequences. In the Marshall Islands, for example, the United States built (only in the 1980s) a massive concrete dome to house the deadly radioactive debris from such tests. But the structure was not built to last. As the dome degrades, the risks of radiation leaks are rising.

Geoengineering is not an entirely new topic to the Pacific. Governments in the region have already been targeted by researchers and proponents. At a 2013 workshop in Suva, Fiji – organized by University of the South Pacific’s Pacific Centre for Environment and Sustainable Development and the Institute for Advanced Sustainability Studies – participants agreed that more research, broader awareness, and transparent debate on the topic were needed.

But, as participants emphasized, no climate engineering technology should be implemented unless it was proven to be a sufficiently safe option – and then only as a last resort. Even field testing should not take place without enforceable regulations and governance structures. Most important, Pacific countries agreed that geoengineering technologies should not be regarded as a substitute to radical global mitigation efforts, including major emissions cuts.

Yet, six years later, the debate is entirely different. More geoengineering research projects, proposals for experiments, and commercial applications are on the agenda. At the same time, mitigation efforts are sorely lacking – specifically in those countries where governments are turning their attention to geoengineering as an excuse for inaction. In effect, responsibility for the climate crisis is being deferred to future generations, especially in the developing countries that have done the least to cause it.

In light of this imbalance, the Pacific Islands Development Forum’s position on geoengineering remains squarely in line with the Convention on Biological Diversity’s 2010 call for a moratorium – agreed to by 196 governments – on all geoengineering activities until “a global, transparent, and effective control and regulatory mechanism” is put in place.

The IPCC has made clear that the only way to address the climate crisis is with “transformation pathways” that slash emissions and protect and restore ecosystems, including through what is effectively a land-use revolution. Such pathways are mapped out not only in IPCC reports, but also in the 2015 Paris climate agreement.

This means replacing fossil fuels with renewable energy sources. It also means making the most of our planet’s natural capacity for carbon capture and storage, by protecting and expanding natural carbon sinks like forests, mangroves, and seagrass meadows. As the IPCC report on land specifies, measures like expanding local and indigenous communities’ role in forest management would bring major benefits, as would a transformation of food systems to ensure sustainable agricultural practices and minimal food waste.

Most of the needed responses will contribute positively to sustainable development and other global goals. For starters, a healthier planet means healthier people: by causing respiratory illnesses, outdoor pollution results in around three million premature deaths per year.

Furthermore, the shift to renewable energy would help create large numbers of quality jobs – far more than the fossil-fuel industry offers. And this does not even account for the massive costs – associated, for example, with increasingly extreme and frequent weather events – that would be avoided if we mitigated climate change effectively.

The longer we delay, however, the more urgent the crisis becomes – and the higher the chances of reckless action. Already, the rapid escalation in the effects of climate change is being used to justify risky outdoor geoengineering experiments that could have devastating and unpredictable environmental consequences, and that could put the world on a slippery slope toward deployment, without the necessary safety assurances or regulatory structures.

We know what we have to do – indeed, we have known for years. If all countries fulfill their responsibilities, we can respond effectively to climate change. But to protect humanity – beginning with ultra-vulnerable Pacific islanders – we must act now.

MEXICO CITY – Although the effects of climate change are becoming increasingly apparent, the progress toward reducing greenhouse-gas emissions remains as disappointing as ever, leading some to tout new technological solutions that could supposedly save the day. Harvard University’s David Keith, for example, would have us consider geoengineering – that is, deliberate, large-scale, and highly risky interventions in the Earth’s climate system.

This past March at the United Nations environmental conference in Nairobi, Kenya, the United States and Saudi Arabia blocked an effort to scrutinize geoengineering and its implications for international governance. Meanwhile, Keith’s Stratospheric Controlled Perturbation Experiment (SCoPEx) in the US – which aims to test a form of geoengineering known as Solar Radiation Management (SRM) – seems to be moving forward.

SRM depends on so-called Stratospheric Aerosol Injection, whereby a high-altitude balloon sprays large quantities of inorganic particles into the stratosphere with the goal of reflecting some sunlight back into space. SCoPEx would send a balloon equipped with scientific instruments some 12 miles (20 kilometers) above the ground to test the reflectivity of various substances.

But these technical aspects of the experiment are far less important than its political, social, and geopolitical implications. After all, the risks of geoengineering could not be more serious. If deployed at scale, SRM could disrupt the monsoons in Asia and cause droughts in Africa, affecting the food and water supplies of two billion people. The use of sulfuric acid – the most studied option, and the one SCoPEx initially intended to test – could further deplete the ozone layer. (More recently, SCoPEx has been mentioning only carbonates.)

The recent launch of an independent advisory committee for SCoPEx seems to be aimed at lending legitimacy to a kind of experiment that the rest of the world has agreed is too dangerous to allow. Moreover, the panel’s membership is exclusively US-based, and mostly linked to elite institutions, which raises questions about whose interests are really being served.

These concerns are reinforced by the fact that the SCoPEx pitch is fundamentally manipulative. The results from a “small-scale” experiment would not amount to a credible assessment of the effects of deploying SRM at the scale needed for geoengineering. As climate scientists have made clear, the only way to know how SRM (or any other geoengineering technique) would affect the climate is to deploy it over several decades on a massive scale. Otherwise, its effects could not be distinguished from other climate variables and “climate noise.”

Given that geoengineering is, by nature, not testable, all experiments like SCoPEx can do is create momentum for larger and longer experiments. Once millions of dollars have been sunk into creating the relevant institutions and employing large numbers of people, it becomes easier to argue that even more data should be collected and, finally, that the technology should be deployed.

In this sense, projects like SCoPEx set a new and dangerous precedent for the unilateral implementation of geoengineering technologies by billionaires and vested interests. Indeed, as the Center for International Environmental Law and the Heinrich Böll Foundation’s recent report, Fuel to Fire, points out, fossil-fuel companies have been investing in geoengineering for decades. For them, the promise of a technological get-out-of-jail-free card is an ideal pretext for continuing their highly profitable, destructive activities.

In fact, Keith’s own company, Carbon Engineering, recently received $68 million from Occidental Petroleum, Chevron, and the coal giant BHP (Billiton) to develop another potentially dangerous geoengineering approach – Direct Air Capture, which takes CO₂ from the atmosphere, to be used or stored. Among the company’s original funders is the oil sands financier N. Murray Edwards (as well as Bill Gates).

Allowing such projects to move forward with no political mandate or institutional oversight could entrench a system of self-regulation that is grossly inadequate for technologies as consequential as geoengineering. That is why the UN Convention on Biodiversity (CBD) has asked governments not to allow any geoengineering activities to be carried out until “a global, transparent, and effective control and regulatory mechanism” is put in place – a mechanism that adheres to the so-called precautionary approach.

The CBD decision made an exception for small-scale experiments, but only under certain conditions, which SCoPEx doesn’t meet: among them, carrying out experiments in “controlled settings” and acquiring the free, prior, and informed consent of indigenous peoples and local communities that may be affected. Furthermore, in the case of SCoPEx, no critical voices from civil society or developing-country governments seem to have been considered.

SCoPEx’s promoters appear determined to take advantage of the US’s failure to ratify the CBD. The fact that the SCoPEx advisory committee is chaired by a California government official, Louise Bedsworth, also raises the question of whether a state that has positioned itself as a climate leader is now embracing the most controversial form of geoengineering.

Rather than allow fossil-fuel companies that have ravaged our planet for profit to continue to act in their own interest, the world must establish a strong, multilateral democratic regulatory mechanism, which includes the option to ban certain technologies outright. Until such an international system is in place, experiments like SCoPEx – which threaten to act as a Trojan horse for deploying dangerous technologies at scale – must not be allowed to move forward.

NEW YORK – Climate change poses an unprecedented threat to humanity, one that appears increasingly likely to reduce global standards of living dramatically within our lifetime, and cause untold damage in the longer term. And, because addressing such a daunting planetary challenge requires radical approaches, there have been wide-ranging discussions about what the world must urgently do to limit the rise in global temperature to less than 1.5°C above pre-industrial levels.

Although reducing greenhouse-gas emissions must remain the highest priority, the United Nations Intergovernmental Panel on Climate Change (IPCC) says this is not enough. Some now suggest that we also need to remove huge amounts of carbon dioxide from the air. Others argue that we may also need to reflect sunlight back into space, to buy the world more time to reduce and remove emissions.

Taken together, these two approaches are known as geoengineering. And as the effects of climate change worsen, a growing number of policymakers, scientists, and entrepreneurs are considering such options more seriously.

But at present, we have no idea what unforeseen and unintended consequences deploying these new technologies might have. The unknown unknowns – especially with solar geoengineering – could be just as bad as the known challenges presented by climate change.

What’s more, as with global warming, the impact of these technologies will transcend national borders. This puts those who have the least say – the vulnerable and the poor – on the front line. It also risks exacerbating wider threats to international peace and security, such as resource scarcity and forced climate migration.

This is why the Elders, a group of independent global leaders, is calling on the international community to agree on a rigorous governance framework for geoengineering, and to put it in place without delay. Such a decision-making system must be transparent, participatory, and accountable. It should include the voices of those most affected and enable all governments and non-governmental stakeholders to gain the fullest possible understanding of these new technologies for more informed decision-making.

Since the Industrial Revolution, we have known that technology is not a panacea, and that it advances human wellbeing only if all those affected are given the chance to participate in its development. This consideration is all especially relevant to geoengineering, because our knowledge of these technologies and their impact remains limited.

Fortunately, efforts are underway to address this. This week, the UN Environment Assembly – the world’s highest-level decision-making body on environmental issues – will consider whether to initiate a global learning process on both the science and governance of geoengineering. To this end, the UNEA would call for a worldwide assessment of these emerging technologies, giving all countries a common platform of knowledge.

This shared understanding is an important first step toward ensuring that decisions concerning the use or non-use of geoengineering are based on the principles of equality, justice, and universal rights. These are the values underlying the 2015 Paris climate agreement and the Sustainable Development Goals, both of which were adopted during my tenure as UN Secretary-General.

The UN is best placed to accommodate the governance framework requirements we now need. Only through the UN’s multilateral processes can we ensure that geoengineering technologies, and how they might be applied, are not the preserve of individual states. This is vital for environmental sustainability, international security, and the wellbeing of future generations around the world.

Many people are wary of this debate, particularly in international fora. They fear that it could be a foot in the door for highly dangerous ideas, and that the very act of drawing attention to these technologies could reduce pressure to cut emissions.

I understand these concerns, and I agree that our main collective priority must still be to cut emissions; end the use of fossil fuels; and promote a zero-carbon, climate-resilient, and people-centered economic transition.

But we also need to acknowledge that the geoengineering genie is already out of the bottle. The likelihood of unilateral deployment of solar geoengineering increases every year. The global community must decide whether to engage now, by setting clear governance rules and guardrails, or allow individual actors to take the lead, creating a fait accompli for the rest of us.

Ignoring this debate would be a mistake. Instead, the world should focus on learning more, including via the process at the UNEA, in order to understand the full range of options and assess their risks with the best information available.

How to understand and potentially harness disruptive new technologies for the benefit of all humanity is one of the defining questions of our age. Future generations will not forgive us if we fail to answer it convincingly.

BERLIN – As the world struggles to rein in emissions of climate-changing gases and limit planetary warming, a new technological silver bullet is gaining supporters. Geoengineering –the large-scale manipulation of the Earth’s natural systems – has been popularized as a means of counteracting the negative effects of climate change.

Proponents of this science feed the illusion that there is a way to engineer an exit from the climate crisis, meet the goals of the 2015 Paris climate agreement, and maintain a consumption-heavy lifestyle.

But this solution is not as simple as proponents would have us believe. Betting on climate engineering – either as a planetary insurance policy or as a last-ditch measure to combat rising temperatures – is not only risky; it also directs attention away from the only solution we know will work: reducing carbon emissions.

Each of the engineered technologies being discussed carries dangers and uncertainties. For example, the only way to test the effectiveness of solar radiation management (SRM) on a global scale would be to carry out experiments in the environment – either by spraying particles into the stratosphere, or by artificially modifying clouds. While such tests would be designed to determine whether SRM could reflect enough sunlight to cool the planet, experimentation itself could cause irreversible damage. Current models predict that SRM deployment would alter global precipitation patterns, damage the ozone layer, and undermine the livelihoods of millions of people.

Beyond the ecological risks, critics warn that, once deployed globally, SRM could spawn powerful weapons, giving states, corporations, or individuals the ability to manipulate climate for strategic gain (an idea that not even Hollywood can resist). But perhaps the most important criticism is a political one: in a world of challenged multilateralism, how would global ecological interventions be governed?

Similar questions surround the other major group of climate engineering technologies under debate – so-called carbon dioxide removal (CDR). Proponents of these technologies propose removing CO₂ from the atmosphere and storing it underground or in the oceans. Some CDR approaches are already prohibited, owing to concerns about possible environmental consequences. For example, fertilization of oceans with carbon-sequestering plankton was banned by the London Protocol on marine pollution in 2008. Parties to that decision worried about the potential damage to marine life.

But other CDR approaches are gaining support. One of the most discussed ideas aims to integrate biomass with carbon capture and storage (CCS) techniques. Called “bioenergy with CCS,” or BECCS, this method seeks to pair the CO₂-absorption capabilities of fast-growing plants with underground CO₂ storage methods. Proponents argue that BECCS would actually yield “negative” emissions.

Yet, as with other engineered solutions, the promises are simply too good to be true. For example, huge amounts of energy, water, and fertilizer would be required to operate BECCS systems successfully. The effects on land use would likely lead to terrestrial species losses, and increase land competition and displacement of local populations. Some forecasts even suggest that the land clearing and construction activities associated with these projects could lead to a net increase in greenhouse gas emissions, at least in the short term.

Then there is the issue of scale. In order for BECCS to achieve emissions limits set by the Paris agreement, between 430 million and 580 million hectares (1.1 billion to 1.4 billion acres) of land would be needed to grow the required vegetation. That is a staggering one third of the world’s arable land.

Simply put, there are safer – and proven – ways to withdraw CO₂ from the atmosphere. Rather than creating artificial CO₂-binding “farms,” governments should focus on protecting already-existing natural ecosystems and allowing degraded ones to recover. Rainforests, oceans, and peatlands (such as bogs) have immense CO₂ storage capacities and do not require untested technological manipulation.

By pushing unproven technologies as a cure for all climate-changing ills, proponents are suggesting that the world faces an unavoidable choice: geoengineering or disaster. But this is disingenuous. Political preferences, not scientific or ecological necessity, explain the appeal of geoengineering.

Unfortunately, current debates about climate engineering are undemocratic and dominated by technocratic worldviews, natural science and engineering perspectives, and vested interests in the fossil-fuel industries. Developing countries, indigenous peoples, and local communities must be given a prominent voice, so that all risks can be fully considered before any geoengineering technology is tested or implemented.

So what conversation should we be having about geoengineering?

For starters, we need to rethink the existing governance landscape. In 2010, parties to the United Nations’ Convention on Biological Diversity (CBD) agreed to a de facto international moratorium on climate-related geoengineering. But today, with powerful advocates generating so much pressure to bring geoengineering technologies out of the lab, informal bans are no longer sufficient. The world urgently needs an honest debate on the research, deployment, and governance of these technologies; the CBD and the London Protocol are essential starting points for these governance discussions.

Among the technologies that require the most scrutiny are CDR projects that threaten indigenous lands, food security, and water availability. Such large-scale technological schemes must be regulated diligently, to ensure that climate-change solutions do not adversely affect sustainable development or human rights.

In addition, the outdoor testing and deployment of SRM technologies, because of their potential to weaken human rights, democracy, and international peace, should be banned outright. This ban should be overseen by a robust and accountable multilateral global governance mechanism.

No silver bullet for climate change has yet been found. And while geoengineering technologies remain mostly aspirational, there are proven mitigation options that can and should be implemented vigorously. These include scaling up renewable energy, phasing out fossil fuels (including an early retirement of existing fossil infrastructure), wider diffusion of sustainable agroecological agriculture, and decreased energy and resource input into our economy.

We cannot afford to gamble with the future of our planet. If we engage in a serious discussion about ecologically sustainable and socially just measures to protect the Earth’s climate, there will be no need to roll the dice on geoengineering.