In February 2026, I was invited to respond to a series of questions from Alma Asfalto (www.almaasfalto.com), a free monthly journal distributed in and around Mexico City. The edition, published in both Spanish and English, features a range of engaging interviews, most with a cultural and artistic focus. Mine is perhaps something of an outlier, but I suggest complements the other contributions.

The March edition of Alma Asfalto includes an abridged version of my responses and is available at: https://almaasfalto.com/marzo/

My full and unabridged responses are provided below .

Entrevista de Profe K. Anderson

(interview with Prof. K. Anderson)

1. Based on the best available data, where exactly are we on the climate timeline right now —before the point of no return, at it, or already past it? And which changes are now irreversible?

With respect to the Paris Agreement’s 1.5°C commitment, this has already been exceeded in any meaningful sense. The weaker commitment to limit warming to “well below 2°C” remains theoretically attainable, but only under extremely demanding conditions. Achieving this outcome would require immediate and sustained global emissions reductions averaging nearly 8% per year. This rate exceeds by 2–3 percentage points the emissions decline observed during the most stringent COVID-19 lockdowns, which themselves were maintained for only a single year.

In the absence of a rapid and fundamental shift away from current global complacency on climate change, the “well below 2°C” objective is likely to become as unattainable within a decade as the Paris 1.5°C commitment is today. Claims to the contrary almost invariably depend on assumptions of planetary-scale deployment of ‘negative emissions technologies’ in the future, effectively shifting the burden of removing today’s emissions onto subsequent generations. These assumptions are highly speculative and function less as credible mitigation strategies than as a means of deferring difficult political and economic decisions that must be taken now if climate change is to be addressed in a serious and credible manner.

In just over a century, human activities have emitted sufficient carbon dioxide to alter the climate in ways that will persist for many generations. Whether these emissions have already triggered critical climatic tipping points remains uncertain. What is unequivocal, however, is that each additional tonne of greenhouse gas emissions and each incremental increase in global temperature raises the probability of crossing irreversible tipping thresholds, several of which would have severe and potentially catastrophic consequences for human societies and natural ecosystems.

2. Based on the carbon budget calculations you work with, what rate of emissions reduction would wealthy, high-emitting countries actually need to achieve starting now to stay within 1.5–2°C?

As noted above, the Paris Agreement commitment to “pursue efforts to limit warming to 1.5°C” is no longer achievable. Even under an optimistic interpretation of the remaining carbon budget for a 50% probability of staying below 1.5°C, here estimated at approximately 130 billion tonnes of CO₂ (130 GtCO₂ from the start of 2026), meeting this would require immediate global emissions reductions now approaching 25% per year. When the Paris Agreement’s equity principle of “common but differentiated responsibilities and respective capabilities” (CBDR-RC) is applied, the required annual reduction for wealthier nations rises closer to 30% or more. Such rates are simply unachievable.

With respect to the Paris Agreement’s “well below 2°C” objective, here associated with a remaining carbon budget of roughly 530 GtCO₂, the required average rate of global emissions reduction is now approaching 8% per year, with high-income countries needing to cut emissions by approximately 10–15% annually. On current trajectories, this remaining window is closing rapidly, and within a short period the Paris-aligned 2°C carbon budget will become as unattainable as the 1.5°C budget is at present.

3. What evidence in the data tells you that climate change is no longer a future risk, but something already shaping everyday life for ordinary people?

This, and question 4, are not my primary areas of expertise, and I therefore rely on the assessments of colleagues with whom I have established long-standing professional trust, as well as on the wider peer-reviewed literature. Based on these sources, there is clear and growing evidence of increasing frequency and severity of extreme weather impacts. The IPCC detail how and where impacts are already being experienced, with their 2022 Summary for Policy Makers capturing the headlines of their analysis: where they note:  “Increasing weather and climate extreme events have exposed millions of people to acute food insecurity and reduced water security”;  “sudden losses of food production and access to food … have increased malnutrition”; and “in all regions extreme heat events have resulted in human mortality and morbidity”.

While some societies might, given sufficient time and financial resources, be able to adapt to a relatively stable “new normal” climate, the continued failure of political and business leaders to address climate change decisively means that climatic conditions will not stabilise at today’s levels. That is to say, there is no “new normal” until we cease emissions of carbon dioxide and other greenhouse gases.

As long as fossil fuel use continues and profound changes are not made to diets, agricultural practices, and land use, including deforestation, global temperatures will keep rising and climate impacts will intensify. This trajectory substantially increases the risk of crossing critical climate tipping points. For detailed assessments of current and projected climate impacts, I recommend consulting Professor Hayley Fowler.

4. From a climate-systems perspective, which feedback loops – once triggered – are the hardest to stop, and which ones do you think the public most underestimates or misunderstands?

The most difficult feedback loops to halt are those that become self-reinforcing after crossing critical thresholds. Large-scale forest dieback in the Amazon, and potentially the Congo Basin, is a prime example. As warming and deforestation reduce rainfall and increase fire frequency, forests can shift toward savanna-like states, releasing vast stores of carbon while losing their capacity to act as carbon sinks. Once such a transition is underway, reduced ‘evapotranspiration’ (water transferred back to the atmosphere) and an altered regional climate can perpetuate further decline, making recovery unlikely on human timescales.

Oceanic feedbacks are similarly concerning. As the oceans warm, their capacity to absorb CO₂ diminishes because gas solubility declines with temperature. Given that oceans currently buffer a significant portion of anthropogenic (human) emissions, reduced uptake, or eventual outgassing, would accelerate atmospheric warming. This process is gradual but difficult to reverse due to the scale and thermal inertia of the oceans.

Accelerated ice melt in Greenland and parts of Antarctica represents another powerful feedback through the ice–albedo effect: as reflective ice is lost, darker surfaces absorb more heat, intensifying warming and further melt. Once dynamic ice-sheet instabilities are triggered, long-term sea-level rise is effectively locked in.

The potential weakening or even collapse of the Atlantic Meridional Overturning Circulation (AMOC) is also a major and hugely underappreciated feedback. AMOC is a massive system of ocean currents that transports warm water from the tropics northwards to the North Atlantic, and is a key regulator of climate and nutrient flows. Increased melt of ice in the arctic makes the water less saline, changing its density which impacts significantly the AMOC conveyor belt of moving water. There is increasing concern that AMOC will likely weaken significantly across this century, and perhaps in just a few decades. The impacts would be devastating. For example, estimates are that a collapse of AMOC would see winter temperatures in Europe fall by 10-15°C, whilst summers would continue to get hotter. North America would face considerable sea level rise and the major monsoon patterns would likely be disrupted.

5. When you compare government climate plans to the physical state of the planet, are those plans consistent with reality?

When government climate plans are measured against the physical limits imposed by our Paris climate commitments, they are plainly inconsistent with reality. Climate stabilisation is governed by cumulative emissions, not distant targets or aspirational pledges. The remaining carbon budgets consistent with the Paris temperature goals are now extremely small. At current global emission rates, less than three years remain for a 50:50 chance of limiting warming to 1.5°C, and roughly twelve years for a likely chance of not exceeding 2°C. These tight timeframes leave no meaningful room for delay or incremental change.

Stripped of dangerously optimistic framings, the conclusion is stark: all existing climate plans fail to match the scale, speed, or seriousness defined by the science. While incremental reductions have occurred in some sectors, they are overwhelmed by the arithmetic of cumulative emissions and shrinking budgets. A credible strategy must begin with an honest acknowledgment that current policies fall far short of anything even approaching the Paris commitments.

6. Based on what climate science has shown for decades, how different would the physical state of the planet be today if that evidence had been acted on – and what damage is now the direct result of delay and denial?

The central point to grasp is that climate change is a dynamic and cumulative process. The approximately 1.5°C rise in global average temperature has already produced severe consequences across many regions and communities. Yet these impacts are only a foretaste of what lies ahead. The trajectory of harm is not static; it intensifies as greenhouse gas concentrations continue to accumulate in the atmosphere.

The failure to deliver the emissions reductions identified by climate science, particularly in relation to fossil fuel production and use, as well as agriculture and deforestation, has entrenched a high-carbon infrastructure that cannot be dismantled overnight. Energy systems, transport networks, industrial processes, and patterns of land use are deeply embedded in economic and political structures. As a result, global emissions, still measured in tens of billions of tonnes annually, are likely to persist at high levels for years, if not decades. This ensures continued increases in atmospheric CO₂ concentrations, rising temperatures, and escalating climate impacts.

Importantly, this is not a linear process in which harms increase in a smooth fashion. As warming progresses, the rate and severity of impacts are expected to accelerate. The risks of crossing tipping points, thresholds beyond which changes become self-reinforcing and potentially irreversible, also grow. These escalating risks are not accidental. They reflect sustained political and institutional choices. Over the past two decades, leaders in government, business, and parts of the media have repeatedly failed to respond to, or accurately communicate, the scale and urgency of the scientific evidence. Short-term political convenience and economic interests have been prioritised over the medium- and long-term wellbeing of citizens.

It is also necessary to acknowledge the distributional dimension of this failure. A disproportionate share of global emissions is associated with wealthier individuals and groups within societies. In that sense, the continued expansion of high-carbon activities reflects a preference for the near-term consumption patterns of a relatively affluent minority over the security, health, and stability of the broader population, including future generations.

Much of the resulting damage is now locked in. It can be measured in terms of floods, droughts, wildfires, crop failures, and heat extremes. Yet these physical events translate directly into destroyed livelihoods, lost lives, and growing social tensions. As climate instability undermines access to water, food, and shelter, pressures within and between communities intensify. Continued failure to curb emissions rapidly is likely to increase displacement and migration, initially exacerbating existing political and economic tensions, and over time becoming a primary driver in its own right.

Alongside these human consequences are profound ecological disruptions. Rapid climate change is destabilising ecosystems upon which societies depend, from pollinating insects essential for agriculture to forests and oceans that regulate atmospheric composition and climate systems. The degradation of these natural systems further compounds human vulnerability.

Ultimately, the most enduring consequence of delayed action is not the impacts already visible, but the entrenchment of high-carbon infrastructure, institutions, and social norms. This structural lock-in constrains present choices and narrows future options. It is this deep embedding of carbon-intensive systems into the fabric of modern society that constitutes the most serious legacy of a failure to act.

7. What is it about our species that causes us to so easily deny the obvious to the point of extinguishing our species? 

We live in an age of extraordinary diagnostic power. Never has a species been able to observe, measure, and model the consequences of its own behaviour with such precision. We track atmospheric chemistry to the part per million, or even billion, map the circulation of oceans, and project future climates with growing confidence, supported by increasingly sensitive instruments and vast, interlinked datasets. The science is not blind; it is detailed, cumulative, and remarkably coherent.

And yet this clarity has not produced commensurate restraint. The expansion of knowledge has unfolded alongside the expansion of harm. The damage is neither unforeseen nor poorly understood; it is documented in real time. What impedes response is not ignorance, but the gravitational pull of convenience, entrenched power, and habitual patterns of consumption and governance. We continue, knowingly, to accelerate processes whose consequences we can quantify with unsettling accuracy.

This is the central contradiction of our era, and perhaps species: a civilisation capable of exceptional foresight, yet persistently unable, or unwilling, to align its actions with its long-term interests. The question that remains is whether this incapacity is transitional or terminal. It may be that societies, when pressed sufficiently by circumstance, can reorganise, adapt, and correct course. Human history contains examples of resilience and transformation.

But there is another possibility. In the deep future, our existence may be visible as a narrow seam in the geological archive, unmistakable in its signature: a sudden pulse of carbon, a sharp contraction in biodiversity, a period of abrupt climatic change. That layer would tell a sombre story of a species that understood the forces it had unleashed, traced the contours of its own vulnerability with precision, and nonetheless chose to persist along the same path.