The Earth is warming faster than models can track – air pollution has so far masked the true severity of the situation

The record-breaking warm periods of the past two years are not isolated anomalies, but part of an accelerating trend. The problem is not just that the planet is warming, but that it is happening faster than previous scenarios predicted.

According to a recent report by risk-analysis mathematicians, the Earth’s energy balance is changing at a rate that could lead to a world 2 degrees Celsius warmer by 2050 on current emissions trajectories. This is a particularly stark warning, as the insurance industry does not think in terms of theoretical models, but in terms of risks that can be measured in money.

The full report can be downloaded here:
https://actuaries.org.uk/media/isvotyer/parasol-lost.pdf

The hidden cooling effect of air pollution is disappearing

Human activity not only emits greenhouse gases, but also tiny solid and liquid air pollutants called aerosols. In addition to their health effects, these particles have had a significant cooling effect for decades: they reflect some of the sun’s radiation and promote the formation of clouds. This unintended “protective umbrella” is estimated to have cooled the Earth by about half a degree Celsius.

In recent years, however, measures aimed at improving air quality – such as the drastic reduction of sulphur emissions from energy production and maritime shipping – have rapidly reduced the amount of aerosol particles in the atmosphere. The decisions were justified from a health perspective, but they also had an important consequence: one of the cooling mechanisms of the climate system has been significantly weakened in a short time. Fewer aerosol particles mean less reflected solar radiation, which leads to faster surface warming.

The climate system is more sensitive, models are not keeping pace

According to ELTE climate model researchers Péter Szabó and Rita Pongrácz, one of the most worrying developments is that observations are increasingly diverging from previous model calculations. Newer satellite data show that the cooling reduction associated with the decline in aerosol particles from human activity has a stronger impact on the Earth’s energy balance than most climate models assumed. The heat accumulation, increasing by 0.45 W/m² per decade, is pumping excess energy into the oceans, ice sheets and atmosphere at a rate that no model predicted for any subsystem.

The observed rate of warming is now closer to the more pessimistic emissions scenarios, while actual emissions have not yet reached them. This suggests that the climate system is more sensitive than researchers previously thought. Regional climate models have consistently underestimated warming over recent decades across Europe, especially in summer and in central Europe. The researchers say this is not a fault of the models, but a sign that the impact of certain feedbacks, particularly those related to clouds, has been consistently underestimated.

Climate risk could tip over into manageable range

Beyond the 1.5 degree Celsius warming threshold, tipping points may become active, where climate change is no longer gradual, but sudden and partly irreversible. The accelerating melting of ice sheets, thawing of permafrost, or the destabilization of the Amazon rainforest could reinforce each other, further accelerating warming.

All this could have serious economic consequences. According to insurance and financial analyses, damage from climate change could reach up to half of the annual GDP of some countries by the end of the century. The effects are already being felt today in inflation, food and water insecurity, and the deterioration of energy security. In some regions, insurance companies have begun to withdraw, which could lead to further economic shocks.

What can we do?

In light of accelerating warming, it is clear that current responses are not proportionate to the risks. More rapid emission reductions, targeted adaptation and informed risk management are needed, especially for the most exposed regions and social groups. The path of the previous “aerosol shield” is not a viable one.