Any lay person wanting to keep abreast of climate science should start by looking up David Borlace, a genial Englishman whose plain-speaking videos have kept a dedicated audience well informed on climate science and technology for many years.
Borlace’s friendly, relaxed demeanour was sorely tested on his “Just Have a Think” channel recently when he explored the implications of a new report by the UK-based Institute and Faculty of Actuaries.
As they tell it, actuaries “measure and manage the impact of risk, uncertainty and opportunity to prepare businesses, communities and governments for the future.” That impact adds up to many trillions of dollars world-wide. These people should never be taken lightly.
Their latest report, supported by a scientific team led by the eminent climatologist Sir David King, is alarming. It says today’s accelerated warming appears set to take the global average temperature rise beyond 2C before 2050.
Science determined more than a decade ago that this would amount to a global catastrophe. Passing the 2C mark means critical water scarcity for billions of people, widespread ecosystem collapse including almost all coral reefs, half a metre of sea level rise by 2100 and more intense heatwaves more often, exposing billions to prolonged overheating at least once every five years.
It all comes down to Earth’s energy imbalance – the amount of energy our planet receives from the sun less the energy it radiates back into space. That figure has doubled over the course of this century.
Evidence for accelerating warming cited in the actuaries’ report included past climate studies showing Earth’s climate sensitivity to be higher when it’s warmer, satellite data showing more absorbed solar radiation than predicted by models, and warming over the past decade well in advance of model projections.
That energy imbalance, says Borlace, is equivalent to every one of Earth’s 8.3 billion people constantly boiling about 60 kettles, every moment of every day throughout the year.
And the recent temperature spike is largely down to the absence of aerosols – fine particles suspended in the atmosphere, mostly human-caused air pollution.
The climate models used by the Intergovernmental Panel on Climate Change in its latest report, published in 2023, did not factor in the impact of lower aerosol levels on global temperature. Aerosols also shade Earth’s surface, lowering the temperature of the air around us by 0.5C.
When that report was published, the world was starting to feel the impact of various global measures to clean up air pollution, notably emissions from the tens of thousands of ships serving global trade. There is now general agreement that a cleaner atmosphere was a big driver of the massive spike in global heat in 2024.
Borlace put it this way: “What if the physics of the very system itself – not the misguided politics, not the disingenuous pledges, but the underlying energy imbalance of the planet – has shifted in a way that our models haven’t quite kept pace with? And what if we’ve been running a gigantic accidental geoengineering experiment for the last century without even realising it?”
Like most people, policymakers focus on middle-of-the-road projections and tend to ignore high-impact but low-probability risk. But not actuaries, who are duty-bound to advise clients on worst-case scenarios.
And there is strong current evidence that high-impact risk is not as improbable as once thought. The most recent Global Tipping Points report advises that many system thresholds are being crossed now and we’re heading into danger more rapidly than leaders appreciate. Along with the rest of us, they’ve been lulled into a false sense of security by those polluting, heat-shielding aerosols from shipping.
The UK actuaries propose a five-part “planetary solvency recovery plan”. It wants us to make climate change a full-on, top-order systemic policy matter; to go for “quick wins” like quickly cutting methane emissions and halting all deforestation; to supercharge the transition to renewables; and to work quickly to restore land and ocean ecosystem health.
The actuaries’ fifth proposal, for an emergency toolkit, raises big questions. It’s essentially geoengineering, including the political fantasy of planet-scale carbon dioxide removal, by what means nobody knows, and the more realistic but super-contentious option of solar radiation modification (SRM).
SRM would involve – wait for it – re-polluting the stratosphere, most likely with sulphur dioxide particles, and continuing to do so indefinitely until carbon dioxide levels come down. That’s assuming all nations are on the same page; that no-one objects to being deprived of sunlight. Dream on.
Meanwhile, science and insurance actuaries say an overheated, destabilised climate might force our hand, and decision time may be just a decade away. We’re fools not to pay attention.