Jim Leightner

We live in one of the coldest epochs in the history of life; and the world is not facing runaway warming. Here is why. Temperatures are currently 'historically low' at 15°C, which includes a rise of only 1.4°C over two centuries. It's 9°C 'colder' than the global average during the entire rise of life on Earth; calculated at 24°C over the 542 million years of the Phanerozoic Eon (Judd et al, Science 2024). Carbon is not a rising toxic cloud. It's astonishingly low compared with almost all past epochs - and vital for biological life. At 420 parts per million, it's amongst the lowest ever measured across geological history. Ideally, carbon dioxide should be around 1,000 ppm. The real story of Earth lies in the oceans; undisputed heavyweights of all regional climates (all 11 of them). Yet even the might of the oceans is not the trigger for ice ages or interglacial cycles; these are guided by the celestial physics of Earth's orbital cycles (the Milankovitch cycles). Among the most influential forces for environmental change are the ponderous movements of tectonic crustal plates, which endlessly grind against one another. Paleontologists have shown how supercontinents have already emerged several times in world history, the most recent being Pangaea. The world's deep oceans are also the planet's air conditioners, which otherwise would be frozen empty wastes of ice and mountains. Earth's five great oceans cover 71% of the world's surface area to an average depth of 2.3 miles. They contain 96.5% of all water and consequently, they hold overwhelming influence over planetary heat distribution, atmospheric moisture and regional climate zones. The oceans have more than 1,000 times the heat capacity of the atmosphere, and they absorb 91% to 93% of all the world's retained heat energy (the atmosphere retains just 1%). They are also the primary source of atmospheric water vapour - which reaches 4% in tropical and subtropical regions - and the principal source of clouds, storms, rainfall and snow. Water vapour is responsible for up to 75% of all atmospheric radiative heat retention, many times higher than carbon dioxide. Oceanic thermohaline currents are the world's planetary conveyor belt for warmth, taking roughly 1,000 years to recirculate warm tropical currents and returning cold, dense deep waters. Without this system - including permanent gyres like the Sargasso Sea and regional eddies - places like Northern Europe would share the frigid fate of Greenland. These ancient ocean patterns have operated continuously for billions of years, stabilising and redistributing energy across the globe. When evaluating the carbon cycle, the ocean's role remains utterly supreme, while atmospheric carbon represents a remarkably small fraction of the active reservoir. The oceans hold 86% of the world’s active carbon reservoir, the atmosphere retains only 1%. There is no global warming crisis. Call it hysteria; call it ideology; or call it a wealth transfer or just purely political. And you would be right. Mankind is not facing a runaway warming crisis; and the rise of turbines and solar panels is a terrible dead end for the natural world. We have better solutions. We should be grateful that we are safely within a warm interglacial period that is likely to continue for tens of thousands of years. We are still in an ice age, which has already lasted for 34 million years. Any warming might see oceans rising by a few millimetres, indistinguishable from temperature variations affecting water volume. But coastal residents would never notice this in their lifetimes, just as no one can see it happening today.