The world is getting darker as the ice melts and that means it is absorbing more and more sunlight that is accelerating the process.

As the earth warms, the ice melts and we lose reflectivity. Even more heat from the sun is absorbed, creating a positive feedback loop that accelerates global warming beyond what the models used to determine the outlook predicted by the Paris Agreements and the timelines left of action to avoid a climate crisis. Global warming is now accelerating faster than all the models drawn up in 2015 predicted.

This is affecting the Earth’s Energy Imbalance and the world is starting to cook according to recent research; more energy than ever before is coming into the planet as absorbed sunlight than is going out, radiated to space, said the scientists. In a study published in 2021, the EEI was found to have doubled in the 14 years from 2005 to 2019 and the latest result suggest the EEI is only climbing higher.

The measure of reflectivity is known as albedo – the portion in percent of incoming solar radiation that is reflected back to space – and it has been falling steadily over the last 25 years, according to measurements from NASA.

Solar radiation reaching Earth is about 340 W per square metre, averaged over Earth’s surface, so the 0.5% albedo decrease is a 1.7W/ m² increase of absorbed solar energy.

The Earth’s albedo has decreased 0.5%, say climatologists James Hansen and Pushker Kharecha in a paper issued on May 14. “A 1.7 W/m² increase of absorbed solar energy is huge. If it were a climate forcing, it would be equivalent to a CO2 increase of 138 ppm".

“Earth’s albedo (reflectivity) declined over the 25 years of precise satellite data, with the decline so large that this change must be mainly reduced reflection of sunlight by clouds. Part of the cloud change is caused by reduction of human-made atmospheric aerosols, which act as condensation nuclei for cloud formation, but most of the cloud change is cloud feedback that occurs with global warming,” the scientists said.

As bne IntelliNews reported, other recently studies also confirmed that cloud cover has been decreasing dramatically in recent years and that fewer clouds have created a feedback loop that is further reducing the cloud cover.

To put those numbers into context, the total human-caused climate forcing from all greenhouse gases (including CO2, methane, etc) was estimated at around 3.2 W/m² as of 2023. So 1.7 W/m² on its own represents over 50% of the total anthropogenic forcing – a major additional energy imbalance. Even a 0.5 W/m² change is considered climatically significant, accelerating warming, ocean heat uptake and ice melt.

Looking at the same increase in terms of CO2: pre-industrial CO2 levels were around 280 ppm, and current levels are just above 420 ppm – meaning human activities have added ~140 ppm since the 18th century.

So an additional 138 ppm is nearly a doubling of the modern increase – a scenario that could be catastrophic in terms of global warming adding ~2°C or more on top of existing warming and bursting through the 1.5-2C temperature rise maximum set out in the Paris Agreements.

As bne IntelliNews reported, the 1.5C-2C Paris temperature increase maximum target has already been missed and the planet is currently on course to see a catastrophic 2.7C-3.1C temperate increase by 2100 as a best-case scenario.

One of the major changes that have darkened the world and affected the cloud cover and its reflectivity has been the cleaning up of ship fuel to remove the sulphur dioxide (SO2) that is a pollutant, but at the same time has a beneficial effect of increasing the reflectivity of clouds and the atmosphere and so cooling the planet by reflecting more of the sun’s radiation back into space.